Medical Microbiology

PrinciplesofSterilizationandDisinfection 41

Alcoholsarethereforeoftencombinedwithotherdisinfectants(e.g.,quater-

naryammoniumcompounds).Iodophoresarealsousedforthispurpose.

Thepurposeofhygienichanddisinfectionistodisinfecthandscontami-

natedwithpathogenicorganisms.Herealso,alcoholsaretheagentofchoice.

Alcoholsand/oriodinecompoundsaresuitablefordisinfectingpatient’s

skininpreparationforsurgeryandinjections.

Strong-smellingagentsarethelogicalchoicefordisinfectionofex-

cretions(feces,sputum,urine,etc.).Itisnotnecessarytokillsporesin

suchapplications.Phenolicpreparationsarethereforefrequentlyused.Con-

taminatedhospitalsewagecanalsobethermallydisinfected(80– 1008 C)

ifnecessary.

Surfacedisinfectionisanimportantpartofhospitalhygiene.Acombination

ofcleaninganddisinfectionisveryeffective.Suitableagentsincludealdehyde

andphenolderivativescombinedwithsurfactants.

Instrumentdisinfectionisusedonlyforinstrumentsthatdonotcauseinju-

riestoskinormucosa(e.g.,dentalinstrumentsforworkonhardtoothsub-

stance).Thepreparationsusedshouldalsohaveacleaningeffect.

Laundrydisinfectioncanbedonebychemicalmeansorincombinationwith

heattreatment.Thesubstancesusedincludederivativesofphenols,alde-

hydesandchlorineaswellassurfactantcompounds.Disinfectionshouldpre-

ferablytakeplaceduringwashing.

Chlorineistheagentofchoicefordisinfectionofdrinkingwaterand

swimming-poolwater.Itiseasilydosed,actsquickly,andhasabroaddis-

infectantrange.Therecommendedconcentrationlevelfordrinkingwateris

0. 1 – 0.3mg/landforswimming-poolwater0.5mg/l.
   Finalroomdisinfectionistheprocedurecarriedoutafterhospitalcareofan
   infectionpatientiscompletedandisappliedtoaroomandallofitsfurnish-
   ings.Evaporationoratomizationofformaldehyde(5g/m^3 ),whichusedtobe
   thepreferredmethod,requiresanexposureperiodofsixhours.Thisproce-
   dureisnowbeingsupersededbymethodsinvolvingsurfaceandspraydis-
   infectionwithproductscontainingformaldehyde.
   Hospitaldisinfectionisanimportanttoolinthepreventionofcross-infec-
   tionsamonghospitalpatients.Theproceduremustbesetoutinwritten
   formforeachspecificcase.

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Kayser, Medical Microbiology © 2005 Thieme