Understanding the seasonality of Campylobacter infection in commercial broiler chickens
Abstract T7
Presenter: Daniel Phillips (Swansea University)
Campylobacter infection in chickens and humans follows a seasonal pattern, with an increase in warmer months. This study aims to determine causal links between the seasonal onset of Campylobacter infection in housed chickens and weather parameters, farm construction and husbandry events. We conducted a time-series investigation of the daily presence/absence of Campylobacter in chicken houses on 11 commercial farms around Herefordshire, UK. The project was split into two phases. The first phase covered 10 consecutive production cycles in each house and assessed whether flocks are infected with Campylobacter earlier in summer than winter and if infection onset was linked to weather. The second phase focussed on a subset of 4 houses for 7 consecutive production cycles and explored whether environmental Campylobacter detection was associated with house infection. For both phases, daily bootsocks were worn by farm staff within the chicken house and were tested using real-time multiplex qPCR for Campylobacter 16S, C. jejuni HipO and C. coli GlyA to identify any infection start/end days. For the second phase, additional bootsocks were taken from each farms yard in front of the chicken houses. Management parameters such as house internal temperature/humidity regulation, weather data and farm construction/geography were recorded. Data were analysed using General Additive Models and Survival Analysis to assess the impact of each parameter on the presence of Campylobacter within each flock. Campylobacter was detected in 54% of production cycles across both phases. Over 90% of infections were caused by C. jejuni. The probability of a house being positive for Campylobacter differed significantly between houses, increased with bird age, and was linked to the interaction between internal house temperature and humidity. Campylobacter were first detected at 28 1 days of age (mean, SEM), but the day of onset did not differ significantly with season or weather. Once Campylobacter positive, flocks rarely became negative again. Less than 3% of samples collected from the farmyard were Campylobacter positive, indicating that it was not a likely source of infection. Internal house temperature was harder to control late in the cycle and during summer, suggesting a heat stress effect on Campylobacter incidence. Reverse flow ventilation (p = 0.014) and steel clearspan construction (p < 0.001) were associated with fewer infections than other house constructions. In conclusion, we found that Campylobacter infection of commercial chickens was not likely to be acquired from the farmyard environment. However, detection of Campylobacter was associated with the type of house construction and with how well house parameters such as temperature and humidity were managed. This study identifies risk factors associated with Campylobacter infection and will inform on-farm biosecurity decisions.
About the presenter
Daniel Phillips is a final year PhD student at Swansea University, who has been working with Campylobacter spp. in chickens and food production since 2012. He has previously attended Cardiff University and Bangor University before working in the poultry industry for Cargill Meats Europe and Avara Foods Ltd. in laboratory, field research and data analysis roles. He has previously been involved in projects studying vertical transmission of Campylobacter in chickens, processing plant based interventions to reduce contamination on carcasses and the use of probiotic agents on poultry.
Presenting in Speaking session 3 - Epidemiology and public health