Risk factors for optic nerve disease in communities mesoendemic for savannah onchocerciasis, Kaduna State, Nigeria
Abstract:Ophthalmic examinations on 6831 individuals aged 5 years or more, living in 34 guinea savannah communities mesoendemic for onchocerciasis, in Kaduna State, Nigeria, revealed a relatively high prevalence (9%) of optic nerve disease (OND). Further investigations were performed to determine what proportion of this burden of OND might be due to onchocercal infection. Information on history of cerebro‐spinal meningitis (CSM), past use of diethylcarbamazine (DEC) and chloroquine, consumption of cassava and locally produced alcohol was collected for all individuals by questioning. In addition, a nested case‐control study of 81 cases of OND and 136 age and sex‐matched controls was performed to investigate whether syphilis or a variety of other neurological disorders were responsible for a substantial proportion of cases of OND. Our data suggest that in this population, onchocercal infection is the single most important cause of OND and may account for 50% of all cases. Some 13% of cases were associated with signs suggestive of glaucoma. DEC use might be responsible for up to 30% of all OND. We found no evidence to suggest that any of the following are important causes of OND in the communities studied: CSM, syphilis, neurological syndromes such as polyneuropathy or other generalized neurological disease, consumption of raw cassava, consumption of locally prepared alcohol.
Document Type: Original Article
Affiliations: 1: Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, London, UK, 2: Ahmadu Bello University Teaching Hospital, Kaduna, Nigeria, 3: Nigerian Institute for Trypanosomiasis Research, Kaduna, Nigeria,
Publication date: January 1, 1997