Intraspecific variation in Schistosoma haematobium from Algeria.

A comparative analysis has been carried out between two populations of Schistosoma haematobium using the same intermediate snail host, Bulinus truncatus, but originating from two distinct ecological areas of Algeria: Khemis-El-Khechna in a sub-humid mediterranean zone and Djanet in a saharan bioclimatic zone. Four parameters have been studied: the growth rate of adult worms, size and shape of the eggs, chronobiology of cercarial emergence and the compatibility with the intermediate host. Results showing divergences for all the characters studied are discussed for the origin of this intraspecific polymorphism of S. haematobium in Algeria.