DETECTING AND PREVENTING RISKS OF TRANSMITTING SALMONELLAS AMONG POULTRY FARMS IN EUROPE

While salmonellas can cause disease problems among poultry, they remai n essentially a concern for public health, as a cause of outbreaks of food poisoning. The principal site of multiplication of these bacteria is the digestive tract, particularly the caecum, which may result in widespread contamination of the environment. The pathogenicity of salm onellas depends on the invasive properties and the ability of the bact eria to survive and multiply within cells, particularly macrophages. T hese properties are the source of vertical transmission which, in the case of survival of the embryo, can result in contamination of a flock or, in the case of embryonic mortality, can result in an explosion of contaminated eggs. Salmonella infection can be diagnosed by isolating the bacteria and/or serological testing of the flock. European Union Directive 92/117/EC, modified by Directive 97/22/EC, stipulates either the destruction of infected flocks of breeding birds, or decontaminat ion of the flock in an effective way, before normal trade in products can be resumed. Noteworthy examples of effective measures suitable for prophylaxis of Salmonella infection in poultry flocks include the sla ughter of infected breeding stock, the creation of sanitary barriers a t building entrances, heat treatment of feed, the use of competitive e xclusion, selection of breeds genetically resistant to Salmonella, and occasional vaccination and antibiotic treatment. However, the most ef fective means of reducing food poisoning remains adequate cooking of f ood and maintenance of the cold chain.