Campylobacter in primary animal production and control strategies to reduce the burden of human campylobacteriosis

Campylobacteriosis is one of the most important bacterial food-borne illnesses in humans. One significant source of infection is the handling and consumption of poultry meat, although other sources also contribute considerably. Controlling Campylobacter in broilers reduces the human burden of illness. Broilers can easily become colonised with Campylobacter and preventive measures in primary production have a limited and unpredictable effect. Vaccination, competitive exclusion, bacteriophage therapy and the use of bacteriocins are not yet commercially available. However, measures in the slaughterhouse can reduce contamination in the final product. At present, the most promising control strategy is to keep colonised and non-colonised flocks separate during slaughter ('scheduled processing'). The virtually Campylobacter-free meat can supply the fresh poultry meat market, while the meat from infected flocks can be treated to reduce the Campylobacter concentration. Meat from infected flocks can be treated by freezing but chemical decontamination appears to be more cost effective. A variant of this scenario is to treat only highly contaminated meat. The authors conclude that, until new techniques become commercially available, scheduled processing is the most cost-effective approach. Finally, the authors describe trends in antimicrobial resistance in Campylobacter

Pre-scald brushing for removal of solids and associated broiler carcass bacterial contamination

The aim of the study was to investigate the effect of brushing prior to scalding on reducing the E. coli and Enterobacteriaceae concentrations on carcasses. Three visits were arranged to a commercial slaughterhouse in which carcasses were cleaned in a separate line. Ten batches were sampled to compare the E. coli and Enterobacteriaceae concentrations on carcasses before and after a stand-alone brushing unit. Per batch, 8 carcasses before and 8 after brushing were sampled by the whole-carcass rinse method. Furthermore, the dry matter content and the pH were determined in these samples, as these parameters indirectly (dry matter) or directly (pH) influence the scalding lethality. Results revealed a small but statistically significant reduction (P < 0.001) in E. coli and Enterobacteriaceae concentrations on the brushed carcasses. The concentrations on whole carcasses were reduced on average by 0.3 log for both E. coli and Enterobacteriaceae. Rinse samples from treated carcasses had significantly less dry matter on average by 2.5 g (P < 0.001) and significantly higher pH by 0.08 units (P < 0.001). Although these differences are statistically significant, they might have rather low biological relevance; thus, further optimization of brushes is needed for more relevant results. This study confirms that brushing reduces bacterial concentrations on carcasses, which may be increased potentially by enlarging the brushed surface of the carcass. Further in-line investigations are needed to observe the effect of brushing on bacterial concentrations in scalding water and on carcasses after scalding and at the end of processing

Immunity to Campylobacter: its role in risk assessment and epidemiology

Acquired immunity is an important factor in the epidemiology of campylobacteriosis in the developing world, apparently limiting symptomatic infection to children of less than two years. However, also in developed countries the highest incidence is observed in children under five years and the majority of Campylobacter infections are asymptomatic, which may be related to the effects of immunity and/or the ingested doses. Not accounting for immunity in epidemiological studies may lead to biased results due to the misclassification of Campylobacter-exposed but apparently healthy persons as unexposed. In risk assessment studies, health risks may be overestimated when immunity is neglected

Calculating disability-adjusted life years to quantify burden of disease

Calculating disability-adjusted life years to quantify burden of diseas