Comparative prevalences of some common intestinal helminth infections in different altitudinal regions in Ethiopia.

Infection prevalences of Ascaris lumbricoides, Trichuris trichiura and the hookworms in school children in several communities of three altitudinal regions in Ethiopia have been analyzed. The prevalence of A. lumbricoides infection was 29% in the highlands, 35% in the temperate areas and 38% in the lowlands. The prevalence of hookworm infection was highest in the lowlands (24%) followed by the temperate (15%) and highland (7%) areas and the difference was significant (p < 0.0001). T. trichiura infection exhibited similar prevalences in all altitudinal regions (13% on the average). The prevalence of infection due to Ascaris lumbricoides and Trichuris trichiura was significantly correlated (rs = 0.55, p < 0.001) in the lowlands hinting the closely related distribution and co-occurrence of these parasites. The prevalence of infection due to the hookworms and T. trichiura in the temperate areas showed some pattern of association (rs = 0.29). A similar pattern has also been noted between the prevalence of infection due to A. lumbricoides and T. trichiura in the highland areas (rs = 0.48). The co-occurrence of A. lumbricoides and T. trichiura infections in the lowlands and in the highlands suggest that a concurrent intervention against infection due to these two parasites using the same control methods would be advantageous.