Onchocerciasis in pre-primary school children in Nigeria: lessons for onchocerciasis country control programme.

There is limited data on the prevalence of onchocerciasis in young children in Nigeria, partly because treatment with the effective drug Ivermectin has been contra-indicated in children less than 5. As the risk of complications of onchocerciasis is related to duration and intensity of infection, it would be beneficial to know the prevalence in young children for design of control programmes. A study was therefore undertaken to determine the prevalence of onchocerciasis in 642 children 0-4 years old in a rain forest endemic community in South East Nigeria. The overall onchocerciasis prevalence (positive skin snips) for children 0-4 years old in three Local Government Areas in Enugu State, Eastern Nigeria was 15.7% with no significant difference in infection rates between male and female children. There was no detectable infection in children less than 1 year old. Characteristic onchocercal rash was identified in 11.1% of the children and presence of typical onchocercal subcutaneous palpable nodules in 4.6%. Total prevalence for adults in the same population was found to be 26.9%. This indicates that in onchocerciasis endemic communities, everybody may be at risk of infection irrespective of age.