Disinfection, Sterilization and Antisepsis:

An OverviewWilliam A. Rutala, PhD, MPH

Director, Hospital Epidemiology, Occupational Health and Safety; Research Professor of Medicine and Director, Statewide Program

for Infection Control and EpidemiologyUniversity of North Carolina at Chapel Hill and UNC Health Care,

Chapel Hill, NC

DISCLOSURES

• Consultation ASP (Advanced Sterilization Products)-2014 Clorox-2014, 2015

• Honoraria (2014, 2015) 3M, ASP, Clorox

• Grants CDC, CMS, Nanosonics

Disinfection, Sterilization and Antisepsis

Provide overview of disinfection, sterilization and antisepsis Indications and methods for sterilization, high-level

disinfection and low-level disinfectionCleaning of patient-care devicesSterilizationDisinfection (high-level and low-level disinfection)Antisepsis

CDC Guideline for Disinfection and Sterilization

Rutala, Weber, HICPAC. November 2008. www.cdc.gov

Disinfection and SterilizationWA Rutala, DJ Weber, and HICPAC, www.cdc.gov

EH Spaulding believed that how an object will be disinfected depended on the object’s intended use.

CRITICAL - objects which enter normally sterile tissue or the vascular system or through which blood flows should be sterile.

SEMICRITICAL - objects that touch mucous membranes or skin that is not intact require a disinfection process (high-level disinfection [HLD]) that kills all microorganisms but high numbers of bacterial spores.

NONCRITICAL -objects that touch only intact skin require low-level disinfection (or non-germicidal detergent).

Processing “Critical” Patient Care ObjectsClassification: Critical objects enter normally sterile tissue or

vascular system, or through which blood flows.

Object: Sterility.Level germicidal action: Kill all microorganisms, including bacterial

spores.Examples: Surgical instruments and devices; cardiac

catheters; implants; etc.Method: Steam, gas, hydrogen peroxide gas plasma,

vaporized hydrogen peroxide, ozone or chemical sterilization.

Sterilization of “Critical Objects”

Steam sterilizationHydrogen peroxide gas plasma

Ethylene oxideOzone

Vaporized hydrogen peroxideSteam formaldehyde

Ozone and Hydrogen Peroxide

• Sterizone VP4, 510(k) FDA clearance,TSO3 Canada

• Sterilizer has a 4.4ft3 chamber

• Advantages/Disadvantages-not yet known

FDA Panel, May 2015, Recommended Sterilization of Duodenoscopes

Disinfection and SterilizationWA Rutala, DJ Weber, and HICPAC, www.cdc.gov

EH Spaulding believed that how an object will be disinfected depended on the object’s intended use.

CRITICAL - objects which enter normally sterile tissue or the vascular system or through which blood flows should be sterile.

SEMICRITICAL - objects that touch mucous membranes or skin that is not intact require a disinfection process (high-level disinfection [HLD]) that kills all microorganisms but high numbers of bacterial spores.

NONCRITICAL -objects that touch only intact skin require low-level disinfection (or non-germicidal detergent).

Disinfection and SterilizationWA Rutala, DJ Weber, and HICPAC, www.cdc.gov

EH Spaulding believed that how an object will be disinfected depended on the object’s intended use (modified).

CRITICAL - objects which directly or secondarily (i.e., via a mucous membrane such as duodenoscopes) enter normally sterile tissue or the vascular system or through which blood flows should be sterile.

SEMICRITICAL - objects that touch mucous membranes or skin that is not intact require a disinfection process (high-level disinfection [HLD]) that kills all microorganisms but high numbers of bacterial spores.

NONCRITICAL -objects that touch only intact skin require low-level disinfection (or non-germicidal detergent).

Processing “Semicritical” Patient Care Objects

Classification: Semicritical objects come in contact with mucous membranes or skin that is not intact.

Object: Free of all microorganisms except high numbers of bacterial spores.

Level germicidal action: Kills all microorganisms except high numbers of bacterial spores

Examples: Respiratory therapy and anesthesia equipment, GI endoscopes, endocavitary probes, etc.

Method: High-level disinfection

High-Level Disinfection of “Semicritical Objects”

Exposure Time > 8m-45m (US), 20oCGermicide Concentration_____Glutaraldehyde > 2.0%Ortho-phthalaldehyde 0.55%Hydrogen peroxide* 7.5%Hydrogen peroxide and peracetic acid* 1.0%/0.08%Hydrogen peroxide and peracetic acid* 7.5%/0.23%Hypochlorite (free chlorine)* 650-675 ppmAccelerated hydrogen peroxide 2.0%Peracetic acid 0.2%Glut and isopropanol 3.4%/26%Glut and phenol/phenate** 1.21%/1.93%___*May cause cosmetic and functional damage; **efficacy not verified

Processing “Noncritical” Patient Care Objects

Classification: Noncritical objects will not come in contact with mucous membranes or skin that is not intact.

Object: Can be expected to be contaminated with some microorganisms.

Level germicidal action: Kill vegetative bacteria, fungi and lipid viruses.

Examples: Bedpans; crutches; bed rails; EKG leads; bedside tables; walls, floors and furniture.

Method: Low-level disinfection (or detergent for housekeeping surfaces)

Low-Level Disinfection for “Noncritical” Objects

Exposure time > 1 minGermicide Use ConcentrationEthyl or isopropyl alcohol 70-90%Chlorine 100ppm (1:500 dilution)Phenolic UDIodophor UDQuaternary ammonium UDImproved hydrogen peroxide 0.5%, 1.4%_____________________________________________________________UD=Manufacturer’s recommended use dilution

Methods in Sterilization

Cleaning

• Items must be cleaned using water with detergents or enzymatic cleaners before processing.

• Cleaning reduces the bioburden and removes foreign material (organic residue and inorganic salts) that interferes with the sterilization process.

• Cleaning and decontamination should be done as soon as possible after the items have been used as soiled materials become dried onto the instruments.

Cleaning

• Mechanical cleaning machines-automated equipment may increase productivity, improve cleaning effectiveness, and decrease worker exposure Utensil washer-sanitizer Ultrasonic cleaner Washer sterilizer Dishwasher Washer disinfector

• Manual

How Clean Is Clean? • AAMI and FDA trying to gain consensus

• Reached consensus on maximum levels of top three common markers after a device is cleaned Less than 6.4 µg/cm2 for protein Less than 12 µg/cm2 for total organic compound Less than 2.2 µg/cm2 for hemoglobin

• Research needs to be performed to determine how healthcare facilities should verify cleanliness (real-time tests and meaningful analytical endpoints)

• Manufacturers’ ensure the HCF can clean the device (time, resources, device design)

Disinfection Practices

Disinfection and Sterilization EH Spaulding believed that how an object will be disinfected

depended on the object’s intended use.CRITICAL - objects which enter normally sterile tissue or the

vascular system or through which blood flows should be sterile.

SEMICRITICAL - objects that touch mucous membranes or skin that is not intact require a disinfection process (high-level disinfection [HLD]) that kills all microorganisms but high numbers of bacterial spores.

NONCRITICAL -objects that touch only intact skin require low-level disinfection .

RECENT ENDOSCOPY-RELATED OUTBREAKS OF MRDO WITHOUT REPROCESSING BREACHES

MDRO Scope No. Recovered From Scope Molecular Link Reference

P. aeruginosa (VIM-2) Duodenoscope 22 Yes, under forceps elevator Yes Verfaillie CJ, 2015

E. coli (AmpC) Duodenoscope 7 Yes (2 scopes) Yes (PFGE) Wendort, 2015

K. pneumoniae (OXA) Duodenoscope 5 No Kola A, 2015

E. coli (NDM-CRE) Duodenoscope 39 Yes Yes (PFGE) Epstein L, 2014

Additional Outbreaks (not published; news media reports)•UCLA, 2015, CRE, 179 patients exposed (2 deaths), 2 colonized duodenoscopes•CMC, 2015, CRE, 18 patients exposed (7 infected), duodenoscopes•Cedars-Sinai, 2015, CRE, 67 patients exposed (4 infected), duodenoscopes•Wisconsin, 2013, CRE, (5 infected), duodenoscopes•University of Pittsburgh, 2012, CRE, 9 patients, duodenoscopes

ENDOSCOPE REPROCESSING: CHALLENGESNDM-Producing E. coli Associated ERCP

MMWR 2014;62:1051; Epstein et al. JAMA 2014;312:1447-1455

NDM-producing E.coli recovered from elevator channel (elevator channel orients catheters, guide wires and accessories into the endoscope visual field; crevices difficult to access with cleaning brush and may impede effective reprocessing)

Reprocessing Channeled EndoscopesCystoscopes, Ureteroscopes, Hysteroscopes

ENVIRONMENTAL CONTAMINATION LEADS TO HAIs

• There is increasing evidence to support the contribution of the environment to disease transmission

• This supports comprehensive disinfecting regimens (goal is not sterilization) to reduce the risk of acquiring a pathogen from the healthcare environment/equipment

Thoroughness of Environmental CleaningCarling P. AJIC 2013;41:S20-S25

0

20

40

60

80

100

HEHSG HOSP

IOWA HOSP

OTHER HOSP

OPERATING ROOMS

NICUEMS VEHICLES

ICU DAILY

AMB CHEMO

MD CLINIC

LONG TERM

DIALYSIS

%

DAILY CLEANING

TERMINAL CLEANING

Cle

aned

Mean = 32%

>110,000 Objects

MONITORING THE EFFECTIVENESS OF CLEANINGCooper et al. AJIC 2007;35:338; Carling P AJIC 2013;41:S20-S25

• Visual assessment-not a reliable indicator of surface cleanliness

• ATP bioluminescence-measures organic debris (each unit has own reading scale, <250-500 RLU)

• Microbiological methods-<2.5CFUs/cm2-pass; can be costly and pathogen specific

• Fluorescent marker-transparent, easily cleaned, environmentally stable marking solution that fluoresces when exposed to an ultraviolet light (applied by IP unbeknown to EVS, after EVS cleaning, markings are reassessed)

NEW “NO TOUCH” APPROACHES TO ROOM DECONTAMINATIONSupplement Surface Disinfection

Rutala, Weber. Infect Control Hosp Epidemiol. 2011;32:743

This technology should be considered for terminal room disinfection (e.g., after

discharge of patients under CP, during outbreaks) if studies continue to

demonstrate a benefit.

Norovirus, C. difficile spores, MERS-CoV, Enterovirus D68, Ebola, MDR organisms such carbapenemase-producing Enterobacteriaceae (CRE), HPV, avian

influenza A (H7N9)

Antisepsis

Antiseptic Agents(used alone or in combination)

• Alcohols, 60-95%

• Chlorhexidine, 2% and 4% aqueous

• Iodophors

• PCMX

• Triclosan

Antiseptics

• Hand Hygiene-improvement and compliance monitoring

• Preoperative showers

• Preoperative skin preparation

• Surgical hand scrub

• Skin preparation prior to insertion of catheters

• Routine daily bathing of patients

Disinfection, Sterilization and Antisepsis• Provide overview of disinfection, sterilization and antisepsis

Indications and methods for sterilization, high-level disinfection and low-level disinfection

Cleaning of patient-care devices Sterilization Disinfection (high-level and low-level disinfection) Antisepsis

Summary

D/S evidenced-based recommendations must be followed to prevent exposure to pathogens that may lead to infection

Antiseptics must be used optimally to prevent infections that originate from the skin and patient contact

THANK YOU!www.disinfectionandsterilization.org