title: Second outbreak of infection with a rare Cryptosporidium parvum genotype in schoolchildren associated with contact with lambs/goat kids at a holiday farm in Norway.
abstract: In March 2012, a second outbreak of Cryptosporidium parvum affected children following a stay at a holiday farm in Norway; the first outbreak occurred in 2009. We studied a cohort of 145 schoolchildren who had visited the farm, of which 40 (28%) were cases. Cryptosporidium oocysts were detected in faecal samples from humans, goat kids and lambs. Molecular studies revealed C. parvum subtype IIa A19G1R1 in all samples including human samples from the 2009 outbreak. A dose-response relationship was found between the number of optional sessions with animals and illness, increasing from two sessions [risk ratio (RR) 2·7, 95% confidence interval (CI) 0·6-11·5] to six sessions (RR 8·0, 95% CI 1·7-37·7). The occurrence of two outbreaks 3 years apart, with the same subtype of C. parvum, suggests that the parasite is established in the farm's environment. We recommend greater emphasis on hand hygiene and routines related to animal contact.
authors.affiliation: Department of Infectious Disease Epidemiology,Norwegian Institute of Public Health,Oslo,Norway.
authors.forename: H
authors.initials: H
authors.lastname: Lange
authors.affiliation: Department of Microbiology, Vestfold Hospital Trust,Tønsberg,Norway.
authors.forename: O H
authors.initials: OH
authors.lastname: Johansen
authors.affiliation: Department of Infectious Disease Epidemiology,Norwegian Institute of Public Health,Oslo,Norway.
authors.forename: L
authors.initials: L
authors.lastname: Vold
authors.affiliation: Department of Food Safety & Infection Biology,Norwegian School of Veterinary Science,Oslo,Norway.
authors.forename: L J
authors.initials: LJ
authors.lastname: Robertson
authors.affiliation: Department of Microbiology, Vestfold Hospital Trust,Tønsberg,Norway.
authors.forename: I L
authors.initials: IL
authors.lastname: Anthonisen
authors.affiliation: Department of Infectious Disease Epidemiology,Norwegian Institute of Public Health,Oslo,Norway.
authors.forename: K
authors.initials: K
authors.lastname: Nygard
mesh_terms: D000293:Adolescent; D000818:Animals; D002648:Child; D015331:Cohort Studies; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000635:transmission / Q000662:veterinary; D016785:Cryptosporidium parvum / Q000235:genetics*; D004196:Disease Outbreaks; D005243:Feces / Q000469:parasitology; D005260:Female; D005838:Genotype; D015511:Goat Diseases / Q000453:epidemiology* / Q000635:transmission; D006041:Goats; D006693:Holidays; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology* / Q000635:transmission