Gastrointestinal Parasite Occurrence and Faecal Parasite Output in Wild Mammals and Livestock Associated with Nature Reserves in South Africa

Gastrointestinal parasites (GIPs) can affect wildlife health and livestock productivity and are of epidemiological interest at wildlife–livestock interfaces. This study characterised GIP occurrence and faecal parasite output (FPO) in wild mammals and livestock associated with Nduli and Luchaba Nature Reserves in the Eastern Cape, South Africa. A total of 1440 faecal samples were collected between November 2025 and August 2026, from wild mammals (n = 800) and livestock (n = 640) in adjacent communal areas. Wild mammals comprised impala, red hartebeest, and zebra, while livestock comprised cattle and sheep. Samples were collected from boundary (0–100 m) and core (>100 m) zones and examined using centrifugal flotation, McMaster, and sedimentation techniques. GIP categories were identified based on the morphological characteristics of eggs and cysts/oocysts. All faecal samples examined were positive for at least one GIP category. Five nematode, two trematode, and two cestode categories, as well as protozoan cysts/oocysts, were detected in wild mammal faecal samples, while livestock samples contained four nematode, two trematode, and one cestode categories, as well as protozoan cysts/oocysts. Eight morphologically identified GIP categories were shared between the two host groups. Strongyle-type nematodes had the highest occurrence and mean faecal parasite output among the categories detected. No significant spatial differences in FPO were detected. Seasonal differences were also non-significant for most host groups, except red hartebeest at Luchaba Nature Reserve, which had lower FPO during the colder period (April–August). Reported percentages reflect faecal samples rather than necessarily the proportion of individual animals infected. The detection of shared parasite categories indicates overlap in the parasite groups detected but does not establish cross-transmission between host species. These findings provide baseline information to support continued surveillance at wildlife–livestock interfaces.