Medical Microbiology

342 4 BacteriaasHumanPathogens

Incidenceisparticularlyhighbetweentheagesoffiveand 15 years.About 10 –

20 %ofallpneumoniascontractedoutsidehospitalsarecausedbythispatho-

gen.M.hominisandU.urealyticumaretransmittedeitherbetweensexual

partnersorfrommothertoneonateduringbirth.Nospecificprophylactic

measuresareavailabletoprotectagainstanyofthemycoplasmainfections.

NosocomialInfections

&Nosocomialinfectionsoccurinhospitalizedpatientsascomplicationsof

theirprimarydisease.Suchinfectionsarereportedinanaverageofapproxi-

mately3.5%(Germany)to 5 %(USA)ofallhospitalizedpatients,intertiary

carehospitalsinabout 10 %andintheintensivecareunitsofthoseinabout

15 – 20 %ofcases.Themostfrequenttypesofinfectionareurinarytractinfec-

tions(42%),pneumonia(2 1 %),surgicalwoundinfections(1 6 %),andsepsis

(8%). The pathogen types most frequentlyinvolved are opportunistic,

Gram-negativerods,staphylococciandenterococci,followedbyfungi.The

bacteriaareoftenresistanttomanydifferentantibiotics.Thehandsofmed-

icalstaffplayamajorroleintransmissionoftheinfections.Controlofnoso-

comialinfectionsrequiresanumberofoperationalmeasures(disinfection,

asepsis,rationalizedantibiotictherapies,isolation),organizationalmeasures

(hygienecommittee,recognitionofinfections,proceduralguidelines,train-

ingprograms),andstructuralmeasures. &

Definition

Thetermnosocomialinfectiondesignatesinfectionscontractedbyhospi-

talizedpatients 48 hoursormorefromthebeginningofhospitalization.

Thesearesecondaryinfectionsthatoccurascomplicationsoftheprimary

diseasestobetreatedinthehospital.

Pathogens,Infections,Frequency

Thesignificanceofthedifferenthumanpathogensinnosocomialinfections

varieswidely:

&Subcellularentities.IsolatedcasesofCreutzfeldt-Jakobdiseasedueto

unsterilizedinstrumentshavebeendescribedintheliterature.Suchacci-

dentsnownolongeroccur.

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Kayser, Medical Microbiology © 2005 Thieme