Helminth parasites of impalas, Aepyceros melampus, in eastern southern Africa, collected during 1973 to 2007.

This paper summarises published and unpublished data on helminths collected systematically from 424 impalas at 11 localities in eastern southern Africa, from St. Lucia in KwaZulu-Natal (KZN) to the Tuli Block in north-eastern Botswana. It includes data on collections in the Kruger National Park (KNP) in the drought of 1982, and in 1992/93 following the 1991/92 drought. Thirty-three species of nematodes, plus six taxa identified only to the generic level, three taxa of trematodes, and three species of cestodes were collected. Helminth species richness was highest in the southern KNP and lowest in the Tuli Block. The prevalence and intensity of infection of several helminths also declined from KZN and the southern KNP to the drier areas in the north and west. With the exception of St. Lucia and Nylsvley, > 80% of the helminths collected at each locality were collected in the southern KNP. St. Lucia was the most dissimilar locality; of the 20 helminths collected, five were unique. Ten of 33 species of nematodes, the paramphistomines (Trematoda) and the cestode Stilesia hepatica were collected at seven or more localities. Six of the most common nematodes, Cooperia hungi, Cooperioides hamiltoni, Impalaia tuberculata, Longistrongylus sabie, Strongyloides papillosus and Trichostrongylus deflexus are primarily parasites of impalas in the southern KNP, whereas many of the helminths collected at only one or two localities are parasites of other hosts. Nematode burdens were increased in the drought affected impalas in 1982, but helminth burdens decreased in 1992/93 following a dry cycle.