A study of blood and gastro-intestinal parasites in Edo state

Abstract

A four-year study to determine the prevalence of both blood and gastro-intestinal parasites of man was done in all the eighteen local government areas of Edo State, Nigeria. The study, which commenced in January of 2000, ended in December of 2004. Of the 136,360 samples examined, 1000 that is 0.7% had parasites. A total of eleven parasites species were identified. A seasonal pattern of parasitic infection was noted with a high prevalence in the rainy (wet) season months of April to November and a low prevalence in the dry season months of December to March. The prevalence was significantly higher in September, October and November at 22, 10 and 10% respectively (P<0.05); than other months of the year. February had the least prevalence of 10%. The local government areas in the rain-forest zone,
south of the state had significantly higher prevalence than the local government areas in the grassland, north of the state (P<0.05). Of the eleven parasite species observed in the study, Ascaris lumbricoides
and Plasmodium falciparum had the highest prevalence of 30 and 35%, respectively. Hookworm parasites, Trichuris triciura and Strongyloides stercoralis had the prevalence of 10, 7 and 1%, respectively. The protozoans, Entamoeba coli, Entamoeba histolytica, and Giardia lamblia had prevalence of 6, 4 and 3% respectively. Schistosoma haematobium, Loa loa and Enterobius vermicularis had the least prevalence of 2, 1 and 1%, respectively. With the exception of S.
haematobium, E. vermicularis, and L. loa, which occurred in few local government areas, the other eight parasite species were encountered in all the local government areas. There was a higher prevalence of parasitic infections in this study than in the hospital records in the state.