Spatial variability in the density, distribution and vectorial capacity of anopheline species in a high transmission district in Tanzania

  • Emmanuel Kigadye The Open University of Tanzania, Dar es Salaam
  • Gamba Nkwengulila University of Dar es Salaam, Dar es Salaam, Tanzania
  • Stephen M. Magesa National Institute for Medical Research
  • Salim Abdulla Ifakara Health Institute, Dar es Salaam
Keywords: Anopheles, mosquitoes, sporozoite rate, malaria, transmission, entomological inoculation rate, Tanzania

Abstract

Malaria transmission varies from one area to another and there are also local difference in time and space. The objective of the study was to determine the local variability of entomological parameters namely, mosquito abundance, human biting rate (HBR), sporozoite rate for Plasmodium falciparum and entomological inoculation rate (EIR). The study was carried out in Rufiji District south eastern Tanzania from October 2001 and September 2004. Adult mosquitoes were collected indoors by CDC light traps. PCR was employed to identify the species within the Anopheles gambiae complex. ELISA was used to determine the sporozoite rate. Over a three year sampling period a total of 64,875 female mosquitoes were caught using light-traps, and of these 28% were Anopheles gambiae complex, 25% An. funestus Giles, 1% An. pharoensis Theobald, 46% Culex species and the rest were Mansonia uniformis Theobald. Mosquito abundance and species composition varied seasonally, spatially and between years. Using PCR, three members of the Anopheles gambiae complex namely An. gambiae s.s. Giles (69%), An. arabiensis Paton (23%) and An. merus Dönitz (7%) were confirmed to occur in the study area. Plasmodium falciparum circumsporozoite antigen (CSA) rates were 3.5% for An. gambiae complex and 2.3% for An. funestus. The mean EIR ranged from 28-275 infective bites/person/year. Transmission indices varied over short distances, seasonally and between years. In conclusion, malaria transmission indices in the study area are one of the highest in Tanzania; and there is high variability of entomological parameters over a small geographical area.

Author Biography

Emmanuel Kigadye, The Open University of Tanzania, Dar es Salaam

Department of Life Sciences

Senior Lecturer

Published
2011-09-16
How to Cite
KigadyeE., NkwengulilaG., MagesaS. M., & AbdullaS. (2011). Spatial variability in the density, distribution and vectorial capacity of anopheline species in a high transmission district in Tanzania. Tanzania Journal of Health Research, 13(4). https://doi.org/10.4314/thrb.v13i4.69639
Section
Articles

Journal Identifiers


eISSN: 1821-9241
print ISSN: 1821-6404