For conservation purposes and because of growing ecotourism, some mountain gorilla (Gorilla gorilla beringei) populations have been habituated to humans. Fecal specimens (n = 100) of nonhabituated and human-habituated gorillas (5 populations; 6 age classes) were tested for Cryptosporidium sp. oocysts and Giardia sp. cysts by conventional staining and immunofluorescent antibody (IFA). Cryptosporidium sp. infections (prevalence 11%) were not restricted to very young gorillas but were observed in 3-yr-old to >12-yr-old gorillas; most of the infections (73%) occurred in human-habituated gorillas. The prevalence of Giardia sp. infections was 2%; 1 nonhabituated gorilla was concomitantly infected. Oocysts of Cryptosporidium sp. in the gorilla stools were morphologically, morphometrically, and immunologically undistinguishable from a bovine isolate of Cryptosporidium parvum oocysts. Mean concentration of Cryptosporidium sp. oocysts and Giardia sp. cysts in gorilla stools was 9.39x10(4)/g, and 2.49x10(4)/g, respectively. There was no apparent relationship between oocyst concentration and gorilla age, sex, or habituation 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 the species of gorilla.

We describe the bacterial diversity in fecal samples of a wild gorilla by use of a 16S rRNA gene clone library and terminal-restriction fragment length polymorphism (T-RFLP). Clones were classified as Firmicutes, Verrucomicrobia, Actinobacteria, Lentisphaerae, Bacteroidetes, Spirochetes, and Planctomycetes. Our data suggest that fecal populations did not change temporally, as determined by T-RFLP.

For conservation purposes and due to growing ecotourism, free-ranging mountain gorillas (Gorilla gorilla beringei) have been habituated to humans. Fecal specimens (n ϭ 62) collected in January 1999 from mountain gorillas of the Bwindi and Mgahinga National Parks, Uganda, were tested for Campylobacter spp., Salmonella spp., and Shigella spp., and the overall prevalence of infection was 19%, 13%, and 6%, respectively. The prevalence of positive specimens was not related to the year of habituation of a gorilla group to humans. Campylobacter spp., Salmonella, and Shigella spp. infections were not distributed equally among the age classes of gorillas; most of the enteropathogens (80%), and all Shigella spp. organisms, S. sonnei, S. boydii, and S. flexneri, were isolated from subadults and adult gorillas with ages ranging from 6.0 to 11.9 yr. The prevalence of Campylobacter spp. and Salmonella spp. infections among human-habituated gorillas has doubled during the last 4 yr, and isolation of Shigella spp. for the first time from mountain gorillas, may indicate enhanced anthropozoonotic transmission of these enteropathogens.

For behavioral research and due to growing ecotourism, some populations of free-ranging mountain gorillas (Gorilla gorilla beringei) have become habituated to humans. Molecular analysis of two Cryptosporidium sp. oocyst isolates originating from two human-habituated gorilla groups and two oocyst isolates from non-habituated gorillas yielded positive identification of C. parvum Genotype 2 (G2; i.e., "cattle", "animal-adapted", or "zoonotic"). As G2 is cross-transmissible between humans and animals, C. parvum infections can be propagated in the habitats of human-habituated, free-ranging gorillas through both zoonotic and anthroponotic transmission cycles.