Control Measures for Salmonella on Pig Farms and Their Effect on Endemic Disease and Productivity

<p>The prevalence of Salmonella in UK in both breeding and slaughter pigs is amongst the highest in Europe. Future regulatory and NCP targets are therefore likely to be very difficult to achieve. There is an urgent need to investigate in detail the effectiveness of control measures in the field, to define the best and most cost-effective methods, their benefit in terms of reduction of public health risk and other pathogens of economic importance in pig production and to effectively transmit the resulting information and guidance to pig producers in a highly motivational way. It is necessary to focus on farm reduction as well as measures in the abattoir as the latter can be undermined by high levels of infection in slaughter pigs and highly infected farms form a reservoir of Salmonella that can spread to other livestock sectors, feed production and contaminate the rural environment.</p>
<p>Objective one focuses on a detailed investigation of the protective factors that operated on low (<10% incidence) Salmonella seroprevalence pig farms, the so called ‘Platinum Pig farms’. Previous limited work and a small number of detailed AHVLA investigations of zero-seroprevalence farms have suggested that management of the time of exposure to infection to enhance ‘herd-immunity’ in finishing pigs is critical. We will carry out intensive veterinary microbiological investigations linked with a case control study to further elucidate protective factors on low prevalence farms. Objective two recognises international scientific evidence that there is no single control measure, or simple combination of control measures that can be successfully and economically applied to all pig farms and so a targeted farm-specific control plan is needed. Accredited pig farms are required to have a Salmonella control action plan in place but this can be a general tick-box exercise and is not based on bacteriological evidence, or monitored for effectiveness. Specific interventions such as feed or water acidification, vaccination, improved cleaning and disinfection of finishing pens, improved pest control, all-in/all out production, changes in feed formulation etc. can be included in such control plans and are being trialled by BPEX, pig veterinarians and pig farming companies in various uncontrolled and statistically non-valid ways. We will aim to link with such initiatives to provide statistical input and detailed investigation of the effects of such farm control plans on Salmonella and other production-limiting conditions. We will apply cost analyses and QMRA studies to these, evaluate compliance and refine applications to demonstrate the effectiveness of properly targeted approaches. Objective three will involve further refinement of the BPEX/FSA farm auditing tool to target it more effectively to evaluate measures associated with improved Salmonella control. Objective four will supply detailed data on the most effective detergent/sanitizers and disinfectants to use for porcine Salmonella. Objective five will investigate associations between social network characteristics and prevalence of Salmonella and other disease surveillance conditions. The objective will also compare bacteriological sampling from the study visits against serological surveillance sampling, and evaluate associations between bacteriological Salmonella prevalence and performance indicators. Objective six will deliver a comprehensive industry education package aimed at updating and consolidating existing sources of guidance in a farmer-friendly way. Objective seven will provide a comprehensive final report document. </p>