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<p>The continued surveillance of campylobacteriosis in Oxfordshire undertaken by this project will establish which Campylobacter (C. jejuni and C. coli) genotypes persistent in the food chain can be eliminated by different intervention methods, contributing to a reduction in the burden of human disease. This will be achieved by:</p>
<p><b>1. Characterisation and storage of isolates (Years 1 - 3):</b><br/>
1.1. Collection and molecular characterisation of isolates from human disease in Oxfordshire, UK (~800 per year) by ten-locus typing (MLST plus flaA, flaB and porA) on a real-time basis (milestones 1-3);<br/>
1.2. Collation and linkage of epidemiological information for all samples (including patient demographic information), in a private database but linked to the publicly accessible isolate genotype data by a unique identifier (milestones 4-6);<br/>
1.3. Storage and cataloguing of isolates for access by the research community (milestones 7-9).</p>
<p><b>2. Data archiving and analysis:</b><br/>
2.1. Quantitative monitoring of human food-chain interventions by comparison of existing baseline and real-time data with that from associated studies (milestones 10-12);<br/>
2.2. Linking of epidemiological and molecular isolate data allowing outputs in a variety of formats compatible with genealogical and attribution analyses programmes (milestones 13-15);<br/>
2.3. Real-time monitoring of molecular data linked with public health information (ongoing throughout project, audited at each year end, milestones 16-18);<br/>
2.4. Attribution analysis of molecular data data with other in-house or published datasets from both agricultural and non-agricultural sources in real time throughout project, audited at each year end (milestones 19-21).</p>
<p><b>3. Data dissemination:</b><br/>
3.1. Publication of data summary on the website to guide users (milestones 22);<br/>
3.2. Publication of analyses in international peer-reviewed journals (milestone 23);<br/>
In conclusion, sentinel surveillance of Oxfordshire human campylobacter isolates will provide invaluable final outcome data to support measurement of the impact of interventions in the human food chain to reduce chicken-associated human campylobacteriosis.</p>
<p>Campylobacter infection is the most common cause of human bacterial gastroenteritis worldwide, causing approximately 400,000 cases annually in the UK at an estimated cost of £580 million each year. These bacteria are widely distributed as apparently harmless commensal gastrointestinal inhabitants of wild and farm birds and animals which provide sources of human infection, both directly and via consumption of the infected animal. Despite the high incidence of human disease, single point outbreaks are not commonly resolved and in any given case, the precise source of infection usually remains unidentified. Over the past 10 years the application of Multilocus sequence typing (MLST), has established that the genetically diverse Campylobacter populations are structured into clonal complexes, groups of related bacteria that share a common ancestor. Data generated from animal and human studies demonstrate that worldwide members of some clonal complexes are associated with certain farm animals and human disease.</p>
<p>Previous collection and sequenc typing of over 5,000 human Campylobacter isolates from Oxfordshire, obtained from 2003 to date, has shown that they are genetically similar to those from an overlapping time period in north-west England, but that they differ from isolates in Australia and especially from Curacao, Dutch West Indies. Additionally, sentinel surveillance of human isolates obtained from Hampshire and Nottinghamshire between 2000 and 2003 display an identical distribution of clonal complexes. Further, comparisons with MLST data from Scottish clinical samples confirm that the Oxfordshire isolates are representative of those causing campylobacteriosis UK-wide. Typing of human disease isolates in New Zealand has confirmed the key role of poultry consumption in human infection and has been successfully used to monitor impact of control programmes in the poultry industry.</p>
<p>This project will continue sentinel surveillance typing of Campylobacter isolates from Oxfordshire during the introduction of interventions in the human food chain to reduce chicken-associated human campylobacteriosis. All human Campylobacter isolates submitted to the John Radcliffe Hospital, Oxford (approximately 800 per year) will undergo 10 locus sequence typing (MLST plus the antigen genes flaA, flaB and porA), to provide a high level of discrimination between more commonly found sequence types and facilitate possible outbreak detection. The strain characterisation data will be published to an Internet-accessible database in real time or near real time, thus making them promptly available to the policy, research, industry and human and veterinary public health communities. This will allow the quantitative monitoring of the impact of interventions against the final outcome of human disease burden. As well as providing essential data to those working at other stages of the food chain, staff on this project will, where requested, collaborate in joint analysis of data from other studies. The publicly available data over the three-year course of this project will span the period of currently planned interventions. Historical data will also be available for joint analysis where a longer baseline is needed for analysis.</p>