A52-75-2007E.pdf - AgroMedia International Inc

Health24Genotype and subtype analyses of Cryptosporidium isolates fromdairy calves and humans in OntarioCorresponding AuthorTrotz-Williams, L.A.University of GuelphCollaboratorsMartin, D.S.Ontario Ministry of Health andLong-Term CareGatei, W.USDHHS Centers for DiseaseControl and PreventionCama, V.USDHHS Centers for DiseaseControl and PreventionPeregrine, A.S.University of GuelphMartin, S.W.University of GuelphNydam, D.V.Cornell UniversityJamieson, F.Ontario Ministry of Health andLong-Term CareParasitology Research (2006) Vol. 99 p. 346-352.Cryptosporidia are protozoan parasites that can infect and cause diarrheain humans and many wild and domestic animals, including cattle.Although effects are usually mild and short-lived, death may occur in newbornanimals and people with compromised immune systems. Treatmentoptions are limited. Hosts excrete large numbers of Cryptosporidium oocystsin their feces. Infections can spread rapidly when others come intodirect contact with feces or consume contaminated water. Several speciesof Cryptosporidium can be passed between humans and animals. Cryptosporidiumparvum is the most common species in domestic ruminants andinfections are common among dairy calves. One study reported that 59%of dairy calves under 24 weeks of age in British Columbia were sheddingoocysts. Another found infected calves on 89% of 505 Quebec dairy farms.In southern Ontario, work carried out on 51 dairy farms found that 40.6% of500 calves aged 7 to 21 days were shedding oocysts. This high prevalenceof Cryptosporidium infections on dairy farms suggested that dairy calvesmight be a potential source of infections in humans. The objective of thepresent study was to determine whether human cases of infection in Ontariowere due to the same species of Cryptosporidium that were foundon dairy farms in that province. Of 44 isolates from infected dairy calves,all were of the same species of Cryptosporidium parvum. Isolates from 11human cases were of a variety of species; 3 were the same as that foundin calves.Health 75