DENV-2 Circulation and Host Preference Among Highly Anthropophilic, Outdoor-Biting Aedes aegypti in Dar es Salaam, Tanzania
Loading...
Date
2025-06-05
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
In Tanzania, dengue outbreaks have occurred almost annually over the past
decade, with each new outbreak becoming more severe. This study investigated the preva-
lence of dengue virus (DENV) serotypes in the wild Aedes aegypti and their blood sources
to determine human exposure risk in Dar es Salaam, Tanzania. A two-year longitudinal
survey was conducted in the Ilala, Kinondoni, and Temeke districts of Dar es Salaam
to sample Ae. aegypti mosquitoes using Biogents Sentinel trap (BGS), Prokopack aspira-
tion, and Gravid Aedes trap (GAT). Collected mosquitoes were pooled in groups of 10
and tested for DENV1–4 serotypes using reverse transcription polymerase chain reaction
(RT-qPCR). Blood meal sources were identified using an enzyme-linked immunosorbent
assay (ELISA). Of 854 tested pools, only DENV-2 was detected and was found in all three
districts: Temeke (3/371 pools), Ilala (1/206 pools), and Kinondoni (1/277 pools). Blood
meal analysis showed a strong preference for humans (81%) as well as for mixed blood
meals that contained human blood and other hosts (17%). Out of 354 collected hosts seeking
Ae. aegypti, 78.5% were captured outdoors and 21.5% indoors. This study confirms the
circulation of DENV-2 in Ae. aegypti populations, indicating a potential dengue outbreak
risk in Tanzania. This study also demonstrates that xenomonitoring may be feasible in this
setting. The mosquitoes’ strong preference for human hosts and predominance in outdoor
settings pose challenges for dengue control effort
Sustainable Development Goals
SDG - 3: Good Health and Well-being
SDG - 6: Clean Water and Sanitation
SDG - 11: Sustainable Cities and Communities
SDG - 13: Climate Action
SDG - 17: Partnerships for the Goals
Keywords
DENV, Dengue fever, Traps, Blood feeding, Longitudinal survey, Serotypes, Xenomonitoring