Infra-specific Variations ofSchistosoma haematobium

Abstract

The varying susceptibility of local races of bulinid snails to different strains ofSchistosoma haematobiumhas been recorded by many workers including Le Roux, 1954; Cridland, 1955, 1957; McCullough, 1957, 1962; Wright, 1962, 1963; Cowper, 1963; Pitchford, 1965 and Paperna, 1968. The respective species groups of snails referred to are those created by Mandahl-Barth (1958). As a result of his experiments Le Roux (1958) suggested that there are two separate species of parasite, the form transmitted in North Africa by thetruncatesgroup of snails being known asS. haematobiumand that developing in Africa south of the Sahara in theafricanusspecies group asS. capense(Harley, 1864), a view which has been supported by many workers.