Distribution of blood groups and secretor status in schistosomiasis.

Urine and stool specimens from 425 school children in Swaziland were examined for evidence of Schistosoma mansoni or Schistosoma haematobium infection. Concurrently, saliva collections were analysed for ABH secretory ability and blood samples were typed for ABO, Rh and Lewis groups. Among individuals infected with S. mansoni, the frequency of blood group B was significantly increased (P < 0.001), and there was a greater prevalence of positive secretor status (P < 0.05). In contrast, the presence and severity of S. haematobium infection did not correlate with any of the variables tested.