disinfection and sterilization: what’s new william a. rutala, phd, mph director, hospital...

Disinfection and Sterilization: What’s New

William A. Rutala, PhD, MPHDirector, 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


• 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 PathogensMERS, HPV, C. difficile, Prions

www.disinfectionandsterilization.org

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 Instruments

Rutala et al. Infect Control Hosp Epidemiol. July 2014.

WD Conditions Organism Inoculum Log Reduction Positives

Routine MRSA 2.6x107 Complete 0/8

Routine VRE 2.6x107 Complete 0/8

Routine P aeruginosa 2.1x107 Complete 0/8

Routine M terrae 1.4x108 7.8 2/8

Routine GS spores 5.3x106 4.8 11/14

No Enz/Det VRE 2.5x107 Complete 0/10

No Enz/Det GS spores 8.3x106 5.5 8/10

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





New low-level disinfectants, curtain decontamination, green products, contact time, iPads, selecting a disinfectant


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), 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

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

ENDOSCOPE REPROCESSING

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

Scope Outbreaks Micro (primary) Pts Contaminated

Pts Infected Cause (primary)

Upper GI 19 Pa, H. pylori, Salmonella

169 56 Cleaning/Dis-infection (C/D)

Sigmoid/Colonoscopy

5 Salmonella, HCV 14 6 Cleaning/Dis-infection

ERCP 23 Pa 152 89 C/D, water bottle, AER

Bronchoscopy 51 Pa, Mtb,Mycobacteria

778 98 C/D, AER, water

Totals 98 1113 249Based 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, 2011

Petersen 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 ERCP

MMWR 2014;62:1051

NDM-producing E.coli recovered from elevator channel

ENDOSCOPE REPROCESSING: CHALLENGES

Complex [elevator channel]-109 bacteriaSurgical instruments-<102 bacteria


MMWR 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)


MMWR 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

Pathogen Microbial Load ATP

C. difficile 106 <100

Acinetobacter baumannii ~104 <100

MRSA ~104 <100

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 useData 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

Investigator Shelf Life Contamination Rate Recommendation

Osborne, Endoscopy 2007

18.8h median

15.5% CONS, Micrococcus, Bacillus

Environmental /process contamination

Rejchrt, Gastro Endosc 2004

5 days 3.0% (4/135), skin bacteria (CONS, diphteroids)

Reprocessing before use not necessary

Vergis, Endoscopy 2007

7 days 8.6% (6/70), all CONS Reprocessing not necessary for at least 7d

Riley, GI Nursing, 2002

24,168h 50% (5/10), <3 CFU CONS, S. aureus, P. aeurginosa, Micrococcus

Left for up to 1 week

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.

LOW-LEVEL DISINFECTION FOR NONCRITICAL EQUIPMENT AND SURFACES

Exposure time > 1 minGermicide Use Concentration

Ethyl or isopropyl alcohol 70-90%Chlorine 100ppm (1:500 dilution)Phenolic UDIodophor UDQuaternary ammonium UDImproved 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

Organism IHP-0.5% 0.5% HP IHP Cleaner-Dis 1.4%

1.4% HP 3.0% HP QUAT

MRSA >6.6 <4.0 >6.5 <4.0 <4.0 5.5

VRE >6.3 <3.6 >6.1 <3.6 <3.6 4.6

MDR-Ab >6.8 <4.3 >6.7 <4.3 <4.3 >6.8

MRSA, FCS >6.7 NT >6.7 NT <4.2 <4.2

VRE, FCS >6.3 NT >6.3 NT <3.8 <3.8

MDR-Ab, FCS

>6.6 NT >6.6 NT <4.1 >6.6

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)

Decontamination of Curtains with Activated HP (1.4%)Rutala, Gergen, Weber. Am J Infect Control. 2014;42:426-428

CP for: Before DisinfectionCFU/5 Rodacs (#Path)

After DisinfectionCFU/5 Rodacs (#Path)

% Reduction

MRSA 330 (10 MRSA) 21*(0 MRSA) 93.6%

MRSA 186 (24 VRE) 4* (0 VRE) 97.9%

MRSA 108 (10 VRE) 2* (0 VRE) 98.2%

VRE 75 (4 VRE) 0 (0 VRE) 100%

VRE 68 (2 MRSA) 2* (0 MRSA) 97.1%

VRE 98 (40 VRE) 1* (0 VRE) 99.0%

MRSA 618 (341 MRSA) 1* (0 MRSA) 99.8%

MRSA 55 (1 VRE) 0 (0 MRSA) 100%

MRSA, VRE 320 (0 MRSA, 0 VRE) 1* (0 MRSA, 0 VRE) 99.7%

MRSA 288 (0 MRSA) 1* (0 MRSA) 99.7%

Mean 2146/10=215 (432/10=44) 33*/10=3 (0) 98.5%

* All isolates after disinfection were Bacillus sp; now treat CP patient curtains at discharge with IHP

Thoroughness of Environmental CleaningCarling et al. ECCMID, Milan, Italy, May 2011

0

20

40

60

80

100

%

DAILY CLEANING

TERMINAL CLEANING

Cle

an

ed

Mean = 32%

>110,000 Objects

MONITORING THE EFFECTIVENESS OF CLEANINGCooper et al. AJIC 2007;35:338

• 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)

ALL “TOUCHABLE” (HAND CONTACT) SURFACES SHOULD BE WIPED WITH DISINFECTANT

“High touch” objects only recently defined (no significant differences in microbial contamination of different surfaces) and

“high risk” objects not epidemiologically defined.

Donskey CJ. Am J Infect Control 2013;41:S12

Environmental Disinfection InterventionsDonskey CJ. Am J Infect Control 2013;41:S12

• Cleaning product substitutions• Improvements in the effectiveness of cleaning and disinfection

practices Education Audit and feedback Addition of housekeeping personnel or specialized cleaning staff

• Automated technologies

• Conclusion: Improvements in environmental disinfection may prevent transmission of pathogens and reduce HAIs

TECHNOLOGIES TO IMPROVE DISINFECTION OF ENVIRONMENTAL SURFACES

• New surface disinfectants Improved hydrogen peroxide Electrochemically activated saline solution

• “No touch” terminal disinfection UV light: UV-C or pulsed xenon Hydrogen peroxide systems: Vapor or aerosol Portable devices: UV, steam

• “Self disinfecting” surfaces Heavy metal surface coatings: Silver, copper Sharklet pattern Germicide impregnated surfaces: Triclosan Light-activated antimicrobial coating

Touchscreen Cleaning

• Follow the manufacturer’s recommendations• QUATS are not recommended by some manufacturer• Prepare the cleaning solution according to the manufacturer’s

instructions (e.g., alcohol, glutaraldehyde, mild soap, phenolic)• Wet a clean, soft cloth with the selected cleaning solution• Remove excess liquid from the cloth and squeeze damp• Wipe exposed surfaces (do not allow liquid to enter interior)• Remove any soap residue by gently wiping with clean cloth

Disinfection iPadsHowell et al. J Hosp Infect. 2014

To limit liability manufacturers warn against all cleaning products

Apple recommends soft, slightly damp, lint-free cloth (AJIC 2013. 41:1136)

Contaminated iPads with MRSA, VRE and C. difficile

Wipes (alcohol/Quat; chlorine dioxide; CHG/alcohol [catheter hubs, injection ports]) most effective for MRSA/VRE. All wipes less effective for C. difficile.

No damage and residual effect with 2% CHG plus 70% alcohol after 480 cleanings.

CONTACT TIMES FOR SURFACE DISINFECTION

Most Prevalent Pathogens Causing Healthcare-Associated Infections

Rutala, Weber. Infect Control Hosp Epidemiol. July 2014

Staphylococcus aureus (15.6%) E coli (11.5%) Coagulase-negative Staphylococcus (CoNS)

(11.4%) Klebsiella (8.0%) Pseudomonas aeruginosa (7.5%) Enterococcus faecalis (6.8%) Candida albicans (5.3%) Enterobacter spp. (4.7%) Other Candida spp. (4.2%) Enterococcus faecium (4.1%) Enterococcus spp. (3.0%) Proteus spp. (2.5%) Serratia spp. (2.1%) Acinetobacter baumannii (1.8%)

Modify Disinfectant Used C. difficile spores-over the past

decade, incidence of C. difficile increasing and now most common in some hospitals

Norovirus

Kill Claims for Most Prevalent Pathogens

• Each disinfectant requires a specific time it must remain in contact with the microbe to achieve disinfection. This is known as the kill time or contact time• Some disinfectants may have a kill time for bacteria of 1m, which

means bacteria in label disinfected in 1m• Other low-level disinfectants, often concentrated formulas

require dilution, are registered by the EPA with contact time of 10m• Such a long contact time is not practical

CONTACT TIMES FOR SURFACE DISINFECTION

• Follow the EPA-registered contact times, ideally Some products have achievable contact times for

bacteria/viruses (30 seconds-2 minutes) Other products have non-achievable contact times

• If use a product with non-achievable contact time Use >1 minute based on CDC guideline and scientific literature Prepare a risk assessment

http://www.unc.edu/depts/spice/dis/SurfDisRiskAssess2011.pdf

http://www.unc.edu/depts/spice/dis/SurfDisRiskAssess2011.pdf

How About “Green” Products?

• Today, the definition of green is unregulated• It can mean:

Sustainable resources/plant-based ingredients Free of petrochemicals Biodegradable No animal testing Minimal carbon footprint Traded fairly

• It can, but does not always mean “safer”

Efficacy of “Green” Products to Inactivate MDR Pathogens

Rutala, Gergen, Weber. Unpublished results. 2013

• No measurable activity against A. baumannii, A. xyloxidans, Burkholderia cenocepacia, K. pneumoniae, MRSA and P. aeruginosa, VRE, Stenotrophomonas maltophilia

Transfer of C. difficile Spores by Nonsporicidal Wipes

Cadnum et al. ICHE 2013;34:441-2

• Detergent/nondisinfectant-nonsporicidal wipes transfer or spread microbes/spores to adjacent surfaces; disinfectants inactivate microbes

Key Considerations for Selecting the Ideal Disinfectant for Your Facility

Rutala, Weber. Infect Control Hosp Epidemiol. July 2014.

Consideration Question to Ask Score (1-10)

Kill Claims Does the product kill the most prevalent healthcare pathogens

Kill Times and Wet-Contact Times

How quickly does the product kill the prevalent healthcare pathogens. Ideally, contact time greater than or equal to the kill claim.

Safety Does the product have an acceptable toxicity rating, flammability rating

Ease-of-Use Odor acceptable, shelf-life, in convenient forms (wipes, spray), water soluble, works in organic matter, one-step (cleans/disinfects)

Other factors Supplier offer comprehensive training/education, 24-7 customer support, overall cost acceptable (product capabilities, cost per compliant use, help standardize disinfectants in facility)

Note: Consider the 5 components shown, give each product a score (1 is worst and 10 is best) in each of the 5 categories, and select the product with the highest score as the optimal choice (maximum score is 50).





New low-level disinfectants, curtain decontamination, green products, contact time, iPads, selecting a disinfectant


Decreasing Order of Resistance of Microorganisms to Disinfectants/Sterilants

Prions (CJD)Bacterial spores (C. difficile)

Protozoal oocystsHelminth eggsMycobacteria

Small, non-enveloped viruses (norovirus)Protozoal cystsFungal spores

Gram-negative bacilli (Acinetobacter)Vegetative fungi and algae

Large, non-enveloped viruses’Gram-positive bacteria (MRSA, VRE)

Enveloped viruses (coronavirus)

Most Resistant

Most Susceptible

Middle East Respiratory Syndrome-CoronavirusMERS-CoV

MERS-CoVMiddle East Respiratory Syndrome

• History and Epidemiology First reported in Saudi Arabia in 2012. Etiologic agent is a coronavirus (MERS-CoV) Nearly all cases in or near Arabian Peninsula Transmission via close contact 536 cases and 145 deaths (27%); most from Saudi Arabia (450

cases and 118 deaths) Two non-linked, imported cases in US (MMWR; May 14, 2014)

• Symptoms Fever, cough, shortness of breath

Inactivation of Coronavirus by Disinfectants/Antiseptics and Survival on Surfaces

• Sattar, Springthorpe, Karim, Loro. Epidemiol Infect 1989;102:493 3 log10 reduction in 1m by 2% glut, 70% alcohol, 1% PI, phenolic, and 5,000 ppm

chlorine

• Hulkower, Casanova, Rutala, Weber, Sobsey. Am J Infect Control 2011;39:401 2 log10 reduction in 1m by phenolic (use-dilution), OPA, 70% ethanol, 62% ethanol, 71%

ethanol

• Casanova, Rutala, Weber, Sobsey. Infect Control Hosp Epidemiol. 2010;31:560 2-3 log10 reduction in 4-24h on gloves, gowns, N95, scrub fabric; 1 log10 reduction at 2h

• Casanova, Jeon, Rutala, Weber, Sobsey Appl Env Micro. 2010;76:2712 4-5 logs persisted for 3 days at 50% RH and 28 days at 20% RH

Disinfectants and antiseptics (e.g., ethanol) effective in 1m; survives on PPE (hours) and surfaces (days)




Small, non-enveloped viruses (papillomavirus, polio)Protozoal cystsFungal spores




Most Resistant

Most Susceptible

ENDOSCOPE REPROCESSING: CHALLENGESSusceptibility of Human Papillomavirus

J Meyers et al. J Antimicrob Chemother, Epub Feb 2014

Most common STD Disinfectants (to include HLD) no effect

on HPV Finding inconsistent with other small,

non-enveloped viruses such as polio and parvovirus

Further investigation warranted: test methods unclear; glycine; organic matter; comparison virus

Use HLD consistent with FDA-cleared instructions (no alterations)




Small, non-enveloped viruses (papillomavirus, polio)Protozoal cystsFungal spores




Most Resistant

Most Susceptible

C. difficile spores

DISINFECTANTS AND ANTISEPSISC. difficile spores at 10 and 20 min, Rutala et al, 2006

• ~4 log10 reduction (3 C. difficile strains including BI-9) Bleach, 1:10, ~6,000 ppm chlorine (but not 1:50) Chlorine, ~19,100 ppm chlorine Chlorine, ~25,000 ppm chlorine 0.35% peracetic acid 2.4% glutaraldehyde OPA, 0.55% OPA 2.65% glutaraldehyde 3.4% glutaraldehyde and 26% alcohol

C. difficile EPA-Registered Products

• List K: EPA’s Registered Antimicrobials Products Effective Against C. difficile spores, April 2014• http://www.epa.gov/oppad001/list_k_clostridium.pdf• 34 registered products; most chlorine-based, some

HP/PA-based, PA with silver




Small, non-enveloped viruses (norovirus)Protozoal cystsFungal spores




Most Resistant

Most Susceptible

Management of Neurosurgical Instruments and Patients Exposed to CJD

Conventional sterilization/disinfection inadequate for prions. Need special prion reprocessing (critical/semi device contaminated with high risk tissue from high-risk patient)

• Belay et al. ICHE 2014;34:1272. Decontamination options-1) immerse in 1N NaOH and heat in gravity at ≥121C for 30m in appropriate container; 2) immerse in 1N NaOH or NaOCl 20,000ppm 1h then transfer into water and autoclave at ≥121C for 1h; 3) immerse in 1N NaOH or NaOCl 20,000ppm 1h, rinse with water, transfer to pan and autoclave at 121C (gravity) or 134C (porous) for 1 hour. Clean and sterilize by conventional means.

• Thomas et al. J Clin Neurosci 2013;20:1207. Reviews prevention strategies

• McDonnell et al. J Hosp Infect. 2013;85:268. Investigates the combination of cleaning, disinfection and/or sterilization on prions

• Rutala, Weber. ICHE 2010;31:107. SHEA Guideline-134C for 18m in prevacuum or NaOH/autoclave (such as CDC option 2)


• New D/S technologies (new disinfectants, BIs) and practices (e.g., curtain decontamination) could reduce risk of infection associated with devices and surfaces.

• Endoscope represent a nosocomial hazard. Urgent need to understand the gaps in endoscope reprocessing. Reprocessing guidelines must be followed to prevent exposure to pathogens that may lead to infection. Endoscopes have narrow margin of safety and manufacturers should be encouraged to develop practical sterilization technology.

• The contaminated surface environment in hospital rooms is important in the transmission of healthcare-associated pathogens (MRSA, VRE, C. difficile, Acinetobacter). Thoroughness of cleaning should be monitored (e.g., fluorescence).

• In general, emerging pathogens are susceptible to currently available disinfectants. However, some pathogens need additional information (e.g., HPV).

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PROPERTIES OF AN IDEAL DISINFECTANT Rutala, 1995. Modified from Molinari 1987.

• Broad spectrum-wide antimicrobial spectrum

• Fast acting-should produce a rapid kill

• Not affected by environmental factors-active in the presence of organic matter

• Nontoxic-not irritating to user

• Surface compatibility-should not corrode instruments and metallic surfaces

• Residual effect on treated surface-leave an antimicrobial film on treated surface

• Easy to use

• Odorless-pleasant or no odor

• Economical-cost should not be prohibitively high

• Soluble (in water) and stable (in concentrate and use dilution)

• Cleaner (good cleaning properties) and nonflammable

disinfection and sterilization: what’s new william a. rutala, phd, mph director, hospital...

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