Cryptosporidiosis: a brief literature review and update regarding Cryptosporidium in feces of Canada geese (Branta canadensis).

Canada geese are increasingly abundant in Ohio, with large nesting populations throughout the state, and goose feces contaminate grassy areas and pavements in many public, commercial, and residential sites. In 1999 the authors found a high prevalence of Giardia, Campylobacter, and especially Cryptosporidium in collected feces of Canada geese. The purpose of this follow-up study was to survey known Canada geese sites in three counties in Ohio (Lucas, Ottawa, and Wood) and to determine the prevalence of sites testing positive for Cryptosporidium. The sites included golf courses, cemeteries, public parks, and health care and teaching facilities. At each of 11 sites, 12 goose feces of wet and loose appearance were collected and manually compressed into one composite sample representing that site. The samples were tested for Cryptosporidium with a sensitive monoclonal enzyme immunoassay (EIA) method. In 2000 and 2001, nine of 11 sites (81.8 percent) and nine of 10 sites (90 percent), respectively, were positive for Cryptosporidium. The species or genotypes of Cryptosporidium found in the geese feces and their potential to infect humans is unknown. A survey of the literature indicates, however, that while C. parvum (human genotype) is the main cause of cryptosporidiosis in humans, C. parvum (zoonotic genotypes), C. meleagridis (bird genotype), and C. felis (cat genotype) have occasionally been isolated from infected people. Further research is required to define the public health importance of Cryptosporidium in feces of Canada geese and other bird species.