MEASLES BULLETIN Volume 2, Issue 1 – January 2008 In the September issue (No. 13) of the Measles Bulletin, measles case classification criteria were outlined and standard indicators for monitoring progress towards measles elimination were described, including surveillance performance indicators. In the November issue (No. 14), the quality of data submitted from epidemiology or programme units and national measles laboratories to the WHO Regional Office for the Western Pacific in 2007 were reviewed, focusing on data completeness and accuracy. Several methods to ensure data quality were recommended. This first issue of 2008 summarizes surveillance data on cases occurring from January to December 2007 based on reports received from countries and areas in the Region as of 11 February 2008. Table 1 lists the dates that the Regional Office for the Western Pacific received reports from 16 Asian countries and areas and 21 Pacific island countries and areas (PICs) as a group. Among all 17 reporting units (i.e., 16 Asian countries and areas and the PICs as a group), completeness and timeliness of reporting to the Regional Office was 50% and 19%, respectively, for 2007. Completeness of reporting by month has varied between 41% and 59% following the initial request for case-based data in February 2007. Timeliness was highest (35%) in February and has not reached the same level since. Timeliness is
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Measles Surveillance in the Western Pacific Region, 2007 defined as the per cent of reports received by the reporting deadline (the 7th of the subsequent month for all countries, except the PICs which are requested to report by the 15th). The PICs led other countries in completeness and timeliness of reporting at 100% and 75%, respectively, for 2007. Macao (China) ranked second in completeness of reporting with 92%, followed by New Zealand and Singapore with 83% each. New Zealand ranked second in timeliness of reporting with 58%, followed by the Philippines with 42%. Only Brunei Darussalam and Japan did not report any data to the Regional Office in 2007. These levels of completeness and timeliness will serve as a baseline upon which the Region may improve in 2008.
Table 1 – Completeness and timeliness of reporting – Western Pacific Region, 2007 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 S ingapore Viet Nam Pacific island countries Completeness (%) Timeliness (%) Date of submission of data* Jan Feb Mar Apr May Jun 09 Jul Jul 09 Aug Aug 10 S ep 10 S ep 13 S ep 09 Oct S ep 19 Oct Oct 07 Nov 17 Nov 13 Nov 07 Nov Nov Dec Completeness (%) 42 0 25 75 75 0 8 92 25 67 83 25 75 25 83 42 100 50 Timeliness (%) 8 0 8 0 25 0 0 17 0 25 58 8 42 8 25 17 75 19
28 Feb
04 Mar 14 Mar
16 Apr 10 May
10 May 06 Jun
11 Jun 06 Jul
16 Jul 14 Aug
07 S ep
07 Dec
11 Jan 07 Jan 10 Jan 07 Jan
09 Mar 24 Jan 23 Mar 07 Mar 02 Mar 07 Mar 06 Mar 15 Feb 18 12 15 Mar 53 35
12 18 06 18
Apr Apr Apr Apr
10 May 10 May 07 May
13 Jun
14 Jun 26 Jun
13 26 03 19
Jul Jul Jul Jul
15 Aug 21 Aug 06 Aug 10 Aug 08 Aug 15 Aug 15 Aug 53 12
19 S ep
02 Apr 15 May 04 Apr 16 Apr 53 18 15 May 41 12
04 Jul 10 Jul 16 Jul 59 12
06 S ep 04 S ep 03 S ep 12 S ep 14 S ep 59 24
16 Oct 12 Nov 15 Oct 05 Oct 08 Oct 11 Oct 08 Oct 29 Oct 15 Oct 59 12
12 Nov
07 Dec 10 04 11 04 Dec Dec Dec Dec
07 Jan 08 Feb 17 Jan 08 Jan 06 Jan 15 Jan 59 29
06 Jun 15 Jun 41 12
14 Nov 16 Nov 15 Nov 47 18
10 Dec 06 Dec 17 Dec 53 29
* Deadline for submission is on the 7th of every month, except for the PICs, which is on the 15th.
Table 2A summarizes measles case classification and incidence data for 2006 and 2007. In 2006, only the Republic of Korea achieved a measles incidence of <1.0 per million. In 2007, four countries reported a measles incidence of <1.0 per million: Australia (0.6), Macao (China) (0.0), Papua New Guinea (0.0) and Viet Nam (0.2). However, these data are not yet final for 2007, as Australia has yet to report data to the Regional Office through December, and both Macao (China) and Viet Nam have cases pending classification. China reported 118 031 (91.6%) of 128 905 suspected measles cases in the Region in 2007; however, the number of confirmed cases has not been reported.
Table 2B summarizes measles surveillance performance indicators. Overall, the nonmeasles suspected case rate was 0.3 per 100 000 population in 2007, the same as in 2006. However, only Cambodia, Hong Kong (China), Macao (China), Malaysia, the Philippines, the Republic of Korea, Viet Nam, and the PICs reported measles case classification status to the Regional Office in 2006 and 2007. Among these countries, the non-measles suspected case rate was 2.0 per 100 000 population in both 2006 and 2007. However, this indicator varied by country: only three countries (Cambodia, Malaysia and Viet Nam) achieved a nonmeasles suspected case rate of ≥ 2 per 100 000 population in 2007, as they did also in 2006. Among the 21 PICs, only
Nauru (7.2) and Palau (20.1) reached or exceeded the non-measles suspected case rate target. Among the 128 905 suspected measles cases reported to the Regional Office in 2007, adequate investigations were reported for 2167 (1.7%), and adequate blood specimens were reported from 5156 (4.0%) overall. However, among those countries submitting data needed to calculate these indicators (Cambodia, Hong Kong (China), Macao (China), Mongolia, the Philippines, the Republic of Korea, Viet Nam, and 20 of the PICs), 7603 suspected cases were reported in 2007, with adequate investigations conducted for 2167 (28.5%) and adequate blood specimens
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collected from 5152 (67.8%). The Marshall Islands led all countries with respect to per cent of suspected cases with adequate investigations (66.7%), followed by the Hong Kong (China) (60.4%), Republic of Korea (58.3%), and Cambodia (42.6%). Papua New Guinea led all countries with respect to per cent of suspected cases with adequate specimens (100%), followed by the Republic of Korea (85.8%), Hong Kong (China) (74.5%), Viet Nam (71.6%), Cambodia (68.2%), the Marshall Islands (66.7%) and New Caledonia (66.7%). National measles laboratories performed particularly well in submitting laboratory results within seven days of receiving blood specimens in the Republic of Korea (98.7%), Hong Kong (China) (92.1%), and the Philippines (84.7%).
The per cent of districts with ≥ 1 nonmeasles suspected case per 100 000 population is an indicator of surveillance representativeness. Cambodia and Viet Nam had the best performance with 38.3% and 22.0%, respectively, of their districts achieving this minimum non-measles suspected case rate. One reason for the relatively low performance in regard to this indicator is that the average population size of districts in many Member States is <100 000 people. The probability of identifying a non-measles suspected case in a district with 50 000 inhabitants is likely to be substantially less than in a district with a population of 100 000, resulting in a large number of “zero-case” districts. For many countries, it may be more meaningful to monitor the per cent of provinces (i.e. one administrative level above districts) with ≥
1 non measles suspected cases per 100 000 population as an indicator of surveillance representativeness. All countries and areas are requested to share their core variable data with the Regional Office in a timely manner so that we can provide individual feedback, monitor regional progress towards measles elimination and provide a forum for countries to share with other Member States their progress towards the common goal of measles elimination. Comments and suggestions from Member States are encouraged regarding the indicators for monitoring progress towards measles elimination in the Western Pacific Region, as well as any other issue related to the Measles Bulletin.
Table 2A – Measles case classification and incidence – Western Pacific Region, 2007 2006 Country Total Population suspected (in millions) measles cases Φ
2007 Confirmed Total measles suspected cases measles (per cases 1 000 000) 6.0 No data
No. confirmed measles Lab 124 2 68 0 2 18 26 1 6 22 28 203 0 0 22 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 522 Epi 0 0 0 0 0 0 0 1 0 3 0 1 412 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Clinical 0 186 38 18 0 965 0 18 210 0 0 357 0 0 110 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total 124 No data
No. of No. No. deaths pending discarded due to measles classification measles 0 No data
No. confirmed measles Lab 12 7 70 122 0 37 10 4 0 174 162 15 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 617 Epi 0 0 0 0 0 0 0 3 0 12 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 Clinical 0 348 18 1 548 0 703 0 14 0 314 35 0 13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 993 Total 12 No data
No. of No. No. deaths pending discarded due to measles classification measles 0 No data
Confirmed measles cases (per 1 000 000) 0.6 No data
Australia† Brunei Darussalam Cambodia China Hong Kong (China) Japan Lao People's Democratic Republic Macao (China) Malaysia Mongolia New Zealand Papua New Guinea Philippines Singapore Viet Nam Pacific island countries and areas American Samoa Cook Islands Fiji French Polynesia Guam Kiribati Marshall Islands Micronesia, Federated States of Nauru New Caledonia Niue Northern Mariana Islands Palau Pitcairn Islands Samoa Solomon Islands Tokelau Tonga Tuvalu Vanuatu Wallis and Futuna Western Pacific Region Ω
20.74 0.39 14.44 7.21 127.97 5.86 0.48 26.57 2.63 4.18 6.33 87.96 48.22 4.44 87.38 0.07 0.02 0.84 0.26 0.17 0.09 0.06 0.11 0.01 0.24 0.00 0.08 0.02 0.00 0.19 0.50 0.00 0.10 0.01 0.23 0.02
124 No data
0 No data
0 No data
12 No data
0 No data
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
508 139 No data
188 106 No data
287 No data
33 No data
0 31 0 No data
13.2 No data
1 177 118 031 106 No data
355 No data
820 No data
2 No data
0 64 0 No data
24.7 No data
1 328.63 107 538 No data No data No data No data No data No data No data
33 No data
0 No data
14.9 No data
88 No data
18 No data
0 No data No data
12.2 No data
22 3 1 731 26 20 No data
18 2 983 26 20 No data
0 1 748 0 0 No data
4 0 No data
0 0 No data
3.1 4.2 37.6 10.0 4.8 No data
1 670 1 1 544 110 26 4 888 400 15 4 888 0 0 9 0 0 0 3 0 1 3 0 0 14 No data
1 670 0 740 10 21 0 500 197 15 17 0 0 0 0 0 0 0 0 0 0 0 0 0 No data
0 0 793 0 0 4 387 202 0 3 458 0 0 9 0 0 0 0 0 1 2 0 0 4 No data
12 0 0 0 0 No data
285.0 0.0 27.8 3.8 5.0 0.0 5.7 4.1 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
1 11 0 1 0 1 1 0 1 413 0 0 0 0 0 0 3 0 0 1 0 0 10 No data
0 0 No data
0 0 No data
No data No data No data
312 112 28 6 461 0 0 132 No data
216 25 28 1 972 0 0 132 No data
96 84 0 4 198 0 0 0 No data
0 3 0 291 0 0 0 No data
3 1 0 3 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
2.5 0.5 6.4 22.9 0.0 0.0 158.5 No data
3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 No data
Republic of Korea
No data No data No data
1 0 6 0 2 2 0 0 1 No data
0 0 0 0 0 0 0 0 0 No data
1 0 0 0 2 1 0 0 0 No data
0 0 6 0 0 1 0 0 1 No data
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 No data
No data No data No data
No data No data No data
10 0 0 2 0 0 0
0 0 0 0 0 0 0 3 840
2 0 0 2 0 0 0 5 455
8 0 0 0 0 0 0 347
0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.2
2 0 1 0 0 0 0 128 905
0 0 0 0 0 0 0 3 625
0 0 0 0 0 0 0 5 698
2 0 1 0 0 0 0 1 447
0 0 0 0 0 0 0 79
0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0
1 776.45 117 180
1 416 1 902
38
* Cases reported through 11 February 2008 Φ † Ω
Reached target of <1 confirmed measles case per 1 000 000 population 1.0 - 1.9 confirmed measles case per 1 000 000 population > 2 confirmed cases per 1 000 000 population
Population figures from World Population Prospects: The 2006 Revision, New York, United Nations, 2007. Reported cases for Australia are either laboratory confirmed or epidemiologically linked to a laboratory-confirmed case Sentinel surveillance system
MEASLES BULLETIN Volume 2, Issue 1 – January 2008 Country No. of Population (in millions) districts† Φ
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Table 2B – Measles surveillance performance indicators – Western Pacific Region, 2007 2006 NonNonAverage measles Total Total measles population suspected Confirmed Discarded suspected suspected Confirmed Discarded suspected per district measles cases cases case rate cases cases measles case rate (per cases cases (per 100 000) 100 000) >2 20.74 No data 0.39 No data 14.44 1 328.63 7.21 5.86 0.48 26.57 2.63 6.33 87.96 48.22 4.44 87.38 0.07 0.02 0.84 0.26 0.17 0.09 0.06 0.11 0.01 0.24 0.00 0.08 0.02 0.00 0.19 0.50 0.00 0.10 0.01 0.23 0.02 1 776.45 180 3 132 1 140 1 132 342 89 186 251 1 673 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5 149 201 303 7 687 71 135 472 903 192 127 129 829 41 850 79 797 424 211 124‡ No data 508 107 538 139 No data 22 3 1 731 26 ‡
2007 Districts with > 1 non-measles suspected case (per 100 000) > 80% No data No data 69 0 (38.3%) No data (0.0%) No data No data 0 (0.0%) No data No data No data No data 10 0 148 0 0 1 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 230 (5.4%) No data (0.0%) (22.0%) (0.0%) (0.0%) (100.0%) (0.0%) (0.0%) (0.0%) (0.0%) (0.0%) (100.0%) (0.0%) (0.0%) (0.0%) (100.0%) No data (0.0%) (0.0%) (0.0%) (0.0%) (0.0%) (0.0%) (0.0%) (4.5%) 76 233 0 64 Suspected cases with adequate investigation > 80% No data No data 501 (42.6%) (60.4%) No data No data No data No data (0.0%) No data No data (8.6%) (58.3%) 4 423 343 803 79 No data Suspected cases with adequate blood specimens > 80% No data No data (68.2%) No data (74.5%) No data No data No data No data No data No data (100.0%) (47.6%) (85.8%) 82 Laboratory results < 7 days > 80% No data No data No data No data (92.1%) No data No data No data No data No data No data No data 486 (84.7%) 370 (98.7%) No data No data Not applicable Not applicable 0 (0.0%) Not applicable Not applicable Not applicable 0 0 0 (0.0%) (0.0%) (0.0%) Not applicable
Target Australia Brunei Darussalam Cambodia China Hong Kong (China) Japan Lao People's Democratic Republic Macao (China) Malaysia Mongolia New Zealand Papua New Guinea PhilippinesΩ Republic of Korea Singapore Viet Nam Pacific island countries and areas: American Samoa Cook Islands Fiji French Polynesia Guam Kiribati Marshall Islands Micronesia, Federated States of Nauru New Caledonia Niue Northern Mariana Islands Palau Pitcairn Islands Samoa Solomon Islands Tokelau Tonga Tuvalu Vanuatu Wallis and Futuna Western Pacific Region Φ † ‡ Ω
>2 12‡ No data 1 177 118 031 106 No data 1 670 1 1 544 110‡ 26‡ 4 888 400 15‡ 4 888 0 0 9 0 0 0 3 0 1 3 0 0 14 No data 2 0 1 0 0 0 0 128 905 12 No data 355 No data 88 No data 1 670 0 740 10 21 0 500 197 15 17 0 0 0 0 0 0 0 0 0 0 0 0 0 No data 0 0 0 0 0 0 0 3 625 0 No data 820 No data 18 No data 0 0 793 0 0 4 387 202 0 3 458 0 0 9 0 0 0 0 0 1 2 0 0 4 No data 0 0 0 0 0 0 0 5 698 0.0 No data 5.7 No data 0.2 No data 0.0 0.0 3.0 0.0 0.0 0.1 0.4 0.4 0.0 4.0 0.0 0.0 1.1 0.0 0.0 0.0 0.0 0.0 7.2 0.8 0.0 0.0 20.1 No data 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3
124 No data 188 No data 106 No data 18 2 983 26 20 No data 216 25 28 1 972 0 0 132 No data 0 0 0 0 0 0 0 0 0 No data 0 0 0 0 0 0 0 3 840
0 No data 287 No data 33 No data 0 1 748 0 0 No data 96 84 0 4 198 0 0 0 No data 1 0 0 0 2 1 0 0 0 No data 2 0 0 2 0 0 0 5 455
0.0 No data 2.0 No data 0.5 No data 0.0 0.2 2.9 0.0 0.0 No data 0.1 0.2 0.0 4.9 0.0 0.0 0.0 No data 0.6 0.0 0.0 0.0 14.5 0.4 0.0 0.0 0.0 No data 1.1 0.0 0.0 2.0 0.0 0.0 0.0 0.3
127.97 No data
4.18 No data
20‡ No data 312 112 28‡ 6 461 0 0 132 No data 1 0 6 0 2 2 0 0 1 No data 10 0 0 2 0 0 0 117 180
No data No data 1 290 (26.4%) 3 499 (71.6%) Not applicable Not applicable 0 (0.0%) Not applicable Not applicable Not applicable 2 0 0 (66.7%) (0.0%) (0.0%) Not applicable Not applicable Not applicable 0 (0.0%) Not applicable Not applicable Not applicable 2 0 2 (66.7%) (0.0%) (66.7%) Not applicable
Not applicable Not applicable 1 (7.1%) No data Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable 2 167 (1.7%)
Not applicable Not applicable 1 (7.1%) No data Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable 5 156 (4.0%)
Not applicable Not applicable 0 (0.0%) No data Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable 938 (0.7%)
* Cases reported through 11 February 2008 Population figures from World Population Prospects: The 2006 Revision, New York, United Nations, 2007. District data from WHO/UNICEF Joint Reporting Forms 2007 Only confirmed cases were reported; in Australia, Mongolia, and Singapore, only laboratory-confirmed cases were reported. Sentinel surveillance system Reached or surpassed target Nearly reached target (1.0 - 1.99 for non-measles suspected case rate; 60-79% for other indicators) Substantially below target
Expanded Programme on Immunization World Health Organization Regional Office for the Western Pacific United Nations Avenue, P.O. Box 2932, 1000 Manila, Philippines Fax No. (632) 5211036, 5260279, 5260362 Tel. No. (632) 5288001 Please send your comments and monthly data to measles_bulletin@wpro.who.int.