1 research outputs found
Spatial variability in the density, distribution and vectorial capacity of anopheline species in Rufiji district, south-eastern Tanzania
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