Epidemiology of intestinal nematodes in school-age children of the Kumba Urban Area, south west Cameroon.
The urban slums, poorly disposed garbage and inadequate toilet facilities in many homes, coupled with the high temperatures, rainfall and humidity that characterise the Kumba urban area, favour the development and transmission of helminth parasites in the area. School-age children are particularly at risk of infection. To determine the pattern of soil-transmitted nematode infections in the Kumba urban area as affected by seasonal changes. Longitudinal study. Ten primary schools in the Kumba urban area. Five hundred and eighty seven randomly selected pupils aged between four and fifteen years of both sexes. Significantly (P<0.005) more children were infected towards the end (69%) than in the early months (38.3%) of the rainy season. The infection rate recorded in December/January (dry season) was significantly reduced in April/May (early months of the rainy season) in male and female (P<0.01) children of different age groups (P<0.005) and classes (P<0.05). Then after, the rate increased significantly (P<0.005) in all the groups to reach a peak in October/November (last months of the rainy season). The intensity of infection more or less followed the same pattern as prevalence, except in hookworms where prevalence increased progressively and significantly (P>0.05) from 10.7% in December/January to 19.4% in October/November, while the worm load decreased. Single and mixed species infections constituted 50.8% and 49.2% respectively of the infections investigated, with Ascaris lumbricoides accounting for the highest number of infections. The most common combination of mixed species infections was Ascaris/Trichuris. The study has revealed that, in general, progressively more school-age children are infected with soil-transmitted nematodes in the course of the rainy season while acquisition of infections in the dry season progressively reduce to the low levels observed in the early months of the rainy season.