HEPATOSPLENIC ALTERATIONS DETERMINED BY ULTRASONOGRAPHY IN A POPULATION RECENTLY INFECTED WITH SCHISTOSOMA-MANSONI IN RICHARD-TOLL, SENEGAL

Three years after intestinal schistosomiasis had been reported for the first time in the delta of the Senegal River Basin, an ultrasonographic study was conducted on 358 subjects of the community of Richard-Toll with a proven Schistosoma mansoni infection and compared with the findings from 352 uninfected subjects of a nearby town. Periportal thickening was found in 119 subjects (33%) in only one of whom it was greater than 10 mm; liver parenchyma lesions were found in 40 subjects (11%), at about the same rate in all age groups. No correlation was found between hepatomegaly and schistosomiasis. Frequency of thickening of the omentum was significantly higher in Richard-Toll than in the control group. 11% of the Richard-Toll subjects had portal vein diameters significantly larger than the values in the control group; of those, 6% had no periportal fibrosis sign in the liver. Significantly more splenomegaly was found in the infected group, though malaria as an aetiological agent cannot be ruled out. Based on periportal alterations and parenchyma lesions only, 141 (39%) subjects in the Richard-Poll group had alterations, corresponding to the World Health Organization proposed criteria for stage I; one subject had alterations corresponding to stage II. As S. mansoni infection is still new in this area, the patho-anatomical pattern is likely to change significantly in the future.