Assessing the Risk of Microbial Pathogens

Abstract

This paper reports the results of a risk assessment of the
adverse health effects from ingesting foods contaminated with
certain microbial pathogens. The risk assessment was performed
as part of a larger project to develop a risk-based sampling
methodology for imported foods inspected by the U.S. Food and
Drug Administration (FDA). The sampling methodology was put
into operation in a computer aid to assist FDA import inspectors
in choosing samples to test for violative substances.
The computer aid was designed to choose samples so as to
maximize the benefit from the sampling plan. The expected
benefit of sampling food depends on the probability that a violation
exists, the probability that it will be detected by testing, and
the risk of illness associated with the violation. While most of this
information is available from data collected by the FDA, very
little information has been published regarding the relationship
between violative substances and human illness, particularly for
microbial pathogens.
To narrow this information gap, we recruited the assistance
of several experts in the fields of microbiology and epidemiology
to evaluate the uncertainty surrounding the intake-response relationships
for several microbial pathogens. The information collected
from the expert elicitation process and documented here
cannot substitute for the scientific data needed to accurately
estimate dose-response relationships and their variances. Our goal
was simply to gather approximations of these relationships to use
in the sampling aid. Our results differ from traditional doseresponse
curves in that we quantified the uncertainty associated
with each probability judgment.