title: Mosquito-borne arbovirus surveillance at selected sites in diverse ecological zones of Kenya; 2007 - 2012.
abstract: BACKGROUND
  Increased frequency of arbovirus outbreaks in East Africa necessitated the determination of distribution of risk by entomologic arbovirus surveillance. A systematic vector surveillance programme spanning 5 years and covering 11 sites representing seven of the eight provinces in Kenya and located in diverse ecological zones was carried out.
  
  
  METHODS
  Mosquitoes were sampled bi-annually during the wet seasons and screened for arboviruses. Mosquitoes were identified to species, pooled by species, collection date and site and screened for arboviruses by isolation in cell culture and/or RT-PCR screening and sequencing.
  
  
  RESULTS
  Over 450,000 mosquitoes in 15,890 pools were screened with 83 viruses being detected/isolated that include members of the alphavirus, flavivirus and orthobunyavirus genera many of which are known to be of significant public health importance in the East African region. These include West Nile, Ndumu, Sindbis, Bunyamwera, Pongola and Usutu viruses detected from diverse sites. Ngari virus, which was associated with hemorrhagic fever in northern Kenya in 1997/98 was isolated from a pool of Anopheles funestus sampled from Tana-delta and from Aedes mcintoshi from Garissa. Insect only flaviviruses previously undescribed in Kenya were also isolated in the coastal site of Rabai. A flavivirus most closely related to the Chaoyang virus, a new virus recently identified in China and two isolates closely related to Quang Binh virus previously unreported in Kenya were also detected.
  
  
  CONCLUSIONS
  Active transmission of arboviruses of public health significance continues in various parts of the country with possible undetermined human impact. Arbovirus activity was highest in the pastoralist dominated semi-arid to arid zones sites of the country where 49% of the viruses were isolated suggesting a role of animals as amplifiers and indicating the need for improved arbovirus disease diagnosis among pastoral communities.
authors.forename: Caroline
authors.initials: C
authors.lastname: Ochieng
authors.forename: Joel
authors.initials: J
authors.lastname: Lutomiah
authors.forename: Albina
authors.initials: A
authors.lastname: Makio
authors.forename: Hellen
authors.initials: H
authors.lastname: Koka
authors.forename: Edith
authors.initials: E
authors.lastname: Chepkorir
authors.forename: Santos
authors.initials: S
authors.lastname: Yalwala
authors.forename: James
authors.initials: J
authors.lastname: Mutisya
authors.forename: Lillian
authors.initials: L
authors.lastname: Musila
authors.forename: Samoel
authors.initials: S
authors.lastname: Khamadi
authors.forename: Jason
authors.initials: J
authors.lastname: Richardson
authors.forename: Joshua
authors.initials: J
authors.lastname: Bast
authors.forename: David
authors.initials: D
authors.lastname: Schnabel
authors.forename: Eyako
authors.initials: E
authors.lastname: Wurapa
authors.forename: Rosemary
authors.initials: R
authors.lastname: Sang
mesh_terms: D000330:Aedes / Q000821:virology*; D000818:Animals; D000852:Anopheles / Q000821:virology*; D001103:Arboviruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D062665:Epidemiological Monitoring; D007630:Kenya; D015995:Prevalence; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014776:Virus Cultivation
chemical_list: D012367:RNA, Viral