Intestinal parasitic infections in schoolchildren of Abha (Asir), Saudi Arabia.

Stool specimens from 1282 children between the age of 5 and 13 years attending 10 primary schools for boys in the city of Abha, southwestern Saudi Arabia, were examined for the presence of intestinal parasites. Of these, 313, (24.4%) were found infected with one or more species of 11 intestinal protozoa and helminths. The most common pathogenic protozoa being Giardia lamblia (10.9%) followed by Entamoeba histolytica (4.1%). The nonpathogenic protozoan, Entamoeba coli had the highest prevalence rate (11.3%) in the children's stools. Hymenolepis nana was the commonest intestinal helminth (3.0%). Other intestinal helminths, including Ascaris lumbricoides, Trichuris trichiura. Schistosoma mansoni, Dicrocoelium dendriticum were detected to a lesser extent. The distribution of the common intestinal infections among the children surveyed were also analysed according to age, nationality and multiplicity of infection. Prevalence of E. histolytica was found to increase with age whereas Giardia infections were less common among older children. This pair of parasite species were strongly associated. Yemeni children had consistently the highest prevalence of infection with protozoa and helminths, followed by Saudi and non-Saudi children.