Hepatitis-B virus in bedbugs (Cimex hemipterus) from Senegal.

Bedbugs of the species Cimex hemipterus (F) were collected on four separate occasions from the bedding in the huts of village dwellers in Senegal, West Africa. Hepatitis-B surface antigen (HBSAg) was detected in unengorged nymph and adult bedbugs in each of the first three collections. 3 of 28 such specimens were HBSAg(+) in the first collection and 3 of 17 specimens were positive in the second collection. In the third, 6 of 9 were HBSAg(+) when the bed occupant was known to be HBSAg(+). 2 of these 6 positive insects did not contain human serum proteins. Bedbugs in the fourth collection were captured and kept alive without a blood meal for 30 days. 3 of 89 of these samples were HBSAg(+). These are the highest field infection-rates of hepatitis-B virus reported in any insect species. The bedbug must be considered a potential vector of hepatitis-B virus.