Probabilistic model for contamination of egg dishes with Salmonella spp. made from shell eggs produced on the island of Ireland.

A quantitative model was constructed to estimate the probability that a serving of food containing eggs produced on the island of Ireland is contaminated with Salmonella spp. The model is based on the prevalence of contaminated eggs at the time of lay and a set of parameters which describe the pooling of eggs in the home and in catering situations. Both external and internal contamination of the eggs by Salmonella spp.

Qualitative exposure assessment for Salmonella spp. in shell eggs produced on the island of Ireland.

A qualitative exposure assessment for Salmonella in eggs produced on the island of Ireland was developed. The assessment was divided into three main modules (production and packing, distribution and storage, and preparation and consumption), and each of these stages into defined steps in the exposure pathway. In the production and packing stage the initial prevalences of Salmonella in the contents and on the shell of eggs were estimated to be negligible and low respectively.

Prevalence of Salmonella in grade A whole shell eggs in the island of Ireland.

Following the emergence of Salmonella Enteritidis as a widespread contaminant of eggs and the role of eggs in the transmission of human salmonellosis, control measures were introduced to curb the spread of infection. Two approaches to Salmonella control are currently used by egg producers in Ireland, because Northern Ireland producers, like those in the rest of the United Kingdom, widely adopted a vaccination regime, whereas the Republic of Ireland does not permit vaccination but introduced controls based on routine monitoring for specific Salmonella serovars and subsequent culling of infected flocks. To compare the efficacy of these two approaches and determine the prevalence of salmonellae in eggs produced for retail sale in the island of Ireland, a major survey of approximately 30,000 grade A eggs was undertaken.