The prevalence of epilepsy follows the distribution of onchocerciasis in a Western Uganda focus

ABSTRACT

Epidemiological surveys indicate that the prevalence of epilepsy is higher in developing countries than in industrialized countries. Except for neurocystocercosis due to Taenia solium; little is known about possible underlying causes. This article reports the relationship between epilepsy and onchocerciasis in an Onchocerca volvulus endemic area in West Uganda. Individuals complaining of seizures were identified by means of apopulation census in 12 villages. Active epilepsy was confirmed in 61 of 4743 inhabitants (crude prevalence rate = 1.3 ; age-standardized rate = 1.1 ). Distribution of epilepsy in the study area was clustered; ranging from a prevalence of 0.2 to 3.4 in difference villages. Age-specific prevalence was highest between 10 and 19 years; with a rate of 3.6 for the study are as a whole; and up to 10.0 in villages of high epilepsy prevalence. The prevalence of onchocerciasis in the 10-19 -year-old age group was assessed by skin-snip biospy and ranged from 15 to 85 in different villages. Epilepsy was significantlymore frequently more frequent in the three villages with the highest levels of O. volvulus emdemicity than in other villages (P0.0001). Serological testing for T. solium infection was positive in one and borderline in three of 53 epilepsy patients tested. The significant correlation between epilepsy and Onchcerciais did not change when these four patients were excluded from the analysis. These findings suggest a strong association between epilepsy and onchocerciasis in this area. This could have significant implications for the concept of morbidity due to O.volvulus