title: Patterns of Cryptosporidium oocyst shedding by eastern grey kangaroos inhabiting an Australian watershed.
abstract: The occurrence of Cryptosporidium oocysts in feces from a population of wild eastern grey kangaroos inhabiting a protected watershed in Sydney, Australia, was investigated. Over a 2-year period, Cryptosporidium oocysts were detected in 239 of the 3,557 (6.7%) eastern grey kangaroo fecal samples tested by using a combined immunomagnetic separation and flow cytometric technique. The prevalence of Cryptosporidium in this host population was estimated to range from 0.32% to 28.5%, with peaks occurring during the autumn months. Oocyst shedding intensity ranged from below 20 oocysts/g feces to 2.0 x 10(6) oocysts/g feces, and shedding did not appear to be associated with diarrhea. Although morphologically similar to the human-infective Cryptosporidium hominis and the Cryptosporidium parvum "bovine" genotype oocysts, the oocysts isolated from kangaroo feces were identified as the Cryptosporidium "marsupial" genotype I or "marsupial" genotype II. Kangaroos are the predominant large mammal inhabiting Australian watersheds and are potentially a significant source of Cryptosporidium contamination of drinking water reservoirs. However, this host population was predominantly shedding the marsupial-derived genotypes, which to date have been identified only in marsupial host species.
authors.affiliation: Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia. mpower@vetsci.usyd.edu.au
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Power
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Sangster
authors.forename: Martin B
authors.initials: MB
authors.lastname: Slade
authors.forename: Duncan A
authors.initials: DA
authors.lastname: Veal
mesh_terms: D000818:Animals; D001315:Australia; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D003458:Cryptosporidium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D005243:Feces / Q000469:parasitology*; D005838:Genotype; D007614:Macropodidae / Q000469:parasitology*; D033661:Oocysts / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D010270:Parasite Egg Count; D015995:Prevalence; D014881:Water Supply