The epidemiology of hookworm infection and its contribution to anaemia among pre-school children on the Kenyan Coast

Intestinal nematode infections are recognized as a major public health. pro blem, and helminth control is currently being directed towards school-aged children who are known to harbour the heaviest infections and are most like ly to suffer from associated morbidity. However, few data are available for the epidemiology of intestinal nematodes in pre-school children in Africa, and the contribution of hookworm infection to: the aetiology and severity of anaemia among pre-school children remains poorly understood. This paper investigates the epidemiology of parasitic infections in 460 pre-school chi ldren who were parr of a larger case-control study of severe malaria in Kil ifi on the Kenyan coast. Almost one-third (28.7%) were infected with hookwo rm, 20.2% with Ascaris lumbricoides and 15.0% with Trichuris trichiura. Inf ection prevalence of each species rose with age, and the prevalence of heav y infection with hookworm and mean intensity of hookworm were markedly age- dependent. One-third (34.3%) of children had malaria. Overall, 76.3% of chi ldren were anaemic (haemoglobin < 110 g/L), with the prevalence decreasing with age. Anaemia was significantly worst in children with heavy hookworm i nfection (> 200 eggs per gram). This relationship held for all ages, both s exes, and was independent of socioeconomic factors. The application of attr ibutable morbidity methods confirmed the contribution of hookworm infection to anaemia.