title: Entomologic investigations of a chikungunya virus epidemic in the Union of the Comoros, 2005.
abstract: From January to April 2005, an epidemic of chikungunya virus (CHIKV) illness occurred in the Union of Comoros. Entomological studies were undertaken during the peak of the outbreak, from March 11 to March 31, aimed at identifying the primary vector(s) involved in transmission so that appropriate public health measures could be implemented. Adult mosquitoes were collected by backpack aspiration and human landing collection in homes and neighborhoods of clinically ill patients. Water-holding containers were inspected for presence of mosquito larvae. Adult mosquitoes were analyzed by RT-PCR and cultivation in cells for the presence of CHIK virus and/or nucleic acid. A total of 2,326 mosquitoes were collected and processed in 199 pools. The collection consisted of 62.8% Aedes aegypti, 25.5% Culex species, and 10.7% Aedes simpsoni complex, Eretmapodites spp and Anopheles spp. Seven mosquito pools were found to be positive for CHIKV RNA and 1 isolate was obtained. The single CHIKV mosquito isolate was from a pool of Aedes aegypti and the minimum infection rate (MIR) for this species was 4.0, suggesting that Ae. aegypti was the principal vector responsible for the outbreak. This was supported by high container (31.1%), household (68%), and Breteau (126) indices, with discarded tires (58.8%) and small cooking and water storage vessels (31.1%) registering the highest container indices.
authors.affiliation: Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Rosemary C
authors.initials: RC
authors.lastname: Sang
authors.forename: Ouledi
authors.initials: O
authors.lastname: Ahmed
authors.forename: Ousmane
authors.initials: O
authors.lastname: Faye
authors.forename: Cindy L H
authors.initials: CL
authors.lastname: Kelly
authors.forename: Ali Ahmed
authors.initials: AA
authors.lastname: Yahaya
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Mmadi
authors.forename: Ali
authors.initials: A
authors.lastname: Toilibou
authors.forename: Kibet
authors.initials: K
authors.lastname: Sergon
authors.forename: Jennifer
authors.initials: J
authors.lastname: Brown
authors.forename: Naftali
authors.initials: N
authors.lastname: Agata
authors.forename: Allarangar
authors.initials: A
authors.lastname: Yakouide
authors.forename: Mamadou D
authors.initials: MD
authors.lastname: Ball
authors.forename: Robert F
authors.initials: RF
authors.lastname: Breiman
authors.forename: Barry R
authors.initials: BR
authors.lastname: Miller
authors.forename: Ann M
authors.initials: AM
authors.lastname: Powers
mesh_terms: D018354:Alphavirus Infections / Q000453:epidemiology* / Q000209:etiology / Q000635:transmission* / Q000821:virology; D000818:Animals; D002646:Chikungunya virus / Q000235:genetics / Q000302:isolation & purification*; D017507:Comoros / Q000453:epidemiology; D009033:Culicidae / Q000821:virology*; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000821:virology*; D007814:Larva / Q000821:virology; D008297:Male; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012367:RNA, Viral