Hepatitis B surface antigen (Australia antigen) in mosquitoes collected in Senegal, West Africa

During July and August of 1973, 9,198 mosquitoes were collected in the Republic of Senegal. Eight species of mosquitoes were found in the collections: Culex thalassius, Culex pipiens quinquefasciatus, Culex trigripes, Culex phillipi, Aedes irritans, Aedes aegypti, Anopheles gambiae, and Mansonia sp. Specimens were sorted by biological condition; those obviously engorged were designated as (E), females with swollen abdomens not conspicuously blooded were considered gravid (G), and those with normal or shrunken abdomens were considered neither blooded nor gravid (U). Representative samples of each species were tested by solid phase radioimmunoassay for hepatitis B surface antigen (HBSAg, Australia antigen). A total of 12 mosquitoes were found to be HBSAg positive out of 1,658 individuals tested. These were: 9 Culex thalassius, 1 (E), 5 (G), 3 (U); 2 Culex pipiens quinquefasciatus, 1 (E), 1 (U); and Aedes irritans, 1 (U).