The coefficient of inbreeding (for Wright) was studied in Catolândia, in the state of Bahia, Brazil, an area considered hyperendemic for manson schistosomiasis in a population of 1,130 inhabitants. The coefficient of inbreeding was estimatedfor 1,123 individuals it was classified as f > 0 in 13.2% (n=148). In the hepatosplenic group the frequency of f>0 was 26.8%, and in the hepatointestinal group the frequency was 12.5%. The frequency of the hepatosplenic diagnosis in whites who weref=0 did not differ from that which was observed in the negroid group. These verifications were confirmed by the Woolf's test; the relative risk of the whites, f > 0 in acquiring hepatosplenic schistosomiasis was 14.1. These observations reinforce the influence of the genetic component in the development of the hepatosplenic form of the mansons schistosomiasis.
Coefficient of inbreeding; Schistosoma mansoni; Hepatosplenic form