Intestinal parasites of school children in urban and rural areas of Eastern Nigeria.

From October 1975 to March 1976 an epidemiological survey was carried out in Anambra and Imo states of Nigeria to determine the rate of intestinal worm and protozoan infections in school children. A total of 1742 children, out of which 813 from the urban and 929 from the rural school were screened of intestinal helminths and 1699 were also examined for intestinal protozoan infections. Concentration methods HCL-Ether centrifugation technique and Heidenhain's iron-hematoxylin staining method respectively were adopted for the identification of helminth eggs and protozoal cysts. 1405, i.e. 81% of the total number examined, eggs of one or more helminth species were detected. Carriage-rates of helminth infections were highest (87%) in children from the rural schools, in whom hookworm (90% of carriers) predominated. Besides high rates of hookworm, ascaris and trichuris infections, other parasites of public health importance (Schistosoma mansoni, Paragonimus uterobilateralis and Diphylobothrium latum) were detected. Significantly an increase in the rate of helminthic infections with age was noted in the survey. 55% of the 1699 children examined were carriers of cysts of one or more protozoa species. Higher carriage-rate (56%) of protozoan infections was noted in urban children. Comparatively lambliasis predominated in the urban children, while infection with E. histolytica was recorded slightly higher in rural children.