Hyperendemicity of Onchocerciasis in Ovia Northeast Local Government Area, Edo State, Nigeria

Background: Onchocerciasis is a chronic parasitic infection caused by the filarial nematode, Onchocerca volvulus. The objective of this study was to determine the prevalence, endemicity, andsymptomatic effects of the disease in Ovia Northeast Local Government Area. Methods: The prevalence of onchocerciasis was investigated in Ovia Northeast Local Government Area of Edo State, Nigeria, between March 2008 and June 2009 using the standard skin-snip method. A total of 2020 subjects, who had visited various primary health centres located in each community, were enlisted using randomised sampling, and the data were analysed using the Chi-squared (χ2) test and logistic regression. Results: A Of the 2020 individuals examined, 1674 (83%) harboured microfilaria in theirskin tissues. On the basis of the standardised scale for microfilaria prevalence—less than 10% isconsidered sporadic, 10%–29% is considered hypoendemic, 30%–59% is considered mesoendemic,and 60% and above is considered hyperendemic—the prevalence (83%) reported in this study ledto the disease being classified as hyperendemic. Females were more frequently infected than weremales, and this was statistically significant (P 0.001). Prevalence was also found to increase withage, and this correlation was significant (P 0.001). The prevalence of the clinical features of thedisease in the local government area was 87.5% for leopard skin, 84.16% for itching, and 75.42% fornodules. Conclusion: A prevalence of 83% was observed and considered hyperendemic. Femalegender and age (50 years or more) were significant risk factors that affected the prevalence ofonchocerciasis. The findings demonstrated the hyperendemicity of infection and the need for urgentattention with ivermectin treatment and other control measures.