Onchocerciasis In Imo State, Nigeria, 7: Prevalence Of Some Non-Classical Signs And Symptoms

Abstract

An assessment of the prevalence of some non-classical signs and symptoms of onchocerciasis was conducted in 38 rural communities in the Imo River Basin, Nigeria between March 1999 and September 2000. A total of 7348 consenting individuals (3756 males and 3592 females) aged 5 years and above were examined for signs and symptoms including musculoskeletal pain, general debility and epilepsy. Two bloodless skin snips were also taken from each individual for microfilariae of Onchocerca volvulus. Out of the 7348 persons examined, 2613 (35.6%) had various non-classical signs and symptoms. The prevalence rates of musculoskeletal pain, general debility and epilepsy were higher in persons with skin microfilariae (67.1%, 54.3% and 1.6% respectively) than in those without skin microfilariae 5.5%, 14.2% and 0.2%. Musculoskeletal pain and general debility increased in relation to microfilarial rate/intensity of infection and age of the subjects while epilepsy was associated only with the 10-59 year age group with peak prevalence (1.5%) in subjects 20-29 years. Females had higher prevalence rates of non-classical signs and symptoms namely, musculoskeletal pain (24.1%), general debility (17.4%) and epilepsy (0.7%) than males 14.8%, 14.1% and 0.3% respectively. Overall, musculoskeletal pain and general debility were strongly associated with intensity of infection (r = 0.64; p<0.001) and (r = 0.53; p<0.001) respectively while epilepsy showed a weak relationship with intensity of infection (r = 0.14, p>0.364). The result shows that non-classical signs and symptoms are important aspects of the onchocerciasis disease in the Imo River Basin, Nigeria. The sustenance of treatment with ivermectin taking into account standard exclusion criteria is advocated.

Key Words: Onchocerciasis, prevalence, musculoskeletal pain, general debility, epilepsy.

Bio-Research Vol.2(2) 2004: 42-45