Abstract:
Arboviruses refer to a group of viruses, which are transmitted by arthropods including
mosquitoes and ticks. The objective of this study was to determine mosquito transmission
potential of arboviruses at the interface of human-livestock-wildlife ecosystem in Kilosa
district, Tanzania. Adult mosquitoes were collected using Mosquito Magnet® Liberty
Plus traps. Reverse transcription polymerase chain reaction assay was performed on
pooled adult Aedes mosquitoes to detect the presence of Dengue virus (DENV),
Chikungunya virus (CHIKV), Rift Valley fever virus (RVFV) and Yellow fever virus
(YFV). A total of 1340 mosquitoes belonging to four genera (Aedes, Anopheles, Culex
and Mansonia) and 6 species were collected. Culex accounted for the largest (48.06%;
n= 644) proportion of the mosquitoes while Anopheles for the lowest proportion
(2.54%; n=34). Of the total mosquitoes collected, Aedes aegypti accounted for the
majority of mosquito species (46%; n=613), followed by Culex quinquefasciatus
(44.1%; n=591). Of the 36 Ae. aegypti pools tested for arbovirus 10 (28%) pools were
positive. Dengue virus was detected in 3% (1/ 36) pools and CHIKV in 25% (9/ 36)
pools. One pool that was positive for DENV also tested positive for CHIKV indicating
the possibility of co-infection whereby, individuals may become infected by more than
one arbovirus at a time thus risk of co-transmission to human and livestock. Nucleotide
sequencing of polymerase chain reaction (PCR) products of the structural polyprotein
region of DENV produced 511 bp fragment. Basic Local Alignment Search tool for
nucleotides (BLASTn) and phylogenetic analysis showed that the
(DENV3/TAN/Mikumi/2020 strain) (Accession number MW133786) obtained from this
study clustered with DENV-3 strains reported in China and Kenya. This information is
important as it gives knowledge on areas at high risk for arboviral disease outbreaks.
The findings indicate that the presence of various mosquito vectors and detection of
arboviruses in wild-caught Aedes mosquitoes leave the population of Kilosa district at a
higher risk of transmission of DENV and CHIKV
