Onchocerciasis in Sierra Leone: Infection in School Children in the Njala Area Southern Province

ABSTRACT

The prevalence of Onchocerca Volvulus infection in school children from five primary schools and one secondary shool in the Njala area; Southern Province was determited in 1985 and 1989 to see the pattern of infection and factors determining prevalence. An infection rate of 42 per cent was found in 1989 compared to the 29.2 per cent infection rate found in 1985. The rate of increase of 222.5 per cent was greater at the University Secondary School over a four year period followed by UMC Pelewahun (138.0 per cent); UMC Mokonde (93.2 per cent); NUC Experimental (71.3 per cent); R.C. Mosongo (55.4 per cent) and NUC International Shool (33.3 per cent). Prevalence of infection rose with age from 3.2 per cent in 1-4 year olds to 75.2 per cent in the over 20 years old there was a significant (P less than 0.005) increase in the intensity of infection between the 10-14 and the 15-19 years old pupils respectively. The proportion of positive skin biopsies and microfilarial densities at the iliac crest was significantly (P less than 0.005) higher than biopsies at the shoulder. There were more palpable nodules at the iliac crest region (pelvic region) than any other anatomical site