The prevalence, intensity and clinical manifestations of Onchocerca volvulus infection in Toro local government area of Bauchi State, Nigeria

Onchocerciasis in Imo state, Nigeria (2): the prevalence, intensity and distribution in the upper Imo river basin

“…The sex-related prevalence was similar in males and females, which is an indication of equal exposure to the vectors of the disease either through involvement in the same occupational activities or by living in close proximity to the breeding sites. Similar observations have been made in previous studies in the forest zone (Nwoke et al 1994;Abanobi et al 1999) but contrasts with studies in the savanna, which showed higher infection rates in males than females (Anosike and Onwuliri 1995;Anosike et al 2001;Dozie and Nwoke 2002). The prevalence and intensity of infection increased with advancing age and is due to a continuous build up of infection acquired early in life.…”

“…Lymphadenopathy, hanging groin and lymphoedema (limb and genital) which have been previously associated with onchocerciasis (Anosike et al 2001) were more prevalent in older than younger persons which is a further confirmation that they are features in persons with long standing infection. Even though hernia was not strongly correlated with onchocercal infection in this study, its prevalence may not be surprising since its aetiology has been associated more with disorders of collagen metabolism caused by the presence of O. volvulus in the groin of infected individuals which in turn results in weakness of the transversalis fascia of the Hessenlback's triangle (Guderian and Kerrigan 1990) rather than the weight of hanging tissues which weaken the inguino-femoral canals (Nelson 1958).…”

“…Visual impairment due to onchocercal eye disease is demonstrable in about 3% of children aged 5 years who live in hyperendemic communities and 35% of males and 26% of females in such communities are visually disabled by the age of 30 years (Nwoke and Dozie 1997). Although, several studies have been carried out on the incidence of the disease in different parts of the country, particularly the northern bioecological savanna zone (Anosike and Onwuliri 1995;Akogun et al 2000;Anosike et al 2001;Dozie and Nwoke 2002), its distribution and complications remain inadequately understood in many endemic communities in the rainforest. This is especially true in the Imo river basin in southeastern Nigeria, where previous entomological studies (Nwoke and Uwazie 1991) as well as a rapid assessment survey to identify communities eligible for mass treatment with ivermectin showed that the disease is endemic in this area (Nwoke et al 1994).…”

The impact of Ivermectin mass treatment on the prevalence of onchocerciasis by rapid epidemiological assessment in Galadimawa, Kaduna state, Nigeria

“…A community-based questionnaire was designed and used for the assessment of the prevalence of the disease in the community using REA method (Gemade et al 1998, Esum et al 2001, Anosike et al 2001. The parameters recorded included sex, marital status, and occupation.…”

“…The demonstration of and excellent correlation between the prevalence of palpable nodules in a community and the microfilarial load has led to the development of Rapid Epidemiological Mapping of Onchocerciasis (REMO), which is geographical and the Rapid Epidemiological Assessment (REA), which is community based. These methods are rapid, safe and non-invasive that have enabled the identification of communities for mass treatment with ivermectin (Gemade et al 1998, Esum et al 2001, Anosike et al 2001. The community based REA method involves the physical examination of individuals for the clinical manifestations of the disease, which include palpable nodules, skin depigmentation (leopard skin), hanging groin and blindness.…”