Project Summary/Abstract
This application seeks to examine arbovirus and mosquito vector prevalence and identify their possible
influence in The Gambia. An existing infrastructure in the country for malaria investigation will jumpstart this
project. Like malaria, mosquito-borne arboviruses can cause febrile illness; with significant morbidity and even
mortality, in multiple regions of the world. Practically nothing is known about the arboviruses that circulate in The
Gambia; except for three instances: an outbreak of Yellow Fever over forty years ago, localized antibody
evidence of Zika virus, and two one-off cases of Rift Valley fever. Arboviral activity of this unique country is poorly
understood. Importantly, there are cases of acute febrile illness in The Gambia that are not attributable to malaria,
and we hypothesize that arboviruses are circulating in the region that could be responsible for a proportion of
such cases. In addition, there is a paucity of data on local mosquito populations, other than the Anopheline
vectors of malaria, and potential vectors of arboviruses. Incrimination of mosquito species responsible for natural
arbovirus transmission is pivotal to understanding pathogen dynamics and designing precise vector control
strategies.
To enhance response to emerging public health threats in The Gambia, the proposed research aims to
address gaps in the knowledge of mosquito-borne arboviruses and their vectors by: (a) sampling mosquitoes in
The Gambia (utilizing a framework already in place for malaria monitoring, with extended sampling locations) to
contrast vector species communities in different landscapes during both the dry and rainy seasons, and to
assess arboviral evidence to determine mosquito infection rates across regions; and (b) evaluating vector
species diversity and abundance, as well as predictors of the risk of detected mosquito species and arboviruses,
considering their prevalence in association with seasonality, macroclimate, and landscape development. Vector
and arbovirus presence can, in future, be compared to potential geographic prevalence of human cases.
When fever is not caused by malaria, local epidemiology, including a baseline knowledge of what arboviruses
and their vectors are circulating in a region, can guide medical decisions. The proposed research is both
significant and novel because it addresses the lack of understanding of arbovirus existence in a previously
unstudied country, one that is experiencing unexplained cases of acute febrile illness. Although neighboring
Senegal has been noted for an arboviral presence, The Gambia has a separate geography, public health system,
and political setting, and is unexplored in this respect. Non-malarial febrile illness occurs in The Gambia, and
we propose initial steps for investigating arboviruses as potential etiological agents, allowing for improved
understanding of infectious disease agents. We aim to generate preliminary data for studies of arboviruses
threatening health in The Gambia and, ultimately, facilitating targeted prevention of arboviral pathogens (as well
as malaria) and a more streamlined approach to addressing vector-borne disease burden.