Transmission of Campylobacter spp. to chickens during transport to slaughter

Aims: To determine the prevalence of Campylobacter- contaminated transport crates and to determine whether contaminated crates represent a risk for contamination of chickens during transport to slaughter. Methods and Results: Samples were collected from cleaned transport crates before they were dispatched to the farms. Chicken groups were sampled within 24 h before transport to slaughter and at the slaughterhouse. Campylobacter spp. were isolated from 69 of 122 ( 57%) sampled batches of transport crates. Twenty- six slaughter groups, negative at farm level, were transported in batches of crates from which Campylobacter spp. had been isolated. In 11 ( 42%) of these 26 slaughter groups, Campylobacter spp. were found in samples taken at slaughter. The corresponding figure for at- farm- negative slaughter groups transported in negative crates was four ( 15%) testing positive at slaughterhouse of 27 slaughter groups [ relative risk ( RR) 2.9, 95% CI 1.1 - 7.3]. In four of 11 slaughter groups, genetic subtyping by pulsed- field gel electrophoresis was able to support the hypothesis of contamination from crates to chickens during transport to slaughter. Conclusions: Despite washing and disinfection, crates were frequently contaminated with Campylobacter and it could have contaminated chickens during transport to slaughter. Significance and Impact of the Study: Campylobacter- positive crates are a risk factor for chickens testing campylobacter- positive at slaughter.