/
WORLD HEALTH ORGANIZATION
ORGANISATION MONDIALE DE LA SANT~
REGIONAL OFFICE FOR THE WESTERN PACIFIC BUREAU R~GIONAL DU PACIFIQUE OCCIDENTAL
wPR/Rc26/Tp!2 28 August 1WS Twenty-sixth session Manila 1-6 September lWS ORIGINAL: TECHNICAL PHESEN'l'ATION
ENGLISH
CONTROL OF TUlERCULOSIS IN THE WESTERN PACIFIC REGION
Dr J. C. Tao and
1
Dr Y. AzUIIIA
2
1 Regional Adviser on Chronic and Degenerative Diseases, WHO. Manila
2 Chief. Educat.1on Department.. Research Inst.1tute ot Tuberculosis. Japan Ant.i-Tuberculosis Association, Tolqo. Japan
TABLE OF CONTENTS
1.
TUBERCULOSIS PROBLEM
......................................... . -
1 1 1 "
1.1
1.2 2.
Assessment ..............•......................•. Tuberoulosis in the Region • • • • • • • • • • • • • • • • • • • e- • • •
CONTROL OF TUBERCULOSIS
2.1 2.2
2.3 2.4 2.5
Guidelines Administration ................................................................ ECG vaooination ................................................................. Case-finding and chemotherapy .••.•.•••••••••••.••• WHO assistanoe ......................................................................
............................ ... . .......................................
:3 4 5 6 6
ACHIEVEMENTS
.................................................................................... ........................... .........................
7 7 8 8 9 9 9 11
Tuberculosis mortality, 1947 - 1972 Prevalence of pulmonary tuberculosis Prevalence of tuberculosis infection
-
4.
FORECASTS
...........................................................................................
4.1 4.2
Targets s.et for Western Pacific countries Epidemiological trend ........................................................
5.
CONCLUSIONS
..........................................................
ANNEXES:
Tables 1 to 10 and Figures 1 to 10
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WPR/RC26/TP/2 page 1 1. TU:EERCULOSIS PROBLEM
1.1
Assessment
The magnitude of the tuberoulosis problem in a oommunity is usually measured by: (i) ( 11 ) (iii) the prevalence of the infection; the preval ence of the disease; and the rate of mortality from the disease.
These three indices show the distribution wi thin a community of different manifestations of the interaction of the tubercle bacilli and the human host. Of these indices, the prevalence of infection, as measured by standard tuberculin tests, is considered the most sensitive; but its sensitivity is markedly influenced by the extent of BeG vaooination in the oommunity. The prevalence of the disease has more direct relevanoe to casefinding and treatment programmes, but this index is usually more diffioult and more costly to determine. Some countries in the Region oonduct nationwide random sample surveys periodically for the purpose (Japan and the Republio of Korea); others, for various reasons, restr.iot suoh surveys to seleoted areas of the oountry (Peninsular Malaysia, Minglanilla in the PhilipPines, Phnom-Penh and some provinoes in Cambodia, Saigon-Cholon in South Viet-Nam) • Of the three indices, the least sensitive is the tuberculosis mortality rate. It is derived from population-based death registers of widely varying degrees of accuracy and completeness. In 1972 only 28% of the world population was covered by oause-of-death statistics; in Asia, the proportion was~; and in the Western Pacifio Region, it was 16%. 1.2 Tuberculosis in the Region
,~
ay consolidating scattered data from countries or areas in the Region since 1950, it has been possible to delineate three geographical zones with vastly different epidemiological patterns, namely: (i) Countries north of the equator along the western rim of the Pacific Ocean, shOwing in the 1950s generally high mortality rates (in excess of 140 deaths per 100 000 population per year), high prevalence of the disease (in excess of two bacteriologically positive cases per 1000 population), and high prevalence of infection (more than 30% reactors to standard tuberculin testa in the age group 7 - 14 years). '!his group of countries or areas contains about 98% of the 1045 million population of the Region.
WPR/RC26/Tp/2 page 2
(ii) New Zealand and Australia (white populations), showing low mortality rates (less than 25 deaths per 100 000 population per year) and correspondingly low morbidity rates and low prevalence of infection. These groups comprise 1.6% of the total population of the Region. (iii) The Pacific island territories, including Papua New GUinea, generally showing low prevalence of infection (a proportion of tuberculin reactors of less than 30% at age 7 - 14 years), low mortality rates and low morbidity rates, and certain'special features such as high proportion of extrapulmonary tuberculosis, a relatively acute form of the disease, a higher fatality in the absence of proper treatment, and a generally very favourable response to chemotherapy. This group comprises 0.4% of the total population in the Region. 1.2.1 Tuberculosis infection
Internationally comparable data were made available through WHO!UNICEF-assisted BeG vaccination programmes. These data refer to the positions in countries or areas before BeG vaccinations were widely applied in the 19505 in the northern part of the Region and in the 19605 in the South Pacific island territories. The findings demonstrate, with some overlap, high prevalence of infection in the former and low prevalence in the latter zone (Table 1, Figures 1 and 2). Among the Pacific island territories, the Gilbert and Ellice Islands had the highest rate in 1967, with 43.9% of reactors at age 7 - 14 years, and Western Samoa the lowest. Of the northern countries or areas, Hong Kong, Singapore and South Viet-Nam had the highest infection rates in the 19505, wi til 77%, 61% and 59% of reactors in the age group 7 - 14 years (Table 2 and Figure 3). 1.2.2 Tuberculosis disease Nine countries or areas in the Region have conducted tuberculosis prevalence surveys one or more times during the last two decades. The results of the latest surveys are shown in Table 3. Certain difficulties underlie between-country comparison of these results, i.e., the long span between some surveys of different countries, different age groups examined, limited geographical coverage in certain surveys and differences in X-ray reading standards. Nevertheless a striking difference is apparent between the six northern countries and the three Pacific islands (Table 3). The prevalence of tuberculosis usually increases with age, as shown by the findings in Japan and the Republic of Korea (Figure 4). The prevalence of bacteriologically positive cases in the six northern countries range between 9.1 per 1000 population (South Viet-Nam. SaigonCholon, 1962) and 0.8 (Japan, 1973). The three Pacific islands - Tonga, New Hebrides and Western Samoa - had rates of less than one per 1000 population.
-'
-
wPR/Rc26!TP!2 page 3
The X-ray findings corresponded in general with the bacteriological findings, with two exceptions: (i) those for West Malaysia. where too few X-ray positives seemed to have been read in relation to bacteriological positives and, (ii) Saigon-Cholon in South Viet-Nam where too many were read. There were generally about five times as many X-ray suspects as bacteriologically confirmed cases. with relatively fewer bacteriologically positive cases when the prevalence of the disease was low. These surveys also revealed the low coverage of the tuberculosis treatment services, even in Japan. which has the most intensive tuberculosis control programme in the Region. Of the total pool of infectious cases, 89% had never been treated in Peninsular Malaysia (1970). 7~ in the Republic of Korea (1970) and 5~ 1n Japan (1973). These figures emphasize the great difficulties that lie 1n the way of effect1ve tu~rculosis casefinding and treatment programmes. 1.2.3 Tuberculosis mortality The Philippines and Hong Kong headed the list of countries or areas providing cause-of-death statistics 1n 1972. ranked ~ magn1tude of the1r tuberculosis mortality rates (Table 4 and F1gure 5). In the Philippines. Hong Kong. Singapore and Japan. tuberculosis still occupied the first ten places among the leading causes of death. Expressed proportionally. 10% of the deaths in the Philippines, ~ in Hong Kong, 4% in Singapore and 2% in Japan in 1972 resulted from tuberculosiS. These proport1ons contrast sharply with those of 0.4% in New Zealand and 0.1% in Australia, recorded in the same year. Tuberculosis mortality data for the Pacific islands, inciuding Papua New Guinea. are not complete. The rates are, howver, probably not more than 10 per 100 000 _per year in mos t of the 1s1andS. 2. 2.1 Guidelines CONTROL OF TUBERCULOSIS
The primary objective of a tuberculosis control programme 1s to reduce the disease problem of the country to the maximum extent possible at the fastest rate, with the resources available. To ach1eve this objective, the following guidelines have been recommended in recent years by the World Health Organization to Member States. Epidemiologically. the control services must be natIonwide and planned on a long-term basis. In most of the developing countries where the major1tyof the population lives in the rural areas, a high proportion of infectious cases of tuberculosis is expected to be found. These cases. mostly diagnosed for the first time, respond in general to treatment exceedingly well. Investment in this group of cases will ensure the highest benefit and a Significant impact. In order to achieve a wider coverage. the utilization of auxiliary personnel to carry out the control measures is absolutely necessary.
WPR/RC26/TP/2 page 4
Administratively, the control activities must be integrated into the general health structure of the country. Reliance on specialized hospitals and clinics invariably leads to a patchy and spasmodic service. Integrated service, on the other hand, leads to decentralization of the activities, enabling more people to benefi t from them and a more permanent service to be maintained. Technically, the selection of target groups for various control measures must be based on the cost/benefit principle •. The methods to be adopted and applied must be accurate, specific, effective, readily learned and carried out by non-professional personnel and acceptable to the consumers; and even more important, they should not be time-consuming and costly. :~ocial1y, the felt needs of the motivated patients must be met first, with the provision of free and adequate treatment service. Active casefinding should not be launched unless the available treatment service can cope with the existing case-load.
-
Economically, all measures adopted in the programme must be within the scope of immediately available resources. Following blindly the practices adopted by affluent countries without taking into consideration the resources in developing countries must by all means be avoided. Operationally, a nationwide programme must be preceded by pilot trials in a defined area on the local applicability and acceptability of the methods which have been of proven value elsewhere. It must also be supported by a permanent training scheme and an efficient post-training supervision system. These guidelines have been widely accepted and adopted in various degree by almost all countries and areas in the Region. It is gratifying to note here that these guidelines are even being followed now by a number of affluent countries, recognizing for instance the efficiency of paSSive as compared with active case-finding, the practicability and efficacy of domiciliary treatment, the need for chemotherapy of sufficient duration, etc. 2.2 Administration
-
Available infortnation shows that the proportion of the national: heal th budget allo(lated to tuberculosis control varies from 1" to 17%. The actual ~capita.amount. spent annually by governments for tuberculOSis control . varies from the equivalent ofUS$ .02 to a maximum of US$1.50. In this connexion, anencoura.ging example has been provided by the .Government of the Republic ·of Korea.. The government expenditure on tuberculosis in 1962, when the organized programme was launched~ wali\ the equivalent of U8$520 9l0,Whlle that in 1973 was us$ 3 080 000; thus it increased :five times in the' span of 12 years.
WPR!RC26!TP!2 page 5
In most countries or areas. tuberculosis control activities. especially EGG vaccination. are decentralized and carried out by the general health workers. with the assistance of a number of specialized tuberculosis centres. However, there are still countries or areas in which tuberculosis control work, particularly diagnosis and treatment, is handled, by tradition. almost entirely by speCialists in chest clinics and hospitals. 2.3 EGG vaccination
The pace of the EGG vaccination programme has accelerated in recent years and a high coverage has been achieved in many countries or areas of the Region by: (i) the introduction of heat-stable freeze-dried EGG vaccine, which has been particularly beneficial for tropical areas; (ii) the practice of direct EGG vaccination, thus eliminating the prevaccination tuberculin tests. For this purpose. it is necessary to determine the age below which direct EGG vaccination may be performed advantageously. i.e •• the age at which the proportion of the naturally infected is no higher than 25%. In most countries. this upper age limit is seven years; (iii) the performance of simultaneous vaccination - for tuberculosis and smallpox in particular. This practice not only can increase the coverage of the service but can also save time and manpower considerably. During the nine-year period (1966-1974), the average number of vaccinations performed in the Region. excluding Australia. China. Japan and a few small territories. was approximately five million per year; during the earlier 15-year period 1951-1965. the average was only 1.6 million a year, Excluding Australia. China and Japan. over 100 million vaCCinations were performed in the countries or. areaS in th~ Region during this 24-year period, among a population of 120 million in 1970. This gives a ratio of over 80%, providing a rough measure of the coverage of the BeG vaccination programmes. It does not, however. take into account the rate of attrition of the vaccinated people due to deaths. the effect of EGG re-vaccinations or the proportion of the susceptible population. Table 5 also provides a list of countries or areas with vaccination/ population ratios for the purpose of comparing their performance. Japan. with a ratio of 143% has the highest BeG coverage and many more vaccinations seemed to have been performed than there were people in 1970. The Pacific island territories and the Republic of Korea have ratios of about 100%. Malaysia and Singapore have a ratio of over 60% and the remaining countries or areas on the list have ratios of less than 50%. Figure 6 shows the average annual number of persons vaccinated with EGG each 5-year period from 1951 to 1974 in the Western Pacific Region, excluding Australia. China. Japan and some small territories and cumulative numbers during the 24-year period.
WPR/RC26/TP/2 page 6
2.4
Case-finding and chemotherapy
In countries or areas where no organized treatment service exists. efforts to find cases serve no useful purpose. Similarly in countries or areas where the morbidity is high. the most that can be hoped is to treat as many of the highly infectious cases as pOSSible, i.e., cases with sputum smears positive for acid-fast bacilli. At this development stage in these countries or areas, any diversion of treatment resources to non-infectious patients would not be to their best advantage. For this reason, the use of X-ray for tuberculosis case-finding, especially repeated examinations of organized groups of younger people, is always discouraged by the Organization. As a result of the effective chemotherapy now available for tuberculosis. there has been no increase in the number of hospital beds for tuberculosis in any country or area in the Region during the last 25 years. On the contrary, in Australia. Japan. New Zealand, Singapore and recently in Papua New Guinea. a considerable number of beds previously reserved for tuberculosis have been made available for other uses. Except in a few countries or areas like Japan and the New Hebrides, the average length of hospitalization is often less than two months and it is reserved mainly for the treatment of newly discovered infectious cases. complications. emergencies or surgery. The routine drug regimens used in the majority of countries or areas of the Region for the initial treatment of tuberculosis during the first 6-8 weeks are either streptomycin, p-aminosalicylic acid and isoniazid or streptomycin, isoniazid and thioacetazone, both regimens being administered daily. These regimens are followed for the rest of the year by (i) streptomycin and isoniazid twice weekly; (ii) p-aminosalicylic acid and isoniazid twice weekly, or (iii) isoniazid and thioacetazone daily. More expensive drugs such as ~ifampicin, ethambutol. ethionamide, etc., are used as primary drugs only in a very few places. Table 6 shows the numbers of tuberculosis patients under treatment at the end of 1974 in different countries or areas.. These numbers no doubt represent only a small proportion of the estimated total number of patients in the country or area. 2.5 WHO assistance
-
-
WHO has provided assistance through country projects and the Regional Tuberculosis Control Team to a number of countries or areas in planning, organizing, implementing, assessing and evaluating their national tuberculosis control services. The shortage of trained personnel 1s always the greatest obstacle to the organization of such services. WHO has frequently been requested to'assist in the training of tuberculosis personnel, such assistance taking the form of seminars, refresher courses and fellowships.
WPR/RC26/TP/2 page 7
Two regional training courses on tuberculosis control are currently in operation: one co-sponsored by the Government of Japan and held once a year, and the other co-sponsored by the South Pacific Commission and held in conjunction with leprosy training once every five years, particularly for the medical officers who graduated from the Fiji School of Medicine. Assistance is also provided through national seminars or training courses organized in certain countries. During the last 25 years, over 100 WHO fellowships have been awarded to key personnel in the field of tuberculosis control from almost all countries or areas in the Region. The fields of study have been epidemiology, public health administration, BOG vaccine production, bacteriology and tuberculosis nursing. Currently, a regional BOG vaccine production centre is being established in Alabang, Philippines, with WHO/UNICEF assistance. Free supply of the vaCCine, in freeze-dried form, is expected to begin late next year to all countries or areas receiving UNICEF assistance. 3. ACHIEVEMENTS
The most impressive feature during the past 25 years has been the change in the people's attitude towards tuberculosis. For thousands of years tuberculosis had been regarded as an incurable wasting disease. Since there was no specific cure," patients accepted their fate and often tried all sorts of "wonder" drugs. No government could afford tuberculosis control services. The introduction of specific preventive measures and chemotherapy changed" the situation completely. 3.1 TuberculosiS mortality. 1947-1972
Tuberculosis mortality soon after the war was around 200 per 100 000 each year in almost all countries or areas of the Region north of the equator. From 1950 to 1970, a marked reduction was observed in many countries or. areas, (Table 7 and Figure 7). During the 20-year span between 1951 and 1970, the tuberculosis death rates fell considerably: in Australia, China (Peking), and Japan by more than 9a%, averaging 11 - 12% per year; in Singapore and New Zealand by about 85%, averaging 9% per year; and the Philippines by a little more than 45%, averaging 3% per year. In the second decade (1961-1970), the rate of reduction for these countries was slower than in the first decade (1951-1960): in Australia and Japan, it was 8 - la% per year; in Hong KOng and Singapore, 6%; in New Zealand, 3 - 4%; and in the Philippines, 1%.
WPR/RC26/TP/2 page 8
There has also been a substantital fall in tuberculosis proportional mortality during the last 25 years. The disease has, correspondingly, ranked lower and lower in these countries or areas, as a cause of death. In Japan, over a period of 20 years beginning in 1951, it dropped from first to tenth place. In Shanghai, China, it dropped from first to eighth place. In Singapore, it dropped to eighth place in 1969. In Bong Kong, it dropped from second place in 1953-1960 to fifth in 1965. In New Zealand, over the same period, it dropped from fourth place to twentieth. In the Philippines, it has remained in second place. The total number of deaths from all forms of tuberculosis in these six countries or areas was 158 008 in 1950, 60 885 in 1960 and 46 576 in 1970. This represents a decrease of 61.5~ during the first decade and 23.5~ during the second, in spite of population growth. When the reduction of tuberculosis mortality by age is taken into consideration, it is the adolescent and the middle-age groups that show a marked change, as illustrated by the figures for .Japan from 1935 :to 1971 (Figure 8). 3.2 Prevaience of pulmonary tuberculosis
--
The national tuberculosis prevalence surveys repeatedly carried out in the past 20 years in Japan and the Republic of Korea have provided invaluable information illustrating changes in the epidemiology of tuberculosis in the two countries. The prevalence of pulmonary tuberculosis, as shown by X-ray and bacteriological examinations (Table 8), has decreased considerably •. The reduction of prevalence has been more marked in_.the adolescent and middle-age groups, as shown in Table 9 and Figure 9.. In the older age groups, .there has, however, been only a slight sign of decrease in prevalence. Apart from a reduction in the number of tuberculosis patients, there has also been a considerable decrease in the proportion of patients suffering from advanced tuberculosis. In the Republic of Korea, the frequency of far advanced lesions, as shown in Figure 10, dropped from 12% in 1965 to 9% in 1970. . .. 3.3 Prevalence of tuberculosis infection It is believed that the prevalence and incidence of tuberculosis infection have been decreasing rapidly in many countries in the past 25 years. As a result of the wide coverage of BOG vaccination in most of the countries or areas in the Region, detailed information on this point is not available. However, as direct BOG vaccination is being applied extensively in many countries or areas, results among the unvaccinated children at a specified age at annual intervals may in future be utilized in measuring the trend of transmission of the infection.
-
WPR/Rc26/Tp/2 page 9
4. 4.1
FORECASTS
Targets set for Western Pacific countries or areas
Medium-term targets for tuberculosis control in the Western Pacific Region have been set as' follows: 4.1.1 The disease should no longer be among the 10 major causes of death and the mortality rate from allforms of tuberculosis should be lower than 10 per 100 000 population annually. 4.1.2
The prevalence of infectious pulmonary tuberculosis, based on the microscopic examination of sputum, should be lower than 1 per 1000.
4.1.3 The risk of tuberculosis infection should ,be lower than 1% per year, i.e., the percentage of tuberculin reactors among the non-vaccinated children at the time of school entrance should be lower than 5%. 4.2
Epidemiological trend
In view of the presence of a considerable amount of information on the prevalence of tuberculosis already available in a number of countries or areas of the Region, it might be useful to make an estimation of the cUl'Tent, even future, status of tuberculOSis in these countries or areas. This can be illustrated by fitting the available information into a model which either simulates the dynamic pattern of the 'epidemiology or shows the relations between epidemiological variables as follows: Table 10 gives a list of seven countries or areas and the State of Sarawak, Malaysia, mere a tuberculin survey has been conducted some time during the past 15 years. The percentage of tuberculin reactors among unvaccinated cnlldren is gi venby 5-year age groups. The columns (3) and (4) in the table show the annual risk of infection respectively for the 5-year period up to the year of the survey and the previous 5-year period. With these two ratios, the rate of reduction of the risk of infection can be calculated as shown in colUllll (5). These figures are calculated on the basis of the following formula: Suppose the proportions of tuberculin reactors of Children under 15 years of age in a community are given as the follOwing:
0-4 Percentage of (P • 1 posi~ives
:!P group
P . 1
5-9 P •
10-14 P •
2
3
+ 2
P .)
2
=
PI
=
Positive rate at age 5
WPR/RC26/TP/2 page 10
(P
2
f
+ 2
P I 3
=
P2 =
Positive rate at the age 10.
'"
= N2 =
Negative rate at age 5. Negative rate at age 10. Average risk of infection to which the cohort of the 5 years of age has been exposed, since the birth up to the survey year.
1 - P
2
=
1 _ N 1/5 1
=r
2
Average risk of infection to which the 10-year age cohort has been exposed since birth up to their 5-year age.
A
=
Average annual reduction rate of the risk of infection.
The above set of equations is based on a model: Nn Nn r =
'"
(1 - r)
n
Tuberculin negative rate at age Average risk of infection for the of life.
n n years
~
Assuming the annual. reduction rate to be applicable also for the years after the survey, the risk of infection was estimated for 1975. by applying the formula:
= m
=
1975 - (survey year)
as given in the column (6) of the table.
WPR/RC26/TP/2
page 11
The prevalence of tuberculosis by bacteriology is given in the column {7}, for five countries where the figure is available for the survey year. Column (8) gives the value of a parameter k, whioh is the ratio of the risk of infection against the prevalence of tuberculosis (r/prevalence). Here, the treatment coverage of bacillary cases was taken into aooount. assuming that treatment of cases makes little contribution to the risk of infection. The parameter k is supposed to be a constant indicating the infectivity of cases under the conditions existing in each country. The value of k varies between the countries in a range 5-9,exeept for the Philippines where it is 2.0, a figure obtained by dividing the r value by the prevalence of smear andlor culture positive tuberculosis (by the smear positive prevalance it was ,.5). The prevalence of tuberculosis in 1975 was estimated as shown in column (9), by dividing the estimated value of the risk of infection by k value. It is observed from the table that the risk of infection is declining in all countries or areas listed. the annual reduction rate varying between 6.21> and 19.7% except in Sarawak where the risk of infection seems to be almost constant at a level of 1.4%. It is also observed that the prevalence of tuberculosis has been declining to 0.1% - O.~ in 1975 in all the countries listed.
5.
CONCLUSIONS
It is clear that a tremendous change has taken place in the tuberculosis field in almost every country or area of the Region during the past thirty years. For such a disease which has taken so many lives and caused so much suffering far so many years, the change is indeed phenomenal. However, it is also the consensus among the medical group that the achievements made so far could have been greater in the past decade and should definitely be still more impressive in the coming years. The main difficulty faced is that the available technical and managerial methods and the operational experience gained in the past years have not been widely and thoroughly applied, particularly in those countries or areas where the services are badly needed. One stumbling block is seemingly the lack of public health orientation of some clinicians who want to do everything possible for their few patients without taking into consideration the total tuberculosis problem of the country. A number of specialists in the field of tuberculosis still stick to the traditional but ineffective individual curative approach. This attitude can be observed not only in affluent countries but unfortunately also in many developing countries.
WPR/RC2.6/TP/2 page 12
Integration of tuberculosis control services into the general health structure is the only way to decentralize the services and thus make them available to the mass of the population which, particularly in Asian countries, is largely rural. Most tuberculosis cases in the rural areas have never been diagnosed or treated, and thus always respond to chemotherapy quickly and completely. So from a cost benefit point of view, government resources should be directed to these areas with higher priority. Integration of a specialized control service for a chronic disease such as tuberculoSiS into. the general health structure is not as simple to organize as many bealtbadministrators have mistakenly believed. I t requires a great deal of preparation and time. !lbe progr8llDDe bas to be supported by intensive and almost permanent training and. retraining for all categories of health worker at all echelons, close field supervision after the training, periodic assessment of the activities, and the necessary adjustment of the strategy of control. For this reason, specialized teams are still required at the national level, and even the regional and provincial levels in large countries. Such teams should be headed by an epidemiologist and assisted by organizers or managers of various aspects of the service such as BOG vaccination, case-finding, treatment, followup and record-keeping. Because of the vast number of people to be served and the need of adequate and regular medication for a prolonged period, expenditure on the tuberculosis control programme, especially in countries or areas with a higher prevalence of the disease, will naturally have to be increased. The WOrld Health Organization recommends that for such a controllable chronic disease, an expenditure of the equivalent of 10 US cents per capita annually is the minimum required to carry out an effective national tuberculosis programme. The tuberculosis control targets set by the Regional Office for the western Pacific in consultation with the Member States should be achieved by a majority of countries or areas in the Region including all those in the northern sector, by the year 1980. It is believed that these targets are attainable; in fact, parts of China, Japan and Singapore have already achieved some of them. For total success, however, special efforts will naturally have to be made by the governments of some of the Member States represented at this meeting.
(
Table 1
PERCENTAGE TUBERCULIN REACTORS BY AGE-GROUP; SELECTED COUNTRIES OR AREAS, 1951-1969 Percentage reactors at age-g rou p Country or area Gilbertand Ellice Is. French Polynesia New Hebrides Tonga Western Samoa Hong Kong Brunei South Viet-Nam Malaysia (Sarawak) Cambodia ----
Year Reaction Tuberculin criterion tested
0-4 0- 6 -
5-9 7 -14 -
10 - 14 43.9 -
~15
1967 1961 1964 1969 1962 1952 1953 1954 1952 1955 --_ .. -
M )( PPO RT 23 1 TU with Tween M x PPD RT 22 5 TU wit hout Tween
11. 6 -
~
7.6 10 mm; -
36.6 4.5 5.3 2. 8
83.9 70.1 61.0 34.2 22.1 94.1 89.0 82.B 79.4 68.3 I ,
2.3 0.9
-
16.0 13.4 11 . 6
I
41. 7 19.0 ~5mm
73.0 54.0 61.3· 44.6
40.3 18.9 13.9
42.0
~~ -_.-~----
-0 ~
..
------
1.Jjf\)
. . . f5
~
0\
~
Figu re
1 'O~
PERCENTAGE TUBERCULIN REACTORS BY AGE GROUP SELECTED COUNTRIES OR AREAS IN THE WESTERN PACIFIC REGION* 100 ~ HONG KONG
~~ I-'~ -"'" I\)
I» '0
~ '0 ';\)
0\
8
a.
GILBERT AND ELLICE ISLANDS
CAMBODIA
60 '\
~~~\
'\o~\v
oLS
\
40 •
'>AQ~'\
y-,.<:.?__'0
501.1' C\ pl\Clfl C IS LI\NDS 20 ,/
WESTERN SAMOA
a
IAlJIIIIIIIIIII,IIIIIIIIIIIIIII~ a 5 10
I 15
* See
AGE table 1 for details
20
( I
(
,,
(
Figure 2
PERCENTAGE OF TUBERCULIN REACTORS BY AGE-GROUP AND BY COUNTRY OR AREA, 1951-1955 (Mx, PPD, RT22 5 TU., ~,5MM)
PERCENTAGE OF TUBERCULIN· REACTORS BY AGE AND BY TERRITORY, 1961 -1969 (MX, PPD, RT 23 WITH TWEEN, IW.~ 10MM)
100
.e 80 .: 60
OIl
.. .. u
.. o
~40
CI
c
" ....
~20 0"-
~
~ ;.:.~
./'
"/5
...........:.;.........
..
.... ~.:
.;:';;::"
.. ---.... :.:::- .. ..... .'
Hong Kong Brune i __ South Viet-Nam __ - - •• , Malaysia ~.••• (Sarawak) •. ' .• ' ___ Cambodia
100
.. .. ~ u ~ ~
OIl
60
60
.
., ~40
o
..
'
.c u
~ 20
O~ - -" - ----"" - ----'
I~'" 5
-,.-., 15
Vles ter " samoa:
10 Age
15
20
10
20
Age
~~ :::0 \Jlru 1-'0
'O~
~ ~
WPR/RC26/TP/2 page
16
T a bl e 2
PERCENTAGE TUBERCULIN REACTORS IN AGE-GROUP 7-14 YEARS; SELECTED COUNTR IES OR AREAS IN TH E WESTERN PAC I FIC REGION 1951-195B. (Mx 5 TU PPD RT 221 ~ 5mm as positive) 1
COUNTRY OR AREA
PERIOD
"'0 REACTORS 77 61 59 49 48 45 45 43
-
Hong Kong Si ng apore Sou th Vi et -Nam Phi I j pp j n e 5 Brunei Cambodia Malaysia (Sarawak) Malaysia (Peninsular)
1 952 1 951 -'1954 1 9 51 1952
- 1955 - 1953 - 1957 - 1957 - 1953
1956 - 19 58 1 952 - 1953 -19 51· - 1953
-'
(
/
/ Figu rE' 3
(
PERCENTAGE TUBERCULIN REACTORS IN AGE-GROUP 7-14 YEARS; SELECTED COUNTRI ES OR AREAS IN THE WESTERN PAC IFIC REGION, 1951-1958. (Mx S"TU PPO RT 22, ~ Smm as posi tive) Hong Kong Sing apor E' Sout h Viet- Nam Phili ppin E's Bru nei Cam bod ia Mala ysia (Sara wak) Mala ysia (P~ninsular)
o
10
20
30
40
50
60
70
80
~! ~K3
Perc en tag E' Tu berc u I in RE'ac tors
~ ~ I\)
0\
Table 3
LATEST TUBERCULOSIS PREVALENCE SURVEY RESULTS, WESTERN PACIFIC REGION Country Sou t h Vie t - Nam (Saigonl Cholon) Republic of Korea Philippines (Minglani lIa) Cambodia (P. Penh, 3 prov'inces) Malaysia (West) Year completed Age-group examined (years) s.urvey X-ray positive Bact. posit ive ( -/0 ) ( 0/00 )
~;g CD-;x,
'O~
O>\¥,
t-JO
%
~
1962 1970 1964 ;
? ~
10 5 5
?(10.4) 4.2 4.0
9. 1 7.4 7.2 1
? ~
I
1968 1970 1973
5
2. 1
3.0 2.5 0.8
~ 15 ~ 15
? (0.7) 0.9
J a pan
New Hebride.s Western Samoa Tonga -
1966 1967 1970 --
a II a II ~ 10 ----
1.2
0.9 0.7 O. 1 ---
----
---------
-
----
(
(
(
(
Figu re 4
AGE-SPECI FIC PREVALENCE OF PULMONARY TUBERCULOSI S; JAPAN (1968) AND REPUBLIC OF KOREA (1970) X-ray posit ive, .,. Bact eriol ogy posi tive, .,••
i
10.0
3.0 Repu blic of Korea, 1970
2.0 5.0 1.0 Japan, 1968
0.0
I
o
----. ...-
20
40 Age
60
10.0 80 'C
~~ \01\)
~
~~
LEGEN 0; Bact eriol ogy, broken edge _ • • • X-ra y, cont inuo s edg e- . . . . .
~ I\)
~ >-3
Table 4
TUBERCULOSIS (ALL FORMS) MORTALITY, 1972; SELECTED COUNTRIES OR AREAS IN THE WESTERN PACIFIC REGION
&;;8 (I)
'O:E:
fg2
..........
% Country or area Philippines Hong Kong 5 i ngapore Japan New Zealand Australia Population (000) Deaths Deaths 1B death rate TB proport ional TB cause of death mortal i tY(O/o) rank order all causes tu bercu losis per 100 000 pop
~
0"\
39 041 4 077 2 .1 47 106 958 2 905 12 959
285 761 21 391 11 522 683 751 24 801 109 760
29 784 1 312 489 12 565
76. 3 32. 2 2 1. 9 11. 7 3. 1 1.2
10. 4 6.1 4. 2
2
5 8 10 20 25
1.8 0.4
91 150
o. 1
(
,.
(
~
(
Figure 5
TUBERCULOSIS (ALL FORMS) MORTALITY, 1972; SELECTED COUNTRIES OR AREAS IN THE WESTERN PACIFIC REGION Western Pacific Region Philippines Hong Kong
5 i n g a po re Japan. New Zealand
~ ~ o • •
Australia
. 60 80
;~ 1-'1\)
't:l ~
20
40 Death Rate per 100,000
I\)~ >-3
~ ~ I\)
Table 5
BCG VACCINATIONS IN COUNTRIES OR AREAS OF THE WESTERN PAC IFIC REGION} 1951-1974 Popu lat ion (197 0)· (000 ) BCG vacc inatio n cumu lated (000 ) 9-yea r 15-y ear perio d peri od 1951 -196 5 1966-1974 103 346 1 881 43 947 2 11 0 20 417 670 4 582 10 782 846 5 588 298 960 (19G6-19~01
'0
()Q
1\1 '"tl ::Xl (1)",",f\)f5 f\)f\)
~
~
Cou ntry or area
Tot a I
Ratio vacc inati on' popu la t ion
%
Japa n Pacif ic Islan ds Rep. of Korea Sing apor e' M alay si a Phili ppin es Hon g Kong Sout h Vlet-Nam New Zeala nd Cam bodi a Brun ei
102 910 3 863 31 469
147 293 3 991 31 400 1 463 6 686 18 21 6 1 800 6 988 686 1 5 L.1 28
143 103 93 68
0/0
oJ. oJ.
B 972 751 2 104 7 434 954 1 400 388 581 16
2 075 10 B 78 36 852 3 959 18 238 2 8 11 6 818
.,. 0/0
6 1 0/0 49
. 45 ·/0
38 0/0 24 23
"10 0/0
135
12 (1966 -19-0 -
2 1 ./.
( /
(
Figu re 6
NUMBER OF PERSONS VACCINATED WITH BCG IN THE WESTERN PACIFIC REGION. CONSOLIDATED FIGURES, ALL COUNTRIES OR AREAS EXCEPT AUSTRALIA, CHINA AND JAPAN. 100.0
--III
C 0
-
--"'0 QI .....
E
39.8
",
c
u u ",
15.81 (,
\.' ,,)\.~
."e
> C 0
,,)~ e~'?
III III "QI
6.3 ~0
Q.
...... 0 "-
0,,)
~\.
0,,)
~'O
at ::J
..0
E
2.5
". , I 1956
~~~
e
Z
1.0 I: 1951
,
1961
,
1966
,
I
1971
,
I
I
'O~
III ...,
,
~~ \>II\,)
~ I\,)
~
1975
WPR/RC26/TP/2 page
24
Table 6
NUMBER OF TUBERCULOSIS PATIENTS UNDER TREATMENT AS AT THE END OF 1974 (UNLESS OTH ERW ISE SP EC I FIE D). SELECTED COUNTRIES OR AREAS/WESTERN PACIFIC REGION.
COUNTRY OR Japan
AREA
NO. OF' PAT I ENTS 51 6 206 148 030 55 350
Republic of Korea (1973) Philippines Malaysia: Peninsular Sabah Sarawak Hong Kong Singapore Austral ia Papua New Guinea Tong a New Caledonia French Polynesia New Hebrides Western Samoa· Trust Territory of the Pacific Islands American Samoa
14 750 3 630
2 610 1 3 655 9 086 3 994
2 335 506 499 400 400 261 80
25
(
( Tabl e 7
TUBERCULOSIS (ALL FORMS) DEATH RATES PER 100 000 POPULATION; SEVEN COUNTRIES OR AREAS IN THE WESTERN PACIFIC REGION, 1950, 1960,1970.
Coun t ry or area
y e a 1950 1960 ..
r
1970 1. 6 36.0 15. 3 3. 7 80. 6 22 . 1 14. 8 lIl'* ----
Aus trali a Hong Kong Japa n New Zeal and Phil ippin es Sing apo re Ch ina (Pek ing City)
20 . 5 144 . 0 146 . 4 22 . 8 152 . 9 145 . 5 230
4 .8 67. 8 34.2 4.8 87. 6 39. 5
I I I
~~ VII\)
'OlE:
I\)~
*
-
~ >-3 ~ I\)
*" *" *"
---
1949 1973
WPR/RC26/TP/2 page 26
Figure 7
TUBERCULOSIS (ALL FORMS) DEATH RATES; SEVEN COUNTRIES OR AREAS IN THE WESTERN PACIFIC REGION, 1950-1972. 200
.... .'.
'.:
,.,'-:-............. .. . , .. ~
100 0 ..... nj
c
., t-:, ... . ......... '
...................
--
.............
~
.
50
~"" .',
.............
... __ ...
............... " ,
--..._...
Philippines
-
:J 0. 0 0. 0 0 0 0 0
.~
..........
.. '~ 25
..
....
- -- .... ........ ' '
'.::.~
.. . .., .. ' ,"
-"
Hong Kong Singapore
...... "QI
.....
China (Peking) Japan
0. til
10
..... nj QI
'-
.r..
..... nj QI
5
........
-.......
0
..........
2.5
---1970
-New Zealand Austral ia
"
1950
1960
Yea r
WPR/RC26/TP/2 page 27
Figure 8
CHANGES IN TUBERCULOSIS DEATH RATES BY AGE-GROUP IN JAPAN (1935-1971 ) 500 450 400 '-,
------C 0
1935 1950
350 300 250 200 150 I
..... <1l :J
1968 --._.-.- . 1971 f
a. 0 a. 0 0 0 0 0
"" \ \
, , , I I I
\ \ \
....
,,
,
.... a. Vl ClJ
, , , I I
I
..... '
--
.....
"-
.
",,
,
.£: ''-
..... <1l ClJ
Cl
100 50 0
I
10
20
30
40
50
80
70
80
90
Age
Ministry of Health and Welfare, Japanese Government (1971)A brief report on public health administration in Japan, Tokyo.
Table 8
'O:e:
&l ;g co,
RESULTS OF PULMONARY TUBERCULOSIS PREVALENCE SURVEYS CONDUCTED IN JAPAN AND REPUBLIC OF KOREA} 1953-1973
oo~
I\.l~
Country
Year survey Age-group Percentage conducted examined x-ray positive
Bacterio\og i ca II y positive in 1000s
J a pa n
1973 1968 1963 1958 1953
~15
0.9 1.5 2.1 3.3 3.4 4.2 5.1 -
0.8 2.3 1. 9 5.5 7.5 7.4 9.4 --
~ 5
>
5
>5
~ 5
I
Republic of Korea
1970 1965
~5
~5
( ~
(
(
Tab I e 9
(
AGE SPECIFIC PREVALENCE OF RADiOlOGICAl_LY POSITIVE PULMONARY TUBERCULOSIS, PER CENT; JAPAN AND TH E REPUBLIC OF KOREA, (1953 -1973) .
Age-group All ages
J a pan
Republic of Korea
1953 3.2 1.0 1.1 1.3 2.5 4.0 5.B 6 '.6 4.9 5.2 4.8 4.8 4.2 4.6 4.9 4.9 4.4 2.8 1 .4
195B 3.2 0.7 0.4 0.4 1.0 2.7 3.7 5.3 5.3 6.0 5.1 6.7 6.6 6.8 6.8 5.7 6.7 7.3 6.6
1963 2. 1 0.4 0.3 0.3 0.6 1 .2 1 .9 2.4 2.4 3.7 3.9 4.4 4.1 4.6 4.8 5.1 4.9 3.7
196B 1.5 0.0 O. 1 o. 1 0.4 O.B 1. 1 1. 1 1.8 2 .6 3.1 3.2 3.2 4.0 4.1 4.1 3.1 -
1973 0.9 -
1965 5 .1
1970 4.2 -
0-4 5- 9 10- 14 15-19 20- 24 25- 29 30-34 35 -39 40-44 45 -49 50-54 55 -59 60-64 65-69 70-74 75 -79 80 -84 85 & over
3.0 1. 7 2. 1 3.7 4.4 5.7 6.6 8.8 8.0 9.8 10.4 12 ·7
2.8 1.9 2.5 3.7 2.5 4.2 5.4 6.8 6.3 5.8 9.8 8.3 14 . 1 'O::e:
0.3
0.7
1 .2
2.3
~~ \O~ IIJO
13 . 7
~ ~ IIJ
'd~
Figu re 9
~<: VI~
PI 'tI
AGE SPECIFIC PREVALENCE OF RADIOLOGICALLY POSITIVE PULMONARY TUBERCULOSIS REPUBLIC OF KOREA, 1965 and 1970 14~--------------------.
°i
8- r-- --- --- --- --- --- -. 1953 6 -l C1I (Jl
JAPAN, 1953 -197 3
/
\
.
,I
1-_-'' ' --" \ \ ,, \ \ I
I I I
,1
12 10 C1I
...... U
rtI
,i-V
" ~ ...... c \ '
~ 4 C1I
,,'1958 I
'-
0...
. I
I ~'
,/
'
I
...... -. /
-'- '. .' .' " "
8
i
\
.
i 61 41 2 0 , ,
/I
IV I I
I
,
" 1970 " I
,,
, , '- ...... ......
'
,
2 -I "
I .' ~'
/
I
0
'-'-'
. .... _--' /' 10
,
/.
...·····1973 30 40 Age (
.... ....
-
.'.' 50
.' .'.'
.'
\.
I
;\ ' I
,I
I I.
I
I
,
"
'" , • I
20
60
70
80
10 (
20
30
40
50
60
70
Age
WPR/RC26/TP/2 page 31
Figure 10
DISTRIBUTION OF PERSONS WITH RADIOLOGICALLY POSITIVE PULMONARY TUBERCULOSIS BY EXTENT OF DISEASE, REPUBL IC OF KOREA
Far advanced Moderatel y advancea
Minimal
64.8 0/0
1965
1970
Tab I e10
FORECASTS OF ANNUAL RISK OF INFECTION AND PREVALENCE OF TUBERCULOSISj SELECTED COUNTRIES, WESTERN PACIFIC REGION Survey year ( 2 ) Annual r estimate TB prevo reduction rate 1975 of r (5) (6) ( 7) 0/ 010 "/. 00 19.7 8.8 11 . 2 6.2 8.4 0.0 8.2 0.02 1.4 0.4 1.5 0.6 1.4 0.5 2.4 o ••
'O~
'vIf5
~~ 1\)1\)
Country Iterritory ( 1 ) Western Samoa South Viet-Nam Philippines Cam bod ia Laos MalaYSia (Sarawak) Tong a Republ ic of Korea
r
1
r
2
k (8)
TB prevo 1975 (9 )
%
~
( 3 )
(4 )
010 1962 0.4 4.7 1.4 2.5
010 1 .1 7.4 2.6 3.5 2.1 1.4 1.2 6.2
0100
·.. 5.9 2.0 8.6 5.2
·.. I
61/63 1964 1967 1967 1968 1969 1970
0.91 0.72 0.3 0.25 •••
0.2 ! ,
0.2 0.2 0.1
,
I
I
1.3 1.4 0.8 3.9
1
, ,
· .. •
·..
I
.. . 0.74
••
· .. 0.3
I I
8.9
8.0
( f
( I
"