Cryptosporidium sp and Giardia sp infections in mountain gorillas (Gorillagorilla beringei) of the Bwindi Impenetrable National Park, Uganda

For conservation purposes and because of growing ecotourism, some mountain gorilla (Gorilla gorilla beringei) populations have been habituated to huma ns. Fecal specimens (n = 100) of nonhabituated and human-habituated gorilla s (5 populations; 6 age classes) were tested for Cryptosporidium sp. oocyst s and Giardia sp. cysts by conventional staining and immunofluorescent anti body (IFA). Cryptosporidium sp. infections (prevalence 11%) were not restri cted to very young gorillas but were observed in 3-yr-old to >12-yr-old gor illas most of the infections (73%) occurred in human-habituated gorillas. T he prevalence of Giardia sp. infections was 2%; 1 nonhabituated gorilla was concomitantly infected. Oocysts of Cryptosporidium sp. in the gorilla stoo ls were morphologically, morphometrically, and immunologically undistinguis hable from a bovine isolate of Cryptosporidium parvum oocysts. Mean concent ration of Cryptosporidium sp. oocysts and Giardia sp. cysts in gorilla stoo ls was 9.39 x 10(4)/g, and 2.49 x 10(4)/g, respectively. There was no appar ent relationship between oocyst concentration and gorilla age, sex, or habi tuation status. Most Cryptosporidium sp. infections found in gorillas with closest proximity to people may be a result of the habituation process and ecotourism. This study constitutes the first report of Cryptosporidium sp. infections in the family Pongidae, in the free-ranging great apes, and in t he species of gorilla.