title: Risk factors for Campylobacter spp. colonization in broiler flocks in Iceland.
abstract: We sampled 1,091 Icelandic broiler flocks at slaughter from May 2001 to December 2003 to determine the prevalence of, and investigate risk factors for the presence of, Campylobacter spp. at the flock level. Approximately 15% of the flocks were positive for Campylobacter spp.; most (95%) of the infected flocks being raised during the months of April-September. Based on the data from the latter months, and using multivariable logistic regression with random effects for herd, we found that the odds of a flock being positive for Campylobacter spp. increased with age and flock size. Additionally, vertical ventilation systems were strongly associated with positive flocks (OR=5.3). After controlling for these variables, we found no evidence of an effect of: year; company; Campylobacter being carried over from one flock to the next; time interval between flocks; using (at the hatcheries) eggs laid on the floor; density of bird housing, or the number of catch lots a flock was divided into for slaughtering purposes on the risk of a Campylobacter-positive flock.
authors.affiliation: Department of Population Medicine, University of Guelph, Guelph, Ont., Canada N1G 2W1.
authors.forename: Pablo Romero
authors.initials: PR
authors.lastname: Barrios
authors.forename: Jarle
authors.initials: J
authors.lastname: Reiersen
authors.forename: Ruff
authors.initials: R
authors.lastname: Lowman
authors.forename: Jean-Robert
authors.initials: JR
authors.lastname: Bisaillon
authors.forename: Pascal
authors.initials: P
authors.lastname: Michel
authors.forename: Vala
authors.initials: V
authors.lastname: Fridriksdóttir
authors.forename: Eggert
authors.initials: E
authors.lastname: Gunnarsson
authors.forename: Norman
authors.initials: N
authors.lastname: Stern
authors.forename: Olaf
authors.initials: O
authors.lastname: Berke
authors.forename: Scott
authors.initials: S
authors.lastname: McEwen
authors.forename: Wayne
authors.initials: W
authors.lastname: Martin
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002167:Campylobacter / Q000302:isolation & purification; D002169:Campylobacter Infections / Q000453:epidemiology / Q000662:veterinary*; D002645:Chickens; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D011201:Poultry Diseases / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors; D012621:Seasons; D014691:Ventilation