The Threat of Vector-Borne Diseases in Sierra Leone

Abstract

Sierra Leone is vulnerable to a wide range of vector-borne diseases transmitted by mosquitoes, tsetse flies, black flies, and other vectors. Malaria, lymphatic filariasis, and onchocerciasis have posed the greatest threat and have received the most attention in terms of vector control and capacity for diagnosis. However, malaria infection rates remain high, and there is evidence of circulation of other vector-borne diseases, such as chikungunya and dengue, which may go undiagnosed and unreported. The limited understanding of the prevalence and transmission of these diseases restricts the capacity for predicting outbreaks, and impedes the planning of appropriate responses. We review the available literature and gather expert opinions from those working in the country to report on the status of vector-borne disease transmission and control in Sierra Leone, and present an assessment of the threats of these diseases. Our discussions highlight an absence of entomological testing for disease agents and the need for more investment in surveillance and capacity strengthening.

Figure 1.

Flow chart to guide qualitative risk assessment in Sierra Leone.

Figure 2.

Geographic distribution of malaria parasitemia in children 6 to 59 months old, by district. Sierra Leone 2016 malaria indicator survey, sourced through the President’s Malaria Initiative, FY 2018–2019 Sierra Leone Malaria Operational Plan.