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Disinfection and Sterilization: What’s New. 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,
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Disinfection and Sterilization: What’s New 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
DISCLOSURES • Consultation and Honoraria • ASP (Advanced Sterilization Products), Clorox • Honoraria • 3M • Grants • CDC, CMS
Learning Objective • Describe two current issues or new technologies used in disinfection/sterilization of: • Critical devices • Semicritical devices • Noncritical devices/surfaces
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 high numbers of bacterial spores • NONCRITICAL - objects that touch only intact skin require low-level disinfection
Disinfection and Sterilization: What’s New • Current Issues and New Technologies • Sterilization of critical items • Biological indicators, cleaning indicators, washer disinfectors • High-level disinfection for semi-critical items • Endoscope reprocessing issues, new high-level disinfectants • Low-level disinfection of non-critical items • New low-level disinfectants, curtain decontamination, green products, contact time, iPads, touchscreens, selecting a disinfectant • D/S and Emerging Pathogens • MERS, HPV, C. difficile, Prions
Disinfection and Sterilization: What’s New • Current Issues and New Technologies • Sterilization of critical items • Biological indicators, cleaning indicators, washer disinfectors • High-level disinfection for semi-critical items • Endoscope reprocessing issues, new high-level disinfectants • Low-level disinfection of non-critical items • New low-level disinfectants, curtain decontamination, green products, contact time, iPads, touchscreens, selecting a disinfectant • D/S and Emerging Pathogens • MERS, HPV, C. difficile, Prions
Rapid Readout BIs for Steam Now Require a 1-3h Readout Compared to 24-48h
Attest™ 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)
Washer/DisinfectorRutala WA, Gergen MF, Weber DJ, ICHE. July 2014 • 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. July 2014.
Washer/disinfectors are very effective (>7 log10 reduction) in removing/inactivating microorganisms from instruments
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 Indicators for Washer Disinfector • Monitor the automated washer and instrument cleaning chemistry functionality; AAMI recommends weekly (preferably daily) • Washer indicators have been used in Europe and Canada and some US hospitals • Indicator includes proteins, lipids, and polysaccharides to mimic common challenging test soils • Washer indicators are chemical indicators imprinted with a dried test soil formula and a dye
Disinfection and Sterilization: What’s New • Current Issues and New Technologies • Sterilization of critical items • Biological indicators, cleaning indicators, washer disinfectors • High-level disinfection for semi-critical items • Endoscope reprocessing issues, new high-level disinfectants • Low-level disinfection of non-critical items • New low-level disinfectants, curtain decontamination, green products, contact time, iPads, selecting a disinfectant • D/S and Emerging Pathogens • MERS, HPV, C. difficile, Prions
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 high 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
ENDOSCOPES • Widely used diagnostic and therapeutic procedure (11-22 million GI procedures annually in the US) • GI endoscope contamination during use (109 in/105 out) • Semicritical items require high-level disinfection minimally • Inappropriate cleaning and disinfection has lead to cross-transmission • In the inanimate environment, although the incidence remains very low, endoscopes represent a significant risk of disease transmission
Transmission of Infection by EndoscopyKovaleva et al. Clin Microbiol Rev 2013. 26:231-254 Based on outbreak data, if eliminated deficiencies associated with cleaning, disinfection, AER , contaminated water and drying would eliminate about 85% of the outbreaks.
Nosocomial Infections via GI Endoscopes • Infections traced to deficient practices • Inadequate cleaning (clean all channels) • Inappropriate/ineffective disinfection (time exposure, perfuse channels, test concentration, ineffective disinfectant, inappropriate disinfectant) • Failure to follow recommended disinfection practices (tapwater rinse) • Flaws and complexity in design of endoscopes or AERs
FEATURES OF ENDOSCOPES THAT PREDISPOSE TO DISINFECTION FAILURES • Require low temperature disinfection • Long narrow lumens • Right angle turns • Blind lumens • May be heavily contaminated with pathogens (9-10 logs inside) • Cleaning (4-6 log10 reduction) and HLD (4-6 log10 reduction) essential for patient safe instrument
MULTISOCIETY GUIDELINE ON REPROCESSING GI ENDOSCOPES, 2011Petersen et al. ICHE. 2011;32:527
ENDOSCOPE REPROCESSINGMulti-Society Guideline on Endoscope Reprocessing, 2011 • PRECLEAN- point-of-use (bedside) remove debris by wiping exterior and aspiration of detergent through air/water and biopsy channels; leak testing • CLEAN- mechanically cleaned with water and enzymatic cleaner • HLD/STERILIZE- immerse scope and perfuse HLD/sterilant through all channels for exposure time (>2% glut at 20m at 20oC). If AER used, review model-specific reprocessing protocols from both the endoscope and AER manufacturer • RINSE- scope and channels rinsed with sterile water, filtered water, or tap water. Flush channels with alcohol and dry • DRY-use forced air to dry insertion tube and channels • STORE- hang in vertical position to facilitate drying; stored in a manner to protect from contamination
Endoscope Reprocessing MethodsOfstead , Wetzler, Snyder, Horton, Gastro Nursing 2010; 33:204
Endoscope Reprocessing MethodsOfstead , Wetzler, Snyder, Horton, Gastro Nursing 2010; 33:204 Performed all 12 steps with only 1.4% of endoscopes using manual versus 75.4% of those processed using AER
Automated Endoscope Reprocessors (AER) Manual cleaning of endoscopes is prone to error. AERs can enhance efficiency and reliability of HLD by replacing some manual reprocessing steps AER Advantages: automate and standardize reprocessing steps, reduce personnel exposure to chemicals, filtered tap water AER Disadvantages: failure of AERs linked to outbreaks, does not eliminate precleaning (until now-EvoTech) BMC Infect Dis 2010;10:200 Problems: incompatible AER (side-viewing duodenoscope); biofilm buildup; contaminated AER; inadequate channel connectors; used wrong set-up or connector MMWR 1999;48:557 Must ensure exposure of internal surfaces with HLD/sterilant
Automated Endoscope Reprocessors with Cleaning Claim (requires procedure room pre-cleaning) Advantage Plus Endoscope Reprocessing System Evo-Tech (eliminates soil and microbes equivalent to optimal manual cleaning. BMC ID 2010;10:200)
ENDOSCOPE REPROCESSING: CHALLENGESNDM-Producing E. coli Associated ERCPMMWR 2014;62:1051 NDM-producing E.coli recovered from elevator channel
ENDOSCOPE REPROCESSING: CHALLENGES Surgical instruments-<102 bacteria Complex [elevator channel]-109 bacteria
ENDOSCOPE REPROCESSING: CHALLENGESNDM-Producing E. coli Associated ERCPMMWR 2014;62:1051 • March-July 2013, 9 patients with cultures for New Delhi Metallo-ß-Lactamase producing E. coli associated with ERCP • History of undergoing ERCP strongly associated with cases • NDM-producing E.coli recovered from elevator channel • No lapses in endoscope reprocessing identified • Hospital changed from automated HLD to ETO sterilization • Due to either failure of personnel to complete required process every time or intrinsic problems with these scopes (not altered reprocessing)
ENDOSCOPE REPROCESSING: CHALLENGESNDM-Producing E. coli Associated ERCPMMWR 2014;62:1051 • Recommendations • Education/adherence monitoring • Certification/competency testing of reprocessing staff • Enforcement of best practices-preventive maintenance schedule • Improved definition of the scope of the issue and contributing factors • Development of innovative approaches to improve and assess the process • Systematic assessment of the ability of AERs/technicians to clean/disinfect scopes • Disinfection evaluation testing that relates to risk of pathogen transmission • Perform periodic microbiologic surveillance of duodenoscopes (e.g., weekly, monthly) to assess whether bacteria have survived the reprocessing procedure.
TRANSMISSION OF INFECTION • Gastrointestinal endoscopy • >150 infections transmitted • Salmonella sp. and P. aeruginosa • Clinical spectrum ranged from colonization to death • Bronchoscopy • ~100 infections transmitted • M. tuberculosis, atypical Mycobacteria, P. aeruginosa • Endemic transmission may go unrecognized (e.g., inadequate surveillance, low frequency, asymptomatic infections) Kovaleva et al. Clin Microbiol Rev 2013. 26:231-254
FEATURES OF ENDOSCOPES THAT PREDISPOSE TO DISINFECTION FAILURES • Require low temperature disinfection • Long narrow lumens • Right angle turns • Blind lumens • May be heavily contaminated with pathogens (9-10 logs inside) • Cleaning (4-6 log10 reduction) and HLD (4-6 log10 reduction) essential for patient safe instrument
GI EndoscopesHLD-Narrow Margin of Safety • Narrow margin of safety associated with high-level disinfection of semicritical items • Instrument contaminated with 9 logs or 1,000,000,000 microorganisms • Cleaning eliminates ~5 logs (or 100,000 fold reduction) • High-level disinfection process inactivates ~ 5 logs of microbes (100,000 fold) • Likely exposed to previous patient’s pathogens if reprocessing protocol is not followed precisely • Encourage manufacturers to develop sterilization technology for endoscopes
Margin of Safety HLD of Colonoscopes vs Sterilization of Surgical Devices
Audit Manual Cleaning of EndoscopesEstablishing Benchmarks • Alfa et al. Am J Infect Control 2012;40:860. Rapid Use Scope Test detects organic residuals: protein (<6.4µg/cm2); hemoglobin (<2.2.µg/cm2); and carbohydrate (<1.2µg/cm2) • Alfa et al. Am J Infect Control 2013;41:245-248. If <200 RLUs of ATP, the protein, hemoglobin and bioburden (<4-log10 CFU/cm2 [>106 per scope]) were achieved. • Alfa et al. Am J Infect Control 2014;42:e1-e5. 200 RLU adequate for ATP.
Audit Manual Cleaning of Endoscopes • Issues for consideration • What is the clinical importance of <6.4µg/cm2 for protein and <4 log10 CFU/cm2 [>106/scope] bioburden: that is, has it been related epidemiologically or clinically to decrease or increase risk of infection? • ATP may be related to markers (e.g., protein) but markers may have no relationship to microbes/disease and providing patient safe instrument. • Ideally, validation of benchmarks should include correlation with patients’ clinical outcome. The CDC has suggested that sampling be done when there are epidemiological data that demonstrate risk (e.g., endotoxin testing and microbial testing of water used in dialysis correlated to increased risk of pyrogenic reactions in patient).
ATP and Microbial ContaminationRutala, Gergen, Weber. Unpublished 2014 ATP no correlation to microbes
The Joint Commission • Greater emphasis on infection prevention by The Joint Commission • Sometimes do not use evidence-based guidelines for citations • 5-7 day endoscope reprocessing-RFI, challenged, revoked • Contact times for disinfectants • Transporting clean scope-RFI, challenged, revoked • Storage of processed scopes
Multi-Society Guideline for Reprocessing Flexible Gastrointestinal Endoscopes, 2011 • Unresolved Issues • Interval of storage after which endoscopes should be reprocessed before use • Data suggest that contamination during storage for intervals of 7-14 days is negligible, unassociated with duration, occurs on exterior of instruments and involves only common skin organisms • Data are insufficient to proffer a maximal outer duration for use of appropriately cleaned, reprocessed, dried and stored endoscopes • Without full data reprocessing within this interval may be advisable for certain situations (endoscope entry to otherwise sterile regions such as biliary tree, pancreas)
Endoscopes Reprocessed If Unused 5 DaysAORN, 2010 Provided all channels thoroughly reprocessed and dried, reuse within 10-14 appears safe. Data are insufficient to offer maximum duration for use.
Fecal Transplants for Refractory C. difficile Infection • Criteria for eligibility -failed standard therapy, no contraindication to colonoscopy, confirmed C. difficile toxin positive, etc • Self-identified donor-donor will respond to eligibility questions: no GI cancer, no metabolic disease, no prior use of illicit drugs, etc • Donor Testing-Stool- C. difficile toxin, O&P, bacterial pathogen panel (Salmonella, Shigella, Giardia, norovirus, etc). Serum-RPR, HIV-1, HIV-2, HCV Ab, CMV viral load, HAV IgM and IgG, HBsAg, liver tests, etc • Stool preparation-fresh sample into 1 liter sterile bottle, 500ml saline added, vigorously shaking to liquefy, solid pieces removed with sterile gauze so sample is liquid, liquid stool drawn up into 7 sterile 50ml syringes, injected into terminal ileum, cecum, ascending colon, traverse colon, descending colon, sigmoid colon. Colonoscope reprocessed by HLD.
Disinfection and Sterilization: What’s New • Current Issues and New Technologies • Sterilization of critical items • Biological indicators, cleaning indicators, washer disinfectors • High-level disinfection for semi-critical items • Endoscope reprocessing issues, new high-level disinfectants • Low-level disinfection of non-critical items • New low-level disinfectants, curtain decontamination, green products, contact time, iPads, touchscreens, selecting a disinfectant • D/S and Emerging Pathogens • MERS, HPV, C. difficile, Prions
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
BACTERICIDAL ACTIVITY OF DISINFECTANTS (log10 reduction) WITH A CONTACT TIME OF 1m WITH/WITHOUT FCS. Rutala et al. ICHE. 2012;33:1159 Improved hydrogen peroxide is significantly superior to standard HP at same concentration and superior or similar to the QUAT tested
Hospital Privacy Curtains(pre- and post-intervention study; sampled curtain, sprayed “grab area” 3x from 6-8” with 1.4% IHP and allowed 2 minute contact; sampled curtain)