title: Distribution of yellow fever vectors in Northwestern and Western Provinces, Zambia.
abstract: OBJECTIVE
  To determine the distribution of yellow fever (YF) vectors species in Northwestern and Western of Zambia, which sampled mosquitoes inside and outside houses in rural, urban, peri-urban and forest areas.
  
  
  METHODS
  Back-pack aspirators spray catches and CDC light traps collected adult mosquitoes including 405 Aedes, 518 Anopheles, 471 Culex and 71 Mansonia. Morphological vector identification and PCR viral determination were done at a WHO Regional Reference Centre (Institute Pasteur Dakar), Senegal.
  
  
  RESULTS
  The two main YF vectors were Aedes (Stegomyia) aegypti (Ae. aegypti) and Aedes (Stegomyia) africanus. The first was collected in peri-urban areas and the later was in forest areas, both sparsely distributed in Northwestern Province, where the 0.43 Breteau and 1.92 container indexes, respectively implied low risk to YF. Aedes (Aedimorphus) mutilus; Aedes (Aedimorphus) minutus and Aedes (Finlaya) wellmani were also found in Northwestern, not in Western Province. No Aedes were collected from rural peri-domestic areas. Significantly more Aedes species (90.7%, n=398) than Anopheles (9.1%, n=40) were collected in forest areas (P<0.001) or Culex species (0.2%, n=2) (P<0.001). Ae. aegypti was found only in a discarded container but not in flower pots, old tyres, plant axils, discarded shallow wells, disused container bottles and canoes inspected.
  
  
  CONCLUSIONS
  Ae. aegypti and Aedes africanus YF vectors were found in the study sites in the Northwestern Province of Zambia, where densities were low and distribution was sparse. The low Breteau index suggests low risk of YF in the Northwestern Province. The presence of Aedes in Northwestern Province and its absence in the Western Province could be due to differing ecological factors in the sampled areas. Universal coverage of vector control interventions could help to reduce YF vector population and the risk to arthropod-borne virus infections.
authors.affiliation: World Health Organization, Lusaka, Zambia. Electronic address: Masaningaf@who.int.
authors.forename: Freddie
authors.initials: F
authors.lastname: Masaninga
authors.affiliation: Tropical Diseases Research Centre, Ndola, Zambia.
authors.forename: Mbanga
authors.initials: M
authors.lastname: Muleba
authors.affiliation: Abt Associates, Harare, Zimbabwe.
authors.forename: Hieronymo
authors.initials: H
authors.lastname: Masendu
authors.affiliation: World Health Organization, Lusaka, Zambia.
authors.forename: Peter
authors.initials: P
authors.lastname: Songolo
authors.affiliation: World Health Organization, Lusaka, Zambia.
authors.forename: Idah
authors.initials: I
authors.lastname: Mweene-Ndumba
authors.affiliation: World Health Organization, Lusaka, Zambia.
authors.forename: Mazyanga Lucy
authors.initials: ML
authors.lastname: Mazaba-Liwewe
authors.affiliation: Ministry of Health, Lusaka, Zambia.
authors.forename: Mulakwa
authors.initials: M
authors.lastname: Kamuliwo
authors.affiliation: World Health Organization Office, Harare, Zimbabwe.
authors.forename: Birkinesh
authors.initials: B
authors.lastname: Ameneshewa
authors.affiliation: The Copperbelt University, School of Medicine, Zambia.
authors.forename: Seter
authors.initials: S
authors.lastname: Siziya
authors.affiliation: World Health Organization, Lusaka, Zambia.
authors.forename: Olusegun Ayorinde
authors.initials: OA
authors.lastname: Babaniyi
keywords: Aedes aegypti; Arthropod-borne; Distribution; Yellow fever vectors; Zambia