Bionomic Characteristics of Major Vector Species and Malaria Transmission in Senegambian Border Areas in Senegal

Malaria is a public health problem in Senegal, with heterogeneous transmission and little known about transmission drivers at the Senegalese border. This study aimed to determine bionomics of major vectors and malaria transmission in the Senegambian border. The study was conducted from July 2023 to March 2024 in Nemataba and Ndrame Ndimb (near the border), and in Medina Dianguette and Paoskoto (farther). Adult mosquitoes were collected using human landing catches and pyrethrum spray catches. Laboratory analyses were performed by Enzyme-Linked Immunosorbent Assay and Polymerase Chain Reaction techniques. Anopheles gambiae s.l. human biting rates (HBRs) were 1.05 bites/person/night (b/p/n) in Nemataba and 6.55 b/p/n in Ndrame Ndimb, while they were 14.73 b/p/n in Medina Dianguette and 1.47 b/p/n in Paoskoto. Anopheles funestus HBR was 2.88 b/p/n in Paoskoto and 0.37 b/p/n in Ndrame Ndimb. Human blood index for An. gambiae s.l. were 77.08% in Medina Dianguette, 66.67% in Nemataba, 2.42% in Ndrame Ndimb and 0 in Paoskoto, while for An. funestus they were 5.93% in Ndrame Ndimb and 3.65% in Paoskoto. Malaria transmission was detected in Medina Dianguette and Paoskoto, with 0.078 and 0.209 ib/p/n, respectively. This study highlights the diverse bionomic characteristics of major malaria vectors along the Senegambian border.