Species composition and risk of transmission of some Aedes-borne arboviruses in some sites in Northern Ghana
Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
PLOS
Abstract
Aedes-borne viral diseases mainly Yellow Fever (YF), Dengue (DEN), Zika (ZIK) and Chi kungunya (CHK) have contributed to many deaths’ in the world especially in Africa. There
have been major outbreaks of these diseases in West Africa. Although, YF outbreaks have
occurred in Ghana over the years, no outbreak of DEN, ZIK and CHK has been recorded.
However, the risk of outbreak is high due to its proximity to West African countries where
outbreaks have been recently been recorded. This study surveyed the mosquito fauna to
assess the risk of transmission of Yellow fever (YFV), Dengue (DENV), Chikungunya
(CHKV) and Zika (ZIKV) viruses in Larabanga and Mole Game Reserve areas in Northern
Ghana. The immature and adult stages of Aedes mosquitoes were collected from Larabanga and Mole Game Reserve area. There was a significant (P>0.001) number of mosquitoes collected during the rainy season than the dry season. A total of 1,930 Aedes
mosquitoes were collected during the rainy season and morphologically identified. Of these,
1,915 (99.22%) were Aedes aegypti and 15 (0.22%) were Aedes vittatus. During the dry
season, 27 Ae. aegypti mosquitoes were collected. A total of 415 Ae. aegypti mosquitoes
were molecularly identified to subspecies level of which Ae. (Ae) aegypti aegypti was the
predominant subspecies. Both Ae. aegypti aegypti and Ae aegypti formosus exist in sympatry in the area. All Aedes pools (75) were negative for DENV, ZIKV and CHKV when
examined by RT- PCR. Three Larval indices namely House Index, HI (percentage of houses
positive for Aedes larvae or pupae), Container Index, CI (the percentage of containers positive for Aedes larvae or pupae) and Breteau Index, BI (number of positive containers per
100 houses inspected) were assessed as a measure for risk of transmission in the study area. The HI, CI and BI for both sites were as follows; Mole Game Reserve (HI, 42.1%, CI,
23.5% and BI, 100 for rainy season and 0 for all indices for dry season) and Larabanga
(39%, 15.5% and 61 for rainy season and 2.3%, 1.3% and 2.3 for dry season). The spatial
distribution of Aedes breeding sites in both areas indicated that Aedes larvae were breeding
in areas with close proximity to humans. Lorry tires were the main source of Aedes larvae in
all the study areas. Information about the species composition and the potential role of
Aedes mosquitoes in future outbreaks of the diseases that they transmit is needed to design
efficient surveillance and vector control tools.
Description
Research Articles