LONGITUDINAL-STUDY OF ONCHOCERCIASIS IN BEBEKA-ETHIOPIA

This paper describes the morbidity, intensity and prevalence of onchoc erciasis in an endemic area of Ethiopia, using a cross-sectional study (n=425) and a longitudinal cohort study (n=98). During the study peri od (February - October 1987), the increase in intensity and in number of cases with dermal lesions was highly significant (p < 0. 005) when compared with the increase in the microfilarial positivity rate (p < 0 . 1). Since the serial increase in dermatologic problems was wt direct ly correlated with an increase in 0. volvulus microfilarial prevalence or intensity, it is suggested that hyper-sensitivity responses to rep eated Simulium bites might exacerbate onchocercal dermal lesions. The controversy concerning Simulium bites as a cause of lesions mimicking those due to O. volvulus parasites is discussed.