Operationalising Environmental DNA (eDNA) Detection of Major Malaria Vector Species in Ghana

The global landscape of vector-borne diseases (VBDs) is shifting, driven by climate change, urbanisation and widespread habitat modification, requiring novel approaches to surveillance, prevention and control. To improve our capacity to respond to real-time emergent VBD threats, this study undertook cross-sectional sampling of suspected mosquito breeding sites in Greater Accra and Western Region, Ghana, to assess the operational feasibility of environmental DNA (eDNA) detection of major malaria vector species. eDNA deposited by wild, immature Anopheles gambiae s.l., isolated from a 50 mL water sample, was detectable using both end-point PCR and qPCR, achieving high levels of sensitivity (76.28%) and specificity (100%). Furthermore, we recovered PCR amplicons covering eight known insecticide resistance mutations from eDNA collected in natural breeding sites. This study represents the first proof-of-concept demonstrating that eDNA can be used for the simultaneous identification of Anopheles vectors and circulating insecticide resistance alleles directly from aquatic habitats in the community, including the first report of the mutation gste2-F120L in Ghana. Our eDNA sampling methodology was designed for citizen scientists as end-point users. We recommend fixed, single-use filters for sampling 50 mL of water as a highly feasible, sensitive and specific, community-led mosquito vector surveillance tool, which requires minimal training or technical infrastructure.