A survey of gastrointestinal parasites in a local government area of south-west Nigeria.

In the course of a survey of gastro-intestinal parasites among humans in Iwo Local Government area in South-Western Nigeria, eggs of helminths found were those of Ascaris lumbricoides, Necator americanus, Trichuria trichiura and Strongyloides stercoralis while protozoan cysts encountered were those of Entamoeba histolytica and Entamoeba coli. About 51% of the 283 faecal samples were positive for parasitic ova or cysts and 24% possessed mixed infection. Incidence of Ascaris was highest followed by Trichuris and Necator. Peak of Ascaris infection was among the 1-10 years age group while that of hookworm and Trichuris was in the 11-20 years age-group. Sixteen (16) combination of mixed infections were found of which that of hookworm and Trichuris was the commonest. Incidence of polyparasitism increases with age until it reached a peak in the 21-40 years age-group.