Medical Microbiology

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556 10 Helminths

Clinicalmanifestations.Theinfectionmayrunaninapparentcourseor,
afteranincubationperiodoffourtosixweeks,becomesymptomaticwith
abdominalpain,hepatomegaly,fever,leukocytosisandeosinophilia(acute
phase),orhepatocholangiticsymptoms(chronicphase)andanemia.Occa-
sionally,theparasitesalsomigrateintootherorgansthantheliver.
Diagnosis.Themanifestationstobeexpectedduringthemigrationphaseof
theliverflukeincludemainlyleukocytosis,eosinophilia,andariseinliver-
specificserumenzymes.Detectionofeggs(Fig. 1 0. 1 ,p.543)instoolorduo-
denalfluidisnotpossibleuntilatleasttwotothreemonthsp.i.Inpatients
fromAsia,differentialdiagnosisoftheeggsofthesmallintestinalparasites
EchinostomaandFasciolopsis(Fig. 1 0. 1 ),whichareverysimilartothoseof
Fasciola,mustbekeptinmind.Otherdiagnostictoolsincludedetectionof
serumantibodies(Table 11. 5 ,p.625)andofcoproantigeninstool.
Therapyandprevention.Thedrugofchoiceistriclabendazole,originallyde-
velopedasaveterinarydrug,isnowregisteredadusumhumanuminseveral
countriesandisrecommendedbytheWHO.Theinfectioncanbeavoidedby
noteatingrawwatercressandotherplantsthatmaybecontaminatedwith
metacercariae.

LiverFlukes

10

m

m

a

5 mm

b

5 mm

c

Fig. 1 0.6 aFasciolahepatica,adultstagewithblood-filledintestinalbranches;
bDicrocoeliumdendriticum,adultstage;cOpisthorchisfelineus,adultstage
(Fig.a:K.Wolff,Zurich;c:V.Kumar,Antwerp).

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Kayser, Medical Microbiology © 2005 Thieme
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