Volume 21, Number 11—November 2015
Dispatch
Serogroup W Meningitis Outbreak at the Subdistrict Level, Burkina Faso, 2012
, Clément Lingani, Mamoudou Djingarey, and Stéphane Hugonnet
Table
Details of the 2012 outbreak of Neisseria meningitidis serogroup W at the district and subdistrict (Kombissiri district) levels, Burkina Faso
| Outbreak level | Population | Duration, wk (starting wk) |
Time, wk, to peak**†† | Attack rate, no. cases/100,000 population |
|||
|---|---|---|---|---|---|---|---|
| Alert plus epidemic*† | Preepidemic‡§ | Epidemic¶# | Weekly maximum‡‡ | Cumulative§§¶¶ | |||
| District, epidemiologic wks 1–17 | |||||||
| Banfora | 312,923 | 4 (11) | 1 | 1 (12) | 0 | 10.5 | 62.0 |
| Bittou | 116,080 | 8 (8) | 5 | 3 (13) | 1 | 20.7 | 92.2 |
| Dafra | 285,184 | 8 (8) | 4 | 3 (12) | 2 | 16.8 | 96.4 |
| Dande | 225,917 | 6 (9) | 3 | 3 (12) | 1 | 12.0 | 70.8 |
| Gourcy## | 196,686 | 5 (12) | 3 | 1 (15) | 0 | 10.2 | 62.5 |
| Kombissiri | 173,885 | 9 (7) | 4 | 3 (11) | 1 | 14.4 | 105.2 |
| Orodara | 346,319 | 7 (9) | 2 | 4 (11) | 2 | 16.2 | 91.2 |
| Pama | 98,308 | 7 (9) | 4 | 1 (13) | 0 | 15.3 | 89.5 |
| Po | 185,632 | 6 (10) | 3 | 1 (13) | 0 | 10.2 | 51.2 |
| Sapone | 96,020 | 6 (9) | 5 | 1 (14) | 0 | 11.5 | 67.7 |
| Seguenega## | 189,363 | 7 (11) | 3 | 1 (14) | 0 | 12.1 | 60.7 |
| Sindou | 147,477 | 7 (9) | 1 | 4 (10) | 2 | 15.6 | 89.5 |
| Solenzo |
314,593 |
7 (8) |
0 |
5 (8) |
2 |
16.2 |
101.7 |
| Kombissiri District, epidemiologic wks 1–16 | |||||||
| Zone 1 | 39,163 | 10 (6) | 2 | 7 (8) | 3 | 38.3 | 153.2 |
| Zone 2 | 32,037 | 15 (1) | 2 | 13 (3) | 10 | 46.8 | 293.4 |
| Zone 3 | 34,591 | 1 (12) | Not applicable | Not applicable | Not applicable | 5.8 | 14.5 |
| Zone 4 | 30,541 | 2 (12) | 0 | 1 (12) | 0 | 13.1 | 39.3 |
| Zone 5 | 37,553 | 9 (6) | 5 | 1 (11) | 0 | 10.7 | 39.9 |
*Defined as time between weekly attack rate crossed at least the alert threshold (5 cases/week/100,000 population) and descended below the alert threshold, (i.e., from alert to alert).
†Mean 6.7; median 7; SD 1.32.
‡Defined as time between weekly attack rate crossed the alert threshold and reached the epidemic threshold (10 cases/week/100,000 population) (i.e., from alert to epidemic). Not applicable if only the alert threshold was crossed.
§Mean 2.9; median 3; SD 1.55.
¶Defined as time between weekly attack rate crossed the epidemic threshold and descended below the epidemic threshold again (i.e., from epidemic to epidemic). Not applicable if only the alert threshold was crossed.
#Mean 2.4; median 3; SD 1.45.
**Defined as time between weekly attack rate crossed the epidemic threshold and reached maximum incidence (i.e., from epidemic to peak). A zero value indicates peak was reached when the epidemic threshold was crossed. Not applicable if only the alert threshold was crossed.
††Mean 0.8; median 1; SD 0.9.
‡‡Mean 14.0; median 14.4; SD 3.9.
§§Over the study period.
¶¶Mean 80.0; median 89.5; SD 18.0.
##A reactive immunization campaign with ACWY polysaccharide vaccine was conducted during week 18, 2012.