Screening for high prevalence areas of onchocerciasis - a feasibility study on the application of the indirect questionnaire approach in Kafa; South Western Ethiopia

ABSTRACT

"A cross-sectional study was undertaken to test the validity and operational feasibilty of the so-called ""indirect questionnaire approach"" for the screening of communities for Onchocerciasis in Kafa; south west Ethiopia. Pretested questionnaire was distributed via the Awraja (district) education office to six junior high schools. Students were interviewed and their perceived morbidity; as reflected by the occurrence of selected features of Onchocerciasis; was recorded by their teachers. Subsequently a medical team has visited the same schools and undertook clinical and parasitological test to validate the first estimates. Using the Spearman's rank correlation; the positive response rate of students was found to be negatively correlated to the parasitological estimates of Onchocercal infection; probably due to the immune tolerance and adaptation to the features among the high prevalence groups; and poor perception of the problem in general. The indirect questionnaire approach using the educational sector is considered to be operationally feasible and 7.5 times less costly than the biomedical approach; but not advantages speed wise. Further study is recommended to assess the applicability of the method in different demographic and socioeconomic situations."