Seasonal prevalence of protozoan parasites in Nsukka, Nigeria.

Five hundred fresh stool specimens of patients with clinical symptoms of protozoan infections were examined for parasites. During June 1988-May 1991, the total number of positive cases was 261 (52.2 per cent). When the infectivity frequencies were segregated among the samples of different localities, it was observed that 6 (1.2 per cent) persons from the University of Nigeria community, 89 (17.8 per cent) urban dwellers and 166 (33.2 per cent) rural populace were infected. The highest incidence of Giardia lamblia (83, 47.8 per cent), Entamoeba histolytica (49, 28.3 per cent) and Chilomastix mesnili (34, 19.7 per cent) was found among the rural community. The infection started in April of each year (onset of rainy season), peaked between July and August, and was the lowest between November and March (dry season). Statistical interpretation of the results indicated that the parasitic infections depended on times of the year x2 0.01 > 4 calculated x2 0.01, 0.05 > 4 tabulated. The vehicle of transmission of the infection was green vegetable (Amaranthus viridans) which gets polluted by sewage oxidation pond at the locality.