Human infection with Campylobacter spp. from chicken consumption : a quantitative risk assessment
Campylobacter is the commonest cause of human acute bacterial-enteritis in the developed world (ACMSF, 1993). Over the last ten years Great Britain has experienced an increase in the number of reported cases of campylobacter associated illness over the last ten years. There are numerous under reporting issues associated with campylobacter-related illness, and as such the actual number of cases that occur each year is unknown and the magnitude of the public health risk posed by this organism can only be hypothesised. Infection with campylobacter has been linked in epidemiological studies with the consumption of poultry, in particular chicken meat. A quantitative risk assessment (QRA) model has been produced to investigate this issue. Through the use of appropriate modelling techniques and collected data the QRA model assesses the risk of human infection with campylobacter consequent upon the consumption of a chicken meal. The model describes each of the stages of the chicken supply chain and the mechanisms by which the chicken/chicken product becomes contaminated was investigated thus allowing the identification of mitigation strategies, which can reduce such contamination. Model results estimate that the risk of infection with campylobacter associated with the consumption of a single serving of chicken has a mean value ranging from 0.040 to 0.070 with a 95th percentile ranging from 0.098 to 0.160. These results have been used as a benchmark to which the impact of mitigation strategies are compared. Results clearly show that a reduction in the national flock prevalence, combined with a reduction in the within flock prevalence of positive flocks can have a dramatic impact upon the risk of infection. Further, freezing of chicken meat prior to consumption also considerably reduces the estimates risk.