Medical Microbiology

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424 8 VirusesasHumanPathogen

beparticularlyimportantareserologicallyproblematicalanyway.Serology
doescontributetoclearinguptheCMVstatusoftransplantrecipientsand
donors.
Epidemiology,prevention,andtherapy.CMVistransmittedbycontactor
smearinfection,usuallyinchildhoodoradolescence.Immunosuppressedpa-
tientscanbetreatedwithhyperimmunoglobulintoprovidepassiveimmu-
nityagainstinfectionorrecidivation.Ganciclovirandfoscarnetaretherapeu-
ticallyusefulintransplantation,andparticularlyinAIDSpatients,tocombat
CMV-inducedpneumonia,encephalitis,andretinitis.

Epstein-BarrVirus(EBV)

Pathogen,pathogenesis,clinicalpicture.EBVinfectsonlyanarrowspec-
trumofhostsandreplicatesveryslowly.ItpersistsinalatentstateinBlym-
phocytesandcanleadtotheirimmortalizationandtumortransformation.
EBVentersthebodythroughthemucosa.Itreplicatesinepithelialcellsof
theoropharynxorcervixandentersBlymphocytes,whereitcontinuesto
replicate.Thisresultsintheclinicalpictureofinfectiousmononucleosis(kis-
singdiseaseorPfeifferdisease),whichischaracterizedbyfeverandageneral-
izedbutmainlycervicalswellingofthelymphnodes,typicallyaccompanied
bytonsillitis,pharyngitis,andsomecasesofmildhepaticinvolvement.This
virusalsopersistsinlatency,probablyforthelifeofthepatient,in(immor-
talized)Bcells.
EBVandEBV-specificsequencesandantigensareisolatedincasesof
Burkittlymphomaandnasopharyngealcarcinoma.Thehigherincidenceof
BurkittlymphomainpartsofAfricaisattributedtoacofactorarisingfrom
thehyperendemicpresenceofmalariathere.EBVexacerbatestheB-cellpro-
liferationresultingfromamalariainfection.EBVhasalsobeenimplicatedin
HodgkindiseaseandT-celllymphomas.Thesetumorformsalsoresultfrom
theinteractionofEBVwithothermechanismsofcelldamage.Inimmuno-
competentpersons,thefollowinglymphoproliferativediseasesaresequelae
ofEBVinfections:
— abenignpolyclonalB-cellhyperplasia,
— itsmalignanttransformationintoapolyclonalB-celllymphoma,and
— amalignant,oligoclonalormonoclonalB-celllymphoma.
Diagnosis.Heterogeneticantibodiesthatagglutinatetheerythrocytesof
severalanimalspeciesandantibodiestoavarietyofviralantigensarefound
inacuteinfectiousmononucleosis:
— VCA(viralcapsidantigen).AntibodiestoVCAappearearlyandpersistfor
life.
— EA(earlyantigen).AntibodiestoEAareonlydetectableduringtheactive
disease.

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Kayser, Medical Microbiology © 2005 Thieme
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