A demonstration of the presence of anti-snail antibodies in individuals infected with Schistosoma haematobium.

An extract of the snail Bulinus (Physopsis) africanus, the intermediate host of Schistosoma haematobium, was used as the antigen in haemagglutination tests in a survey of the prevalence of anti-snail antibodies in various population groups. It was found that sera from known bilharzia-infected individuals and randomly selected individuals from bilharzia endemic areas had significantly higher incidences as well as higher titres of antibodies to this snail antigen than non-infected individuals and individuals from non-endemic areas.