Medical Microbiology

344 4 BacteriaasHumanPathogens

Therearenoreliablefiguresavailableonviralnosocomialinfections.Arough

estimateputsviralnosocomialinfectionsatlessthan 1 %ofthetotal.Anex-

ampleofaviralnosocomialinfectionisinfectioushepatitistransmittedby

bloodorbloodproducts.

&Bacteriaarethemainpathogensinvolvedinnosocomialinfections.Most

ofthecausativeorganismsarefacultativelypathogenic(opportunistic)bac-

teria,whicharefrequentlyresistanttomanydifferentantibiotics.Thesebac-

teriahavefoundnichesinwhichtheypersistasso-calledhospitalflora.The

resistancepattersseeninthesebacteriareflecttheoftenwidevariationsbe-

tweenanti-infectiveregimensaspracticedindifferenthospitals.

&Fungi.Fungalnosocomialinfectionshavebeenontheincreaseinrecent

years.Itcanbesaidingeneralthattheyaffectimmunocompromisedpatients

andthatneutropenicpatientsareparticularsusceptible.

Table4. 17 liststhepathogensthatcausethemostsignificantnosocomialin-

fectionsasdeterminedinaprevalencestudydoneinGermany(Eastand

West)in 1995 (NIDEPStudy).

Table4. 18 showstheprevalencelevelsatwhichnosocomialinfectionsoc-

curredin 72 selectedhospitalsonagivendateintheabovestudy.Thepre-

valenceandpathogendatashownhereapproximatewhatotherstudieshave

found.Prevalenceandincidencelevelscanvaryconsiderablyfromhospitalto

Table4. 18 Frequency(prevalence)oftheMostImportantNosocomialInfec-

tionTypes(%)^1

Infection Internal

medicine

Surgery Gyneco-

logy

Intensive

care

All

patients

Urinarytractinfections 1 .5 7 1 .45 0.9 1 2.35 1 .46

Lowerrespiratorytract

infections

0.63 0.30 0.09 9.00 0.72

Postoperativewound

infections

0.03 1 .34 0.05 1 .3 7 0.55

Primarysepsis 0.3 1 0. 15 0. 14 2. 15 0.29

Otherinfections 0.52 0.7 4 0.2 7 1 .96 0.62

Patientswithatleast

oneinfection

2.9 7 3.80 1 .45 1 5.30 3.46

(^1) Figuresfrom“NosokomialeInfektioneninDeutschland–ErfassungundPrevention
(NIDEP–Studie).”Vol.56,PublicationSeriesoftheGermanFederalHealthOffice.
NomosVerlagsgesellschaft,Baden-Baden, 1 995.
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Kayser, Medical Microbiology © 2005 Thieme