MEASLES BULLETIN Volume 2, Issue 2 – April 2008
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News in Brief Mark your calendar: The 17th Meeting of the Technical Advisory Group for Vaccine Preventable Diseases will take place in Manila from July 7 to 11, 2008. The first three days will consist of an integrated surveillance and laboratory workshop and meeting, and the last two days will be devoted to formal TAG deliberations. Papua New Guinea is currently implementing a nationwide measles Supplementary Immunization Activity (SIA) targeting children from 6 months to 6 years, 11 months of age. Several provinces in China and Viet Nam are also conducting large-scale SIAs in 2008. In 2007, SIAs were successfully carried out in Cambodia; Hebei, Shaanxi and Sichuan provinces of China; the Lao People’s Democratic Republic; Mongolia; the Philippines; and in 17 northern provinces of Viet Nam. A cluster of eight measles cases occurred in Queensland, Australia, in February and March, five of which were students ages 11-15. This cluster caused international concern because of potential contact with students from other countries preparing to return home on holiday. High population immunity was likely responsible for the apparently limited transmission of measles virus among these five cases only. China recently announced the introduction of a two-dose schedule of rubella containing vaccine into its routine immunization programme.
Monitoring Progress Towards Measles Elimination Nearly three years have passed since the adoption of the Regional Committee resolution WPR/R54.R3 to eliminate measles by 2012; the Region has four more years to achieve the goal. The WHO Regional Office for the Western Pacific began monitoring indicators of progress towards measles elimination in 2007, and requested all Member States to do likewise. These 10 indicators are grouped into three categories: incidence, surveillance quality, and population immunity. The indicator data for 2007 in Table 1 provide a baseline from which regional progress can be monitored. It is important to note that many countries still do not report core variable data that form the basis for calculating these indicators, which explains why many indicators are so far below their respective targets. Nevertheless, several countries are demonstrating progress towards measles elimination, as is apparent from Table 3A.
Table 1: Indicators to monitor measles elimination progress, Western Pacific Region, 2007-2008*
Category
Target
2007
(annualized rates) 0.51 Virus is present 0.1 1.0% 1.1% 2.1% 95.2% ----------------
2008*
Incidence: Confirmed measles cases (confirmed by lab, epidemiologic linkage or clinically) Absence of endemic measles virus < 1.0 per 1 000 000 Virus is absent > 2 per 100 000 > 80% > 80% > 80% > 80% > 80% > 95% ≥ 80% 2.1 Virus is present 0.4 5.4% 1.7% 4.1% 92.0% ---89.4% MCV1 ------
High Quality Surveillance: National reporting of non-measles suspected cases % of districts reporting ≥ 1/100 000 non-measles suspected cases % of suspected cases with adequate investigation within 48 hours of notification % of suspected cases with adequate blood specimens % of specimens with lab results ≤ 7 days after arrival to the laboratory Transmission chains (outbreaks) with sufficient samples for virus isolation
High Population Immunity: National Measles Containing Vaccine (MCV) 1 and MCV2 coverage † Percentage of outbreaks or transmission foci with <10 cases * Surveillance data from January-March 2008
† Data from 2006 as reported in the 2007 Joint Reporting Form (JRF) surveillance data with the Regional Office, and encourage all to collect and analyse all measles core variable data at national and subnational levels to monitor progress towards elimination and to share these data with the Regional Office by the 7th of every month.
Completeness and timeliness of reporting to the Regional Office improved considerably in the first three months of 2008 compared to all of 2007 (Table 2). Countries with consistently high (≥ 80%) completeness and timeliness of reporting include Hong Kong (China), Macao (China), New Zealand and Singapore. We thank all countries and areas for sharing measles
MEASLES BULLETIN Volume 2, Issue 2 – April 2008
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Table 2: Completeness and timeliness of reporting – Western Pacific Region, 2007 and 2008
Country Australia Brunei Darussalam Cambodia China Hong Kong (China) Japan Lao PDR Macao (China) Malaysia Mongolia New Zealand Papua New Guinea Philippines Republic of Korea Singapore Viet Nam Pacific island countries
2007 Completeness Timeliness 50% 0% 33% 75% 75% 0% 8% 92% 25% 67% 83% 25% 75% 33% 83% 42% 100% 51% 19% 8% 0% 8% 0% 25% 0% 0% 17% 0% 25% 58% 8% 42% 8% 25% 17% 75%
2008 Date of submission of data* Jan 20 Feb
Feb 07 Mar 12 Mar 13 Mar 07 Mar
Mar 08 Apr 31 Mar 07 Apr
Apr
May
Jun
Completeness 100% 0% 67% 67% 100% 0% 0% 100% 67% 100% 100% 100% 33% 33% 100% 100% 67% 67%
Timeliness 33% 0% 33% 0% 100% 0% 0% 100% 0% 67% 100% 67% 33% 0% 100% 67% 33% 43%
14 Feb 05 Feb
06 22 22 04 08 07 26 06 07 18
Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb
05 24 05 03 03
Mar Mar Mar Mar Mar
02 Apr 04 Apr 07 Apr 01 Apr
05 Mar 22 Mar 15 Mar 71% 47%
04 Apr 07 Apr 53% 47%
Total Completeness Total Timeliness
76% 35%
* Deadline for submission is on the 7th of the following month of reporting, except for the PIC, which is on the 15th.
Legend: black=timely report; red=late report
Table 3A: Measles case classification and incidence, by country, Western Pacific Region, 2007-2008* 2007 Country Population (in millions) † Suspected measles cases 2008 * Confirmed measles Suspected Discarded Pending Deaths due Population cases (per 1million measles cases classification to measles (in millions) pop.) cases 0 No data
Confirmed measles cases Lab Epi-linked Clinical Total
Confirmed measles cases Lab 31 1 8 0 0 1 0 0 0 3 0 10 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 55
Epi-linked Clinical 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 1 10 0 10 0 1 0 24 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 175
Anualised Deaths Discarded Pending measles due to cases classification incidence per Total measles 1 million pop. 31 128 9 10 0 11 0 1 0 27 0 10 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 230 0 302 4 5 0 49 47 0 0 0 5 0 62 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 474 0 No data
Australia ‡ 20.74 11 11 0 0 11 No data No data No data No data No data Brunei Darussalam 0.39 Cambodia 14.44 1 294 8 0 386 394 China 1 329 118 031 No data No data No data No data Hong Kong (China) 7.21 106 70 0 18 88 Japan No data No data No data No data No data 127.97 Lao People's Democratic Republic 5.86 1 670 122 0 1548 1670 Macao (China) 0.48 1 0 0 0 0 Malaysia 26.57 1 544 37 0 703 740 Mongolia 2.63 110 10 0 100 110 New Zealand 4.18 26 4 3 14 21 Papua New Guinea 6.33 4 0 0 0 0 Philippines 87.96 888 174 12 314 500 Republic of Korea 48.22 451 181 0 37 218 Singapore ‡ 4.44 15 15 0 0 15 Viet Nam 87.38 5 286 4 0 13 17 Pacific island countries and areas 0.07 0 0 0 0 0 American Samoa Cook Islands 0.02 0 0 0 0 0 Fiji 0.84 9 0 0 0 0 French Polynesia 0.26 0 0 0 0 0 Guam 0.17 0 0 0 0 0 Kiribati 0.09 0 0 0 0 0 Marshall Islands 0.06 3 0 0 0 0 Micronesia, Federated States of 0.11 0 0 0 0 0 Nauru 0.01 1 0 0 0 0 New Caledonia 0.24 3 0 0 0 0 Niue 0.00 0 0 0 0 0 Northern Mariana Islands 0.08 0 0 0 0 0 Palau 0.02 14 0 0 0 0 Pitcairn Islands 0.00 No data No data No data No data No data Samoa 0.19 2 0 0 0 0 Solomon Islands 0.50 0 0 0 0 0 Tokelau 0.00 1 0 0 0 0 Tonga 0.10 0 0 0 0 0 Tuvalu 0.01 0 0 0 0 0 Vanuatu 0.23 0 0 0 0 0 Wallis and Futuna 0.02 0 0 0 0 0 Western Pacific Region 1776.44 129 470 636 15 3133 3784 * Monthly reports from January - March 2008 † Population figures from World Population Prospects: The 2006 Revision, New York, United Nations, 2007. ‡ Reported cases for Australia and Singapore are laboratory confirmed
0 No data
0 No data
0.5 No data
900 No data
0 No data
18 No data
0 No data No data
0 64 0 No data
27.3 No data
12.2 No data
0 1 793 0 0 4 387 233 0 5209 0 0 9 0 0 0 0 0 1 2 0 0 4 No data
0 11 0 1 0 1 0 0 0 0 0 0 0 0 0 3 0 0 1 0 0 10 No data
12 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 No data
285.0 0.0 27.8 41.8 5.0 0.0 5.7 4.5 3.4 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 No data
20.95 0.40 14.70 1336.31 7.28 127.94 5.96 0.48 27.03 2.65 4.21 6.46 89.65 48.39 4.49 88.54 0.07 0.02 0.84 0.27 0.18 0.09 0.06 0.11 0.01 0.25 0.00 0.08 0.02 0.00 0.19 0.51 0.00 0.10 0.01 0.23 0.02 1788.49
31 No data
0 No data
5.9 No data
No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data
463 26 684 20 No data
33 No data
7 No data
0 36 0 No data
34.8 No data
4.9 No data
43 0 134 47 2 8 32 5 10 119 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 27 600
28 0 74 0 1 8 5 0 0 49 0 0 2 0 0 0 0 0 0 0 0 0 0 No data
No data 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 No data
6.7 0.00 1.6 0.00 0.95 0.00 1.2 0.00 8.9 0.14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 No data
No data No data No data No data No data No data
0 0 0 0 0 0 0 7561
2 0 1 0 0 0 0 30 Green Yellow Red
0 0 0 0 0 0 0 79
0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.1
0 0 0 0 0 0 0 207
0 0 0 0 0 0 0 36
0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.51
Reached target of <1 confirmed measles case / 1 000 000 population 1-1.9 confirmed measles case / 1 000 000 population > 2 confirmed cases / 1 000 000 population
Annualized measles incidence is >1 per million population in Australia, Cambodia, Hong Kong (China), the Lao People's Democratic Republic, Malaysia, the Philippines and Singapore (Table 3A). For the remaining countries with an annualized measles incidence consistent with elimination, it is necessary to review measles surveillance performance indicators to determine if surveillance data accurately portray measles virus circulation. Very low reported measles incidence in countries with nonmeasles suspected case rates < 2.0 per million can not be interpreted as suggesting absent or very low measles virus transmission. Moreover, annualized incidence based on a single
quarter may not accurately predict the final incidence at year-end, as seasonal differences in measles virus transmission may occur. Current annualized non-measles suspected case rates (Table 3B) suggest that Cambodia and Mongolia are well on the way to achieving non-measles suspected case rates ≥2. Several countries have collected blood specimens from ≥ 80% of suspected cases, including Mongolia, Republic of Korea, Singapore and Viet Nam. The most noteworthy improvement occurred in Mongolia, which increased its percentage of suspected cases with blood specimens from 7.3% in 2007 to 100% in the first quarter of 2008.
MEASLES BULLETIN Volume 2, Issue 2 – April 2008 Country 2008 Non-measles Districts with ≥ 1 nonPopulation (in case rate (per measles suspected case millions) † 100 000 pop.) (per 100 000 pop.) ≥ 80% ≥2 2007 Suspected cases with adequate investigation ≥ 80%
2008 * Suspected cases with adequate investigation ≥ 80%
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Table 3B: Measles surveillance performance indicators, by country, Western Pacific Region, 2007-2008* Suspected cases with Laboratory adequate blood results ≤ 7 days specimens ≥ 80% ≥ 80% Anualised nonmeasles rate per 100 000 pop. ≥ 2.0 Districts with ≥ 1 nonmeasles suspected case (per 100 000 pop.) ≥ 80% Suspected cases with adequate blood specimens ≥ 80% 0 (0.0%) No data
Laboratory results ≤ 7 days ≥ 80% No data No data No data No data
No data No data 20.95 No data Australia ‡ 0.0 0 (0.0%) 0 (0.0%) 0.00 0 (0.0%) No data No data No data Brunei Darussalam 0.40 No data No data No data No data No data 14.70 Cambodia 6.2 72 (40.0%) 550 (42.5%) 874 (67.5%) 8.22 36 (20.0%) 183 (39.5%) No data No data No data 1336.31 No data No data No data No data China 7.28 Hong Kong (China) 0.2 0 (0.0%) 64 (60.4%) 79 (74.5%) 82 (94.3%) 0.22 0 (0.0%) 4 (20.0%) No data No data 127.94 No data No data No data No data No data Japan No data No data 5.96 No data No data No data No data Lao People's Democratic Republic 0.0 0.34 No data 0.48 Not applicable Macao (China) 0.2 0 (0.0%) 0 (0.0%) 0 (0.0%) 0.00 0 (0.0%) No data No data No data No data No data 27.03 Malaysia 3.0 0.73 2 (1.5%) No data No data 2.65 Mongolia 0.0 0 (0.0%) 8 (7.3%) 10 (100%) 7.08 21 (44.7%) No data No data No data 4.21 New Zealand 0.0 0 (0.0%) 0 (0.0%) 0.00 0 (0.0%) 6.46 No data No data No data Papua New Guinea 0.1 0 (0.0%) 4 (100%) 0.00 2 (25.0%) 89.65 Philippines 0.4 10 (5.4%) 76 (8.6%) 423 (47.6%) 486 (85.7%) 0.00 0 (0.0%) 2 (6.3%) No data 48.39 No data Republic of Korea 0.5 132 (29.3%) 382 (84.7%) 413 (98.3%) 0.04 0 (0.0%) 4.49 Singapore ‡ 0.0 0 (0.0%) 0 (0.0%) 0 (0.0%) 15 (100%) 0.00 0 (0.0%) 3 (30.0%) Viet Nam 88.54 6.0 193 (28.7%) 1375 (26.0%) 3522 (66.6%) No data 0.28 13 (1.9%) 92 (77.3%) Pacific island countries and areas Not applicable Not applicable 0.07 No data Not applicable 0.0 0 (0.0%) 0.00 0 (0.0%) American Samoa Not applicable Not applicable No data 0.02 Not applicable Cook Islands 0.0 0 (0.0%) 0.00 0 (0.0%) No data 0.84 0 (0.0%) Fiji 1.1 1 (100.0%) 0 (0.0%) 0 (0.0%) 0.00 0 (0.0%) No data Not applicable Not applicable French Polynesia 0.27 Not applicable 0.0 0 (0.0%) 0.00 0 (0.0%) No data Not applicable Not applicable 0.18 Not applicable Guam 0.0 0 (0.0%) 0.00 0 (0.0%) No data Not applicable Not applicable 0.09 Not applicable Kiribati 0.0 0 (0.0%) 0.00 0 (0.0%) No data 0.06 Not applicable Marshall Islands 0.0 0 (0.0%) 1 (33.3%) 1 (33.3%) 0.00 0 (0.0%) No data Not applicable Not applicable 0.11 Not applicable Micronesia, Federated States of 0.0 0 (0.0%) 0.00 0 (0.0%) No data 0.01 Not applicable Nauru 9.9 1 (100.0%) 0 (0.0%) 0 (0.0%) 0.00 0 (0.0%) No data Not applicable 0.25 New Caledonia 0.8 0 (0.0%) 0 (0.0%) 2 (66.7%) 0.00 0 (0.0%) No data Not applicable Not applicable Not applicable 0.00 Niue 0.0 0 (0.0%) 0.00 0 (0.0%) No data Not applicable Not applicable Not applicable 0.08 Northern Mariana Islands 0.0 0 (0.0%) 0.00 0 (0.0%) No data Not applicable 0.02 Palau 20.0 1 (100.0%) 0 (0.0%) 1 (7.1%) 0.00 0 (0.0%) No data No data No data No data 0.00 No data No data Pitcairn Islands No data No data 0.19 Not applicable Samoa 0.0 0 (0.0%) 0 (0.0%) 0 (0.0%) 0.00 0 (0.0%) No data Not applicable Not applicable 0.51 Not applicable Solomon Islands 0.0 0 (0.0%) 0.00 0 (0.0%) No data Not applicable 0.00 Tokelau 0.0 0 (0.0%) 0 (0.0%) 0 (0.0%) 0.00 0 (0.0%) Not applicable No data Not applicable Tonga 0.10 Not applicable 0.0 0 (0.0%) 0.00 0 (0.0%) Not applicable No data Not applicable 0.01 Not applicable Tuvalu 0.0 0 (0.0%) 0.00 0 (0.0%) Not applicable Not applicable No data 0.23 Not applicable Vanuatu 0.0 0 (0.0%) 0.00 0 (0.0%) Not applicable Not applicable No data Not applicable 0.02 Wallis and Futuna 0.0 0 (0.0%) 0.00 0 (0.0%) Western Pacific Region 1788.49 0.4 278 (5.4%) 2198 (1.7%) 5 296 (4.1%) 1011 (92.0%) 0.11 49 (1.0%) 309 (1.1%) Green Reached or surpased the target * Monthly reports from January - March 2008 † Yellow Nearly reached target: 1.00-1.99 for non-measles suspected case rate; 60%-79% for other indicators Population figures from World Population Prospects: The 2006 Revision, New York, United Nations, 2007. ‡ Red Reported cases for Australia and Singapore are laboratory confirmed Substantially below target
328 (70.8%) No data
10 (50.0%) No data No data Not applicable
11 (100%) No data No data Not applicable
66 47 0 4 16 4 8 99
(49.3%) (100.0%) (0.0%) (50.0%) (50.0%) (80.0%) (80.0%) (83.2%)
47 (95.9%) 47 (100%) No data
0 (0.0%) No data
5 (100%) 9 (90.0%) No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data No data
Not applicable Not applicable 0 (0.0%) Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable No data Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable
582 (2.1%)
119 (95.2%)
Table 4: Rubella data reported by the Measles Laboratory Network, Western Pacific Region, 2007-2008* Country Routine MCV1 type (age)*** MMR MMR M M MMR MR M MMR MMR M MMR M M MMR MMR M MMR MR MR MMR MMR MR MMR MMR M MMR MMR MMR MMR MR M MR MR MR M MMR (12m) (15m) (9m) (8m) (12m) (12m) (9m) (12m) (12m) (8m) (15m) (9m) (9m) (12m) (12m) (9m) (12m) (12m) (12m) (12m) (12m) (12m) (12m) (12m) (12m) (12m) (15m) (12m) (12m) (12m) (9m) (12m) (12m) (12m) (12m) (12m)
Routine MCV2 type (age)***
2007 2008 Last year Number of Specimens Rubella Number specimens Measles Number Number Specimens Rubella Number specimens of tested for of tested for tests / of Rubella of tested for tests / of measles tested for tests / MR/MMR IgM (−) measles Rubella Measles Rubella measles Rubella Measles Rubella IgM(+) measles Rubella IgM(-) ** IgM(-)* IgM(−) IgM(-)* cases IgM(−) IgM (−) cases SIA *** cases cases 8 11 777 0 322 781 0 29.3 1.0 313 623 0 11 781 305 0.0 1.3 0 158 0 414 44 16 1070 1778 49 373 233 134 3972 0 1567 142 554 440 344 3980 0.9 2.9 1.5 1.9 2.6 1.0 553 141 355 389 330 1385 1130 2022 52 557 440 147 4022 3.7 0.4 1.6 1.1 0.4 2.9 964 1 171 17 10 2547 158 29 46 156 249 29 94 164 1.6 1.0 2.0 1.1 160 25 89 61 249 34 58 164 125 47 10 322 417 17 16 0 47 1.0 43 1.0 0.4 1.0 286 14 15 417 55 16 200 47 1.3
Measles Number tests / of Rubella Rubella IgM(+) IgM(-)** cases 1.6 1.5 3.9 1.1 2 131 3 1
cases 8 13
Australia Brunei Darussalam Cambodia China Hong Kong (China) Japan Lao People's Democratic Rep. Macao (China) Malaysia Mongolia New Zealand Papua New Guinea Philippines Republic of Korea Singapore Viet Nam American Samoa Cook Islands Fiji French Polynesia Guam Kiribati Marshall Islands Micronesia, Federated States of Nauru New Caledonia Niue Northern Mariana Islands Palau Samoa Solomon Islands Tokelau Tonga Tuvalu Vanuatu Wallis and Futuna
MMR (4y) MMR (4y) M (7y) MMR (6y) MR (5y) MMR (18m) MMR (7y) M (14m) MMR (4y) M (18m) MMR (4y) MMR (11y) M (6y) MMR (4y) MR (15m) MR (6y) MMR (2y) MMR (4y) MR (6y) MMR (13m) MMR (13m) MR (15m) MMR (2y) MMR (4y) MMR (4y) MMR (15m) MR (16m & 5y) # MR (15m) MR (18m) MR (18m) MMR (2y)
1998 None None None 1997 None 2007 None 2005 None 1997 None 2007 2001 None None None 2006 2006 1998 2003 2006 2004 2004 2003 1997 2003 None 1998 2005 None 2003 1998 2005 None None
1.1
4
1.6 1.4 0.7 2.7
77 3 5 102
11
12
1.1
10
12
1.2
1
8408
8142
1.0
4099
9479
2.3
3869
1043
1365
1.3
701
1253
1.8
328
Empty cells indicate no reported data; * number of cases with specimens tested for rubella per measles IgM-negative case;
# = for children not haing received MCV2 at 13m ** number of cases with specimens tested for measles per rubella IgM negative case
Source: WHO/UNICEF JRF 2008 reports;
MEASLES BULLETIN Volume 2, Issue 2 – April 2008
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Rubella As case-based surveillance for measles improves and transmission of the measles virus decreases, most countries discover an increasing number of suspected measles cases that are confirmed as rubella, revealing a potential risk for rubella infection among pregnant women. As many as 85% of children born to women infected with rubella during their first trimester have congenital rubella syndrome (CRS). CRS can present as deafness, congenital cardiac disease, cataracts, microcephaly, mental retardation and other pathologic conditions. Administration of rubella vaccine as either measles-rubella (MR) or measles-mumps-rubella (MMR) is an easy way to prevent rubella infection in children. Rubella elimination strategies often include vaccination of child-bearing age women and, if a rapid decrease in the force of infection is desired, adolescents and young adults of both sexes. One dose of MR vaccine costs $0.30 more than measles vaccine alone when procured through UNICEF. To date, 27 countries and areas of the Western Pacific Region provide MR or MMR vaccine to children through their routine immunization programme, and 12 have conducted large-scale, wide age-range SIAs that include rubella containing vaccine (RCV) (Table 4). Many that do not yet offer RCV, including Mongolia, the Philippines and Viet Nam, are considering this option. China's recent decision to introduce RCV (as either MR or MMR) in its routine immunization programme should result in a very large decrease in rubella cases regionally. The Regional Office recommends that all suspected measles cases that are IgM negative for measles should be tested for rubella. Moreover, using a more simplified surveillance case definition such as acute fever and rash (AFR) to identify potential measles and rubella cases can increase surveillance sensitivity for both diseases. When measles incidence is very low, and case-based measles surveillance is adequately sensitive, blood specimens from AFR cases may be tested first for rubella IgM, with all rubella IgM negative specimens then tested for measles IgM. A summary of measles and rubella lab data are presented in Table 4. Lab reports on rubella testing were received from nine countries in 2007 and in 2008. A total of 3869 laboratory confirmed cases of rubella were reported in 2007 (14.8 per 1 million population), and 328 have been reported in the first quarter of 2008 (annualized rate of 5.0 per 1 million population). The ratio of rubella tests to measles IgM negative specimens is an indicator of the surveillance system's capacity to identify rubella cases among reported suspected measles cases. A ratio of 1.0 suggests that the country is testing all measles IgM negative samples for rubella. In Cambodia, Mongolia and Viet Nam, the ratio was approximately 1.0 in both 2007 and the first quarter of 2008. Malaysia, with a ratio of 0.0, apparently does not evaluate any measles IgM negative specimens for rubella. The ratio of 0.4 in Hong Kong (China) in the first quarter of 2008 suggests that the national lab evaluates approximately 40% of measles IgM negative samples for rubella. The Philippines and Singapore had ratios well in excess of 1.0 in both 2007 and 2008, indicating that more samples are tested for rubella than were negative for measles IgM.
Table 5: Epidemiologic surveillance and laboratory data from country reports, Western Pacific Region, 2007-2008* Suspected measles cases Epid reports † Lab reports ‡ Suspected Epid to Lab Number of Number of cases with suspected IgM neg. IgM neg. specimens case ratio cases (Epid) cases (Lab) 11 15 781 417 300 55 1130 200 2022 47 557 249 640 34 648 186 4235 164 1.0 1.1 1.2 0.8 0.3 0.1 0.5 0.4 0.1 1.0 1.0 0.1 0.7 0.1 0.0 0.0 0.9 0.7 0 0 900 302 18 4 50 0 47 381 4 204 5 0 0 3650 52 8 777 414 0 44 1070 125 1778 47 373 158 233 29 134 46 3972 156
Measles Epid to Lab Number of Number of discarded IgM pos. IgM pos. case ratio cases (Epid) cases (Lab) 0.0 1.2 0.7 0.1 0.4 0.0 1.0 1.0 0.0 0.9 0.2 0.0 0.0 0.9 0.3 11 17 8 1 71 2 37 2 10 0 175 3 195 0 15 8 7 1 5 4 3 67 10 44 5 12 0 166 88 160 4 10 7 26 3
Rubella Epid to Lab Rubella pos. Rubella pos. Epid to Lab confirmed cases (Epid) cases (Lab) rubella case ratio case ratio 3.4 2.0 0.3 1.1 0.2 0.8 0.4 0.8 1.1 0.0 1.2 0.0 1.5 1.1 0.3 0.3 2 158 131 0 3 0 0 964 4 171 77 17 3 10 5 2547 102
Country
Year
Total suspected cases 11 17 1294 463 106 13 1544 134 110 47 888 32 451 5 15 8 5286 119
Suspected cases with specimens 11 17 908 336 89 6 510 72 110 47 574 25 421 5 15 8 3822 119
Australia Cambodia Hong Kong (China) Malaysia Mongolia Philippines Republic of Korea Singapore Viet Nam
2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008 2007 2008
174
1.1
100 173 2
0.1 1.0 0.1
* Monthly reports from Jan - Mar 2008; † Epid: data reported through epidemiologic surveillance administered by either epidemiology or program units ‡ Lab = Data reported by the national measles laboratory Epid to Lab case ratio: if >1.0, the epidemiologic surveillance/program unit reports more cases than the national measles laboratory by that factor if < 1.0, the epidemiologic surveillance/program unit reports fewer cases than the national measles laboratory by that factor
Data Quality Table 5 reviews discrepancies between data submitted by members of the measles laboratory network (MLN) and epidemiology/programme units from selected member states. It is noteworthy that, in general, member laboratories of the MLN report more suspected cases tested, discarded and confirmed as measles and rubella than do national epidemiology/programme units. In fact, very few national epidemiology/programme units report any rubella cases. These data suggest that communication between national measles laboratories and epidemiology and immunization programme units is inadequate in most countries, leading to potentially misinformed programmatic decision-making at every level. To ensure adequate programme monitoring and appropriate decision-making, communication between laboratories, epidemiology and programme units should be conducted regularly and institutionalized so that data are shared, reconciled and updated in a timely manner.
Expanded Programme on Immunization Regional Office for the Western Pacific World Health Organization United Nations Avenue, P.O. Box 2932, 1000 Manila, Philippines Please send your comments and monthly data before the 7th of the month to: Fax No. (632) 5211036, 5260279, 5260362 Tel. No. (632) 5288001
measles_bulletin@wpro.who.int.