Hyperendemicity of onchocerciasis in Ovia Northeast local government area, Edo State, Nigeria.

Abstract

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, and symptomatic 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 (χ 2 ) test and logistic regression. Results: A Of the 2020 individuals examined, 1674 (83%) harboured microfilaria in their skin tissues. On the basis of the standardised scale for microfilaria prevalence-less than 10% is considered 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 led to the disease being classified as hyperendemic. Females were more frequently infected than were males, and this was statistically significant (P < 0.001). Prevalence was also found to increase with age, and this correlation was significant (P < 0.001). The prevalence of the clinical features of the disease in the local government area was 87.5% for leopard skin, 84.16% for itching, and 75.42% for nodules.Conclusion: A prevalence of 83% was observed and considered hyperendemic. Female gender and age (50 years or more) were significant risk factors that affected the prevalence of onchocerciasis. The findings demonstrated the hyperendemicity of infection and the need for urgent attention with ivermectin treatment and other control measures.

The Prevalence and Distribution of Human Onchocerciasis in Two Senatorial Districts in Ebonyi State, Nigeria

“…One-way analysis of variance of the number of cases of the disease (prevalence) in the different Local Government Areas (L.G.As) shows that there is no significant difference in the prevalence rate of the disease in the L.G.As (P = 0.9986). Reports [15,16] show that the occurrence of Onchocerciasis varies from one geographical region to another and these zones belong to a common region. The prevalence of Onchocerciasis in Nigeria has significant variation in different villages with the villages that are near the breeding sites of vector showing higher infection prevalence [17].…”

Onchodermatitis: Where Are We Now?

“…The area was hyperendemic for onchocerciasis with a skin snip positivity rate of 83%. The prevalence of depigmentation was very high at 87.5%, itching was 84.16% and nodules 75.42% [20]. Another pre-control study in Anfilo District of West Wellega, Ethiopia used a multistage sampling technique and a total of 1114 individuals ≥ 15years were examined [21].…”

Evaluation of Treatment Coverage and Enhanced Mass Drug Administration for Onchocerciasis and Lymphatic Filariasis in Five Local Government Areas Treating Twice Per Year in Edo State, Nigeria

“…Compared with other parts of Nigeria, this area is notorious for entrenched onchocerciasis prevalence, presumably due to poor MDA coverage. [5][6][7][8] Precontrol nodule prevalence was 36.4%, and annual treatment began in mesoand hyperendemic villages in 1994 and continuously until 2016. 8 The five LGAs in question had nodule rates ranging from 42% to 62% and had microfiladermia as high as 83% in 2008/2009.…”

“…8 The five LGAs in question had nodule rates ranging from 42% to 62% and had microfiladermia as high as 83% in 2008/2009. 5 Recent surveys by African Programme for Onchocerciasis Control (APOC) and others have demonstrated persistent microfiladermia and ongoing transmission in this area. 9,10 For example, studies by APOC in 2010 showed continued high prevalence in Edo state, with 33.4% of participants positive by skin snip.…”