Epidemiology of human hookworm and Ascaris lumbricoides infestations in rural Gambia.

In a cross-sectional study of helminth infections in a rural village in The Gambia, West Africa, hookworm, probably Necator americanus and Ascaris lumbricoides were found to be the most prevalent helminths present at prevalence levels of 30% and 25% respectively. Other parasites present were Trichuris trichiura (2.4%) and Schistosoma mansoni (1.5%). The mean egg counts of N. americanus and A. lumbricoides in all age groups and in the total population were low. Egg counts between age and sex groups were not statistically significant. The frequency distributions of both N. americanus and A. lumbricoides were overdispersed with the majority of the sample population producing none or few eggs, and a small minority producing relatively large amounts of eggs. Large variance: mean ratios within age groups and the total study population suggested a high degree of aggregation of the parasites in this community.