House-level risk factors associated with the colonization of broiler flocks with Campylobacter spp. in Iceland, 2001 – 2004

• Published in: BMC Veterinary Research
• Main Authors: Berke Olaf, Reiersen Jarle, Martin Wayne, Guerin Michele T, McEwen Scott A, Bisaillon Jean-Robert, Lowman Ruff
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2007
• Subjects: Veterinary medicine; SF600-1100; Slaughter; Iceland
• Online Access: https://doi.org/10.1186/1746-6148-3-30; https://doaj.org/article/2f627474c34c4c83a66dd1d031957b93

Abstract Background The concurrent rise in consumption of fresh chicken meat and human campylobacteriosis in the late 1990's in Iceland led to a longitudinal study of the poultry industry to identify the means to decrease the frequency of broiler flock colonization with Campylobacter . Because horizontal transmission from the environment is thought to be the most likely source of Campylobacter to broilers, we aimed to identify broiler house characteristics and management practices associated with flock colonization. Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for Campylobacter . Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Logistic regression models with a farm random effect were used to analyse the association between flock Campylobacter status and house-level risk factors. A two-stage process was carried out. Variables were initially screened within major subsets: ventilation; roof and floor drainage; building quality, materials and repair; house structure; pest proofing; biosecurity; sanitation; and house size. Variables with p ≤ 0.15 were then offered to a comprehensive model. Multivariable analyses were used in both the screening stage (i.e. within each subset) and in the comprehensive model. Results 217 out of 792 flocks (27.4%) tested positive. Four significant risk factors were identified. Campylobacter colonization was predicted to increase when the flock was raised in a house with vertical (OR = 2.7), or vertical and horizontal (OR = 3.2) ventilation shafts, when the producer's boots were cleaned and disinfected prior to entering the broiler house (OR = 2.2), and when the house was cleaned with geothermal water (OR = 3.3). Conclusion The increased risk associated with vertical ventilation shafts might be related to the height of the vents and the potential for vectors such as flies to gain access to the house, or, increased ...