title: Giardia and Cryptosporidium on dairy farms and the role these farms may play in contaminating water sources in Prince Edward Island, Canada.
abstract: BACKGROUND
  Cattle represent a reservoir for Giardia and Cryptosporidium and may contaminate water sources.
  
  
  OBJECTIVE
  To determine the distribution of Cryptosporidium and Giardia on dairy farms and in water bodies near the farms. FARMS AND WATER SOURCES: Twenty dairy farms and 20 wells and 13 surface water samples associated with dairy farms.
  
  
  METHODS
  Proportions of samples positive for Cryptosporidium or Giardia were determined by a direct immunofluorescence assay. Fecal and water samples were taken at different times.
  
  
  RESULTS
  Thirty-two (95% CI: 29-35%) and 14% (95% CI: 12-17%) of fecal samples, and 100 (95% CI: 96-100) and 55% (95% CI: 32-77%) of herds, were positive for Giardia and Cryptosporidium, respectively. Giardia duodenalis assemblage E was detected in high proportions (90%) of fecal samples. Cryptosporidium bovis predominated (51%) in all cattle. C. andersoni predominated in adult cattle (53%), whereas the predominant species in animals < 2 months and 2-6 months was C. bovis, respectively. Only calves < 2 months of age were positive for C. parvum. In 46% (95% CI: 19-75%) and 85% (95% CI: 55-98%) of surface water, concentrations of Giardia cysts and Cryptosporidium oocysts were higher in downstream, than in upstream, locations of farms, whereas only 1 groundwater sample was positive for Cryptosporidium.
  
  
  CONCLUSIONS
  This sample of dairy cattle was predominantly infected with nonzoonotic species and genotypes of Cryptosporidium, Giardia, or both. More studies are needed to determine if the presence of Giardia or Cryptosporidium in surface water was associated with shedding in animals from nearby farms.
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada. EBAMOAKO@biofoodtech.ca
authors.forename: E
authors.initials: E
authors.lastname: Budu-Amoako
authors.forename: S J
authors.initials: SJ
authors.lastname: Greenwood
authors.forename: B R
authors.initials: BR
authors.lastname: Dixon
authors.forename: H W
authors.initials: HW
authors.lastname: Barkema
authors.forename: J T
authors.initials: JT
authors.lastname: McClure
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology*; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D003458:Cryptosporidium / Q000235:genetics / Q000302:isolation & purification*; D016054:DNA, Protozoan / Q000737:chemistry / Q000145:classification / Q000235:genetics; D003612:Dairying; D005243:Feces / Q000469:parasitology; D005260:Female; D005838:Genotype; D005872:Giardia / Q000235:genetics / Q000302:isolation & purification*; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D060587:Groundwater / Q000469:parasitology*; D010270:Parasite Egg Count / Q000662:veterinary; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011325:Prince Edward Island / Q000453:epidemiology
chemical_list: D016054:DNA, Protozoan