The use of questionnaires for the identification of high risk areas for urinary schistosomiasis: the Ethiopian experience.

The applicability and usefulness of questionnaires directed at school children and teachers and routed through the usual administrative/educational system for the identification of communities at risk for urinary schistosomiasis in Ethiopia was assessed in the Awash Valley in 1992 as part of a multi-country study. Pre-tested questionnaires were distributed to 28 elementary schools. A total of 2918 children and 56 teachers completed the questionnaires. Teachers and the biomedical team tested 2662 and 2602 children by reagent strips in 24 schools. The prevalences of children with questionnaire positive (yes) answers for indicators of urinary schistosomiasis, "blood in urine" and "schistosomiasis" or "pain when urinating", were 4.1%, 3.6% and 11.2%, respectively. The median rank given by teachers for "blood in urine" and "schistosomiasis" from among a list of symptoms/diseases that were affecting children in the area was 7 (not cited by the respondent). The prevalence of haematuria at the 1+ limit by teacher and biomedical team reagent testing was 21.9% and 17.5%, respectively. Prevalence of urinary schistosomiasis among the children tested by urine filtration was 2.7%. The relation between children's and teachers's questionnaire answers for the markers of urinary schistosomiasis, on the one hand, and between children's questionnaire answers and teacher stick testing results, on the other, gave no significant correlation. Conventional parasitological testing required US+ 226 per screened school as opposed to US+ 47 and US+ 153 for questionnaires and teacher testing, respectively. The approach worked well operationally and was cheaper. Nevertheless, it did not serve its diagnostic purpose in the Awash Valley. This is explained, among others, by the low prevalence of urinary schistosomiasis in the study area which probably resulted in low perception of the disease by the immigrant population from the highlands who constituted the majority of the study population. However, as the feasibility and the cost-effectiveness of questionnaires for large-scale screening provide many possibilities in the frame of a PHC approach to disease control, a similar investigation should be carried out in a different urinary schistosomiasis endemic area before sound conclusion is given as to the diagnostic capability of the approach.

Evaluation of reagent strips for detection of Schistosoma haematobium infection in the lower Awash valley, Ethiopia.

The use of reagent strips as indirect morbidity indicators in Schistosoma haematobium infection has been assessed in comparison with urine filtration technique in the lower Awash valley of Ethiopia in 1991. The prevalence of infection by reagent sticks and urine filtration was 16.0% and 3.6%, respectively. Reagent stick haematuria was highly related with urine filtration at the 2+ limit rather than the 1+ limit. A strong association was also obtained between prevalence rate and intensity of infection of all children at both haematuria limits. The prevalence of haematuria was not sex-related but there was age-associated infection and the prevalence was highest in the 10-13 year age group. The possible use of reagent stick haematuria in the monitoring of S. haematobium infection in Ethiopia is discussed.