The prevalence, intensity and ecological determinants of helminth infection among children in an urban and rural community in Southern Malawi.

Rapid urbanisation and poor town planning in Malawi has been associated with poor environmental hygiene and sanitation. The aim of the present study was to investigate the prevalence, intensity and some potential risk factors of intestinal helminth infections among children aged 3 - 14 years in an urban and rural community in Southern Malawi. A randomised cross-sectional survey was conducted in July, 1998. Data were collected through questionnaire interview regarding socio-demographic and environmental conditions from households in both areas. Stool samples were collected from 273 children in the urban community and 280 in the rural. There was a significant difference (p<0.001) in the prevalence of helminth infections between the urban and rural communities, 16.5% and 3.6% respectively. Most of the infections were light (93.2% for Ascaris lumbricodes, 85.7% for hookworm). Large variance to mean ratios of egg intensity within age groups and the total study population suggested a high degree of aggregation of the parasites in the communities. Multiple logistic regression analysis showed that certain groups of children in the urban community were much more likely to develop helminth infection. They included children who had pools of water/sewage around houses (OR = 3.0, 95% CI = 1.4 ñ 6.5), did not wear shoes (OR a 7.1, 95% CI = 2.7 - 19.2), did not attend school (OR = 2.8, 95% CI = 1.2 ñ 6.5), had mothers who had 4 to 8 years of education (OR = 5.2, 95% CI = 2.0 - 14.0), had mothers below 35 years of age (OR = 4.09, 95% CI = 1.39 - 16.28) and living in an urban community (OR = 5.3, 95% CI = 2.6 - 12.1). Efforts to reduce helminth infections should focus on reducing exposures.