Mosquito species composition, abundance and transmission Risk of dengue in Kinondoni district, Dar es salaam, Tanzania

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Date

2020

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Publisher

Sokoine University of Agriculture

Abstract

Dar es Salaam city of Tanzania has experienced continued Dengue outbreaks with increased incidence since 2010. However, there is inadequate evidence of vector dynamics and transmission risk in the region. This study aimed to determine mosquito species composition, abundance and transmission risk of Dengue in Kinondoni district, Dar es Salaam, Tanzania. Specifically, this study aimed to: (i) determine mosquito species composition and abundance in Kinondoni district; (ii) examine Aedes mosquito breeding sites and establish container productivity rates; (iii) determine Dengue virus (DENV) infection rate and genetically characterize DENV in mosquito vectors. This cross-sectional study was conducted in Kinondoni district, Dar es salaam, Tanzania. Three wards: Mikocheni, Mwananyamala and Mzimuni were purposively selected. In each ward, three streets were randomly selected as sampling sites. The study involved sampling adult and immature mosquitoes, morphological identification and screening for DENV in collected female Aedes mosquitoes using a one-step reverse transcription polymerase chain reaction (RT-PCR). Three mosquito species were identified in 2001 collected mosquitoes namely Culex quinquefasciatus (53.1%), Aedes aegypti (23.2%) and Mansonia mosquitoes (23.6%) of which Culex quinquefasciatus was observed to be the most abundant species in Kinondoni district. The common water-holding containers observed to be breeding sites of Aedes mosquitoes included used car tires, flowerpots and plastic water buckets. The overall House Index (HI), Container Index (CI) and Breteaux Index (BI) of Kinondoni district were 55.1%, 60.4% and 114.2, respectively. DENV was not detected in all collected female Aedes Mosquitoes. Generally, Kinondoni district continues to be at risk of transmission of Dengue as Aedes aegypti, a DENV vector was observed to be present. Although DENV was not detected in mosquito vectors, the presence of potential breeding sites around Kinondoni district and higher Aedes HI, CI and BI put Kinondoni at risk of DENV transmission. Vector control interventions specifically integrated mosquito control approaches are recommended to be directed towards the elimination of breeding sites and adult mosquitoes.

Description

PhD Thesis

Keywords

Mosquito species, Dengue, Transmission Risk, Kinondoni, Dar es salaam, Tanzania

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