Spatial Variability in the Density, Distribution and Vectorial Capacity of Anopheline Species in a High Transmission District in Tanzania
Loading...
Date
2011
Journal Title
Journal ISSN
Volume Title
Publisher
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.
Description
Keywords
Anopheles, Mosquitoes, Sporozoite rate, Malaria, Transmission, Entomological inoculation rate, Tanzania
Citation
Kigadye, E., Nkwengulila, G., Magesa, S.M. and Abdulla, S., 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).