Rift Valley fever virus epidemic in Kenya, 2006/2007: the entomologic investigations.
In December 2006, Rift Valley fever (RVF) was diagnosed in humans in Garissa Hospital, Kenya and an outbreak reported affecting 11 districts. Entomologic surveillance was performed in four districts to determine the epidemic/epizootic vectors of RVF virus (RVFV). Approximately 297,000 mosquitoes were collected, 164,626 identified to species, 72,058 sorted into 3,003 pools and tested for RVFV by reverse transcription-polymerase chain reaction. Seventy-seven pools representing 10 species tested positive for RVFV, including Aedes mcintoshi/circumluteolus (26 pools), Aedes ochraceus (23 pools), Mansonia uniformis (15 pools); Culex poicilipes, Culex bitaeniorhynchus (3 pools each); Anopheles squamosus, Mansonia africana (2 pools each); Culex quinquefasciatus, Culex univittatus, Aedes pembaensis (1 pool each). Positive Ae. pembaensis, Cx. univittatus, and Cx. bitaeniorhynchus was a first time observation. Species composition, densities, and infection varied among districts supporting hypothesis that different mosquito species serve as epizootic/epidemic vectors of RVFV in diverse ecologies, creating a complex epidemiologic pattern in East Africa.
Sang
Rosemary
R
Arbovirology/Hemorrhagic Fevers Laboratory, Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya. rsang@kemri.org
Kioko
Elizabeth
E
Lutomiah
Joel
J
Warigia
Marion
M
Ochieng
Caroline
C
O'Guinn
Monica
M
Lee
John S
JS
Koka
Hellen
H
Godsey
Marvin
M
Hoel
David
D
Hanafi
Hanafi
H
Miller
Barry
B
Schnabel
David
D
Breiman
Robert F
RF
Richardson
Jason
J
D000330:Aedes / Q000821:virology; D000818:Animals; D000829:Animals, Domestic / Q000821:virology; D000852:Anopheles / Q000821:virology; D003465:Culex / Q000821:virology; D009033:Culicidae / Q000145:classification / Q000821:virology; D004196:Disease Outbreaks; D006801:Humans; D007303:Insect Vectors / Q000145:classification / Q000821:virology; D007630:Kenya / Q000453:epidemiology; D012367:RNA, Viral / Q000032:analysis / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012295:Rift Valley Fever / Q000453:epidemiology* / Q000635:transmission* / Q000662:veterinary / Q000821:virology; D012296:Rift Valley fever virus / Q000235:genetics / Q000302:isolation & purification*; D013045:Species Specificity
D012367:RNA, Viral