Schistosomiasis infection in relation to the ABO blood groups among school children in Zimbabwe.

The study aimed to establish if there was any relationship between the blood group of the human host and schistosomiasis prevalence, intensity, incidence and related organ pathology. Urine and stool specimens were collected from the 735 school children attending a rural school in Zimbabwe to determine the Schistosoma haematobium and S. mansoni infection status of the children. The parasitology results were used to calculate prevalence and intensity of schistosomiasis infection. All the children, irrespective of infection status, were examined for signs of organ damage using ultrasonography before those that were infected were treated using a single dose of praziquantel. A blood specimen was taken from each child for blood group determination. Exactly 1 year later, parasitology was repeated to allow calculation of annual incidence of schistosomiasis infection. Of the children studied, 212 (28.8%) were of blood group 'A', 156 (21.2%) were of blood group 'B' while 367 (49.9%) belonged to blood group 'O'. The prevalence of S. haematobium was 59.6% (n = 438) while that of S. mansoni was 15.60% (n = 115). S. haematobium infection was detected among 129 (60.8%) children belonging to blood group 'A': 225 (61.30%) of blood group 'O' and 84 (53. 80%) of those belonging to blood group 'B'. S. mansoni infection was detected among 65 (30.70%) blood group 'A' children while 37 (10.10%) blood group 'O' and 13 (8.30%) blood group 'B' children were infected. Intensity, annual incidence of S. haematobium infection and related organ pathology was significantly higher among children of blood group 'A' and lowest among blood group 'O' children (P < 0.01, F-value = 6.13). Similarly, S. Mansoni intensity and incidence of infection and related liver lesions were highest among children of blood group 'A' (P < 0.005, F-value = 11.45).