World Health Organization Regional Office for the Western Pacific
STI HIV STATUS AND TRENDS OF STI, HIV/AIDS AT THE END OF THE MILLENNIUM Western Pacific Region 1999
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
i
STATUS AND TRENDS OF STI, HIV AND AIDS AT THE END OF THE MILLENNIUM Western Pacific Region, 1999
STI/HIV
CONTENTS
Abbreviations and Acronyms Acknowledgements
iii iv 1 13 13 19 22 28 33 37 42 46 50 53 58 61 66 71 76 81 85
1 Regional Overview 2 Country Status and Trends Australia Brunei Darussalam Cambodia China Hong Kong, China Japan Republic of Korea Lao People’s Democratic Republic Macao Malaysia Mongolia New Zealand Papua New Guinea Philippines Singapore South Pacific Islands Viet Nam
3 Regional Tables
91
ii
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
WHO Library Cataloguing in Publication Data
ANNEXES
Status and Trends of STI, HIV and AIDS at the End of the Millennium Western Pacific, 1999
Examples of National Policy and Priority 23 1. Sexually transmitted diseases - epidemiology. 2. HIV infections - epidemiology. Strategies for Prevention and Control of 3. Acquired immunodeficiency syndrome - epidemiology. Sexually Transmitted Infections I. Western Pacific 23 ISBN 92 9061 151 0Introduction National STI prevention and control policies 25 National welcomes STI prevention and control 26 The World Health Organization requests for permission to reproduce or translate its strategies 1999 2002 publications, in part or in full. Applications and enquiries should be addressed to the Office of Publications, World Health Organization, Geneva, Switzerland or to the Regional Office for the Western Pacific, Manila, Philippines which will be glad to provide the latest information on any changes made to the text, plans new editions, and reprintson andSTI translations Outline of for a Technical Guideline 31 already available.
1
2 Partner Referral
© World Health Organization 1999
Publications of the World Health Organization enjoy copyright protection in accordance with the provisions of Protocol 2 of the Universal Copyright Convention. All rights reserved. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
iii
ABBREVIATIONS AND ACRONYMS
AIDS CDC FSW GASP HIV IDU Lao PDR MIC MSM NGU QRNG RSW SHC STD STI SW TB UNDP WHO WPRO
acquired immuno deficiency syndrome Centers for Disease Control and Prevention female sex worker Gonococcal Antimicrobial Surveillance Programme human immunodeficiency virus injecting drug user Lao People’s Democratic Republic minimal inhibitory concentration men who have sex with men non-gonococcal urethritis quinolone resistant gonococcus registered sex worker social hygiene clinic sexually transmitted disease sexually transmitted infection sex worker tuberculosis United Nations Development Programme World Health Organization Western Pacific Regional Office (of WHO)
iv
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
ACKNOWLEDGEMENTS
The Western Pacific Regional Office of the World Health Organization would like to thank the epidemiologists and other experts from the Region who contributed to this document.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
1
1
REGIONAL OVERVIEW
It is estimated that more than 700 000 people were living with HIV infection in the Western Pacific Region in 1998 (Figure 1), with more than 18 000 new AIDS cases occurring in the same year . In contrast, the cumulative number of HIV diagnoses reported in all countries of the Region was about 100 000 and reported AIDS incidence in 1998 was 3300. This reflects a very high level of underdiagnosis and underreporting of HIV and AIDS cases in the Region. The number of people living with HIV infection is projected to reach 1 million in 2000, and the yearly number of new cases of AIDS to doubled.
Figure 1: HIV prevalence and prevalence rate in selected
0
50
100
150
200
prevalence (thousand) 250 300
350
400
450
China
Prevalence Rate Prevalence
Cambodi
Viet Nam
Malaysia
0
0.5
1
1.5
2
2.5
3
3.5
4
prevalence rate in adult population (15-49) (%)
Analysis of the trend of the relative proportion in HIV risk exposure based on reported cases in the Region suggests that there have been three waves. First, sexual contact among men was the driving force in the early epidemic in Australia and New Zealand, with rapid decrease in prevalence by the late 1980s. Second, the widespread sharing of equipment among injecting drug users (IDUs), primarily in Malaysia, China and Viet Nam was most important during the late 1980s and early 1990s, eventually leveling off around 40% of reported cases (it should be noted that this mode of transmission is probably overrepresented due to the mandatory HIV testing of injecting drug users in rehabilitation centres or prison). Finally, the more recent trend has been a steady
2
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
increase in the proportion of reported cases associated with heterosexual contact. Transmission of the virus through this mode has been gradually increasing since the beginning of the epidemic and is expected to continue to increase in the future (Figure 2).
Figure 2: Proportion of reported HIV/AIDS by risk exposure category, 1987-1998
% 70 60 50 40 30 Heterosexual Homo/bisexual IDU 87 88 89 90
Percentage in 1998: 40% IDU 33% Heterosexual 4% Homo/bisexual
20 91
10 92 93 94
0 95 96 97 98
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
3
As the HIV epidemic has developed in Asia and the Pacific, a wide range of transmission patterns has emerged and it is possible to identify several broad categories of transmission patterns in the Region. u Countries with declining HIV prevalence (Australia and New Zealand). In these countries the vast majority of HIV infections have been acquired through sexual contact between men, a mode of transmission that reached a peak in the mid-1980s (Figures 3 and 4). Surveillance of clientele of needle exchange and methadone programmes reveals that HIV prevalence among IDUs has remained very low. Heterosexual transmission remains quite rare in these countries.
Figure 3: Reported number of HIV/AIDS cases in Australia, 1985-1998 2500 2000 1500 1000 500 0 <85 85 86 87 88 89 90 91 92 93 94 95 96 97 98 AID S H IV
Figure 4: Reported number of HIV/AIDS cases in New Zealand, 1986reported number of cases
reported number of cases
140 120 100 80 60 40 20 0 <86 86 87 88 89 90 91 92 93 94 95 96 97 98
AID S H IV
4
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
u
Countries with high HIV prevalence among injecting drug users (China, Malaysia and Viet Nam). The pattern of HIV transmission in these countries has predominantly involved IDUs (Figures 5 and 6). High levels of transmission among IDUs probably began in the late 1980s in Malaysia, the early 1990s in China, and even more recently in Viet Nam. Based on surveillance data, prevalence among IDUs in Malaysia ranges from 15% to 20%. In Viet Nam, rapid increases in prevalence in some areas have been observed (from 0.4% in 1995 to 66% in 1998). The epidemic among IDUs in that country started in the south and has spread to the north in the last few years. Reported prevalence among IDUs in parts of Yunnan and Xinjiang provinces, China, has been about 60% to 80%.
Figure 5: Proportion of risk exposure categories among reported HIV cases in Malaysia, Viet Nam and China
Malaysia
IDUs Viet Nam
sexual contact others/unkn own
China
0%
20%
40%
60%
80%
100%
Figure 6: Trends in HIV prevalence among IDUs in selected areas of Viet Nam, 1994-1998
%
100 80 60 40 20 0
Hai phong Binh dinh Da nan
1994
1995
1996
1997
1998
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
5
u
Countries with increasing HIV prevalence due to heterosexual HIV transmission (Cambodia and Papua New Guinea). In these countries, the dominant transmission pattern has been through heterosexual contact (Figures 7 and 8). HIV seroprevalence surveys among antenatal women in Cambodia have shown rapid and steady increase in prevalence (from 0% in 1992 to 3.2% in 1997). HIV seroprevalence among SWs has reached 43% in 1998. In Papua New Guinea a steady increase in HIV prevalence has been observed among pregnant women in Port Moresby (from 0.05% in 1994 to nearly 0.2% in 1996). Reported cases of HIV infection have nearly doubled every year for the last several years.
Figure 7: HIV sentinel surveillance, Phnom Penh, Cambodia, 1991-1998
prevalence rate % 45 40 35 30 25 20 15 10 5 0 91 92 93 94
Female sex workers Blood donors Pregnant / Married women STI patients
95
96
97
98
Figure 8: Reported number of HIV/AIDS cases in Papua New Guinea, 1990-1998 reported number of cases
700 600 500 400 300 200 100 0 <90 90
AIDS HIV
91
92
93
94
95
96
97
98
u Countries with limited HIV transmission (all other countries). There is so far little indication of rapid increases in infection rates due to sexual contact or injecting drug use.
6
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
STI other than HIV WPRO receives annual sexually transmitted infection (STI) data on reported cases and surveillance data from member states. However, the data vary greatly in coverage and prevalence surveys are not conducted regularly in most countries. While they must be interpreted cautiously, working estimates of the prevalence of selected STI in the general population of reproductive age (15-49) have been developed from available STI prevalence surveys. Following are some key points. u Chlamydia infections appear to be the most prevalent STI in the Region. Prevalence rates in the general population are estimated to be as high as 20% in Papua New Guinea and 13% in Pacific Island countries (excluding Australia, New Zealand and Papua New Guinea). Estimated prevalence rates of between 4% and 10% are found in Australia, Cambodia, Japan and the Philippines. China and Viet Nam have rates of about 2% (Figure 9).
Figure 9: Estimated chlamydia prevalence rate (%) in the adult population (over 15 years of age), 1990s
V ie t Nam S o uth P ac if ic P hil ip p i nes P ap ua Ne w G uine a J ap an C hina C am b o d ia A ustrali
2.3% 13% 6% 20%
7% 2% 4% 5% 0 5 10 15 20
prevalence rate (%)
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
7
u
The highest estimated prevalence rates for gonorrhoea (3% or greater) are found in Cambodia and Papua New Guinea. In other countries, estimated rates are below 1% (Figure 10).
Figure 10: Estimated gonorrhoea prevalence rate (%) in the adult population (over 15 years of age), 1990s
V ie t N a m S o u th P a c if ic P h ilip p in e s P a p u a N e w G u in e a M a la y s ia C h in a C a m b o d ia
0 .5 % 0 .4 % 1 .0 % 3 .5 % 0 .5 % 0 .1 5 % 3 .0 % 0 1 2 p re v a le n c e ra te (% )
3
u Relatively high syphilis prevalence rates characterize Cambodia (4%), Papua New Guinea (3.5%) and the South Pacific (8%) (Figure 11). In all other countries, estimated rates are below 1%.
Figure 11: Estimated syphilis prevalence rate (%) in the adult population (over 15 years of age), 1990s
C ambodia M alaysia M ongolia Papua N ew G uinea Philippines South Pac ific Vietnam 0 .3 % 0 .5 % 1 .0 % 0 .1 3 %
4 .0 %
3 .5 % 8 .0 %
0
2
4
6
8
prevalen ce rate (% )
8
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Gonococcal Susceptibility to Antimicrobials The WHO Western Pacific Gonococcal Antimicrobial Surveillance Programme (WHO WPR GASP) has undertaken antibiotic susceptibility surveillance of gonococci since 1992. Sixteen countries in the Region contributed data on about 10 000 isolates in 1998. u Resistance to the penicillins is widespread. The highest rates of penicillin resistance are reported from the Republic of Korea (90%); the Philippines (82%); Viet Nam (76%); Mongolia (70%); Hong Kong, China (69%); China (62%); and Singapore (59%). These percentages represent the total of all forms of penicillin resistance (Figure 12).
Figure 12: N. gonorrhoeae penicillin resistance in selected countries 1992-1998
00 80 60 40 20 0 1992
Viet Nam Vanuatu Singapore
1993
1994
1995
1996
1997
1998
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
9
u
Quinolone resistance was assessed in 13 countries in 1998, with quinolone resistant gonococcus (QRNG) found in 11 countries. Fiji and the Solomon Islands are the only countries in which this resistance is not observed. More than 90% of isolates in China and Hong Kong, China are QRNG. The Philippines has a high proportion of high level QRNG (63%), continuing a pattern that has been observed for some time. The Republic of Korea (62%) and Japan (52%) report a high percentage of QRNG. Papua New Guinea, Singapore and Viet Nam show a lower proportion of mixed low and high level QRNG. In other countries (Australia and New Zealand), QRNG generally occurs in imported strains, although some endemic transmission also occurs. Overall, more countries in the Region are recording the presence of QRNG, a higher proportion of QRNG is being recorded each year, and higher minimal inhibitory concentration (MIC) are being found in the existing QRNG.
Figure 13: Evolution of quinolone resistant N. gonorrhoeae in Australia; Hong Kong, China; and Singapore, 1992-1998 50 % 45 % 40 % 35 % 30 % 25 % 20 % 15 % 10 % 5% 0% 19 92 19 93 19 94 19 95 19 96 19 97 19 98 Au stralia Ho ng Kong, China Singapo re
proportion q uino lone resistance
u Spectinomycin resistance is rarely encountered in the Region and occurs only in sporadic cases. Incremental changes were observed in susceptibility patterns of gonococci in the Region in 1998. However, the observed increases are occurring on top of an already high and somewhat alarming level of resistance. This worsening resistance will continue to limit options for treatment in the countries and areas of the Region.
10
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Sexual Behaviour Sentinel surveillance on risk behaviour has been conducted in the Philippines and Cambodia. In the Philippines the surveys among high risk groups have shown low levels of consistent condom use and condom use at the last sex with non-regular partner. The perception of their own risk of AIDS was low (Figure 14).
Figure 14: Behavioural survey among high risk groups in the Philippines, 1998
% 80 70 60 50 40 30 20 10 0 IDUs IDUs MSM MSM FCSW FSW RCSW RSW
consistent condom use condom use at the last se x with non regular partner perception of o wn risk ofHIV infection
IDUs: injecting drug users; FSW: female sex workers;
MSM: men who have sex with men RSW: registered sex workers
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
11
In Cambodia, condom use in high-risk groups increased in groups surveyed: beer girls (9.6% in 1997 to 29.7% in 1998), sex workers (42% in 1997 to 53.4% in 1998), students (71.5% in 1997 to 77.4% in 1998) and other groups (Figure 15). There were also decreases in: (a) the proportion of men who reported purchasing commercial sex between 1997 and 1998 (Figure 16); and (b) the proportion of sex workers who had more than three clients in one day (38.3% in 1997 to 22.4% in 1998).
Figure 15: ‘Always use’ condom in commercial sex for selected population groups in Cambodia
% 100 80 60 40 20 0 beer girls sex w orkers students military/police motor driver 1997 1998
workers
Figure 16: Men’s past month commercial sex use for selected population groups in Cambodia % 80 60 40 20 0 military/police motor drivers students 1997 1998
Ad hoc surveys conducted in many countries and areas in the Region show low condom use among risk groups; lifetime condom use was low (40%-50%) among high risk groups in Lao People’s Democratic Republic (PDR); 36% of sex workers use condoms in Mongolia; a high percentage of sex workers did not use condoms in China (1998, median 65%, range 5% to 100%). Sharing equipment among IDUs in China increased from 25% (range, 20% to 100%) in 1997 to 60% (range, 20% to 100%) in 1998.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
13
2
COUNTRY STATUS AND TRENDS AUSTRALIA Summary Australia was among the first countries in the world to report AIDS cases. Retrospective analyses of epidemiological data indicate that HIV incidence peaked in 1984, followed by a rapid decline. This trend has continued in the 1990s, with a decrease in AIDS cases from 954 in 1994 to 273 in 1998. This decline in incidence is projected to continue. Annual reported diagnoses of HIV infection have also declined steadily, from more than 2300 in 1987 to about 720 in 1998. An estimated 10 800 people were living with HIV infection in Australia at the end of 1998. The number of people living with HIV/AIDS may increase slightly due to the introduction of antiretroviral therapy and associated longer survival. It is estimated that there have been 530 fewer AIDS diagnoses since 1995 than would have been the case in the absence of potent combination therapies that have reduced the rate of progression from asymptomatic HIV infection to AIDS. The proportion of women among reported cases has been gradually increasing, from 0% until 1983 to 13% in 1999. HIV infection in children remains rare. Overall rates for other STI have declined since the mid-1980s, with particular reduction among high-risk groups such as male homosexuals and FSWs. However, rates of STI among indigenous populations continue to be substantially higher (by a factor of 10 to 100 times) than in the non-indigenous population.
Surveillance Structure
•
Newly diagnosed HIV infections and AIDS cases are notifiable in all State/Territory health jurisdictions. AIDS Surveillance Definitions by Centers for Disease Control and Prevention (CDC 1987) were used before 1993. Since then, the modified case definition described in ANCA Bulletin 18: Definition of HIV Infection and AIDS-defining Illnesses (Australian National Council on AIDS 1994) has been used. Three AIDS defining illnesses were added to the CDC 1993 revision of the AIDS case definition as part of the current Australian AIDS case definition. However, individuals with an HIV seropositive test result and a CD4+
•
Australia
14
cell count of less than 200 are not defined as having AIDS unless they have an AIDS defining illness.
•
Beginning in 1991, national surveillance for cases of newly diagnosed HIV infection was extended to include data on probable or estimated date of infection. Newly acquired HIV infections are identified by the diagnosis of an HIV seroconversion illness or a negative or indeterminate HIV antibody test result during the 12 months prior to HIV diagnosis. HIV seroprevalence surveys have been conducted regularly. The population surveyed in 1998 included blood donors, STI clinic clients, needle exchange clients and prison entrants. Diagnoses of gonorrhoea and syphilis are notifiable in all States/ Territory health authorities, while chlamydia is notifiable in all health jurisdictions except New South Wales. STI may be reported by doctors, laboratories, or both, depending on the jurisdiction. Donovanosis is notifiable in the Northern Territory, Queensland, and Western Australia. Chancroid is notifiable in all State/Territory health jurisdictions, except for South Australia and New South Wales.
•
•
•
HIV/AIDS "Reported HIV cases" refers both to AIDS cases and HIV antibody positive asymptomatic patients. At the end of June 1999, a total of 19 738 cases of HIV had been reported including 8140 AIDS cases (Table 1). The annual number of cases of newly diagnosed HIV infection has declined steadily since 1987. AIDS incidence peaked at 954 cases in 1994, then gradually declined to 273 diagnosed cases in 1998. It is recognized that some reports may duplicate previously reported cases. As a consequence, estimates have been made of the extent of duplication, resulting in revised figures.
Reported cases as of June 1999
15
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Australia as of June 1999 <1985 AIDS 54
85 128
86 234
87 385
88 533
89 614
90 675
91 803
92 787
93 844
94 954
95
96
97
98
99 44
Total 8 140
801 654 357 273
HIV/AIDS 467 1922 1815 2305 1691 1633 1423 1415 1239 1098 1030 946 927 794 720 313 19 738
The vast majority of reported cases of HIV infection and AIDS have been diagnosed in males. Sexual contact between men was the predominant route of HIV transmission. While the absolute number of women diagnosed with HIV has been stable over time, the relative proportion of women represented has increased steadily (0% in 1983 to 13% in 1999). Exposure to HIV among women occurs predominantly through heterosexual contact. HIV prevalence rates are low in most population groups surveyed, as illustrated by the following breakdowns:
Table 2: Distribution of cumulative Reported HIV/AIDS cases by sex and mode of transmission in Australia as of June 1999 HIV (%) Sex Male Female Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown AIDS (%)
94 6 66 4 7 3 <1 20
96 4 85 3 5 3 <1 3
Australia
16
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Active HIV/AIDS surveillance
• •
Pregnant women (0.005% in 1995-1996) Homosexual men < 23 years old living in metropolitan areas (declined from 3% in 1992 to 1.4% in 1997) Military entrants (less than 0.1% for 1988-1996) Female sex workers (steady at about 0.1% since 1992) Prison entrants (0.1% in 1997) Individuals attending selected sexual health clinics (0.5% among males, 0.05% among females in 1997).
• • • •
HIV prevalence was higher among IDU participants in needle exchange programmes (2.1% in 1995 and 1.5% in 1998). The rate was substantially higher among homosexual IDUs (31% in 1997). These results show that circulation of HIV is limited in the general population. Higher prevalence continues to exist among homosexual, IDUs, sex workers and their clients. Estimates and projections for the number of people living with HIV are based on analysis of epidemiological data from surveillance of diagnosed HIV cases and from sentinel surveillance in populations known to be at high risk for HIV infection. Projection for future HIV prevalence was obtained using back-projection methods. The annual number of AIDS diagnoses, after adjusting for reporting delay, reached a peak in 1994 (954 cases), and declined to 273 cases in 1998. AIDS incidence is projected to continue to decline slowly over the next few years. It was estimated that there were 10 800 people living with HIV infection in Australia by the end of 1998, representing a prevalence rate of 0.1% in the adult population aged 15-49 (Table 3 and 4). Estimated HIV prevalence is projected to increase to 11 420 by the year 2000 (Table 3). This can be attributed to the recent introduction of highly active antiretroviral therapy and the prolonged transition period from asymptomatic HIV carrier status to AIDS patient.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
17
Table 3: Estimates and projections for HIV/AIDS in Australia, 1998 and 2000 1998 Population (15-49) AIDS HIV Incidence Incidence rate in adults (15-49) Prevalence Prevalence rate in adults (15-49) 9 600 000 500 0.0065% 10 800 0.1% 2000* 9 700 000
11 420 0.1%
* Projections for AIDS incidence were not made given the need to adjust for the impact of antiretroviral treatment.
Table 4: HIV/AIDS epidemiological features in Australia (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Sexual contact Infection by mode of Injecting drug use transmission
10 800 0.1% 5% 91% 5% 4% >95% >95%
Others
Estimated reporting rate for HIV Estimated reporting rate for AIDS
STI other than HIV Reported cases Diagnoses of STI reported to the National Notifiable Diseases Surveillance System show generally moderate incidence rates: gonorrhoea (29/10 000); syphilis (6/10 000); chlamydia (62/10 000) in 1998. There has been a steady decline in the reported rates of STI in some states since the early 1980s. Reported incidence rates among indigenous people are 10-100 times higher than in non-indigenous people. A survey of women attending a sexual health clinic in 1992 documented a gonorrhoea prevalence rate of 1.0% and a chlamydia prevalence rate of 6.4%. Surveys of STI have shown substantially higher incidence rates in many indigenous communities than in the non-indigenous population.
Active STI surveillance
Australia
18
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Estimates for STI Gonococcal antimicrobial resistance
Information is not available. Data from GASP indicates an increase in gonococcal resistance. Resistance to penicillin increased from 17% to 28% between 1982 and 1998; resistance to quinolones increased from <0.1 % to 3% in the same period.
STI and HIV Risk Behaviour Surveillance Behavioural surveys among homosexual men suggest that there has recently been an increase in the proportion of respondents reporting unprotected anal sex with casual sex partners (up to 25%). The proportion of IDUs reporting shared use of equipment in the previous month declined from 29% in 1995 to less than 20% in 1997. Surveys among first year university students in Sydney since 1988 show that the proportion of respondents with previous sexual experience has remained constant (6%), and that a higher proportion of students report using condoms with casual sexual partners (80%).
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
19
BRUNEI DARUSSALAM
Summary Since the first case of HIV infection was diagnosed in Brunei Darussalam in 1986, HIV prevalence has remained low. A cumulative total of 498 HIV cases, including 12 AIDS cases, had been reported by the end of July 1999. The reported number of HIV/AIDS cases has decreased since 1994. The large majority of new reported HIV cases occur among immigrant workers. Nearly all reported HIV/AIDS cases are among men (96%) and among heterosexuals. Levels among women have stayed low, with no apparent increase. HIV seroprevalence surveys show low HIV prevalence rates, even among individuals at high-risk for HIV and STI . Reported seroprevalence of syphilis is also low (0.15% - 0.3%).
Surveillance Structure
• •
The CDC AIDS case definition (1993) is used. All HIV and AIDS cases are mandated as reportable by the Ministry of Health. Information on other STI is not available.
• HIV/AIDS Reported cases as of 31 July 1999
The first HIV infection in Brunei Darussalam was reported in 1986. By the end of July 1999, a cumulative total of 498 HIV infections had been reported, amongst 18 Bruneians and 480 foreigners. The cumulative number of long term residents reported as HIV cases remains very low (less than 20). The number of reported AIDS cases is also quite low (Table 1).
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Brunei Darussalam as of July 1999 <1990 AIDS 1 90 1 3 91 0 0 92 0 1 93 1 69 94 3 153 95 2 80 96 2 78 97 2 63 98 0 34 99 0 14 Total 12 498
HIV/AIDS 3
Brunei Darussalam
20
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Most reported cases of HIV infection are among men and heterosexuals (Table 2). The distribution of reported HIV by sex has not changed substantially during the past few years.
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Brunei Darussalam through July 1999 (including immigrant workers) HIV (%) Sex Male Female Mode of transmissio Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown AIDS (No.)
96 4 2 <1 87 <1 <1 10
12 0 1 0 9 2 0 0
Active HIV/AIDS surveillance
Serologic studies carried out in selected population groups have shown very low HIV prevalence rates. No cases of HIV infection among blood donors were found in 1993, 1994 and 1998, as well as among pregnant women in 19931994. All pregnant women are tested for HIV during their antenatal check-ups, and in 1998 only one pregnant woman out of 7933 (0.01%) was found to be HIV positive. Among individuals perceived as being "at risk" (STI patients, foreign workers, other individuals) in 1993-1994, the HIV prevalence rate was 0.3%. However, one survey among prisoners in 1994 reported a relatively high HIV prevalence rate of 2.6%. The number of HIV infections and AIDS cases is so low that estimates or projections would be inappropriate.
Estimates and projections for HIV/AIDS
STI other than HIV Reported cases Active STI surveillance Information is not available. Prevalence rates for syphilis among blood donors was 0.3% in 1997 and 0.15% in 1998. Additional data on STI are not available.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
21
Gonococcal antimicrobial resistance
Data from GASP identified penicillin resistance among 40% to 42% of gonococcal isolates during 1992-1993, and quinolone resistance among 10% of gonococcal isolates in 1996.
HIV and STI Risk Behaviour Surveillance Information is not available.
Brunei Darussalam
22
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
CAMBODIA
Summary Rapid increases in HIV transmission have been reported in Cambodia since the first case of HIV infection was notified in 1991. By 1998, an estimated 180 000 adults and 4600 children were living with HIV infection. Prevalence among those ages 15 to 49 years is estimated to be 3.7%. The cumulative reported number of individuals with HIV/AIDS reached 24 028 by the end of June 1999. HIV is transmitted primarily through sexual contact. The estimated reporting rate of HIV is low (8%). Highest HIV prevalence is observed among FSWs (42.6% in 1998). An estimated one third of HIV/AIDS cases are among women of child bearing age. STI are highly prevalent and condom use is low among both FSWs and their male customers (36%). Gonococcal antimicrobial resistance is high for both penicillin (79%) and quinolones (53%). Surveillance Structure
• •
The expanded WHO AIDS case definition (1994) is used. All HIV and AIDS cases are mandated to be reported to the Ministry of Health. Reporting of other STI is based on the syndromic approach and laboratory testing is used where available. HIV sentinel surveillance began in 1994 in five provinces and was extended to 22 provinces by 1997. However, the sequencing of surveillance surveys and the composition of population groups included have not always been consistent. Population groups covered by HIV sentinel surveillance include women of child bearing age (antenatal clinic attendees prior to 1998), military and police personnel, FSWs, patients, and hospital inpatients.
•
•
•
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
23
HIV/AIDS Reported HIV/AIDS cases as of 30 June 1999 HIV infection was first detected through serological screening of blood donors in 1991. Sentinel surveys in 1995 provided the first evidence of a highly disseminated epidemic. A total of 24 028 cases of HIV infection, including 4834 cases of AIDS, had been reported by the end of June 1999. The rapid increase in the numbers of AIDS cases since 1991 is shown in Table 1.
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Cambodia as of June 1999 Not known AIDS HIV/AID 906 906 1991 0 3 92 0 91 93 1 205 94 14 660 95 91 2611 96 30 45 97 572 4674 98 1494 7646 99 1456 2691 Total 4834 24 028
The predominant mode of transmission is through heterosexual contact, and transmission through homosexual or bisexual contact or intravenous drug use appears minimal (Table 2). During early phases of the epidemic, reported HIV infections were distributed equally among men and women. This profile has changed, as reflected in the fact that about two thirds of reported infections in 1998 were among women. Both the sex ratio of reported HIV/AIDS cases and data on mode of transmission should be interpreted with caution given data limitations. Data on sex and/ or mode of transmission are not reported in about half of HIV cases (Table 2). Of 24 028 reported cases of HIV infection, 1636 were among children believed to have been infected perinatally.
Cambodia
24
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Cambodia as of June 1999 HIV (%) Sex Male Female Unknown Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown AIDS (%)
28 28 44
6 1 93
0 <1 50 0 7 43
<1 0 35 0 23 42
Active HIV/AIDS surveillance
•
Ad hoc studies conducted in selected population groups in 1992 identified high HIV prevalence among FSWs at that early point in the epidemic (10%). However, no cases of HIV infection were found in the police, military, TB patients or pregnant women. The HIV sentinel surveillance system, established in 1994 in five provinces, was expanded to 22 provinces by 1997. Initially, populations surveyed included direct FSWs, the police, the military, antenatal clinic attendees, and TB patients. However, sample size was too small to obtain meaningful assessment of prevalence in certain groups. In later years, indirect FSWs, men and women of child-bearing age with no known risk, and hospital inpatients were surveyed. HIV prevalence rate increased over time in most population subgroups. However, inconsistencies in sample size, study sites, and population groups imply that survey findings are of limited value for trend analysis (Table 3). HIV prevalence rate is the highest among FSWs (Table 3).
•
•
•
•
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
25
Table 3: Prevalence rate of HIV in selected populations in Cambodia, 1992-1998 HIV prevalence rate (%) 1992 Married women child bearing age Antenatal clinic attendees Direct female sex workers Indirect female sex workers Female dancers / bar attendants Police Military TB patients Hospital in patients Blood donors 0 9 0 0 1994 39 1995 0 2.6 38 25.3 8.1 8 5.9 1996 1.7 40.9 5.5 5.9 1997 3.2 39.3 10.2 6 7.1 6 1998 2.4 42.6 19.1 5.2 12.2 4
Estimates and projections for HIV/AIDS
National and international experts held a consensus meeting endorsed by the Government of Cambodia in 1999. They developed working estimates of HIV/ AIDS prevalence in 1998 and projections through 2000. The group concluded that widespread HIV transmission had begun in early 1989 and expanded rapidly thereafter. However, they also projected that the rate of spread would reach a peak in 2000.
Table 4: Estimates and projections for HIV/AIDS in Cambodia, 1998 and 2000 Adults 1998 Population (15-49) (thousands) HIV Prevalence Prevalence rate Incidence Incidence rate 180 000 3.7% 5800 0.1% 257 500 5.7% 11 000 0.2% 4600 1300 8000 2160 2000 Children 1998 2000
AIDS
An estimated 180 000 adults (15-49) and 4600 children were living with HIV infection in 1998 (Table 4). It is projected that the number of people living with HIV will increase by 40% by 2000, and that about one third of HIV/AIDS cases will be among women. Heterosexual contact remains the predominant mode of transmission (Table 5). The overall reporting rate of HIV/AIDS is low (Table 5)
Cambodia
26
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Table 5: HIV/AIDS epidemiological features in Cambodia (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
180 000 3.7% 30% 95% 5%
Sexual contact Others
Estimated reporting rate for HIV Estimated reporting rate for AIDS
8% 11%
STI other than HIV Information is not available. Surveillance studies conducted in 1996 indicate high rates of STI among FSWs (Table 6). Based on the limited data available on STI prevalence, the annual incidence of gonococcal infections is estimated at 170 000 and of chlamydia infections at 240 000. The prevalence of syphilis seropositivity is estimated at 240 000.
Table 6: Prevalence rate (%) of selected STI in Cambodia, 1996 Chalamydia Women in reproductive health links Female sex workers Male police / military 5.3 38.7 2.1
Gonorrhea 5.3 10 to 39 5
Syphilis 3 to 7 4 to 25 6.6
Gonococcal antimicrobial resistance
Data for 1996 from GASP indicate that 79% of gonorrhoea isolates were penicillin-resistant and 53% quinolone-resistant.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
27
HIV and STI Risk Behaviour Surveillance Behavioural surveillance conducted in 1997 and 1998 showed increased condom use among high risk groups (Table 7).
Table 7: ‘Always use’ condoms in commercial sex in Cambodia, by group Population group Military/Police FSWs Motor drivers Beer girls Student 1997 (%) 54.2 42.0 53.8 9.6 71.5 1998 (%) 62.8 53.4 61.8 29.7 77.4
The same survey suggests that fewer men reported purchasing commercial sex in 1998 than in 1997 (Table 8).
Table 8: Men’s commercial sex use in Cambodia, previous month Population gr Military/Police Motor driver Student 1997 (%) 58.0 42.1 26.7 1998 (%) 36.1 33.9 17.7
Cambodia
There was a decline in the proportion of FSWs who had sex with more than 3 clients per day from 38.3% in 1997 to 22.4% in 1998. However, there was also a significant increase in the percentage of beer promoters who reported exchanging sex for money or gifts in the past year (21.1% in 1997, increasing to 31.1% in 1998). Although these data show positive trends, findings should be considered only as suggestive given that these differences are available only for the two cities within one year interval.
28
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
CHINA Summary HIV/AIDS was first reported in China in 1985. By March 1999, the cumulative reported number of people with HIV/AIDS reached 13 051, with a total of 419 AIDS cases and 226 AIDS-related deaths. An estimated 400 000 persons were living with HIV in 1998. The prevalence rate among people aged 15 to 49 years is <0.1%. However, only about 5% of estimated HIV/AIDS are reported. HIV prevalence data indicate a focused, explosive spread of infections among IDUs and no significant spread in the non-IDU population. Although HIV/AIDS cases have been detected in all provinces, HIV transmission is focused primarily among IDUs in certain provinces. For example, the HIV prevalence rate among IDUs was found to range from 44% to 85% in selected communities of drug users in Yunnan and Xinjiang. The percentage of female prostitutes who do not use condoms changed little over time (median 65%). The percentage of IDUs who report sharing of equipment increased from 25% in 1997 to 60% in 1998. Trichomoniasis and chlamydia infections are the most prevalent STI.
Surveillance Structure
• • •
The CDC AIDS case definition (1993) is used. All HIV and AIDS cases are notifiable to the Ministry of Health. Other notifiable STI to the Ministry of Health are gonorrhoea, syphilis, non gonococcal urethritis (NGU), venereal warts, chancroids and genital herpes, etc. About 100 HIV sentinel surveillance centres were operated in 30 provinces in 1998. The surveyed population included STI patients, female prostitutes, IDUs, truck drivers, blood donors and antenatal clinic attendees. Some behavioural data have been collected from IDUs and female prostitutes.
•
•
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
29
HIV/AIDS Reported cases as of March 1999 The first cases of HIV were reported in 1985, with a cumulative total of 13 051 reported by March 1999 (Table 1). This included 419 AIDS cases and 226 AIDS-related deaths. Reported cases of HIV have doubled since 1994.
Table 1: Reported cases of HIV/AIDS by year of diagnosis in China as of March 1999 <1989 AIDS 3 90 2 299 91 3 216 92 5 261 93 23 274 94 29 531 95 52 1567 96 38 2649 97 126 3343 98 136 3306 99 2 412 Total 419 13 051
HIV/AIDS 193
The majority of reported HIV/AIDS cases occurred in the male population, with 71% being among IDUs (Table 2). Mode of transmission is unknown for about one fifth of reported HIV/AIDS cases.
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in China as of March 1999 HIV (%) Sex Male Female Unknown Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 85 14 1 AIDS (%) 85 10 5
<1 71 7 <1 <1 22
2 48 26 <1 <1 23
Explosive increases in HIV prevalence have been noted among IDUs in certain provinces in recent years. HIV infection has been detected in more than half of
China
Active HIV/AIDS surveillance
In 1998, close to 100 HIV sentinel sites were operational in 30 provinces. There were 36 sites for STI patients, 22 for female prostitutes, 19 for IDUs, 7 for long distance truck drivers, 12 for blood donors, and one for antenatal clinic attendees.
30
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
the 19 sentinel sites for IDUs, with HIV prevalence rates ranging from 0% to 85% in 1998. Very high HIV prevalence rates have been observed among IDUs in Yunnan (1991-1994, 40% to 50%) and Xinjiang (1998, 40% to 85%). However, even among IDUs in such provinces, the rate of HIV infection varies widely from community to community. HIV prevalence among other population groups studied in Yunnan and Xinjiang remains very low. HIV sentinel surveillance indicates no major spread of HIV in the non-drug using population (Table 3).
Table 3: Prevalence rate of HIV in the non drug using population in China, 1991 through 1998 Surveillance population STI clinic attendees Female prostitutes Antenatal clinic attendees Blood donors 1991-1994(%) 0.01% 0.02% 0% 1998(%) 0.1% 0.1% 0.3% 0.0%
Estimates and projections for HIV/AIDS
Estimates for HIV prevalence and AIDS incidence were developed in 1997 and revised in 1998 by national experts. HIV appears to have begun its spread in the early 1990s. In 1998, an estimated 400 000 people were living with HIV in the country (prevalence rate of <0.1% in people aged 15 to 49 years) (Table 4) and 6000 people with AIDS.
Table 4: Estimates and projections for HIV in China, 1998 and 2000 1998 Population (15-49)(thousands) HIV prevalence Adults (15-49) Total population 709 468 400 000 <0.1% <0.1% 2000 722 122 600 000 <0.1% <0.1%
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
31
The 1998 estimates indicate that (a) the sharing of needles among IDUs accounts for more than half of HIV infections; (b) 15% of infections are sexually transmitted; and (c) 12% of HIV infections occur among women (Table 5). The number of reported HIV/AIDS cases suggests a very low reporting rate for HIV/ AIDS. Reported HIV/AIDS cases accounted for 3% of estimated HIV cases, while reported AIDS cases accounted for 5% of estimated AIDS cases in 1998 (Table 5).
Table 5: HIV/AIDS epidemiological features in China (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
400 000 <0.1% 12% 15% 65% 20% 3% 5%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
STI other than HIV Reported cases After a series of major intervention campaigns in 1964, the Chinese Government declared that STI had been eliminated in the country. Over the last decade, however, the number of reported cases of STI has increased consistently. In part, this can be attributed to improved reporting systems. The incidence of gonorrhoea at sentinel sites was between 73/100 000 and 83/100 000 from 1993 to 1998, while syphilis incidence increased from 1.4/100 000 to 31.1/100 000 during that same period. Reported cases of congenital syphilis at sentinel sites increased from 2 in 1993 to 73 in 1998. Active STI surveillance Mass screening for STI among the female population took place in rural and urban areas of Yunnan between 1990 and 1996. Prevalence rates ranged from 0.3% to 0.9% for gonorrhoea, from 7.4% to 16.2% for trichomoniasis, and from 9.8% to 38.9% for candidiasis. Another study of the same population in 1996 reported a chlamydia prevalence rate of 5.5%. In Nanjing, chlamydia prevalence rate in a population of STI clinic patients was found to be 10% in 1993.
China
32
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Estimates for STI
Estimates for STI were developed by WPRO based on results of various prevalence surveys (Table 6).
Table 6: Estimated prevalence of selected STI in China, 1996 Gonorrhoea Prevalence Prevalence rates Adults (15-49) Total population 1 385 000 Chlamydia 18 202 000
0.2% 0.1%
2% 1.5%
Gonococcal antimicrobial resistance
Gonococcal resistance to antibiotics is high, although no particular pattern or trend in resistance was apparent from 1992 to 1998. During that period, the percentage of gonorrhoea strains resistant to penicillin varied from 44% to 84%. Resistance to quinolones was identified in 52% to 81% of gonococcal strains.
HIV and STI Risk Behavioural Surveillance Limited information on behaviour related to HIV/STI transmission has been available since 1995. There is wide variation in prevalence of high-risk behaviour, both between provinces and among communities in the same province. The percentage of female prostitutes who do not use condoms is high (1998, median 65%, range 5% to 100%). The percentage of drug users who are IDUs varied little from 1995 through 1998 (median 25%, range 5% to 90%). Among IDUs, the percentage who shared needles increased from 25% (range from 20% to 100%) in 1997 to 60% (ranging from 20% to 100%) in 1998.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
33
HONG KONG, CHINA
Summary Since the first HIV/AIDS cases were reported in 1984, there has been a slow increase in reported cases in Hong Kong, China. At the end of June 1999, 1255 cases (including 409 AIDS cases) had been reported. The best estimate of HIV prevalence as of early 1999 was about 2000-3000. Although there is a steady increase in the number of HIV cases, the prevalence rate is estimated to be <0.1% in the adult population. The majority of reported cases occurred among men (84%). Mode of transmission was largely through either heterosexual contact (56%) or homo-bisexual contact (26%). STI are reported only from social hygiene clinics (SHC), with data showing an increase in reported STI over time. Periodic surveys of private medical practitioners are conducted to complement passive STI surveillance. However, it appears that only about 20% of all STI are taken care of by public doctors. Gonococcal antimicrobial resistance has increased. Data on HIV/STI risk behaviour are available through monitoring of STI patients, methadone clinic attendees and prison inmates.
Surveillance Structure
• •
The modified 1993 CDC definition is used for the diagnosis of AIDS. The reported HIV/AIDS statistics are updated quarterly based on the data reported from medical practitioners and laboratories through voluntary reporting to the Department of Health. In addition, seroprevalence monitoring of selected groups and unlinked anonymous screening are conducted to supplement the surveillance data. Population groups surveyed included STI clinic patients, blood donors, and drug users. Reporting systems for curable STI exist only in the public health sector. STI in the private sector have been estimated periodically (every 5 years) through surveys of private medical practitioners. HIV sentinel surveillance was established in 1994 and continues to be conducted every year.
•
•
Hong Kong, China
34
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
HIV/AIDS Reported cases as of June 1999 The first case was reported in 1984, and reported cases have gradually increased. By the end of June 1999, 1255 cases including 409 AIDS cases and 196 HIV/AIDS-related deaths had been reported (Table 1). Of these, 84% occurred among men. Heterosexual HIV transmission was identified for 56% of reported cases (Table 2). The percentage of reported HIV infections due to heterosexual contact increased over the last 8 years.
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Hong Kong, China as of June 1999 1984 85 AIDS 0 3 46
86 0 20
87 6 33
88 7 28
89 17 38
90 13 34
91 14 60
92 14 71
93 19 79
94 37
95 45
96 70 134
97 64
98 63
99 37
Total 409
HIV/AIDS 7
104 122
181 189 109 1255
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Hong Kong, China as of June 1999 HIV (%) Sex Male Female Mode of transmissio Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown AIDS (%)
84 16 26 2 56 5 <1 10
89 11 28 2 60 4 1 5
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
35
Active HIV/ AIDS surveillance
Population groups surveyed for HIV include STI clinic patients, blood donors, and drug users (Table 3). Although serological studies show slight a increase between 1994 and 1996 in some target groups, HIV prevalence remains low. Unlinked anonymous screening among TB patients found an HIV prevalence rate of 0.22% in 1995 and 0.40% in 1996. Unlinked anonymous screening among women delivering babies in hospitals showed an increase from zero in 1994 to 0.03% in 1996.
Table 3: HIV seroprevalence rate (%) in selected populations in Hong Kong, China
1985 Blood donors STI patients Drug abusers* * methadone clinic attendees
1994 0.004 0.1 0.05
1996 0.003 0.07 0.03
1998 0.003 0.06 0.21
0.003 0.06 0
Estimates and projections for HIV/AIDS
In 1994, the cumulative number of HIV infections was estimated at 3000 (prevalence rate at <0.1% among general population aged 15-49 years). The best estimate of HIV prevalence as of early 1999 remains at about two to three thousand. Up to June 1999, the cumulative reported number of HIV cases constituted about 38% to 57% of the estimated cumulative HIV numbers.
HIV
Prevalence Prevalence rate in adults (15-49)* Women among HIV infected population
2000 to 3000 <0.1% 40% 80% 15% 5% 38%-57% 38%
HIV Infection by mode of transmission
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
* Estimated population aged 15 to 49 years in Hong Kong, China in 1998 was 3 388 600.
Hong Kong, China
Table 4: HIV/AIDS epidemiological features in Hong Kong, China (1999 estimates)
36
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
STI other than HIV Reported cases of STI from Government social hygiene clinics Data on reported STI indicate an increase from 1989 to 1996 in the number of all STI, with the exception of gonorrhea (Table 5).
Table 5: Trends in number of STI reported in Hong Kong, China Government social hygiene clinics Year 1989 Syphilis Gonorrhea NGU NSGI Herpes Genitals Genital wart Other Total STI 382 3075 2330 1745 834 2007 2118 12491 1994 384 2521 3431 2759 766 2418 2569 14848 1996 1053 2775 7247 5549 1343 3641 5157 26765
Active STI surveillance
A survey on Herpes Simplex Virus 2 (HSV2) seroprevalence among risk groups conducted in 1995 showed prevalence rate of 17-18% in the general population, 12.8% among antenatal clinic attendees, and 77.5% among FSWs. In early 1997, a survey of medical practitioners involved suggested that about 80% of STI patients were managed in the private sector and 20% in the public sector. Data from the GASP showed that the percentage of gonococcal isolates resistant to penicillin ranged from 66% to 78% from 1992 to 1998. Resistance to quinolones increased from 3% to 49% over the same period.
Estimates for STI
Gonococcal antimicrobial resistance
HIV and STI Risk Behaviour Surveillance Information is not available.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
37
JAPAN
Summary Japan continues to report HIV prevalence rates below 1% for most population groups, except among female sex workers of foreign nationality (2.7%) during 1987-1999. A total of 6102 HIV/AIDS cases had been reported as of 27 June 1999. The reporting rate for HIV infection is believed to be high (74%). In 1998, there were an estimated 7300 HIV-infected persons living in the country (prevalence rate <0.1% among adults aged 15 to 49 years). Most reported cases during the early phases of the epidemic were due to blood transfusions. However, in 1999, about 70% of diagnosed HIV infections appear to have been acquired through sexual contact. Reported HIV/AIDS cases include more men (76%) than women (24%). STI prevalence surveys show high prevalence rates of chlamydia among SWs (55% to 58%) and in the general population (6% to 22%). Behavioural data show low condom use, both in the general population and among SWs (6% to 25%).
Surveillance Structure
• •
The expanded WHO AIDS case definition (1994) is used. All HIV and AIDS cases are notifiable to the Ministry of Health and Welfare. STI are monitored through reports from 900 sites (600 until 1998) and ad-hoc prevalence studies. HIV prevalence surveys have been conducted in certain populations and sites at varying intervals.
•
•
HIV/AIDS Reported cases as of 27 June 1999 The first case of AIDS was reported in 1985. By June 27, 1999, 6102 HIV infections, including 2066 AIDS cases and 1130 HIV/AIDS related deaths, had been reported. The reported number of HIV cases has increased each year (Table 1).
Not known 85 AIDS 631 HIV/AIDS 1434 6 0
86 87
88
89
90
91
92
93
94
95
96
97
98 99
Total
5 14 14 11 69 23
21 31 38 101 97 238
51 86 136 169 235 250 493 363 434 543 610 647
231 148 2066 663 386 6102
* All are haemophiliacs infected by transfusion of blood products before 1985, for which reported year is unknown.
Japan
Table 1: Reported cases of HIV/AIDS in Japan as of June 27, 1999
38
The number of reported HIV/AIDS cases includes more males (76%) than females (24%) (Table 2). Most of the cases diagnosed prior to 1985, the year in which blood safety measures were implemented, were attributable to contaminated blood products administered to haemophiliac patients. After February 1988, HIV/AIDS cases among haemophiliac patients were no long reportable, and thus are not included in reported cases since then. Among recently reported HIV/AIDS cases, heterosexual contact is the most common mode of transmission (Table 2). For 20% of cases, mode of transmission remains unknown.
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Japan as of June 27, 1999 HIV (%) Sex Male Female Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown AIDS (%)
76 24 19 <1 35 24 <1 20
90 10 16 <1 31 31 <1 20
Active HIV/AIDS surveillance
The Epidemiology Study Group on HIV has conducted surveys among both high-risk (FSWs, IDUs, homosexual men, STI patients) and low risk groups (antenatal patients). Data on HIV are derived from such surveys, as well as from reported cases and data from blood screening programmes. HIV prevalence has been consistently below 1% in groups surveyed, with the exception of FSWs of foreign nationality (2.7% during 1991-1996). No infections were identified in FSWs of Japanese nationality. In 1987-1991, HIV prevalence was 0.05% among STI clinic patients in Tokyo. No HIV infections have been identified in this population since that time, neither in Tokyo nor in the country as a whole. Between 1986 and 1998, HIV seroprevalence among blood donors was <0.001% countrywide. The highest rate of infection (0.002%) was observed in metropolitan areas (1997). Only one HIV case was reported among 179 462 antenatal attendees screened at 89 health facilities in 1998. A survey on HIV seroprelance among MSM in one area showed the prevalence rate of <1%
39
between 1986 and 1994. Another study conducted in metropolitan area in 1996 among MSM with high-risk sexual behaviour indicated a prevalence rate as high as 10%. HIV prevalence rate among IDUs has been <0.05% between 1988 and 1996. Estimates and projections for HIV/AIDS Estimates and projections of HIV in Japan were revised in 1999 by the Ministry of Health and Welfare Panel (Table 3). Estimates suggest that, by the end of 1998, 8000 persons were living with HIV (prevalence of <0.01% in people aged 15-49 years). It is projected that the number of people living with HIV will double by the year 2003 (Table 3).
Table 3: Estimates and projections for HIV in Japan by 1998 and 2003* 1998 Population (15-49)(thousands) HIV Prevalence Prevalence rate in adults (15-49) 60 809 7 300 <0.1% 2003* 56 865 15 400 <0.1%
*Projections of AIDS incidence were not made as it requires adjustment for the impact of antiretroviral treatment.
Japan
40
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Based on 1998 estimates, sexual contact has been the dominant mode of transmission (92%, see Table 4). An estimated one third of HIV infections are among women (Table 4).
Table 4: Selected HIV/AIDS epidemiological features in Japan (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
8000 <0.1% 33% 92% <1% 7% 74% 83%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
*Includes homosexual and heterosexual contact
STI other than HIV
Reported cases
Reported data from 600 reporting sites are available for chlamydia, gonorrhoea, trichomonas, genital herpes, and venereal warts. No data on syphilis are available. The majority of reported STI are curable, and chlamydia is the most commonly reported curable STI (Table 5).
Table 5: Reported STI from 600 sites in Japan in people aged 15 years or older 1993 through 1997 Total Year 1993 1994 1995 1996 1997 Number 32 981 32 588 31 994 33 369 34 868 All STI 32 31 30 32 33 Chlamydia 9.7 13.8 13.1 13.7 14.9 Rate/100 000 Gonorrhoea Trichomonas 6.5 6.0 6.4 7.5 8.1 3.8 3.7 3.2 2.6 2.2
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999 Although periodic surveillance of STI has not been established, some information is available from ad hoc studies (Table 6). Variations in prevalence of STI within population groups may be attributed to methodological issues (e.g., inconsistencies in site selection, populations, sample size and laboratory tests). However, these data provide an overview of the burden of STI in Japan. The seroprevalence of herpes simplex virus type 2 (HSV2) varies substantially by population group. Studies have shown prevalence rates of zero percent
41
Active STI surveillance
Table 6: Prevalence rate of selected curable STI in selected populations in Japan
Population Pregnant women Blood donors Married women Sex workers
Syphilis % (year) -0 (1982) -16.2 (1992) 0.5 (1993)
Gonorrhoea % (year) ---17.4 (1992) 8.7 (1993)
Chlamydia % (year) 18.2 (1984) 5.6 (1994) 22.1 (1986) 6.3 (1986-89) 58.9 (1990) 55.3 (1993)
among female blood donors, 2% among male blood donors, 3-18% among pregnant women , 23% among male STI patients, 24% among MSM, and 7291% among FSWs. Estimates for STI Gonococcal antimicrobial resistance Estimated chlamydia prevalence in 1996 was 7 380 000 (7% among adults aged 15 years and older). During 1992-1998, the percentage of gonococcal isolates resistant to penicillin varied from 3.5% and 26%, and from 2.6% and 41% for quinolones.
HIV and STI Risk Behaviour Surveillance A survey conducted in 1996 only 25% of respondents always used condoms during casual sexual encounters during the previous four weeks. Findings also showed that 13% of respondents with steady partners (including spouse) had sex with other partners during the previous year (mean of 2.4 non-steady partners). Among FSWs in Fukuoka, percentage always using condoms increased from 6.3% in 1990-1991 to 25.3% in 1992-1993.
Japan
42
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
REPUBLIC OF KOREA
Summary The Republic of Korea has a low HIV prevalence rate. By the end of June 1999, a cumulative total of 964 HIV cases including 145 AIDS cases had been reported. An estimated 3400 HIV-infected individuals were living in the country in 1998 (prevalence of <0.1% among people aged 15 to 49 years). The great majority (93%) of HIV infections are estimated to be sexually transmitted, with 13% occurring among women. National seroprevalence surveys have identified only sporadic cases of HIV infection. The seroprevalence of syphilis is also very low (0.07% among blood donors). Gonococcal antimicrobial resistance is high; in 1997, penicillin resistance was 91% and quinolone resistance 20%. Behavioural surveys in 1996 found that 48% of SWs reported using condoms during all sexual contacts .
Surveillance Structure
• •
The European AIDS Case definition (1993) is used. All HIV infection and AIDS cases are notifiable to the Ministry of Health Other reportable STI are syphilis, gonorrhoea, non-gonococcal urethritis, chancroid, granuloma inguinale, and lymphogranuloma venereum.
•
HIV/AIDS Reported cases as of June 1999 The first case of HIV infection was reported in the Republic of Korea in 1985 and the first AIDS case in 1987. Reported cases of HIV/AIDS have gradually increased (Table 1). By the end of June 1999, a total of 964 HIV infections, including 145 AIDS cases, had been reported.
Table 1: Reported cases of HIV/AIDS by year of diagnosis in the Republic of Korea as of June 1999 <1990 90 AIDS 5 2 54 91 1 42 92 2 76 93 6 78 94 11 90 95 14 108 96 22 102 97 33 124 98 35 129 99 14 88 Total 145 964
HIV/AIDS 73
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
43
The majority of reported HIV/AIDS cases have occurred among males (87% for HIV, 91% for AIDS) and heterosexuals (62% for HIV and 74% for AIDS) (Table 2). The second highest number of HIV infections were reported among homo-/bisexuals (22% for HIV, 9% for AIDS). No infections occurred among IDUs.
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in the Republic of Korea through June 1999 HIV (%) Sex Male Female Mode of transmission Homo/bisexual IDUs Heterosexual Blood products Mother to infant Other/unknown 22 0 62 4 <1 12 9 0 74 0 3 15 AIDS (%)
87 13
91 9
Active HIV/AIDS surveillance
Republic of Korea
General population surveys have been conducted since the late 1980s, and the number of HIV infections detected has remained quite low (prevalence rate of 0.002% in 1996, 0.003% in 1998). HIV prevalence rate among SWs varied from 0.015% to 0.039% in 1993-1995. HIV prevalence rates among seafarers were between 0.007% and 0.071% (Centre for AIDS Research of the Ministry of Health and Welfare). HIV prevalence rate among blood donors was 0.001% in 1993-1995.
44
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Estimates and projections for HIV/AIDS
Estimates for HIV prevalence and AIDS incidence developed in 1996 by national and international experts and endorsed by the government are shown in Table 3. An estimated 3400 HIV infected persons were living in the country in 1998. This number will continue to grow at a slow rate, and is projected to reach 3880 by 2000 (Table 3). An estimated 13% of HIV infections occurred in women (Table 4).
Table 3:
Estimates and projections for HIV/AIDS in the Republic of Korea, 1998 and 2000 1998 Population (15-49) (thousands) AIDS HIV Incidence Incidence rate in adults (15-49) Prevalence Prevalence rate in adults (15-49) 27 001 160 <0.1% 3400 <0.1% 2000* 27 442 --3880 <0.1%
*Projections of AIDS incidence were not made because it would have required adjustment for the impact of antiretroviral treatment.
1 Table 4: Selected HIV/AIDS epidemiological Population (15-49) (thousands) features 2 in the Repubic of Korea (1998 estimates) Incidence Prevalence 3400 < HIV Incidence rate in adults (15-49) Prevalence rate in adults (15-49) <0.1% Prevalence Women HIV infected population < Prevalence rate among in adults (15-49)
13% 93% <1% 7% 21% 29%
HIV Infection by mode of transmission
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
45
STI other than HIV Reported cases The number of STI reported by all Health Centers, which regularly screen registered high-risk groups (including sex workers), was between 51 905 and 38 220 in 1991-1998. Prevalence rates of syphilis and gonorrhoea among registered women in 1998 were 0.39% and 1.11%, respectively. Periodic active surveillance of STI has not been established yet.
Active STI surveillance
Estimates for STI
National estimates for syphilis were developed based on prevalence data from syphilis screening among blood donors. In 1998, the estimated number of people with syphilis was 32 500 (representing a prevalence rate in the total population of 0.07%). Data from the GASP show that, from 1992 through 1998, 80 to 91% of gonococcal isolates were resistant to penicillin and 16 to 20% were resistant to quinolones. No trends were noted in gonococcal antimicrobial resistance.
Gonococcal antimicrobial resistance
HIV and STI Risk Behaviour Surveillance Results of ad hoc studies among 4635 FSWs conducted during 1995-1996 indicate that 31% were less than 20 years old and that 58% worked in urban areas. Many of these FSWs reported using drugs and most had a history of STI. One study of 610 Seoul FSWs found that 48% reported using condoms most of the time and 84% knew that condoms could prevent HIV transmission.
Republic of Korea
46
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
LAO PEOPLE'S DEMOCRATIC REPUBLIC
Summary Lao People's Democratic Republic (Lao PDR) remains a low HIV prevalence country. The first HIV case was detected in 1990. By the end of December 1998, a total of 367 HIV/AIDS cases had been reported. The majority of people with HIV infections lived in areas close to the border with Thailand and China, including the capital city of Vientiane. An estimated 1200 people had been infected with HIV in 1998 (prevalence of <0.1% in people aged 15 to 49 years). The majority of reported HIV/AIDS cases were among heterosexuals (96%). Estimates suggest that men and women are equally affected by HIV. It is estimated only about one fifth of the HIV are actually reported. Serological surveys indicate very low HIV prevalence rates in most population subgroups (<1%), and HIV has not been detected at all in some subgroups. Few data on STI are available, and behavioural surveillance is not routinely conducted. Ad hoc surveys among men at high-risk for HIV/STI infection show that only 40% reported lifetime condom use.
Surveillance Structure
• • • •
The expanded WHO AIDS case definition (1994) for AIDS is used. All HIV and AIDS cases are notifiable to the Ministry of Health. STI are not included in the list of notifiable diseases. HIV Sentinel surveillance is not yet in place. Available data on HIV prevalence are from blood donors and ad hoc surveys. During 1995-1996, these surveys covered bar workers, military personnel, truck drivers, and refugees. In 1996, surveyed populations included hospital patients, volunteers, students, pregnant women, and citizens returning from overseas. However, sample sizes in most subgroups are too small to draw conclusions about HIV prevalence.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
47
HIV/AIDS Reported HIV/AIDS cases as of December 1998 The first case of HIV was diagnosed in 1990. By the end of December 1998, 367 HIV infections had been reported; this included 105 AIDS cases and 45 HIV/AIDS deaths (Table 1). The majority of reported HIV/AIDS cases (96%) were among heterosexuals (Table 2). The majority of HIV infections have been found in areas close to the border with Thailand and China, including the capital city of Vientiane.
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Lao PDR as of December 1998 1990 AIDS 0 HIV/AIDS 1 91 1 8 92 0 11 93 5 18 94 4 17 95 4 31 96 16 71 97 48 108 98 27 102 Total 105 367
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Lao PDR as of December 1998 HIV (%) Sex Male Female Unknown Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 53 32 15 AIDS (%) 50 31 19
0 <1 96 0 3 0
0 0 96 0 4 0
Active HIV/ AIDS surveillance
Seroprevalence surveys carried out in early 1990s showed only sporadic cases of HIV infection. In 1993, HIV seroprevalence ranged from 0.17% (one case) to 1.16% (3 cases) among FSWs in two sentinel sites. In 1994, 4 HIV infections were detected among refugees and returnees from Thailand and China.
Lao PDR
48
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Recent seroprevalence data do not indicate any significant spread of HIV infection in the general population (Table 3). No cases were found among the military, police, students or pregnant women during the early 1990s, and no infections were detected in blood donors until 1994. Lao PDR citizens returning from other countries appear to have the higher HIV prevalence (Table 3).
Table 3: HIV seroprevalence in selected population subgroups in Lao PDR, 1995 through 1998 Number of HIV cases / sample size 1995 Blood donors Bar workers Military Refugees Hospital patients Students Returning citizens Employed people Volunteers Prisoners Long distance drivers Labourers Villagers Pregnant women Other 12 / 3564 0 / 303 0 / 266 1 / 120 12 / 170 -----1/ 6 0/3 2 / 337 --------------------1/4 2/2 1996 3 / 4349 1 / 421 0 / 38 -----28 / 308 2 / 246 0/1 0 / 61 9 / 543 0 / 20 -----------0 / 45 2 / 502 26 / 54 1997 1 / 10444 2 / 137 0/1 -----81 / 729 0 / 103 16 / 336 0 / 119 5 / 234 2 / 12 0/1 0/1 -----0 / 80 1 / 11 1998 2 / 2171 0 / 21 1 / 14 -----48 / 513 1 / 132 20 / 467 2 / 141 13 / 314 4 / 10 1/8 2 / 38 8 / 96 0 / 15 0 / 142
Estimates and projections for HIV/AIDS
An estimated 1200 HIV infected persons were living in Lao PDR in 1998 (prevalence of <0.1% in people aged 15 to 49 years). Half of the HIV infections are believed to occur among women, and heterosexual contact is the dominant mode of transmission (Table 4). Underreporting of HIV/AIDS remains high, and the reported number of HIV accounts for only 20% of estimated cases.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
49
Table 4: HIV/AIDS epidemiological features of HIV/AIDS in Lao PDR (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49)* Women among HIV infected population HIV Infection by mode of transmission
1200 <0.1% 50% 95% 3% 2% 20% 60%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
* Estimated population aged 15 to 49 years in 1998 was 2 335 600.
STI other than HIV Reported cases Active STI surveillance Information is not available . Limited data on STI prevalence are available. A prevalence rate for reactive syphilis of 1-2% was found during syphilis screening at the National Institute for Hygiene and Epidemiology in 1996. Some surveillance of syphilis among pregnant women, bar workers and truck drivers/boat operators was carried out in Khammouane and Champassack provinces in 1997. Syphilis was found in 0.4% and 1% of pregnant women, 0.6% and 2.9% of bar workers and 1.7% and 6.3% of truck drivers/boat. Insufficient information does not allow for estimates to be made. Information is not available.
Estimates for STI Gonococcal antimicrobial resistance
HIV and STI Risk Behaviour Surveillance
Lao PDR
Behavioural information is not routinely collected. Ad hoc surveys conducted in 1992 suggest that 40% of the "urban high-risk population of men" reported lifetime sexual contact with men, and 10% reported multiple sex partners during the previous year. Lifetime condom use was only 40- 50%.
50
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
MACAO
Summary Although HIV infection was first identified in 1986 in Macao, its spread has been very limited. At the end of June 1999, a total of only 197 HIV infections, including 17 AIDS cases, had been reported. The reported number of HIV/ AIDS cases has decreased since 1994. Few HIV infections have been found in most population groups surveyed, with the exception of SWs and those engaged in the entertainment industry (1998 prevalence of 0.8% and 5.8% respectively). A large proportion of reported HIV cases have occurred among women through heterosexual contact (62%), while men are more represented in reported AIDS cases. Data on HIV spread among IDUs are not available, but this would not appear to be a major concern. Data on STI prevalence and HIV risk behaviour are unavailable.
Surveillance Structure
• •
The 1994 WHO AIDS case definition (1994) is used. All HIV infections and AIDS cases are notifiable to the Sanitary Authority (Medical and Health Department). STI are included in routine disease reporting forms. HIV serosurveillance was established in 1987 and expanded in 1992.
• •
HIV/AIDS Reported cases as of June 1999 The first case of HIV infection was diagnosed in 1986. By the end of June 1999, a total of 197 HIV infections, including 17 AIDS cases and nine HIV/AIDS related deaths, had been reported (Table 1). The number of reported HIV/ AIDS cases has been stable since 1994. The increase in reported HIV/AIDS cases in 1993-1994 is attributable to active surveillance among entertainment industry workers initiated at the end of 1992 by the Public Health Laboratory. A large proportion of reported HIV cases have occurred among heterosexual women through heterosexual contact (62%), most of whom are SWs while men make up over three-quarters of reported AIDS cases. This different pattern may be attributable to selection bias of serosurveillance target groups or to higher case detection rates among women than men.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
51
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Macao through June 1999 <1990 90 AIDS HIV/AIDS 1 2 0 1 91 1 4 92 2 13 93 2 40 94 2 33 95 0 29 96 1 21 97 2 19 98 4 31 99 2 4 Total 17 197
• Routine screening of selected population groups began in 1987 and was expanded in 1992.
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Macao as of June 1999 HIV - No. (%) Sex Male Female Unknown Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 61 (31) 135 (69) 1 (<1) AIDS – No. 13 4 0
22 (11) 6 (3) 140 (71) 1 (<1) 1 (<1) 27 (14)
4 3 8 0 1 1
Active HIV/AIDS surveillance
•
Serological surveys identified positive cases sporadically in patients referred from hospitals and health centres (0/59 in 1996, 1/88 in 1997 and 3/7748 in 1998). Among entertainment industry workers surveyed, no positive cases were found in 1996. In 1998, 9 of 1 169 (0.8%) SWs and 8 of 139 (5.8%) entertainment industry workers tested HIV-positive. No HIV infections have been found in tests done among TB patients and other non-hospital populations (including blood donors and security force recruits).
•
•
Macao
52
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
•
In 1998, very few cases were detected among prisoners (1/466, 0.2%) and hospital outpatients tested for infections other than HIV (3/7748, 0.04%).
No estimates have been developed for overall rates of HIV infection in Macao's general adult population. It is believed that transmission is low and occurs largely among SWs and their clients. Estimates for HIV/AIDS
STI other than HIV Although STI are nationally reportable, fewer than 10% of cases appear to be reported. In 1996, only one syphilis case (0.32 per 100 000 people aged 15 years or older) and five gonorrhea cases (1.6 per 100 000 people aged 15 years or older) were reported.
Reported cases of STI
No STI surveillance has been implemented.
Active STI surveillance
No estimates have been developed
Estimates for STI
Information is not available.
Gonococcal antimicrobial resistance
HIV and STI Risk Behaviour Surveillance Although drug dependence is considered to be a problem in Macao, no estimates of the number of drug users are available. About 98% of drug users use heroin, and of these 82% are IDUs.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
53
MALAYSIA
Summary Since the first HIV infection was identified in Malaysia in 1986, 30 593 HIV/AIDS cases have been reported (as of 30 June 1999). The reported number of people with HIV/AIDS is believed to represent about two thirds of actual cases. Among population subgroups screened for HIV, prevalence is highest among IDUs. Estimated prevalence rate in 1998 for this group was 18%, with a probable range from 15% to 20%. An estimated 80% of all drug users in Malaysia are IDUs, and nearly all IDUs are men. In 1998, only 6% of reported HIV infections were among women; after adjusting for female SWs and underreporting of STI, however, the estimate for HIV infected women is slightly higher (9%). In the general population, HIV transmission appears to have stabilized and there is no evidence of widespread transmission of HIV infection. Although most gonorrhoea is penicillin-resistant (59%-74%), resistance to quinolones has not been detected. Behavioural surveillance data have not been included in HIV/STI surveillance in Malaysia.
Surveillance Structure
• •
The Expanded WHO AIDS case definition (1994) is used. HIV and AIDS cases are notifiable and are reported directly to the AIDS/STD Section at the state level, then subsequently reported to national level. Only registered medical practitioners are required to report notifiable diseases. Chancroid, gonorrhoea and syphilis are notifiable and are reported through the Information and Documentation Units in each state, with the data then passed on to the national level. Routine surveillance for drug users admitted to drug rehabilitation centres, blood donors, and high risk prisoners began in 1986. Anonymous, unlinked HIV sentinel seroprevalence surveillance was formally established in 1994 among women attending antenatal clinics, IDUs, blood donors, STI patients, and with TB patients. However, sentinel surveillance has been phased out because these population subgroups are now routinely tested for HIV.
•
•
•
Malaysia
54
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
• •
Routine surveillance has not been conducted among SWs. Some prevalence surveys have been completed among fishermen.
HIV/AIDS Reported HIV/AIDS cases as of June 1999 Since HIV/AIDS cases were first reported in 1986, reported HIV/AIDS cases have increased steadily (Table 1). Most reported cases are identified through screening. Overall, 96% of the reported 30 593 HIV infections have been in men. IDUs accounted for 77% of all reported HIV cases (Table 2).
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Malaysia as of June 1999 <1989 AIDS 2 89 2 90 18 778 91 60 1794 92 73 2512 93 71 2507 94 105 3393 95 233 4198 96 347 4597 97 568 3924 98 875 4624 99 540 2052 Total 2894 30593
HIV / 14 200 AIDS
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Malaysia as of June 1999 HIV (%) Sex Male Female Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 96 4 1 77 9 <1 <1 13 AIDS (%) 94 6 2 58 21 <1 1 17
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
55
Active HIV/AIDS surveillance
•
HIV infection among IDUs increased from 0.1% in 1988 to 20% in 1994. One 1992 study in the northern State of Kelantan reported an even higher HIV prevalence rate (30%). Recent studies suggest that HIV prevalence rate among IDUs nationally has stabilized in the range of 15%-20%. HIV prevalence increased rapidly among SWs during 1992-1993. Although prevalence rates among SWs in the 5%-10% range were reported in 1996, prevalence appears to have decreased or stabilized in the last 3 years. HIV prevalence among blood donors and pregnant women remains below 1%.
•
•
Table 3: HIV seroprevalence in selected population subgroups in Malaysia, 1998 HIV prevalence (%) Average IDUs TB patients SWs STD patients Blood donors Blood dependent Pregnant women 18.00 6.00 3.00 2.00 0.01 1.00 0.32
Low* 15.00 4.00 1.50 1.00 0.003 0.00 0.19
High* 20.00 8.00 5.80 5.00 0.02 2.00 0.52
*Based on low or high reported rates; these are not confidence limits, with the exception of the estimates for pregnant women
Estimates and projections for HIV/AIDS
Estimates for HIV prevalence and AIDS incidence for 1998 and projections through 2003 were developed by national experts in collaboration with the WHO/WPRO in 1999. This profile, which was endorsed by the Government, traced the rapid spread of HIV in the late 1980s and the expansion of the epidemic through the early 1990s. Experts concluded that the epidemic has reached its peak. About 41 000 adults are believed to be living with HIV in Malaysia in 1998 (0.36% prevalence among people aged 15 to 49 years) (Table 4). HIV transmission appears to have stabilized and incidence may decrease in coming years (Table 4). However, prevalence will continue to increase for a few more years.
Malaysia
56
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Table 4: Estimates and projections for HIV/AIDS in Malaysia, 1998 and 2003 1998 Population (15-49) (thousands) AIDS HIV Incidence in adults (15-49) Prevalence Prevalence rate in adults (15-49) 11 300 1 200 41 000 0.36 2003 4 400 71 500
Because estimated HIV/AIDS cases include adjustments for female SWs and underreporting of STI, the estimate for HIV infected women is slightly higher (9%) than the reported rate of 6% in 1998 (Table 5).
Table 5: HIV/AIDS epidemiological features of HIV/AIDS in Malaysia (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
41 000 0.36% 9% 11% 88% <1% 64% 73%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
STI other than HIV Reported cases The reported rate of syphilis decreased from 7.4/100 000 in 1986 to 6/100 000 in 1997, but increased to 11/100 000 in 1998. Reported cases of syphilis were equally distributed among men and women. Reported rates of gonorrhoea decreased from 8/100 000 in 1986 to 6/100 000 in 1998; more cases of gonorrhoea were reported among men than women. Reported rates of chancroid increased from 0.03/100 000 in 1986 to 0.08/100 000 in 1998. One recent study comparing reported STI to the number of STI treated by private practitioners concluded that reported STI may represent only about 7% of all STI diagnosed and treated in the country.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
57
Active STI surveillance
STI have not been included in the HIV sentinel surveillance system. A 1994 survey in Kuala Lumpur showed high prevalence rates among SWs (gonorrhoea, 14.3%; syphilis, 13.6%, chlamydia, 26.5%). Another study in Kuala Lumpur in 1989 showed prevalence rate for syphilis of 1% among pregnant women. All pregnant women are tested for syphilis during their first prenatal visits, with testing coverage approaching 100%. However, prevalence data on syphilis among pregnant women are not available. Information is not available. Results from the GASP indicate that prevalence of penicillin resistant gonorrhoea varied from 59% and 69% during the 1992-1997 period. Quinolone resistance, however, has not been detected.
Estimates for STI Gonococcal antimicrobial resistance
HIV and STI Risk Behaviour Surveillance Data on behavioural risk factors for HIV/STI are not systematically collected, although recently completed surveys among fishermen and IDUs include behavioural components. An estimated 80% of all drug users in Malaysia are IDUs. A 1994 study of women attending STI clinics revealed that 42% reported engaging in commercial sex work, 58% had 100 or more sex partners in the past month, and only 5% had partners who used condoms most of the time. Among men attending STI clinics, 78% reported sex with SWs and 74% never used condoms.
Malaysia
58
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
MONGOLIA
Summary Mongolia has remained nearly free from HIV over the past 2 decades, as evidenced by the fact that only 2 cases have been reported to date. The first case was diagnosed in a male homosexual in 1992, while the second case was detected through screening of SWs in 1998. No HIV infections have been detected in other population groups in which HIV seroprevalence surveys are regularly conducted (i.e., blood donors, people attending STI clinics or prenatal clinics, and SWs). Syphilis prevalence in 1997 was low among blood donors (1.9%), pregnant women (0.5%), and male truck drivers (0.2%). One study of SWs found that 58% had at least one STI. A study of risk behaviour among 436 SWs in 1999 found that only 36% reported using condoms in every instance of sexual intercourse; only 9% of clients were reported to have initiated condom usage.
Surveillance Structure
• • • •
The 1994 expanded WHO AIDS case definition (1994) is used. All HIV and AIDS cases are reportable to the Ministry of Health. Other reportable STI are syphilis, gonorrhoea and trichomoniasis. HIV routine surveillance is carried out among SWs, STI clinic attendees, prenatal clinic attendees, and blood donors.
HIV/AIDS Reported cases as of August 1999 There have been only 2 cases reported as of August 1999. The first case was diagnosed in a male homosexual in 1992 who acquired HIV abroad and died of AIDS in 1999. The second case was detected through screening of SWs in 1998. HIV surveillance activities and testing started in 1987, with an average of 50 000 - 70 000 tests being conducted annually. HIV testing has been done annually for blood donors, high-risk groups (e.g., STI clinic attendees, SWs, homosexuals) and voluntary clients. In 1998, only 1 of 101 SWs tested was HIV positive. No other positive tests have been reported in other sentinel surveillance populations. No estimates or projections for HIV/AIDS in Mongolia have been developed.
Active HIV/AIDS surveillance
Estimates and projections for HIV/AIDS
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
59
STI other than HIV Reported cases A total of 358 300 members of the general population were examined for STI in 1998. Findings showed a 3-fold increase in reported syphilis cases and 16% increase in reported gonorrhoea cases compared to 1993 prevalence. This increase may be attributed to the reintroduction of active screening of the sexually active population aged 15-45 years in 1996 and 1997 after an interruption between 1990 and 1995. Reported cases of STI in Mongolia are shown in Table 1.
Table 1: Reported cases of STI in Mongolia, 1993, 1997 and 1998 STI 1993 Number 400 3010 n/a 1997 Number (rate per 10 000) 1291 (5.4) 2934 (12.3) 10 706 (44.7) 1998 Number (rate per 10 000) 1329 (5.6) 3486 (14.6) 5353 (22.4)
Syphilis Gonorrhoea Trichomoniasis
Active STI surveillance
•
Surveys conducted in 1993 among truck drivers yielded prevalence rates of between 0.04% and 0.19% for syphilis, 0.4% for trichomoniasis, and 0.3% for gonorrhoea. A 6-fold increase in the prevalence of syphilis was observed in a five-year period among blood donors (from 0.19% in 1992 to 1.19% in 1997). Nationwide routine screening for pregnant women (average of 23 000 women tested annually) showed an increase in the syphilis prevalence rate from 0.1% in 1993 to 0.5% in 1997. Highest STI prevalence rates are observed among SWs. One survey conducted in the capital city in 1993 revealed that 58% of SWs had had at least one STI. Observed prevalence rates were 12.9% for syphilis, 14.8% for trichomoniasis, and between 6.4% and 14.3% for gonorrhoea. Results of a prevalence survey among 260 persons attending STI clinic in Ulan Bataar in 1997 showed prevalence rates among men of 31.1% for gonorrhoea, 8.1% for chlamydia, and 8.6% for syphilis. For women, prevalence rates were 10.3% for gonorrhoea, 9.9% for chlamydia, and 6.0% for syphilis. Trichomonasis was the most
•
•
•
•
Mongolia
60
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
common STI, with an observed prevalence rate of 67% among women. Estimates for STI Estimated prevalence rates for curable STI at the national level have been developed by WPRO. These estimates are based on prevalence survey data in selected population groups.
Table 2: Estimated prevalence of STI in Mongolia, 1996 1996 Prevalence* (No. of cases) Prevalence rate in adult population (15-49) Gonorrhoea 4600 0.1% Syphilis 8000 0.16% Chlamydia n/a n/a Trichomoniasis 6200 0.13%
* Population 15 and above
Gonococcal antimicrobial resistance
No data are available.
HIV and STI Risk Behaviour Surveillance No systematic behavioural surveillance has been carried out in Mongolia. Adolescent's reproductive health survey in 1995 showed that average age at first sexual intercourse is 16.8 years for men and 17.2 for years for women. About 6% of teenage women have been pregnant. A study of STI patients in Ulaanbaatar conducted in 1996 indicated that excessive alcohol intake was the primary risk factor for STI. Results of one recent (1998) survey covering 436 SWs showed that 60% are between the ages of 20 and 29 years old and that 76% reside in Ulaanbaatar. Of the FSWs surveyed, 27 had had an STI in the 3 months prior to the study. More than half (55%) of the SWs knew that condoms prevented HIV and other STI. Nevertheless, only 36% reported condom use for every sexual intercourse and only 9% reported that their clients initiated condom usage.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
61
NEW ZEALAND
Summary The first AIDS cases in New Zealand were reported in 1983. The incidence of AIDS increased progressively until 1989, but has decreased since 1991. As of the end of June 1999, 1371 HIV infections (including 681 AIDS cases and 532 HIV/AIDS related deaths) had been reported. Reporting of AIDS in New Zealand appears to be nearly complete. The majority of reported HIV infections occur among men (88%). The largest representation is among MSM infected through homo-/bisexual contacts (54%). While the percentage of reported HIV cases attributable to heterosexual transmission increased from 0% in 1985 to 44% in 1998, most such cases were acquired outside the country. Many refugees from high prevalence geographic areas contributed to the increase in reported cases of HIV in 1998. The number of STI reported remains low. Gonococcal antimicrobial resistance is lower than most countries in the region (up to 15% for penicillin, <2% for quinolones). The percentage of people who report use of condoms is low, both among men (23%) and women (19%)
Surveillance Structure
•
The CDC AIDS case definition (1993) is used (excluding CD4 count of less than 200). AIDS cases are notifiable to the Ministry of Health. Although new HIV cases are not formally notifiable, they are re ported by the two laboratories performing confirmatory tests. Curable STI are not notifiable.
• •
• HIV/AIDS Reported cases as of June 1999
Since the first case of AIDS was reported in 1983, 1371 HIV infections including 681 AIDS cases have been reported. Reported AIDS cases have decreased since 1992 (Table 1). Although the number of annual HIV/AIDS decreased between 1991 and 1997, an increase occurred in 1998. This may be attributed to a large number of refugees from certain high prevalence areas. The decline in AIDS incidence since 1990 is related to an earlier decrease in HIV incidence among homo-/bisexual men.
New Zealand
62
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Table 1: Reported cases of HIV/AIDS by year of diagnosis in New Zealand as of June 30 1999 <86 87 30 105 88 44 96 89 71 108 90 71 104 91 69 111 92 62 106 93 53 88 94 47 88 95 60 82 96 59 93 97 31 63 98 26 105 99 9 34 Total 681 1371
AIDS 21 HIV/ 125 AIDS
The majority of diagnosed HIV infections and AIDS cases have occurred among MSM through homo-/bisexual contacts (Table 2). Twenty four per cent of data on mode of transmission for HIV infections were missing for some of the early years of surveillance. Since the first heterosexually acquired HIV case was reported in 1986, the proportion of diagnosed HIV infections from heterosexual contact increased steadily, reaching 30% by 1998. Most of these infections were acquired outside New Zealand. The increase in observed HIV infections in 1998 was associated with a large number of refugees from high prevalence areas.
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in New Zealand as of June 1999 HIV (%) Sex Male Female Unknown Mode of transmissio Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 88 11 1 AIDS (%) 95 5 0
54 15 4 3 <1 24
80 9 4 2 <1 4
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
63
Active HIV/AIDS surveillance
HIV serological surveillance suggests generally low HIV prevalence rates in New Zealand.
•
Anonymous, unlinked seroprevalence studies of STI clinic patients were carried out in 2 centres in 1992-1993 and 4 centres 19961997. Moderate prevalence rates have been found among MSM and low rates among heterosexual men and women (Table 3).
Table 3:
HIV/AIDS seroprevalence rates in unlinked, anonymous studies among sexual health clinic attendees 1991-1992 Auckland and Christchurch 1996-1997 Auckland, Hamilton Wellington & Christchurch No. per 95% CI 1000 3/3816 5/266 2/2980 0.8 18.8 0.7 0.2-2.4 6.2-43.3 0.1-2.5 Auckland and Christchurch No. per 1000 95% CI 0.2-3.0 10.2-71.0 0.06-3.4
No. Heterosexual men MSM Heterosexual women
per 1000
95%CI 0.5%-2.9 23.5-75.4 0.3-2.8
6/4486 1.3 13/295 44.1 4/3660 1.1
3/2972 1.0 5/161 31.1 2/2138 0.9
•
Voluntary, anonymous prevalence studies in 1992 and 1997 used saliva testing among IDUs participating in needle exchange programmes (Table 4). Prevalence rate was found to be 0.3% in both years. Prevalence rate among IDUs enrolled in sexual health clinic studies was also found to be less than 1%.
Table 4: HIV prevalence rates among needle exchange programme attendees in New Zealand (1992 and 1997) 1992 No. IDUs 2/591 % 0.3 95% CI 0.04-1.2 No. 4/1193 1997 % 0.3 95% CI 0.09-0.9
•
An unlinked anonymous prevalence study of SWs attending sexual health clinics in 1996-1997 showed prevalence rate less than 1%.
New Zealand
64
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
•
Only one of more than 750 000 voluntary, unremunerated blood donations since mid-1994 has been identified as HIV infected.
Estimates and projections for HIV/AIDS
A comprehensive profile of the present and future epidemiological situation was developed by a group of international experts in 1998; their estimates and other analyses were subsequently endorsed by New Zealand's government. An estimated 1200 persons were living with HIV infection (prevalence in people aged 15-49 years, <0.1%) (Table 5). It is believed that the prevalence of HIV infection will rise slightly, not due to the immigration of HIV infected people, but due to new infections occurring in New Zealand, and the prolonged transition period from asymptomatic HIV infection to AIDS attributable to the recent introduction of highly active antiretroviral therapy.
Table 5: Estimates and projections for HIV/AIDS in New Zealand adults (15 years or older) and total population in 1998 and 2000 1998 Population (15-49) (thousands) AIDS Incidence Incidence rate in adults (15-49) Prevalence Prevalence rate in adults (15-49) 1941 35 <0.1% 1200 <0.1% 2000* 1959 1250 <0.1%
HIV
*Projections of AIDS incidence were not made given the need to adjust for the impact of antiretroviral treatment.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
65
Sexual contact accounts for 95% of all HIV infections. The proportion of cases occurring in women remains low (an estimated 15%, Table 6).
Table 6: HIV/AIDS epidemiological features of HIV/AIDS in New Zealand (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
1200 <0.1% 15% 95% 3% 2% >95% >90%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
STI other than HIV Reported cases Active STI surveillance STI cases are not reported. Some data on prevalence of STI are available from ad hoc studies. One survey of patients attending family planning clinics in 1987 reported prevalence of 15.8% for chlamydia. In 1990, a sample of women with pelvic inflammatory disease showed chlamydia prevalence of 40%. In a cohort of young people, 7.5% of males and 16% of females reported having had an STI (1993). Sufficient survey data are not available to develop national prevalence estimates for STI. Data from indicate that, during 1992 through 1997, the percentage of gonococcal strains resistant to penicillin ranged from 9 to 15%. Resistance for quinolones was less than 2%.
Estimates for STI
Gonococcal antimicrobial resistance
HIV and STI Risk Behaviour Surveillance Results of a 1995 national survey showed that 32% of men and 20% of women aged 20 to 24 years reported two or more sexual partners in the previous 12 months. Recent condom use rates were 23% for men and 19% for women.
New Zealand
66
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
PAPUA NEW GUINEA
Summary HIV prevalence in Papua New Guinea remains at a relatively low level compared to other countries in the Region. The first cases were reported in 1987, with HIV prevalence increasing annually throughout the early 1990s. In March 1999, cumulative reported HIV infections reached 1741, including 618 people with AIDS. More than 4400 adults and 300 children were estimated to be living with HIV in 1998, representing a prevalence rate among adults of 0.19%. About one fifth of all cases are reported. Reported cases are equally distributed among men and women, and infection appears to be concentrated in the capital city of Port Moresby. Although the mode of transmission is unknown for a significant proportion of cases, 90% of cases for which the mode is known resulted from heterosexual contact. Prevalence remains low among blood donors (0.015%, 1997) and pregnant women (0.37%, 1998). Higher HIV prevalence rates were reported among patients with other STI (1995, Port Moresby, 1.7%), FSWs (1998, Port Moresby, 16.7%; Lae 3.1%), and TB patients (1998, Port Moresby, 7.7%). Systematic STI surveillance has not been established. However, prevalence rates as high as 58% have been observed among rural men and women in the highlands. The most common STI were trichomoniasis (46%) and chlamydia (26%). Available data on STI/HIV risk behaviour indicate very low levels of condom use (7%).
Disease Surveillance Structure
• • •
The expanded WHO AIDS case definition (1994) is used. All HIV and AIDS cases are notifiable to the Ministry of Health. Reported cases of HIV refer to both AIDS cases and HIV antibody positive asymptomatic patients. Notifiable STI are gonorrhoea, NGU, syphilis, trichomoniasis, donovanosis, venereal warts, and genital herpes. HIV sentinel surveillance has been initiated among antenatal clinic attendees, SWs, STI patients, and military personnel.
•
•
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
67
HIV/AIDS Reported cases as of March 1999 The first cases of HIV/AIDS were reported in 1987, followed by a broad spread of the virus during the early 1990s. At the end of March 1999, there had been 1741 reported HIV infections, including 618 AIDS cases.
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Papua New Guinea as of March 1999 <1990 AIDS 17 HIV/AIDS 35 90 17 35
91 21 36
92 19 32
93 12 40
94 26 69
95 44 124
96 69 192
97 120 351
98 232 635
99 41 192
Total 618 1714
Although the mode of transmission is unknown for two thirds of reported cases, the equal sex distribution suggests that most transmission is by heterosexual contact (Table 2).
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Papua New Guinea as of March 1999 HIV (%) Sex Male Female Unknown Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 50 45 5 AIDS (%) 51 46 3
<1 0 26 2 <1 71
1 0 70 6 0 23
Papua New Guinea
68
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Active HIV/AIDS surveillance
•
HIV prevalence among FSWs was 16.7% in Port Moresby and 13.1% in Lae in 1998. Surveys of STI clinic attendees in Port Moresby show a rapid increase in HIV prevalence (from 0.25% to 0.65% in 1995 to 6% in 1998). Among STI clinic attendees in rural areas, HIV prevalence was found to be 0.15% in 1992 and 1.7% in 1995. Among TB patients, 7.7% of those tested in 1996 were HIV positive. HIV prevalence among antenatal patients in Port Moresby increased from 0.06% in 1994 to 0.23% in 1996 to 0.37% in 1998. A national-level survey involving 6656 tests was conducted during April and May 1997. Findings showed a prevalence rate of 0.015% among blood donors. Of the 5091 tests done in clinical settings, 78 (1.53%) were positive for HIV.
•
•
• •
•
Estimates and projections for HIV/AIDS
Working estimates of 4000 people living with HIV in 1997 and 4400 in 1998. were made in 1998 Projections are that cases will exceed 5500 by 2000 (Table 3).
Table 3: Estimates and projections for HIV/AIDS in Papua New Guinea, 1998 to 2003 1998 Population (15-49) (thousands) AIDS HIV Incidence Prevalence Prevalence rate in adults (15-49) 2316 1999 2369 2000 2422 2003 2942
420 4400 0.2
450 4700 0.2
480 4900 0.2
540 5500 0.2
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
69
Based on 1998 estimates, heterosexual contact is the primary mode of HIV transmission (Table 4). Reporting of HIV cases remains incomplete, and reported HIV cases are believed to make up about 22% of total estimated HIV/ AIDS cases.
Table 4: Selected epidemiological features of HIV/AIDS in Papua New Guinea (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
4400 0.2% 48% 95% <1% (*) <5% 22% 28%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
* No cases of IDUs with HIV/AIDS have been reported
STI other than HIV
Active STI surveillance
A survey in Port Moresby in 1992 among women attending antenatal clinics found a prevalence of 3.4% for syphilis and 17.7% for chlamydia. A 1995 study conducted among adult men and women in rural settings (Lowa Asaro census divisions, Eastern Highlands Province) found very high prevalence of chlamydia (26.4%) and trichomoniasis (46.5%). Prevalence for syphilis (3.9%) and gonorrhoea (1.5%) were lower. However, 59% of the women surveyed had at least one STI.
Papua New Guinea
Reported cases
No information is available.
70
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Estimates for STI
Results from prevalence surveys in selected populations provided a basis for national level STI estimates (Table 5).
Table 5: Estimated prevalence of STI in Papua New Guinea, 1996 1996 Rates in adults* Prevalence Gonnorrhoea 3.5% 93 000 Syphilis 3.5% 93 000 Chlamydia 20% 533 000
* Population 15-49 years Gonococcal antimicrobial resistance Data from the GASP from 1992 through 1998 indicated no specific trends. The percentage of gonococcal isolates resistant to penicillin varied between 3.4% and 12.5% and for quinolones from 1.2% to 6.5%.
Behavioural Surveillance No systematic surveillance on HIV/STI risk behaviour has been carried out in Papua New Guinea. In a survey of 192 randomly selected women of reproductive age in 1995, 9% had had more than one sexual partner in the previous year, 16% had been diagnosed with an STI in the previous 3 months, and only 7% reported ever using condoms. A survey of 300 STI clinic attendees in the highlands found that only 9% of patients were familiar with the role of condoms in HIV/STI prevention.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
71
PHILIPPINES
Summary The Philippines remains a low HIV prevalence country. Since the first cases of HIV/AIDS were reported in 1984, 1259 HIV infections including 404 AIDS cases and 199 HIV/AIDS-related deaths had been reported as of July 1999. An estimated 29 000 people were believed to be living with HIV in 1998 (prevalence <0.1% in people aged 15 to 49 years). The estimated reporting rate of HIV infection is low (5%). HIV in the Philippines is predominantly sexually transmitted (90%). The number of HIV/AIDS cases is not expected to increase substantially over the next few years. There is a high prevalence of STI among SWs, with the prevalence rate of selected STI reaching more than 40% (predominantly chlamydial infections). Prevalence rate of STI among women attending antenatal clinics was <1% for STI other than chlamydia (5.6%). Gonococcal resistance to penicillin, tetracycline, and ciprofloxacin is high. Nearly all gonorrhea isolates (95%) were resistant to penicillin in 1997 and 63% were resistant to quinolones in 1998. Behavioural surveillance data in 1997 and 1998 indicated high prevalence of HIV/STI risk behaviour. Sharing of needles was reported by 77% of IDUs and unprotected sex was reported by 92% of MSM and 96% of IDUs.
Surveillance Structure
• • • •
The CDC AIDS case definition (1993) is used. All HIV and AIDS cases are notifiable to the Department of Health. Information on notifiable STI is only partial. HIV sentinel surveillance is carried out in 10 major cities. Populations surveyed include registered and freelance FSWs, MSM, IDUs, and men who attend STI clinics. Surveillance of STI and HIV risk behaviour has been conducted since 1997.
•
Philippines
72
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
HIV/AIDS Reported HIV/AIDS cases as of July 1999 The first cases of HIV and AIDS were reported in 1984. By the end of July 1999, a cumulative total of 1259 HIV infections had been reported; this included 404 AIDS cases and 198 HIV/AIDS related deaths. Reported HIV/ AIDS cases have been slowly increasing each year (Table 1).
Table 1: Reported cases of HIV/AIDS by year of diagnosis in the Philippines as of July 1999 <1989 AIDS HIV/AIDS 53 153 90 19 68 91 13 79 92 93 94 95 96 97 98 41 190 99 41 91 Total 404 1259
19 36 56 69 100 119
52 51 23 117 156 117
The majority (59%) of reported HIV infections have occurred in men (Table 2) and have been primarily sexually transmitted (80%). Heterosexual contact was reported in more than half of cases (58%). The proportion of HIV among IDUs remains small (Table 2).
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in the Philippines as of July 1999 HIV (%) Sex Male Female Unknown Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 59 40 1 AIDS (%) 63 37 0
22 <1 58 1 1 17
35 <1 55 2 2 5
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
73
Active HIV/AIDS surveillance
HIV serological surveys have been performed in 10 sentinel sites throughout the country since 1993; data were collected every 6 months until 1997 and annually since 1998. Only sporadic cases of HIV (<0.3%) have been detected among registered FSWs, IDUs, MSM, and men who attend STI clinics. There has been no evidence of a significant increase in HIV seroprevalence over time and no significant differences in population groups studied in 1998. In 1998, only 3 of 2075 registered FSWs, 1 of 2068 freelance FSWs, none of 532 MSM and none of 120 IDUs tested HIV-positive. HIV prevalence data from testing and counseling services showed no significant increase in prevalence between 1991 and 1998. HIV testing and counseling services increased the number of HIV tests from 350 959 (prevalence of 0.002%) in 1991 to 687 150 in 1997 (prevalence of 0.002%).
Estimates and Projections for HIV/AIDS
In order to develop estimates and projections for HIV/AIDS in the Philippines, a consensus meeting of national and international experts was convened in 1998. These experts adapted earlier estimates of HIV and AIDS from a consensus meeting that had been held in 1996. The sentinel serosurveillance data showed that HIV prevalence remains low in the country, and revising the 1996 estimates and projections was deemed unwarranted.
Table 3: Estimates for HIV/AIDS in the Philippines, 1998 1998 Population (15-49) (thousands) 36 501 29 000 <0.1% 650 <0.1%
HIV AIDS
Prevalence Prevalence rate in adults (15-49) Prevalence Prevalence rate in adults (15-49)
Philippines
74
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
There were an estimated 29 000 persons living with HIV in the Philippines in 1998 (prevalence, rate of <0.1%, adults aged 15-49 years) (Table 3). The reporting rate for HIV infections is believed to be low (Table 4). An estimated 90% of HIV infections are sexually transmitted.
Table 4: Selected epidemiological features of HIV/AIDS in the Philippines (1998 estimates) Prevalence HIV Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
29 000 <0.1% 30% 90% <5% 5% 5% 40%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
STI other than HIV Reported cases There are 128 Social Hygiene Clinics (SHC) which regularly screen registered SWs for STI every one to four weeks. The number of STI cases detected by SHCs in 1993-1997 ranged from 30 000 to 51 000; cases included syphilis, gonorrhoea and non-gonococcal urethritis. The prevalence of syphilis was between 0.4% and 1.66%, and of gonorrhoea between 5% and 17%. Syphilis seroprevalence was added to national HIV surveillance in 1994. Prevalence was higher among MSM (3% to 7%), freelance FSWs (4% to 6%). Lower prevalence rates were observed among male STI patients (2% to 4%) registered FSWs (1% to 4%), and male SWs (1% to 3%). . High prevalence rates have been reported among FSWs in Cebu (22.2% for gonorrhoea, 22.7% for chlamydia, 6.7% for syphilis, 30.9% for trichomoniasis) and Manila (10.6% for gonorrhoea, 17.3% for chlamydia, 2.8% for syphilis, 6.7% for trichomoniasis). Prevalence rates among women attending antenatal clinics were 1% for gonorrhoea, 5.6% for chlamydia, 0.5% for syphilis, and 1% for trichomoniasis. In a study of FSWs in Manila currently being completed in 1999, a third of registered FSWs without self-identified STI symptoms have been found to have an STI (primarly chlamydia, gonorrhoea, or both infections).
Active STI surveillance
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
75
Table 5: Estimated prevalence of selected STI in the Philippines, 1998 Gonorrhoea Prevalence Prevalence rate in adults (15-49) 428 000 1% Syphilis 214 000 <1% Chlamydia 2 560 000 6% Trichomoniasis 428000 1%
* Population 15 and above
Estimates for STI
Estimated prevalence rates for selected STI in the general adult population were extrapolated based on various point prevalence estimates (Table 5). Chlamydia is the most prevalent STI. Gonococcal resistance for most drugs has been found to be high in the past few years (penicillin, 69 to 100%; tetracycline, 45%; ciprofloxacin, 82%, quinolones, 50 to 95%).
Gonococcal antimicrobial resistance
STI and HIV Risk Behaviour Surveillance The first behavioural sentinel surveillance survey (1997) found a high prevalence of sharing needles among IDUs (77%). Condom use among all population groups studied was low (IDUs, 4%; MSM, 23%; FSW, 28%; RSW, 48%), as was condom use at last sexual contact with non-regular partner (IDUs, 34%; MSM, 41%; FSW, 55%; RSW, 72%). More than half of all persons in high-risk groups reported knowledge of at least three ways to prevent HIV transmission. Knowledge was lowest among IDUs (50%) and highest among MSM ( 68%). Self-perception of their own personal risk of AIDS was low (IDUs 27%; MSM 20%; FSW 25%; RSW 30%).
Philippines
76
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
SINGAPORE
Summary Singapore has a low HIV prevalence. Since the first case of HIV infection was reported in 1985, annual reported cases have increased steadily (from 2 in 1985 to 199 in 1998). The cumulative total of 930 HIV infections at the end of December 1998 included 484 AIDS cases and 288 HIV/AIDS-related deaths. Eighty-nine percent of reported HIV/AIDS cases have occurred among men, and two thirds of cases have been heterosexual. Before 1991, the majority of reported HIV infections were among homo-bisexual men (70%). However, the proportion of heterosexuals in reported HIV/AIDS cases has increased in recent years (from 29% in 1990 to 78% in 1998). HIV transmission among IDUs remains limited. Seroprevalence surveys show that the HIV prevalence among blood donors has been low (0.007 in 1993; 0.008% in 1998). No HIV positive case was detected during seroprevalence surveys among prenatal clinic attendees since 1995. However, slight increases in HIV prevalence have been noted among STI patients (from 0.5% in 1994 to 0.7% in 1998) and TB patients (from 0.7% in 1996 to 1.3% in 1998). Prevalence rates for curable STI have been low in existing studies (<1% for syphilis and gonorrhoea, 2% for chlamydia). Overall incidence of reported STI has declined over time. Gonococcal antimicrobial resistance increased between 1992 and 1998, both to penicillin (35% to 56%) and quinolones (0.35% to 7.2%). The prevalence of condom use is high among MSM (82 to 86%) and SWs (75%).
Surveillance Structure
• • •
The CDC AIDS case definition is used. All HIV and AIDS cases are notifiable to the Ministry of Health Other STI notifiable to the Ministry of Health are chancroid, gonorrhoea, NGU, syphilis and genital ulcers. HIV seroprevalence surveys conducted since 1989 have covered blood donors, antenatal clinic attendees, and patients with STI or TB.
•
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
77
HIV/AIDS Reported cases as of December 1998 The first case of HIV was reported in 1985. By the end of December 1998, the cumulative total of 930 reported HIV infections included 484 AIDS cases and 288 HIV/AIDS-related deaths. The number of reported cases increased each year (Table 1).
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Singapore as of December 1998 <1990 AIDS HIV/AIDS 15 44 90 8 17 91 12 42 92 18 55 93 22 64 94 48 86 95 56 111 96 92 139 97 88 173 98 125 199 Total 484 930
The majority (89%) of reported cases were in men. Heterosexual contact was reported in two thirds of reported cases and homo-bisexual contact in about one quarter (Table 2). Before 1991, the majority of HIV infections occurred in MSM through homo-/bisexual contact (70%). In the past 9 years, the percentage of reported HIV infections attributed to heterosexual contact has increased substantially (from 29% in 1990 to 78% in 1998).
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Singapore as of December 1998 HIV (%) Sex Male Female Mode of transmission Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown 89 11 25 2 68 1 1 3 AIDS (%) 92 8 25 2 69 1 1 2
Singapore
78
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Active HIV/AIDS surveillance
Serological surveillance has been implemented in various population groups since 1989. HIV seroprevalence remains low, although slight increases in HIV seroprevalence have been noted among patients with STI and TB.
•
Screening of SWs attending public STI clinics showed HIV prevalence rates of 0.07% in 1993, 0.06% in 1994, 0.05% in 1995, and 0.09% in 1996. Among STI clinic patients (N = >500 per year), HIV prevalence increased from 0.5% in 1994 to 0.7% in 1998. Among TB patients (N = 300 per year), HIV prevalence remained at zero until 1995, then increased from 0.7% in 1996 to 1.3% in 1998. A total of 500 to 700 women attending antenatal clinics were screened from 1993 through 1998. Only one woman in 1995 tested HIV positive (0.14%). Among blood donors (N = >7000 annually), HIV prevalence has stayed consistently low (0.007% in 1993, 0.008% in 1998).
•
•
•
•
Estimates and projections for HIV/AIDS
The number of people living with HIV in 1998 was estimated at 3800 (prevalence rate of 0.2% in people aged 15 to 49 years). Heterosexual contact has been the predominant mode of transmission (Table 3).
Table 3: Selected epidemiological features of HIV/AIDS in Singapore (1998 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
3800 0.2% 20% 95% <1% 5% 22% 64%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
79
STI other than HIV Reported cases Over the past 15 years, incidence of reported STI has steadily declined. Overall reported rates for all STI decreased from 946/100 000 in 1980 to 162/ 100 000 in 1998. In 1999, disease-specific reported incidence rates were 47/ 100 000 for gonorrhoea, 33/100 000 for syphilis, and 29/100 000 for NGU. The prevalence rate of syphilis among blood donors decreased from 0.24% in 1994 to 0.13% in 1998. Screening of SWs attending the public STI clinic has shown a decline in gonorrhoea and chlamydia prevalence. Prevalence rates were 0.5% for gonorrhoea and 2.0% for chlamydia in 1996. Among blood donors in 1992 and 1993, syphilis prevalence rate was 0.2%. Estimates for the prevalence of STI at country level have been developed by WPRO based on STI surveys in selected population groups (Table 4).
Active STI surveillance
Estimates for STI
Table 4: Estimated prevalence of selected STI in Singapore, 1997 Gonorrhoea Prevalence rate in adults (15-49) Prevalence 0.2% 4200 Syphilis 0.18% 3700 Chlamdia 0.23% 4700
Gonococcal antimicrobial resistance
Data from the GASP from 1992 through 1998 indicated increased gonococcal antimicrobial resistance to both penicillin (35% to 56%) and quinolones (0.3% to 7.2%).
Singapore
80
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
HIV and STI Risk Behavioural Surveillance Surveys on STI/HIV risk behaviour are not routinely conducted in Singapore. An ad hoc survey in 1997 among MSM indicated that 18% did not use condoms with regular partners and 14% did not use condoms with casual partners. Seventy five to 83% of persons arrested for a controlled drug between 1996 and 1998 were heroin users (Table 5). A 1992 survey of FSWs indicated that 75% used condoms.
Table 5: Breakdown of persons arrested for consumption of a controlled drug in Singapore, 1996-1998 Year 1996 1997 1998 Total number 5744 4752 4502 Heroin consumption 4431 3549 3727 Percentage 77 75 83
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
81
SOUTH PACIFIC
Summary Data from the following 20 Pacific Island countries and territories were colleted and analyzed for this report: American Samoa, Cook Islands, Fiji, French Polynesia, Guam, Kiribati, Marshall Islands, Micronesia, Nauru, New Caledonia, Niue, Northern Mariana Islands, Palau, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu, Vanuatu, and Wallis and Futuna. Only sporadic HIV/AIDS cases have been reported in the South Pacific, which suggests that HIV seroprevalence remains low. As of September 1999, 612 HIV infections (including 223 AIDS cases) had been reported to the WHO Regional Office for Western Pacific. Three territories (French Polynesia, Guam and New Caledonia) have accounted for 80% of reported HIV infections and 81% of AIDS cases. The majority of reported cases occurred among men, with sexual contact being the most frequently reported mode of transmission. The proportion of heterosexual cases has increased over the last few years. Surveys conducted in some countries and territories show that curable STI are common.
Surveillance Structure
•
The case definition used for AIDS surveillance varies by country and territory. HIV and AIDS cases are notifiable to the Health Authorities in all countries and territories. Other notifiable STI also vary by country and territory.
•
• HIV/AIDS Reported cases as of September 1999
A total of 612 HIV infections, including 223 AIDS cases, had been reported to WPRO as of September 1999 (Table 1). Five countries/territories (American Samoa, Cook Islands, Niue, Tokelau, Vanuatu) have not as yet reported any HIV infections.
South Pacific
82
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Table 1: Reported cases of HIV/AIDS by year of diagnosis in the South Pacific as of September 1999 1985 or 85 unknown AIDS 6 HIV/ 5 AIDS 1 2 86 7 29 87 9 37 88 12 37 89 13 39 90 20 49 91 22 55 92 7 37 93 25 47 94 31 50 95 13 51 96 21 54 97 16 50 98 13 47 99 7 23 Total 223 612
* Some countries/territories have not reported to WPRO for 1997, 1998, and/or 1999. Thus, data from 1997 to 1999 do not include all countries/territories in the South Pacific.
Most cases occurred in male, although sex remained unknown for large proportion of cases (Table 2). Homo-/bisexual and heterosexual contacts were the most frequently reported modes of transmission (Table 2). However, data should be interpreted with caution given the high number of unspecified cases for sex and mode of transmission.
Table 2: Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in the South Pacific through September1999 HIV (%) Sex Male Female Unknown Mode of transmissio Homo-/bisexual IDU Heterosexual Blood products Mother to infant Other/unknown AIDS (%)
62 18 20
50 9 41
31 7 23 3 2 34
30 6 20 3 2 39
Active HIV/AIDS surveillance
Few HIV seroprevalence studies have been conducted in the South Pacific. Limited data have been collected in some countries among populations of blood donors, pregnant women, STI clinic patients, and immigrant groups. Most such studies have identified few if any HIV infections.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
83
A survey conducted in French Polynesia in 1991 reported an HIV prevalence rate of 1.4% among FSWs and 3.8% among homosexuals. However, the sample size was small and results should be interpreted with caution. Estimates and projections for HIV/AIDS Data are insufficient to allow estimates on magnitude of HIV infections in the general adult population in the South Pacific.
STI other than HIV Reported cases In New Caledonia, reported cases of syphilis, chlamydia, and gonorrhoea decreased from 1990 to 1997 (Table 3).
Table 3: Reported number of STI cases in New Caledonia, 1990-1997 1990 Syphilis Gonorrhoea Chlamydia 276 350 528 1991 272 265 442 1992 246 212 348 1993 211 161 312 1994 195 178 317 1995 175 142 198 1996 60 80 157 1997 49 100 149
Reported gonorrhoea cases decreased in Guam (from 395 in 1990 to 131 in 1994), North Mariana Islands (from 125 in 1990 to 49 in 1994), and Tonga (from 46 in 1988 to 14 in 1989). In the Marshall Islands, there were 109 gonorrhoea cases in 1993 (1.9/1000) and 35 in 1994 (0.62/1000). Only a few syphilis cases were reported in Guam (2-4 during 1990 to 1994). Fewer than 10 cases were reported in North Mariana Islands (1991-1993) and no cases were reported in Palau or Vanuatu (1990-1994). Reported STI cases are increasing in the Solomon Islands. There were 901 gonorrhoea cases and 104 syphilis cases in 1993; these numbers increased to 974 and 224, respectively, in 1994. Active STI surveillance An STI survey assessed prevalence among pregnant women in Suva, Fiji in 1985-1986 and again in 1997. Findings showed decreases in STI (8.9% to 8.2% for syphilis, 2.3% to 0.5% for gonorrhoea, 45% to 19.5% for chlamydia). Recent studies of pregnant women found chlamydia prevalence rates of 12% in Cook Islands and 33% in Marshall Islands. Another study in French Polynesia in 1991 found a chlamydia prevalence rate of 67.9% among homosexuals and 60.8% among FSWs. The same study reported a syphilis prevalence rate of 16.7% among homosexuals and 60.8% among FSWs.
South Pacific
84
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Estimates for STI
Estimates for prevalence of STI in the South Pacific have been developed by the WHO Office for Western Pacific Region. These figures are based on available STI surveys in selected population groups (Table 4).
Table 4: Estimated prevalence of selected STI in the South Pacific, 1996 Gonorrhoea Prevalence rate in adults (*) Prevalence 0.4% 9000 Syphilis 8% 180 000 Chlamydia 13% 290 000 Trichomoniasis 11% 248 000
(*) Population 15 and above
Gonococcal antimicrobial resistance
Penicillin resistance data are available for Fiji, New Caledonia, Solomon Islands, Tonga, and Vanuatu. Resistance in 1998 was relatively high in Solomon Islands (35.9%), but low in other areas (0%-9%). Quinolone resistance in 1998 was 0% in Fiji, 7.5% in New Caledonia, and 0% in Solomon Islands. These were the only areas for which resistance data were available.
HIV and STI Risk Behaviour Surveillance Sexual behaviour and social norms vary considerably in these diverse countries and territories. Although there are no organized sex industries, SWs are present. One study of 3500 people between the ages of 16 and 25 years in New Caledonia found that 68% of respondents had had at least one sexual experience (74% of males, 63% of females). Findings also showed that 3% had been involved in sex work either as a client or as a SW (5% for males, 1% for females); 25% had had more than 2 sexual partners during the previous year. Among those who had had sexual intercourse at least once, 65% used condoms at least once. Among those with regular partners, 60% had used condoms at least once, but this was true for only 38% of subjects with no regular sexual partner.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
85
VIET NAM
Summary After the first HIV case was reported in Viet Nam in 1990, the number of reported HIV infections and AIDS cases grew rapidly in all provinces. The total had reached 14 509 by August 1999. An estimated 86 500 people were living with HIV/AIDS in 1998. HIV prevalence is highest among IDUs (17%). Although data on HIV/STI risk behaviour are not included in routine HIV surveillance, studies of IDUs indicate that 28% share equipments. Sexual transmission of HIV has increased among FSWs (prevalence rate increased from 0.6% in 1994 to 3.0% in 1998). While the majority of reported HIV infections occur among IDUs (64%), estimates of HIV/AIDS indicate that the majority of HIV infections are sexually transmitted (77%). Available data from point prevalence studies suggest that there is a major burden of STI, and particularly syphilis, among SWs. There is a lower, but still significant, STI prevalence among women, including pregnant women. Gonococcal resistance to penicillin is high (77%) and quinolone resistance is emerging (3.3% to 8.1%).
Surveillance Structure
• •
The expanded WHO AIDS case definition (1994) is used. All HIV and AIDS cases are notifiable to the Ministry of Health through the National Institute of Hygiene and Epidemiology. Sentinel surveillance for HIV infection was established in 1994 in four provinces, and was expanded to include 20 provinces in 1996. The HIV sentinel surveillance population includes antenatal clinic attendees, FSWs and massage girls, military recruits, IDUs, and patients with TB and STI. For other STI, 61 provincial Dermatology and Venereology centres report STI based on clinical criteria to the National Institute of STDs and Dermatology. However, most patients with STI seek care from
•
•
•
Viet Nam
86
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
private practitioners, and the reported number of STI would appear to constitute only about 10% to 20% of all STI diagnosed.
•
STI prevalence surveys were conducted during 1995-1996 among FSWs and women attending mother and child health clinics in two cities.
HIV/AIDS Reported cases as of August 1999 The first HIV infection was reported in 1990. By 7 August 1999, 14 509 HIV/ AIDS cases and 2736 AIDS cases had been reported (Table 1). HIV infections were reported in all provinces. Annual increases in the number of reported cases has been moderate for AIDS and HIV infection cases.
Table 1: Reported cases of HIV/AIDS by year of diagnosis in Viet Nam as of August 1999 Not <1992 known AIDS HIV/ AIDS 279 103 0 1 92 0 11 93 106 1148 94 116 1340 95 201 1405 96 380 1660 97 400 2654 98 935 4271 99 319 1916 Total 2736 14 509
A total of 85% of reported HIV/AIDS cases were among men. This reflects the fact that the majority of cases were among IDUs (Table 2), nearly all of whom are male. Reported proportion of mother-to-child transmission is less than 1%. For about a quarter of HIV, mode of transmission is not reported.
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
87
Table 2:
Distribution of cumulative reported HIV/AIDS cases by sex and mode of transmission in Viet Nam as of August 1999
HIV (%) Sex Male Female Unknown Mode of transmissio Homo-/bisexual IDUs Heterosexual Blood products Mother to infant Other/unknown 85 14 1
AIDS (%) 60 12 28
0 64 9 0 <1 27
0 47 15 0 <1 37
Active HIV/AIDS surveillance
•
HIV prevalence rates in most sentinel HIV populations showed substantial increases between 1994 and 1998. However, there has been considerable variation in HIV prevalence rates by surveillance site (Table 3). HIV prevalence rates among pregnant women and military recruits suggest a limited spread of HIV in the general population (Table 3). HIV prevalence rates were consistently high among IDUs from the southern regions of the country in 1994 (15%-20%). HIV prevalence rates reached 50% in some communities of IDUs investigated in 1998. This suggests a developing and sustained HIV epidemic among IDUs in the southern regions.
•
•
Viet Nam
88
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Table 3: HIV seroprevalence (%) in selected population subgroups in Viet Nam, 1994 and 1998 Survey Population Pregnant women Military recruits IDUs FSWs Blood transfusion/products Male STD patients 1994 Average (range) 0.01 (0 to 0.1) 0 18.25 (0 to 33.7) 0.59 (0 to 2.8) 0.03 0.56 (0 to 1.1) 1998 Average (range) 0.08 (0 to 0.96) 0.15 (0 to 1.9) 17.0 (0 to 85.0) 2.44 (0 to 14.6) 0.08 0.98 (0 to 11.8)
Estimates and projections for HIV/AIDS
Estimates for HIV prevalence and AIDS incidence were developed during a consensus meeting of national and international experts in 1998; these estimates were endorsed by the government. Specifically, HIV/AIDS estimates for 1997 and projections through 2000 were prepared based on HIV prevalence surveys. This analysis identified an extensive spread of HIV beginning in 1993, and projected that HIV transmission would continue to increase after 1997.
Table 4: Estimates and projections for HIV/AIDS in Viet Nam, 1997 and 2000 1997 Population (15-49)(thousands) HIV Prevalence IDUs Heterosexual (15-49 years) - Northern region - Central region - Southern region Incidence IDUs AIDS deaths (overall) 39 908 66 700 11 200 9 900 12 800 32 800 1 700 300 2100 2000 43 493 1 35 000 20 700 20 200 26 300 67 800 5 000 800 11 700
AIDS
The estimated cumulative number of people with HIV/AIDS in 1997 was about 75 000, and an estimated 66 700 people were living with HIV (Table 4). By 2000, the estimated number of people living with HIV may reach 135 000. Although reported HIV infections have occurred predominantly among men and IDUs, nearly half of all HIV infections appear to be in women. The majority of HIV infections
WHO WPRO
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
89
are transmitted through sexual contact (77%) (Table 5). About 80% of HIV infections and three quarters of AIDS cases are not reported.
Table 5: HIV/AIDS epidemiological features of HIV/AIDS in Viet Nam (1997 estimates) HIV Prevalence Prevalence rate in adults (15-49) Women among HIV infected population HIV Infection by mode of transmission
66 700 0.2% 44% 77% 20% 3% 12% 24%
Sexual contact Injecting drug use Others Estimated reporting rate for HIV Estimated reporting rate for AIDS
STI other than HIV Reported cases The reported number of STI in Viet Nam increased by two thirds from 1995 (about 44 000) to 1997 (about 71 000). It is unclear, however, how much of this increase is attributable to improvements in case detection or reporting.
Active STI surveillance
•
STI prevalence surveys in the 1990s showed a high prevalence of STI among FSWs. Syphilis appears to be the most prevalent STI.
•
Table 6:
Range of prevelance of STI in selected populations in selected cities during the 1990s Syphilis (%) Gonorrhoea (%) -0.3* to 0.7 2.6 to 30 0.6 Chlamydia (%) -2.2* to 2.5 --Trichomonas (%) --30 to 50 0.6
Pregnant women 1.5* to 1.7 MCH clinic attendees 0.2* to 2.5 FSW 30-40* to 50-60 Female hotel workers* 3.3
* Hanoi. Other rates are from Ho Chi Minh City or other locations
Viet Nam
90
Status and Trends of STI, HIV/AIDS in Western Pacific 1999
WHO WPRO
Estimates for STI
National prevalence estimates for STI other than HIV were developed based on point prevalence surveys or data from the literature during 1990 through 1997.
Table 7: Estimated prevalence for selected STI in Viet Nam in 1997 Gonorrhoea General Population Prevalence Prevalence rate (%) in population 15-49 Sex workers Prevalence Prevalence rate (%) in among SWs 130 000 0.5 Syphilis 130 000 0.5 Chlamydia 650 000 2.5
20 000 10
70 000 35
10 000 5
Gonococcal antimicrobial resistance
Data from GASP indicate that penicillin-resistant gonorrhoea increased from 55% in 1992 to 77% in 1998. Quinolone resistance ranged between 3.3% to 8.1%.
HIV and STI Risk Behaviour Surveillance Risk behaviour surveillance is not included in the HIV sentinel surveillance system. A study of 968 FSWs in 1995-1996 found that only 0.5% used drugs. A study of 105 drug users found that 96% used opium and that 28% shared needles.
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
3. REGIONAL TABLES
1 2 3 4 5 6 7 8 9
Epidemiological features of the HIV epidemic............................................. 92 AIDS case definition in selected countries.................................................. 93 of the Western Pacific HIV/AIDS estimated reporting rates in......................................................... 94 selected countries Reported HIV/AIDS cases by year of report................................................ 95 Estimated/projected HIV prevalence in selected......................................... 97 countries, adults and children, 1990-2000 Estimated HIV prevalence in selected countries,........................................ 98 adult population age 15-49, 1998 Estimates and projections for AIDS incidence, .......................................... 99 adults and children Estimated prevalence and prevalence...................................................... 100 rates for selected STI, 1998 Summary of GASP reports for .................................................................. 101 penicillin and quinolone resistent ................................................................... N. gonorrhoeae, 1992-1998 Population groups surveyed for HIV and ................................................. 102 types of HIV surveillance in selected countries, 1998 Behavioural surveillance 103
10 11
91
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 2: AIDS case definition in selected countries of the Western Pacific, 1998 AIDS case definition 1985 WHO Definition (Bangui) Country Cook Islands Niue Samoa Vanuatu
1985 WHO Definition (Bangui) with HIV antibody positive 1994 Expanded WHO Definition (Abidjan)
A. Samoa Cambodia Japan Lao PDR Macao Malaysia Mongolia Papua New Guinea Solomon Islands Viet Nam Australia (*) Brunei Darussalam(*) China Hong Kong, China (*) New Zealand (*) Philippines Singapore Republic of Korea
1993 CDC Definition
1993 European Definition (*) modified
NOTE: The AIDS case definition in use for the following countries is not currently available: Federated States of Micronesia, Fiji, French Polynesia, Guam, Kiribati, Marshall Islands, Nauru, New Caledonia, Palau, Tokelau, 93 Tonga, Tuvalu and Wallis and Futuna.
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 3: Estimated reporting rates of HIV/AIDS in selected countries Country Reporting year 1998 1994 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1997 Estimated reporting rate for HIV >95% 76% 8% 3% 48% 74% 21% 20% 64% >95% 22% 5% 12% Estimated reporting rate for AIDS >95% >80% 11% 5% 38% 83% 29% 60% 82% >95% 28% 40% 24%
Australia Brunei Darussalam Cambodia China Hong Kong, China Japan Republic of Korea Lao PDR Malaysia New Zealand Papua New Guinea Philippines Viet Nam
94
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 4: Reported HIV/AIDS cases by year of report Country/Area pre-1989 1989 1990 1991 1992 1993 1994 1995 1996 1997 or unknown 1334 614 675 803 787 844 954 801 654 357 8200 1633 1423 1415 1239 1098 1030 946 927 794 0 3 906 906 3 22 0 0 9 57 5 13 16 134 670 1537 2 0 4 36 0 0 0 1 2 14 2 6 0 0 0 0 0 171 1 4 5 17 1 1 17 38 21 101 0 0 1 37 0 0 1 1 2 200 0 0 2 3 0 0 2 299 2 3 9 22 2 12 13 34 31 97 0 0 2 54 0 1 0 1 18 778 0 0 0 0 0 3 3 216 1 3 7 19 4 13 14 60 38 238 0 2 1 42 1 8 1 4 60 1794 0 0 0 1 0 91 5 261 1 4 3 8 2 11 14 71 51 493 0 0 2 76 0 11 2 13 73 2512 0 0 1 69 1 205 23 274 1 3 8 12 5 10 19 79 86 363 0 0 6 78 5 18 2 40 71 2507 0 1 3 153 14 660 29 531 2 6 3 9 11 9 37 104 136 434 0 0 11 90 4 17 2 33 105 3393 0 1 2 80 91 2611 52 1567 0 8 6 13 2 12 45 122 169 543 0 1 14 108 4 31 0 29 233 4198 0 0 2 78 300 4541 38 2649 0 4 4 7 10 15 70 134 235 610 0 11 22 102 16 71 1 21 347 4597 0 1 2 63 572 4674 126 3343 0 4 0 10 5 10 64 181 250 647 2 4 33 124 48 108 2 19 568 3924 0 0 7 15 63 189 231 653 2 2 35 129 27 102 4 31 875 4624 0 0 2 4 540 2052 6 8 37 109 148 386 0 3 14 88 1998 1999 Cumulativ e total 44 313 0 14 1456 2691 2 412 8140 19 738 12 498 4834 24 028 419 13 051 8 43 54 174 60 129 409 1255 2066 6102 6 23 145 964 105 367 17 197 2894 30 593 2 9 Date cumulative to
Australia Brunei Darussalam Cambodia China Fiji French Polynesia Guam Hong Kong, China Japan Kiribati
AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV AIDS HIV
273 720 0 34 1494 7646 136 3306 0 4
30 Jun 99 31 Jul 99 30 Jun 99 31 Mar 99 11 Aug 98 31 Oct 97 31 Jul 99 30 Jun 99 27 Jun 99 31 Jul 99
Republic of Korea Lao PDR
30 Jun 99 31 Dec 98
Macao Malaysia Marshall Islands
30 Jun 99 30 Jun 99 31 Dec 97
95
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 5: Estimated/projected HIV prevalence in selected countries, adults and children, 1990-2000 Country Start of HIV spread 1990 Australia Cambodia China Hong Kong, China Japan Republic of Korea Malaysia New Zealand Papua New Guinea Philippines Singapore Viet Nam TOTAL 1987 1981 1990 1991 1982 1986 1990 1988 1990 1981-1991 1981 1990 1200 60 ? 580 1650 80 1300 2000 180 2000 +/-20 000 Estimated HIV Projected HIV 1998 10 800 185 000 400 000 2500 8000 3400 41 000 1200 4800 2900 3800 86 500 >740 000 2000 11 420 265 000 600 000 2500 11000 3880 58 000 1250 5300 ? 5700 135 000 >1 million
1995 11 150 73 000 ? 2300 4900 2000 15 700 1200 3700 12 500 1840 34 000 >150 000
97
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 6: Estimated HIV prevalence in selected countries, adult population age 15-49, 1998
Country/Area
HIV prevalence adults (15-49) 10 800 300 180 000 400 000 2500 8000 3400 1200 41 000 1200 4400 29 000 3800 86 000 772 100
HIV prevalence rate adults (15-49)
% women among HIV positive
Mode of Transmission Sexual contact 91% 97% 95% 15% 80% 92% 93% 95% 11% 95% 95% 90% 95% 77% Injecting drug use 5% <1% <1% 50% 15% <1% <1% 3% 88% 3% <1% <5% <1% 20% Others
Australia Brunei Darussalam (1994) Cambodia China Hong Kong, China Japan Republic of Korea Lao PDR Malaysia New Zealand Papua New Guinea Philippines Singapore Viet Nam
0.1% 0.2% 3.7% <0.1% <0.1% <0.1% <0.1% <0.1% 0.4% <0.1% 0.2% <0.1% 0.2% 0.2%
5% 10% 30% 12% 40% 33% 13% 50% 9% 15% 48% 30% 20% 44%
4% 3% 5% 35% 5% <7% 7% 2% 1% 2% <5% 5% 5% 3%
TOTAL
98
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 7: Estimates and projections for AIDS incidence, adults and children Country 1995 Australia Yearly Cumulative Cambodia Yearly Cumulative China Yearly Cumulative Hong Kong, China Yearly Cumulative Japan Yearly Cumulative Republic of Korea Yearly Cumulative Malaysia Yearly Cumulative New Zealand Yearly Cumulative Papua New Guinea Philippines Yearly Cumulative Yearly Cumulative Singapore Yearly Cumulative Viet Nam Yearly Cumulative TOTAL Yearly Cumulative 820 6812 1500 2410 107 314 160 1340 50 100 150 220 60 531 370 1510 200 310 30 60 310 360 >3700 >14 000 Estimates 1998 500 7100 17 000 1000 1130 2370 35 500 3860 980 2340 2700 5700 >12 000 >30 000 Projections 2000 13 200 40 250 2350 6420 570 4000 5000 1400 >21 000 >65 000 2003 23 700 100 850 4430 17 600 650 5800 >28 000 >124 000
99
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 8: Estimated prevalence and prevalence rate for selected STI, 1998 Country Australia Brunei Darussalam Cambodia China Hong Kong, China Japan Republic of Korea Malaysia Mongolia Pacific Islands Papua New Guinea Philippines Singapore Viet Nam Gonorrhoea n/a n/a 177 000 1 365 000 2342 n/a n/a 64 000 4600 9000 93 000 428 000 4200 239 000 (<1%) (<1%) (<1%) (4%) (1%) (<1%) (<1%) (3%) (<1%) (<1%) Syphilis n/a 1400 236 000 n/a 600 n/a 52 500 128 000 8000 180 000 93 000 214 000 3800 143 000 (<1%) (1%) (<1%) (8%) (4%) (<1%) (<1%) (<1%) (<1%) (<1%) (4%) Chlamydia 709 000 n/a 236 000 18 202 000 3745 7 380 000 n/a n/a n/a 290 000 533 000 2 560 000 4700 1 000 000 (13%) (20%) (6%) (<1%) (2%) (4%) (2%) (<1%) (7%) (5%) Trichomoniasis 59 000 n/a n/a n/a 460 n/a n/a n/a 6200 248 000 n/a 428 000 n/a n/a (1%) (<1%) (11%) (<1%) (<1%)
1. All rates are calculated per population over age 15. A more detailed description of the data used to calculate these estimates can be obtained from the Regional Office of the Western Pacific (see contact information on the back page of this report). 2. These are working estimates based on available information, and could be plus or minus 1%. n/a indicates data not available
100
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 9: Summary of GASP reports for penicillin and quinolone resistent N. gonorrhoeae , 1992-1998 Total penicillin resistant Country/Area 1
Quinolone sensitivity and resistance
1
% 92 93 17.1 42 n/p 44 11.5 73.5 20.4 90.1 64.1 n/p 0 16.4 12.5 n/a 44.6 46.6 n/a 1.4 64.6
% Less sensitive 96 15.6 78 79* 82.1 4.5 70.4 5.5 90 58.7 n/p 6 8.9 9.3 78 55.7 n/a 44.3 n/a 97.5 *
% Resistant 98 2.0 n/a n/p 36.4 n/a 44.0 50.0 51.5 n/a n/a 3.0 1.4 0.5 1.2 4.4 0 n/a n/a 9.4
94 18.4 n/p n/p 53.8 10.6 77.9 11 87.5 69 n/p 0 15.5 8.7 100 66.4 20 55.6 1 88.7
95 15.8 n/p n/p 84 5 77.6 25.8 90.5 73.8 n/p 15.8 15.2 3.4 68.8 54.5 25 52 9.1 97.9
97 19.2 n/a n/p 55 8 66.4 3.5 91.3 n/a n/a 6 14.5 n/a 95.4 62.3 n/a 44 16.4 76.9
98 27.5 n/a n/p 62.6 8.8 69.0 8.4 89.6 n/a 70 9 10.6 37 82 59.0 0 10.8 35.9 76.6
93 2.7 6.6 n/p n/a 0 n/a 46.8 12 0.1 n/p 0 1.1 12.5 n/a 2.8 0 n/a n/a 2.6
94 1.4 n/p n/p n/a 0.1 55.9 38 25 1.4 n/p 6.2 2.4 0 0 11.2 0 n/a n/a 4.6
95 1.6 n/p n/p 80.7 0 57.5 17.6 15.6 1.9 n/p 31.6 2.3 0 0 8.1 0 n/a n/a 8.2
96 2 n/a n/a 69.4 0 55.2 n/a 38 0 n/p 11.7 3 0 0 6.5 n/a n/a n/a 5.6
97 1.6 n/a n/p 51.5 0 42.1 20 46.8 0 n/a 18 5.8 n/a 0 4.8 n/a n/a n/a 3.3
93 0.001 0 n/p n/a 0 n/a 0 0 0 n/p 0 0 0 n/a 0.33 0 n/a n/a 0
94 0.4 n/p n/p n/a 0 3.3 0 0 0 n/p 0 1.6 5 95 1.8 0 n/a n/a 6.9
95 1.9 n/p n/p 15.5 0 7.7 29.4 0 0 n/p 0 0.3 1.2 68.8 2.9 0 n/a n/a 5.5
96 2.6 10 53 13.5 0 24 n/a 15.6 0 n/p 0 0.7 6.5 66 3.5 n/a n/a n/a 5.6
97 5.6 n/a n/p 28.5 0 38.6 41.2 20.4 0 n/a 0 1.9 n/a 50 3.8 n/a n/a n/a 3.3
98 3.2 n/a n/p 54.2 n/a 48.8 2.6 11.2 n/a n/a 7.5 1.2 3.2 63 7.2 0 n/a n/a 8.1
Australia Brunei Darussalam Cambodia China Fiji Hong Kong, China Japan Republic of Korea Malaysia Mongolia New Caledonia New Zealand Papua New Guinea Philippines Singapore Solomon Islands Tonga Vanuatu Viet Nam
16.9 40.0 n/p 62.1 10.5 66.6 7.9 80 60 n/p 0 10.1 n/a 83.7 43 n/a n/a n/a 55
1 Either plasmid-mediated or chromosomally-mediated penicillin resistance.
n/a - data not available n/p - not participating in the GASP network
2 Less sensitive strains respond to high doses of the agent whereas resistant strains do not. * Specimens tested for PPNG only.
101
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 10: Population groups surveyed for HIV and types of HIV surveillance in selected countries, 1998 Population target Sex workers Routine screening Singapore, Macao, Republic of Korea Sentinel surveillance Cambodia, China, Macao, Mongolia, Philippines, Viet Nam, Papua New Guinea China; Hong Kong, China, Philippines; Singapore; Viet Nam; Papua New Guinea; Mongolia Viet Nam, China, Philippines Ad hoc surveys Australia, Japan, Malaysia, New Zealand, Lao PDR
STD clinic patients
Malaysia,
Australia, Japan, New Zealand
IDU
Malaysia*
Australia; China; Hong Kong, China; Japan; Macao Australia (*), Japan, Malaysia, New Zealand Australia; Hong Kong, China; Lao PDR
MSM
Philippines
Pregnant women
Brunei Darussalam, Malaysia
Cambodia, China, Hong Kong, Mongolia, Singapore, Viet Nam, Papua New Guinea Cambodia, China, Macao, Viet Nam Macao
Police and Defence Forces Prisoners
Malaysia
Australia, Lao PDR
Australia, Malaysia, Republic of Korea
Brunei Darussalam; Hong Kong, China; Lao PDR Malaysia, Lao PDR
Students Blood donors TB patients All countries Macao, Malaysia, Singapore Australia, Malaysia
Lao PDR
Cambodia, Viet Nam
Hong Kong, China; Papua New Guinea New Zealand
Drug rehabilitation programs Hospitals/clinics HIV testing services Seafarers Truck drivers Foreign workers
Papua New Guinea Philippines Republic of Korea China Brunei Darussalam 102
* Ongoing cohort studies as well.
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
Table 11: Behavioural surveillance Population target Sex workers Ad hoc survey Cambodia , China, Japan, Singapore, Viet Nam Malaysia, Mongolia, Papua New Guinea China, Malaysia , Singapore, Viet Nam Philippines (1997, 1998) Philippines (1997, 1998) Cambodia Papua New Guinea Japan, Mongolia, New Zealand, Viet Nam Cambodia (1997, 1998) Cambodia (1997, 1998) Cambodia (1997, 1998) Sentinel surveillance Philippines (1997, 1998) Cambodia (1997, 1998)
STI clinic patients IDU MSM Police and defence forces Women 15-49 General population Women factory workers Motor taxi drivers
103
Status and Trends of STI, HIV and AIDS in Western Pacific, 1999
WHO/WPRO
WORLD HEALTH ORGANIZATION Regional Office for the Western Pacific STI, HIV and AIDS Focus United Nations Avenue (P.O. Box 2932) 1000 Manila, Philippines Fax: (63-2) 521-1036, 526-0279, 526-0362 Tel: (63-2) 528-800 E-mail: sti@who.org.ph Web site: www.who.org.ph
104