variouspathogensto the totalnumber of foodborne illnessesand deathsare
givenin Figs2.1 and 2.2 respectively, for surveys fromthe USA(Meadet al.,
1999),the UK (Adaket al., 2002)and France(Vaillantet al., 2004).
As describedbefore, thereis underreportingin the number of documented
foodborne illnesses.To account for this underreporting,varioussurveysuse an
underreportingfactorto obtain a realistic estimateof the real number of illnesses
basedon documented cases. The USAsurveyis basedon surveillance systems
and usesunderreportingfactors that are eitherbasedon literaturestudies or are
estimated basedon, for example, expert opinions (Meadet al., 1999).The UK
survey(Adaket al., 2002)usesunderreportingfactors that are basedon data
fromlaboratoryreportsand the incidence rate in the populationin 1995foundin
a studyto infectious intestinal disease. Thisfactoris thenappliedto datafrom
laboratory reportsin otheryears.Whichpathogensare most importantin a
country,therefore,also depends on the underreportingfactorused(Table2.3).
It can be seenthatin all three countries noro-virus, Campylobacterand
Salmonellaare veryimportantpathogensfor causingfoodborne illnesses.In the
UK,ClostridiumperfringensandYersiniaspp.are alsoin the top five of the
mostimportantpathogens.However,in thesecases much higherunderreporting
factors are usedthanin the USA.Foodborne deaths in the three countries are
Fig. 2.1 The contributionof variouspathogensto the totalnumberof foodborne
illnessesin percentages.No dataavailableforToxoplasmagondiiin the UK.The rangeof microbialrisksin foodprocessing 33