Copyright © 2004 WA Rutala The Benefits of Surface Disinfection William A. Rutala, Ph.D., M.P.H. UNC Health Care System and UNC School of Medicine, Chapel

Copyright © 2004 WA Rutala

The Benefits of Surface Disinfection

William A. Rutala, Ph.D., M.P.H.UNC Health Care System and UNC School of Medicine,

Chapel Hill, NC



Introduction and principles of disinfection Review the contribution of the noncritical environment to

disease transmission Justify the use of a disinfectant on noncritical surfaces Provide recommendations for surface disinfection


Disinfection Introduction

Effective use of disinfectants constitutes an important factor in preventing healthcare-associated infections

Spaulding proposed three categories of germicidal action to prevent a risk of infection associated with the use of equipment or surfaces

Three categories: critical; semicritical; noncritical Surfaces considered noncritical (contact intact skin) Use of noncritical items or contact with noncritical surfaces carries a low

risk of transmitting a pathogen to patients


Surface Disinfection

Noncritical Surfaces Medical equipment surfaces (BP cuff, stethoscopes)

May frequently become contaminated with patient materialRepeatedly touched by health care personnelDisinfectant may be used

Housekeeping surfaces (bed rails, bedside tables)May play a theoretical but less significant role in diseases transmissionDisinfectants or detergents may be used


Low Level Disinfection for “Noncritical” Objects

Exposure time >60 secGermicide Use ConcentrationEthyl or isopropyl alcohol 70-90%Chlorine 100ppm (1:500 dilution)Phenolic UDIodophor UDQuaternary ammonium UD_____________________________________UD=Manufacturer’s recommended use dilution


Surface Disinfection Introduction (continued)

Use of noncritical items or contact with noncritical surfaces carries little risk of transmitting pathogens to patients

Thus, the routine use of disinfectants to disinfect housekeeping surfaces (e.g., bedside tables, bed rails) is controversial

However, while noncritical surfaces have not been directly implicated in disease transmission, they may potentially contribute to cross-transmission by acquisition of transient hand carriage by HCW due to contact with a contaminated surface, or patient contact with contaminated surfaces or medical equipment



The Benefits of Surface Disinfection Justification for Using a Disinfectant

Surfaces may contribute to transmission of epidemiologically important microbes (e.g., VRE, MRSA, C. difficile)

Needed for surfaces contaminated by blood and OPIM Disinfectants are more effective in reducing microbial load Detergents become contaminated and result in seeding the patients

environment with bacteria CDC recommends disinfection of noncritical equipment and surfaces for

patients on isolation precautions One product for decontamination of noncritical surfaces (that is, floors

and equipment)


Surfaces May Contribute to Transmission Pathogens implicated in transmission via contaminated noncritical surfaces Bacteria

Acinetobacter, Pseudomonas, Clostridium difficile Oxacillin-resistant Staphylococcus aureus Vancomycin-resistant Enterococcus spp.

Viruses SARS Rotavirus Respiratory syncytial virus (RSV)


Surfaces May Contribute to Transmission Why do we believe that surfaces may contribute to

transmission of epidemiologically important microbes (e.g., VRE)? Does VRE survive in the environment? Are surfaces near infected/colonized patients contaminated and

does surface contamination play a role in patient-to-patient transmission?

Are there trials demonstrating reduced transmission with disinfection?


Surfaces May Contribute to Transmission VRE ENVIRONMENTAL SURVIVAL

Enterococcus Countertops: E. faecalis = 5 d, E. faecium = 7 d Bedrails = 24 hours Telephone handpieces = 60 minutes Stethoscopes = 30 minutes Gloved and ungloved fingers >60 minutesNoskin G, et al. ICHE 1995;16:577-581.


Surfaces May Contribute to Transmission Why do we believe that surfaces may contribute to

transmission of epidemiologically important microbes (e.g., VRE)? Does VRE survive in the environment? Are surfaces near infected/colonized patients contaminated and

does surface contamination play a role in patient-to-patient transmission?

Are there trials demonstrating reduced transmission with disinfection?


Surfaces May Contribute to Transmission VRE ENVIRONMENTAL CONTAMINATION

Reference Sites Contaminated Frequency Karanfil 1992 EKG pressure monitor

dials, doorknob 12%

Boyce 1994 Patient gowns, linens, bedrails, IV pumps, BP cuff

28%

Boyce 1995 Patient gowns, linens, bedrails, BP cuff, IV pump

37%

Slaughter 1996 Bed linen, siderails, BP cuffs, bedside tables

7%

Weber DJ, Rutala WA. ICHE 1997;18:306-309.


Surfaces May Contribute to Transmission Why do we believe that surfaces may contribute to transmission of

epidemiologically important microbes (e.g., VRE)? Does VRE survive in the environment? Are surfaces near infected/colonized patients contaminated and does

surface contamination play a role in patient-to-patient transmission? Do antibiotic-resistant organisms (e.g., VRE) develop cross-resistance to

commonly used environmental disinfectants or antiseptics? Are there trials demonstrating reduced transmission with disinfection?


Surfaces May Contribute to Transmission Surfaces in the Spread of Infections

In experimental settings, treatment of surfaces with germicide has been found to interrupt transmission Prevention of surface-to-human rotavirus transmission by treatment with disinfectant

spray (J Clin Microbiol 1991;29:1991) Interrupts transfer of rhinovirus from environmental surfaces to hands (Appl Environ

Microbiol 1993;59:1579) Studies demonstrating reduced transmission with improved disinfection

Aggressive environmental control program credited with eradicating VRE from a burn unit and Acinetobacter from a neurosurgical ICU

Reduction in C. difficile-associated diarrhea rates in the BMTU (8.6 to 3.3) during the period of bleach disinfection (1:10)


Surfaces May Contribute to Transmission CONCLUSIONS

Widespread surface contamination may occur with some pathogens (e.g. VRE) and hands may become transiently colonized from contact with surfaces

Noncritical surfaces may play a role in the transmission of some pathogens (e.g., VRE, C.difficile)

Meticulous disinfection and handwashing will prevent transmission


Impact of Surface Disinfection on HAIs Dharan et al, 1999

No change in incidence of HAIs during 4 mo trial compared to preceding 12 mo; but detergents associated with increase in bacterial counts.

Danforth et al, 1987 NI rate did not differ between disinfectant (8.0/100 patients) and detergent

(7.1/100 patients); 8 acute care units; 3 mo periods; phenol. Daschner et al, 1980

No difference in NI rate in ICU over 6 mo (15.6% vs 15.5%).Comment: Studies are small, short duration and suffer from low statistical power since

the outcome (HAI) is one of low frequency (not detect small decrease-0.1%, 1750 HAIs). Requirement for reducing HAI stringent, not met by most infection control interventions.







and equipment)


The Benefits of Surface Disinfection Needed for surfaces contaminated by blood and OPIM

In the US, to comply with OSHA rule on bloodborne pathogens, a blood spill must be cleaned using a disinfectant

The compliance directive states that the blood should be disinfected using an EPA-registered disinfectant, a disnfectant with a HBV/HIV claim, or a solution of bleach between 1:10 and 1:100 with water.







and equipment)


Cleaning and Disinfection of Floors% Reduction

Soap and water 80.4%

Phenol 99.0%







and equipment)


Microbial Contamination of Mop WaterSoap(CFU/ml)

Phenol(CFU/ml)

Before cleaning 10 20

After cleaning one-third of ward

650 10

After cleaning two-thirds of ward

15,000 30

After cleaningcomplete ward

34,000 20




Needed for surfaces contaminated by blood and OPIM Disinfectants are more effective in reducing microbial load Detergents become contaminated and result in seeding the

patients environment with bacteriaDharan found use of detergents alone on floors and furniture led to

an increase in contamination in patients environmental surfaces after cleaning (average increase 103.6cfu/24cm2)





environment with bacteria CDC recommends disinfection of noncritical equipment and

housekeeping surfaces for patients on isolation precautions (eg, MRSA) One product for decontamination of noncritical surfaces (that is, floors

and equipment)


Recommendations for Surface DisinfectionEurope

Dettenkofer, Merkel, Mutter, Daschner – 2004 Recommended that the MRSA patient room be disinfected 3

times per day on intensive care units and once per day on normal wards

But given the high prevalence of MRSA among hospitalized patients in many countries and routine screening is rarely conducted, shouldn’t we employ disinfectants for all hospitalized patients as unspecified colonization is a routine occurrence?






patients on isolation precautions One product for decontamination of noncritical surfaces (that is,

noncritical housekeeping and equipment, isolation, blood)


The Benefits of Surface Disinfection Reasonable to use hospital disinfectants on noncritical

patient equipment surfaces (e.g., blood pressure cuffs, stethoscopes, radiograph machines), and housekeeping surfaces (e.g., bedside tables and bed rails).


Recommendations for Surface DisinfectionEurope

Robert Koch Institute, Germany Tasked to produce guidelines by a federal infection protection

law Recommends the use of surface disinfectants for patient

equipment surfaces and noncritical housekeeping surfaces in patient care areas.

French Authorities Recommends using disinfectants for surface disinfection in

patient care areas


Surface Disinfection Concerns?

Allergy-Literature review (Medline) from 1966 to April 2004, provided no evidence that suggests the use of LLD results in allergic symptoms in health care workers. “BAC is one of the leading allergens affecting HCP” discussed Quat use as a risk factor for allergies in pig farmers.

Environment-Adverse effects on human health, due to the disposal of LLD into soil/rivers/streams, have not been proposed or demonstrated. EPA does not regulate the discharge of LLD via waste water.

Increased resistance-No evidence that using LLD selects for antibiotic-resistant organisms in nature or mutants survive.



Introduction and principles of disinfection Review the contribution of the noncritical environment to

disease transmission Justify the use of a disinfectant on noncritical surfaces Provide recommendations for surface disinfection

Documents

Copyright © 2004 WA Rutala The Benefits of Surface Disinfection William A. Rutala, Ph.D., M.P.H. UNC Health Care System and UNC School of Medicine, Chapel