title: Environmental and geographical factors contributing to watershed contamination with Cryptosporidium parvum oocysts.
abstract: Cryptosporidium parvum is a waterborne parasite which infects cattle and produces life-threatening zoonosis in people with impaired immune systems. Digital maps of 100-year floodplain boundaries, land use/cover, and livestock operations were used to select and characterize cattle farms in the floodplain area in Lancaster County, Pennsylvania, U.S.A. Over 21% of the cattle farms were located within 100-year floodplain boundaries. On average, a single farm comprised 12.8 ha of pasture (including buildings and farmyard) at risk of inundation. In all farms cattle had unlimited access to the creek. Manure samples collected from closed-in calf pens, cow/heifer yard runoff, and cattle paths through the creek were tested for C. parvum. On 64% of the farms (n=50) at least one sample was positive for C. parvum, and 44% of the farms had oocysts in all manure samples. Concentration varied from 90 to 371 oocysts/g and was significantly higher (P<0.02) in calf samples than in manure from cow and cow/heifer.
authors.affiliation: Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, Maryland 21205, USA.
authors.forename: T K
authors.initials: TK
authors.lastname: Graczyk
authors.forename: B M
authors.initials: BM
authors.lastname: Evans
authors.forename: C J
authors.initials: CJ
authors.lastname: Shiff
authors.forename: H J
authors.initials: HJ
authors.lastname: Karreman
authors.forename: J A
authors.initials: JA
authors.lastname: Patz
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002417:Cattle; D003457:Cryptosporidiosis / Q000453:epidemiology*; D016785:Cryptosporidium parvum / Q000302:isolation & purification*; D007171:Implosive Therapy; D010414:Pennsylvania / Q000453:epidemiology; D011634:Public Health; D018570:Risk Assessment; D014873:Water Pollutants / Q000032:analysis*; D014881:Water Supply
chemical_list: D014873:Water Pollutants