Prevalence of lymphatic complications due to onchocerciasis infection in Imo State, Nigeria

Abstract

The study was conducted to determine the prevalence of lymphatic complications due to onchocerciasis infection
in 38 endemic rural communities in the Imo River Basin, Nigeria. Using standard parasitological and clinical
methods of diagnosis, 7,144 consenting individuals aged 5 years and above were examined for Onchocerca volvulus
microfilaria and clinical lymphatic symptoms of onchocerciasis. Of the 7,144 individuals, examined, 1,646 (23.0%)
were positive for O. volvulus microfilariae, while 1,045 (14.6%) had various degrees of lymphatic complications.
The prevalence of lymphatic complications were lymphadenopathy (7.9%), hanging groin (3.2%) and inguinal
hernia (3.5%). Subjects 30 years and above had the highest microfilarial densities which coincided with higher
prevalences of these lesions suggesting their chronicity. Sex-prevalence showed an insignificant borderline
difference, 17.3% in males and 14.3% in females (p > 0.05). Lymphadenopathy and hanging groin were strongly
associated with microfilarial density (r = 0.54; p<0.001) and (r = 0.59; p<0.001) respectively. The study shows
that lymphadenopathy, hanging groin and inguinal hernia are lymphatic manifestations of onchocerciasis in the
rain-forest. Their chronic and irreversible nature however creates a strong imperative for their prevention/control
by the use of an annual dose of ivermectin..

Keywords:Onchocerciasis, lymphatic complications, prevalence, ivermectin, Imo River Basin, Nigeria.

Nigerian Journal of Parasitology Vol. 27 2006: pp. 23-28