Role of mosquitoes in transmission of hepatitis B antigen.

Abstract

Seven species of mosquitoes were fed artificially on blood containing hepatitis B antigen. Radioimmunoassay revealed that all the ingested antigen disappeared in parallel with digestion of the blood meal by the mosquito. There was no evidence of replication of hepatitis B antigen, and the results indicate that the species of mosquitoes examined do not serve as biological vectors of this infection. The possibility of mechanical transmission of hepatitis B antigen by mosquitoes is discussed. Seroepidemiologic surveys on selected groups of persons in tropical countries have shown that hepatitis B antigen (Australia antigen) is detected in individuals of all ages but most frequently in children aged five to 15 years. The carrier rate of this antigen in some tropical regions may be as high as 20%. Although some modes of transmission of hepatitis B infection in the tropics are similar to those in other parts of the world, additional factors may be of importance in these regions. These include tattooing, ritual circumcision, scarification, and the bites of blood-sucking insects. There is one report, as yet unconfirmed, that some species of mosquito may serve as biological vectors for hepatitis B infection [1]. Hepatitis B antigen was found by the immunofluorescent anti