Current status of soil-transmitted helminthiases among pre-school and school-aged children from Ile-Ife, Osun State, Nigeria

A cross-sectional survey was conducted to determine the prevalence and intensity of soil-transmitted helminths among pre-school and school-aged children attending nursery and primary schools in Ile-Ife. Single stool samples were collected between January and March, 2009 from 352 children randomly selected from a total of 456 children attending both private and government schools. The stool samples were processed using the modified Kato-Katz technique, and then examined for the eggs of soil-transmitted helminths (STHs). One hundred and twenty-one (34.4%) samples were positive for STH eggs. The overall prevalences of Ascaris lumbricoides, Trichuris trichiura and hookworm were 33.2%, 3.7% and 0.9%, respectively. The prevalence of STH infection in government schools (47.8%) was significantly higher than in private schools (16.1%) (P < 0.001). The most common type of mixed infection was the combination of A. lumbricoides and T. trichiura (6.8%). The prevalence and intensity of A. lumbricoides rose with age. The lowest prevalence and intensity (7.7%; 0.240 +/- 0.136 eggs per gram (epg)) were recorded in the 2- to 3-year-old age group, while the highest prevalence and intensity (58.7%; 1.820 +/- 0.237 epg) were recorded in children aged 10 years and above. A questionnaire survey indicated that 73% of the children attending private school had been treated with anthelminthics less than 2 months prior to the collection of stool specimens, while 43% of the children attending government school received anthelminthic treatment during the same period. The findings indicate that STH infections are endemic among schoolchildren in Ile-Ife and that the burden of parasitic infections is greater in government schools than in private schools.