title: Blood meal analysis and virus detection in blood-fed mosquitoes collected during the 2006-2007 Rift Valley fever outbreak in Kenya.
abstract: BACKGROUND
  Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Blood-fed mosquitoes collected during the 2006-2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the blood meals.
  
  
  METHODS
  Blood meals from individual mosquito abdomens were screened for viruses using Vero cells and RT-PCR. DNA was also extracted and the cytochrome c oxidase 1 (CO1) and cytochrome b (cytb) genes amplified by PCR. Purified amplicons were sequenced and queried in GenBank and Barcode of Life Database (BOLD) to identify the putative blood meal sources.
  
  
  RESULTS
  The predominant species in Garissa were Aedes ochraceus, (n=561, 76%) and Ae. mcintoshi, (n=176, 24%), and Mansonia uniformis, (n=24, 72.7%) in Baringo. Ae. ochraceus fed on goats (37.6%), cattle (16.4%), donkeys (10.7%), sheep (5.9%), and humans (5.3%). Ae. mcintoshi fed on the same animals in almost equal proportions. RVFV was isolated from Ae. ochraceus that had fed on sheep (4), goats (3), human (1), cattle (1), and unidentified host (1), with infection and dissemination rates of 1.8% (10/561) and 50% (5/10), respectively, and 0.56% (1/176) and 100% (1/1) in Ae. mcintoshi. In Baringo, Ma. uniformis fed on sheep (38%), frogs (13%), duikers (8%), cattle (4%), goats (4%), and unidentified hosts (29%), with infection and dissemination rates of 25% (6/24) and 83.3% (5/6), respectively. Ndumu virus (NDUV) was also isolated from Ae. ochraceus with infection and dissemination rates of 2.3% (13/561) and 76.9% (10/13), and Ae. mcintoshi, 2.8% (5/176) and 80% (4/5), respectively. Ten of the infected Ae. ochraceus had fed on goats, sheep (1), and unidentified hosts (2), and Ae. mcintoshi on goats (3), camel (1), and donkey (1).
  
  
  CONCLUSIONS
  This study has demonstrated that RVFV and NDUV were concurrently circulating during the outbreak, and sheep and goats were the main amplifiers of these viruses respectively.
authors.affiliation: 1 Kenya Medical Research Institute (KEMRI) , Nairobi, Kenya .
authors.forename: Joel
authors.initials: J
authors.lastname: Lutomiah
authors.forename: David
authors.initials: D
authors.lastname: Omondi
authors.forename: Daniel
authors.initials: D
authors.lastname: Masiga
authors.forename: Collins
authors.initials: C
authors.lastname: Mutai
authors.forename: Paul O
authors.initials: PO
authors.lastname: Mireji
authors.forename: Juliette
authors.initials: J
authors.lastname: Ongus
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Linthicum
authors.forename: Rosemary
authors.initials: R
authors.lastname: Sang
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000821:virology; D009033:Culicidae / Q000821:virology*; D004196:Disease Outbreaks / Q000662:veterinary*; D006041:Goats; D006801:Humans; D007303:Insect Vectors / Q000821:virology*; D007630:Kenya / Q000453:epidemiology; D012367:RNA, Viral / Q000097:blood; D012295:Rift Valley Fever / Q000453:epidemiology* / Q000821:virology; D012296:Rift Valley fever virus / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D012756:Sheep
chemical_list: D012367:RNA, Viral
keywords: Aedes ochraceus; Alphavirus.; Blood meal identification; Bunyavirididae; Host animals; Mansonia uniformis; Mosquito vectors; Ndumu virus; Rift Valley fever virus