Schistosomiasis in the Finchaa River Valley, Wellega Region, western Ethiopia

Parasitological and malacological surveys were carried out in the Finchaa Valley; Wallega Region; Western Ethiopia. Stool examination of 960 persons in the 10 communities surveyed showed an average human prevalence of 12.4 per cent for Schistosoma mansoni. Infected individuals were present in 6 communities; but prevalence was greater than 10 per cent in only three of them; reaching 40 per cent among school children in one community. In endemic localities; the intensity of infection in terms of eggs per gram of faeces were 200 and 199 among school children and farm labours respectively. The age specific prevalence and intensity of infection were highest among the 5-14 year age group. The intermediate host of S. mansoni; Biomphalaria pfeifferi were collected from three sites; but transmission was identified at only one site located in the lower portion of the valley. Bulinus truncatus; the potential intermediate host of S. haematobium in Ethiopia; was also present in the area. The occurrence of infected human subjects and snail intermediate host confirm that Schistosoma mansoni is well established in the valley; particularly in the lower portion where a large irrigation development is under way. In this report; the threat posed by the S. mansoni and S. haematobium is discussed and the preventive/control measures to be taken are suggested

The incidence of schistosomiasis in Bahir-Dar; Ethiopia

A study was made in Bahir-Dar; North-Western Ethiopia; for a period of twelve months; to determine the incidence of Schistosomiasis mansoni. All children aged 10 years and younger in Dil Chibo and Teyima Elementary Schools were stool-examined by the formol-ether concentration technique at the beginning of the study to select schistosomiasis mansoni negative children for a later incidence study. Accordingly; 139 children in Dil Chibo and 104 children in Teyima were found negative and used for an incidence study. In the incidence surveys; the stool specimens were examined by the Kato method. The overall annual incidence rates for Dil Chibo and Teyima school children were 194/1000 and 382/1000 respectively. The rates obtained at the second survey were higher than the rates obtained at the first survey; 164/1000 and 36/1000; respectively; for Dil Chibo and 292/1000 and 77/1000; respectively; for Teyima schools. Males had a higher schistosomiasis incidence than females (P0.01). The incidence also appeared to vary with age. The value of incidence as a measure of transmission is discussed

Intestinal helminth infections at Zeghie; Ethiopia; with emphasis on schistosomiasis mansoni

A total of 460 stool specimens were examined by Kato thick smear technique to determine the prevalence of schistosomiasis mansoni and other helminth infections among people living in Zeghie town; Northwest Ethiopia. The most prevalent infections were schistosomiasis; ascariasis; and trichuriasis. The infection rates among school children for Schistosoma mansoni; Ascaris lumbricoides and Trichuris triciura were 69.7 per cent; 77.7 per cent and 64.7 per cent; respectively. The respective infection rates of these helminths among the residents were 53.1 per cent; 60.6 per cent and 50 per cent. The prevalence of schistosomiasis appeared to be higher for males than for females. The high prevalence of infection observed for these helminths in the present study clearly indicates the need for timely control measures

Transmission of schistosoma mansoni in three ecological settings in Ethiopia : epidemiological aspects

The epidemiological indices of Schistosoma mansoni for three communities in Ethiopia; Jigga (Northwest); Metahara sugar estate (Southeast) and Lake Zway (Central); each representing the three major transmission ecologies in the country; the stream; irrigation scheme and lake; respectively were studied and compared. A total of 2897 people (913; 1614 and 370 from the stream; irrigation scheme and lake; respectively) was examined for S. mansoni ova by the Kato's smear method. The highest human prevalence (58 per cent) and intensity of infection (geometric mean of 450 EPG) were recorded for the lake ecology; whereas the irrigation scheme and stream showed moderate (218 EPG) and light (172 EPG) intensities of infection; despite fairly high disease prevalences of 20 per cent and 41 per cent respectively. Age-specific analysis of prevalence; intensity of infection and relative index of potential contamination (RIPC) indicated that children in their second decade of life to be most responsible. Nevertheless; the decline of all indices with increasing age was less obvious in the lake area than others. The disparity between prevalence and intensity of infection and their implication in disease control tactics are discussed