SCHISTOSOMIASIS IN DOGON COUNTRY, MALI - IDENTIFICATION AND PREVALENCE OF THE SPECIES RESPONSIBLE FOR INFECTION IN THE LOCAL-COMMUNITY

The prevalence of schistosomiasis amongst the Dogon people in 4 villag es and one school of the Bankass district of Mall was determined durin g 2 surveys in 1992; 1398 urine and 1199 stool samples were examined. The most common schistosome was Schistosoma haematobium, with an overa ll prevalence of 51.3%; S. mansoni had a prevalence of 12%. No S. inte rcalatum egg was seen in the stools. Biomphalaria Pfeifferi and Bulinu s truncatus were found in pools at the base of the Dogon cliffs; Bulin us forskalii was found in smaller numbers in brick pits. Two isolates from urine samples of children were identified as S. haematobium in th e laboratory using an alpha-glycerophosphate marker, restriction enzym e analysis of ribosomal deoxyribonucleic acid (rDNA) and random amplif ication of polymorphic DNA. The isolates did not develop in Bulinus fo rskalii or B. crystallinus of the B. forskalii group. Some evidence fo r past hybridization of S. haematobium and S. intercalatum is provided by the enzyme and rDNA results as well as the positive Ziehl-Neelsen staining of polymorphic eggs in urine samples. The findings are discus sed in relation to the published observations concerning schistosomias is in travellers returning from this region of Mali.