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<p>The relative importance of the sources of Campylobacter in broilers will be determined using a modelling approach. The hypothesis on which the work plan is based is that some Campylobacter strains and some Campylobacter reservoirs are much more important than others in this process.</p>
<p>The study will determine the relative importance and the interaction of each strain/reservoir to identify the sources of Campylobacter, this will be used to establish the extent that other animals in the vicinity of the broiler house pose a risk for broiler colonisation. The study will also identify which intervention strategies would be best in reducing the risk of colonisation.</p>
The project approach follows three main work areas:
<ol><li>The dose response of eight different Campylobacter strains in broilers will be determined by looking at chicken to chicken colonisation efficacy of different Campylobacter strains. Once this has been achieved the work will go on to investigate the efficacy of chicken colonisation from Campylobacter strains originating from cattle, sheep and pigeons. Competitive colonisation and competitive exclusion between the different strains will be examined with the data finally used to develop a mathematical dose response model which incorporates the complex interactions of strains.</li>
<li>The survival of different Campylobacter strains in key environmental matrices will be determined. Survival studies will be performed in a range of matrices associated with the broiler environment, including faeces from cattle, sheep, pigeons and chickens, loam soil, water and chicken litter waste. Faeces from cattle, sheep and chicken will be naturally contaminated while soil and water will be spiked. A range of models will be applied to investigate survival and test the goodness of fit for each method. Using this method the time for a single log reduction in Campylobacter will be estimated and compared with each of the different strains and matrices.</li>
<li>The relative importance of the sources causing Campylobacter infection in broiler farms will be investigated and strategies to mitigate these risks developed. To achieve this a transmission model will be developed to simulate the flow of Campylobacter from animal sources. This will be developed in stages starting with a single strain of Campylobacter, single source animal and a single broiler house. Using these models the relative risk of infection by animal source and strain will also be determined. Finally, intervention simulations will be performed using the models. Amongst others, these will investigate the effect of the removal of certain farm animals from the environment, restriction of access to poultry and the reduction of wild birds in the vicinity of the broiler house.</li></ol>
<p>Background: Studies have shown that the main causes of human Campylobacter infection is from eating improperly cooked meat or because of cross-contamination to uncooked foods.</p>
<p>To reduce the burden of human infection, it is believed that informed biosecurity interventions on broiler farms are most likely to achieve a reduction in Campylobacter in poultry. This project will investigate and develop a number of novel biosecurity controls on high throughput broiler production.</p>
<p>Previous studies of the sources of Campylobacter infection in humans identified the principle source as broiler chickens. It has also been shown that strains found in humans, chickens, cattle, sheep, wild birds, pigs were quite distinct with some strains common to several hosts. This study will aim to better understand the relative importance of the potential sources of Campylobacter in broilers by using a modelling approach. By quantifying their relative importance and interaction, it is hoped that the source of Campylobacter in the broiler house will be identified.</p>
<p>This information will be used to inform and introduce effective measures to prevent colonisation of these birds. Further, these findings will enable policy to be developed to define which control measures are most effective. </p>