Volume 15, Number 8—August 2009
Research
Entomologic and Virologic Investigation of Chikungunya, Singapore
Lee-Ching Ng
, Li-Kiang Tan, Cheong-Huat Tan, Sharon S.Y. Tan, Hapuarachchige C. Hapuarachchi, Kwoon-Yong Pok, Yee-Ling Lai, Sai-Gek Lam-Phua, Göran Bucht, Raymond T.P. Lin, Yee-Sin Leo, Boon-Hian Tan, Hwi-Kwang Han, Peng-Lim S Ooi, Lyn James, and Seow-Poh Khoo
, Li-Kiang Tan, Cheong-Huat Tan, Sharon S.Y. Tan, Hapuarachchige C. Hapuarachchi, Kwoon-Yong Pok, Yee-Ling Lai, Sai-Gek Lam-Phua, Göran Bucht, Raymond T.P. Lin, Yee-Sin Leo, Boon-Hian Tan, Hwi-Kwang Han, Peng-Lim S Ooi, Lyn James, and Seow-Poh KhooTable 2
Summary of the characteristics and entomologic data of chikungunya cluster areas, Singapore
| Location | Type | No. cases* | Adult female mosquito collection† |
Aedes larval abundance index‡ | |
|---|---|---|---|---|---|
| Aedes aegypti | Ae. albopictus | ||||
| Little India | Urban | 13 | 10 | 0 | 1.77:1 (826:466) |
| Queen Street | Urban | 1 | 0 | 2 | 0:1 (0:127) |
| Teachers’ Estate | Suburban | 1 | 0 | 10 | 0.03:1 (40:1,261) |
| Kranji Way | Rural | 41 | 0 | 77 | 0.04:1 (1,129:26,546) |
| Sungei Kadut | Rural | 33 | 0 | 7 | 0.001:1 (70:77,086) |
| Mandai Estate | Rural | 11 | 0 | 23 | 0.02:1 (30:1,260) |
| Bah Soon Pah Road | Rural | 21 | 0 | 45 | 0:1 (0:3,465) |
*Numbers are preliminary data from press releases.
†Species of adult mosquitoes collected in each location where entomologic surveillance was conducted. The numbers do not necessarily represent adult mosquito density in each area as the numbers of traps and man-hours committed were not consistent.
‡Aedes larval abundance index is expressed as the ratio between the number of Ae. aegypti and Ae. albopictus larvae collected through routine surveillance, 3 months before and up to 3 months after the detection of the first case at respective locations. Number of larvae (Ae. aegypti; Ae. albopictus) collected in each cluster is shown in parentheses.
