Infectious gastroenteritis - opportunities for dose response modeling
Infectieuze gastro-enteritis - mogelijkheden voor dosis-responsmodellering
26 May 2012, PDF |
57 pages |
RIVM Report 284550003
When pathogenic microorganisms enter the human body via ingestion of food or drinking water, they encounter a system of barriers mounted by the host. Defense mechanisms against microbial infection and invasion may be immunological or non-immunological. To reach parts of the intestinal tract that are suitable for growth and attachment, they must overcome each of the barriers successfully. According to the present view on infection, at least one of the ingested pathogens must survive if colonization is to start. This is the basis for dose response models used for quantitative risk assessment. The validity of such a model, the Beta Poisson model, was demonstrated for multiple barriers, with some attention being given to the single-hit principle. Also discussed was an approach to the derivation of the Beta Poisson model, an aspect which is usually neglected. This approach was shown here to produce results for certain parameter values that were different from the exact formula. Finally, several initiatives for new models are presented in which extra information on infection and illness is incorporated.