Disinfection and Sterilization: Current Issues and New Technologies

Disinfection and Sterilization: Current Issues and New Technologies William A. Rutala, PhD, MPH Director, Hospital Epidemiology, Occupational Health and Safety, UNC Health Care; Research Professor of Medicine and Director, Statewide Program for Infection Control and Epidemiology, University of North Carolina School of Medicine, Chapel Hill, NC Disclosure: Clorox

Disinfection and Sterilization: Current Issues and New Technologies • Current Issues and New Technologies • Sterilization of critical items • Cleaning, washer disinfectors, biological indicators • High-level disinfection for semi-critical items • New HLDs, prostate probes, cystoscopes, laryngoscopes • Low-level disinfection of non-critical items • Role of the environment, curtain decontamination, room decontamination, thoroughness of cleaning • D/S and Emerging Pathogens • MERS-CoV, Enterovirus D68, Ebola

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 except for low numbers of bacterial spores • NONCRITICAL - objects that touch only intact skin require low-level disinfection

Sterilization of “Critical Objects” Steam sterilization-1970s Hydrogen peroxide gas plasma-1993 Ethylene oxide-1970s Vaporized hydrogen peroxide-2011

Some Potential Future Low-Temperature Sterilization Technologies Rutala WA, Weber WA. Infect Control Hosp Epidemiol 2015, In press • Ozone plus hydrogen peroxide vapor • Nitrogen dioxide • Supercritical CO2 • Peracetic acid vapor

Cleaning • Purpose: remove all adherent debris from an item and to reduce the number of particulates, microorganisms, and pyrogens. • Removes debris such as blood, mucus, oil, salts or other foreign matter interferes with the sterilization process • Reduces the bioburden and enhances the probability of sterilization

Bioburden on Surgical Devices • Bioburden on instruments used in surgery (Nystrom, 1981) • 62% contaminated with <101 • 82% contaminated with <102 • 91% contaminated with <103 • Bioburden on surgical instruments (Rutala, 1997) • 72% contained <101 • 86% contained <102 • Bioburden on surgical instruments (50) submitted to CP (Rutala, 2014) • 58% contained <10 • 20% contained < 102 • 16% contained <5x102 • 6% contained <103

Washer/DisinfectorRutala et al. Infect Control Hosp Epidemiol 2014. 35:883-885. • Five Chambers • Pre-wash: water/enzymatic is circulated over the load for 1 min • Wash: detergent wash solution (150oF) is sprayed over load for 4 min • Ultrasonic cleaning: basket is lowered into ultrasonic cleaning tank with detergent for 4 min • Thermal and lubricant rinse: hot water (180oF) is sprayed over load for 1 min; instrument milk lubricant is added to the water and is sprayed over the load • Drying: blower starts for 4 min and temperature in drying chamber 180F

Washer/DisinfectorRemoval/Inactivation of Inoculum (Exposed) on InstrumentsRutala et al. Infect Control Hosp Epidemiol 2014. 35:883-885.

Bioburden on surgical instruments is lowWasher/disinfectors are very effective (>7 log10 reduction) in removing/inactivating microorganisms from instruments Huge margin of safety

Rapid Readout BIs for Steam Now Require a 1-3h Readout Compared to 24-48h

Super Rapid Readout Biological IndicatorsCommercially available 1491 BI (blue cap) • Monitors 270°F and 275°F gravity –displacement steam sterilization cycles • 30 minute result (from 1 hour) 1492V BI (brown cap) • Monitors 270°F and 275°F dynamic-air-removal (pre-vacuum) steam sterilization cycles • 1 hour result (from 3 hours)

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 except for low numbers of bacterial spores • NONCRITICAL - objects that touch only intact skin require low-level disinfection

High-Level Disinfection of “Semicritical Objects” Exposure Time > 8m-45m (US), 20oC Germicide Concentration_____ Glutaraldehyde > 2.0% Ortho-phthalaldehyde0.55% 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 ppm Accelerated 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

ResertTM HLD • High Level Disinfectant - Chemosterilant • 2% hydrogen peroxide, in formulation • pH stabilizers • Chelating agents • Corrosion inhibitors • Efficacy (claims need verification) • Sporicidal, virucidal, bactericidal, tuberculocidal, fungicidal • HLD: 8 mins at 20oC • Odorless, non-staining, ready-to-use • No special shipping or venting requirements • Manual or automated applications • 12-month shelf life, 21 days reuse • Material compatibility/organic material resistance (Fe, Cu)? *The Accelerated Hydrogen Peroxide technology and logo are the property of Virox Technologies, Inc. Modified from G MacDonald. AJIC 2006;34:571

Reprocessing Semicritical Items • New Developments in Reprocessing • Endoscopes • Cystoscopes, ureteroscopes, hysteroscopes • Prostate biopsy probes • Laryngoscopes

Reprocessing Channeled EndoscopesCystoscopes, Ureteroscopes, Hysteroscopes

Reprocessing Channeled EndoscopesRutala, Gergen, Bringhurst, Weber, 2015 • Pathogens must have exposure to HLD for inactivation • Immerse channeled flexible scope into HLD will not inactivate channel pathogens • Completely immerse the endoscope in HLD and ensure all channels are perfused, complete inactivation • Air pressure in channel stronger than fluid pressure at fluid-air interface

Prostate Biopsy ProbeRutala, Gergen, Weber. ICHE. 2007;28:916 • Evaluated effectiveness of HLD when assembled (needle biopsy holder in probe) and unassembled. • Inoculated (106-107 P.aeruginosa): internal lumen/outside surface of needle biopsy holder; internal lumen of probe with and without needle biopsy holder in place • Conclusion: HLD achieved when unassembled but not when assembled

Disinfection of Prostate ProbeRutala, Gergen, Weber. ICHE. 2007;28:916 Needle guide must be removed from the probe for disinfection

Disinfection of Prostate ProbeRutala, Gergen, Weber. ICHE; 2007;28:916

Do Not Reuse Single Use Devices • Federal judge convicted a urologist who reused needle guides meant or single use during prostate procedures (Sept 2014) • Criminal prosecution (conspiracy to commit adulteration)

Reprocessing of Rigid LaryngoscopesJHI 2008, 68:101; ICHE 2007, 28:504; AJIC 2007, 35: 536 • Limited guidelines for reprocessing laryngoscope’s blades and handles • Many hospitals consider blade as semicritical (HLD) and handle as noncritical (LLD) • Blades linked to HAIs; handles not directly linked to HAIs but contamination with blood/OPIM suggest its potential and blade and handle function together • Ideally, clean then HLD/sterilize blades and handles (UNCHC-blades wrapped in a tray-Sterrad; handle wrapped in tray [without batteries]-steam); the blades and handles placed together in a Ziploc bag. Blades and handles checked for function prior to packaging.

Contamination of Laryngoscope Handles J Hosp Infect 2010;74:123 • 55/64 (86%) of the handles deemed “ready for patient use” positive for S. aureus, enterococci, Klebsiella, Acinetobacter Anesth Analg 2009;109:479 • 30/40 (75%) samples from handles positive (CONS, Bacillus, Streptococcus, S. aureus, Enterococcus) after cleaning AANA J 1997;65:241 • 26/65 (40%) of the handles and 13/65 (20%) of the blades were positive for occult blood. These blades and handles were identified as ready for patient use.

Laryngoscopes BladesThe Joint Commission, FAQ, October 24, 2011 • How should we process and store laryngoscope blades? • Processed via sterilization or HLD • Packaged in some way • Stored in a way that prevents recontamination. Examples of compliant storage include, but are not limited to, a peel pack post steam sterilization (long-term) or wrapping in a sterile towel (short term) • Should not place unwrapped blades in an anesthesia drawer

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 except for low numbers of bacterial spores • NONCRITICAL- objects that touch only intact skin require low-level disinfection

LOW-LEVEL DISINFECTION FOR NONCRITICAL EQUIPMENT AND SURFACES Exposure time > 1 min Germicide Use Concentration Ethyl or isopropyl alcohol 70-90% Chlorine 100ppm (1:500 dilution) Phenolic UD Iodophor UD Quaternary ammonium UD Improved hydrogen peroxide (HP) 0.5%, 1.4% ____________________________________________________ UD=Manufacturer’s recommended use dilution

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 ENVIRONMENTAL CONTAMINATION LEADS TO HAIs

MRSA VRE Acinetobacter spp. Clostridium difficile Norovirus Rotavirus SARS KEY PATHOGENS WHERE ENVIRONMENTIAL SURFACES PLAY A ROLE IN TRANSMISSIONWeber, Rutala et al. AJIC 2010. 38:S25-33

ENVIRONMENTAL CONTAMINATION ENDEMIC AND EPIDEMIC MRSA Dancer SJ et al. Lancet ID 2008;8(2):101-13

ENVIRONMENTAL SURVIVAL OF KEY PATHOGENS ON HOSPITAL SURFACES Adapted from Hota B, et al. Clin Infect Dis 2004;39:1182-9 and Kramer A, et al. BMC Infectious Diseases 2006;6:130

FREQUENCY OF ACQUISITION OF MRSA ON GLOVED HANDS AFTER CONTACT WITH SKIN AND ENVIRONMENTAL SITES No significant difference on contamination rates of gloved hands after contact with skin or environmental surfaces (40% vs 45%; p=0.59) Stiefel U, et al. ICHE 2011;32:185-187

Thoroughness of Environmental CleaningCarling et al. Am J Infect Control. 2013;41:S20-S25 >110,000 Objects Mean = 32%

EVALUATION OF HOSPITAL ROOM ASSIGNMENT AND ACQUISITION OF CDI • Study design: Retrospective cohort analysis, 2005-2006 • Setting: Medical ICU at a tertiary care hospital • Methods: All patients evaluated for diagnosis of CDI 48 hours after ICU admission and within 30 days after ICU discharge • Results (acquisition of CDI) • Admission to room previously occupied by CDI = 11.0% • Admission to room not previously occupied by CDI = 4.6% (p=0.002) Shaughnessy MK, et al. ICHE 2011;32:201-206

RELATIVE RISK OF PATHOGEN ACQUISITIONIF PRIOR ROOM OCCUPANT INFECTED~120% * Prior room occupant infected; ^Any room occupant in prior 2 weeks infected. Otter , Yezli, French. ICHE. 2012;32:687-699

ACQUISITION OF MRSA ON HANDS AFTER CONTACT WITH ENVIRONMENTAL SITES

TRANSFER OF MRSA FROM PATIENT OR ENVIRONMENT TO IV DEVICE AND TRANSMISSON OF PATHOGEN

Disinfection and Sterilization: Current Issues and New Technologies