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

• Consultation and Honoraria

ASP (Advanced Sterilization Products), Clorox
• Honoraria

3M
• Grants

CDC, CMS

• Describe two current issues or new technologies used in disinfection/sterilization of:

Critical devices

Semicritical devices

Noncritical devices/surfaces

• 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 lowlevel 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

www.disinfectionandsterilization.org

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

Commercially 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)

Rutala 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 (150 o F) 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 (180 o F ) 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

Removal/Inactivation of Inoculum (Exposed) on Instruments
Rutala et al. Infect Control Hosp Epidemiol. July 2014.
WD Conditions
Routine
Routine
Routine
Organism Inoculum Log Reduction Positives
MRSA 2.6x10
7 Complete 0/8
VRE
P aeruginosa
2.6x10
2.1x10
7
7
Complete
Complete
0/8
0/8
Routine
Routine
M terrae 1.4x10
8
GS spores 5.3x10
6
No Enz/Det VRE 2.5x10
7
No Enz/Det GS spores 8.3x10
6
7.8
4.8
Complete
5.5
2/8
11/14
0/10
8/10

10

• 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.





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

• 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 lowlevel disinfection

Exposure Time > 8m-45m (US), 20 o C
Germicide 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 ppm
Accelerated hydrogen peroxide
Peracetic acid
2.0%
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

TM









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 20 o C
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

• Widely used diagnostic and therapeutic procedure (11-22 million
GI procedures annually in the US)
• GI endoscope contamination during use (10 9 in/10 5 out)
• Semicritical items require high-level disinfection minimally
• Inappropriate cleaning and disinfection has lead to crosstransmission
• In the inanimate environment, although the incidence remains very low, endoscopes represent a significant risk of disease transmission

Kovaleva 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/Disinfection (C/D)
Sigmoid/Colon oscopy
ERCP
5
23
Salmonella, HCV 14
Pa 152
6
89
Cleaning/Disinfection
C/D, water bottle, AER
Bronchoscopy 51 Pa, Mtb,
Mycobacteria
778 98 C/D, AER, water
Totals 98 1113 249
Based on outbreak data, if eliminated deficiencies associated with cleaning, disinfection, AER , contaminated water and drying would eliminate about 85% of the outbreaks.

• 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







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 log
10 and HLD (4-6 log
10 reduction) reduction) essential for patient safe instrument

Petersen et al. ICHE. 2011;32:527

Multi-Society Guideline on Endoscope Reprocessing, 2011
• PRECLEANpoint-of-use (bedside) remove debris by wiping exterior and aspiration of detergent through air/water and biopsy channels; leak testing
• CLEANmechanically cleaned with water and enzymatic cleaner
• HLD/STERILIZEimmerse scope and perfuse HLD/sterilant through all channels for exposure time (>2% glut at 20m at 20 o C). If
AER used, review model-specific reprocessing protocols from both the endoscope and AER manufacturer
• RINSEscope 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

Ofstead , Wetzler, Snyder, Horton, Gastro Nursing 2010; 33:204

Ofstead , 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






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

(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)

MMWR 2014;62:1051
NDM-producing E.coli recovered from elevator channel

Surgical instruments-<10 2 bacteria
Complex [elevator channel]-10 9 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.

• 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







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 log
10 and HLD (4-6 log
10 reduction) reduction) essential for patient safe instrument

• 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

HLD of Colonoscopes vs Sterilization of Surgical Devices

Establishing Benchmarks

Alfa et al. Am J Infect Control 2012;40:860. Rapid Use Scope
Test detects organic residuals: protein (<6.4µg/cm 2 ); hemoglobin (<2.2.µg/cm 2 ); and carbohydrate (<1.2µg/cm 2 )

Alfa et al. Am J Infect Control 2013;41:245-248 . If <200 RLUs of ATP, the protein, hemoglobin and bioburden (<4-log
10
CFU/cm 2 [>10 6 per scope]) were achieved.

Alfa et al. Am J Infect Control 2014;42:e1-e5. 200 RLU adequate for ATP.

• Issues for consideration

What is the clinical importance of <6.4µg/cm 2 for protein and <4 log
10
CFU/cm 2 [>10 6 /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).

Rutala, Gergen, Weber. Unpublished 2014
Pathogen Microbial Load ATP
C. difficile 10 6 <100
Acinetobacter baumannii
MRSA
~10 4
~10 4
<100
<100

• 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

• 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)

AORN, 2010
Provided all channels thoroughly reprocessed and dried, reuse within 10-14 appears safe. Data are insufficient to offer maximum duration for use.
Investigator Shelf Life Contamination Rate Recommendation
Osborne,
Endoscopy 2007
18.8h
median
15.5% CONS, Micrococcus,
Bacillus
Environmental /process contamination
Rejchrt, Gastro
Endosc 2004
Vergis, Endoscopy
2007
Riley, GI Nursing,
2002
5 days
7 days
24,168h
3.0% (4/135), skin bacteria
(CONS, diphteroids)
8.6% (6/70), all CONS
50% (5/10), <3 CFU CONS, S. aureus, P. aeurginosa,
Micrococcus
Reprocessing before use not necessary
Reprocessing not necessary for at least 7d
Left for up to 1 week

• 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

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

BACTERICIDAL ACTIVITY OF DISINFECTANTS (log
10 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
Organism IHP-0.5% 0.5% HP IHP Cleaner-Dis
1.4%
1.4% HP 3.0% HP QUAT
MRSA
VRE
MDR-Ab
>6.6
>6.3
>6.8
MRSA, FCS >6.7
<4.0
<3.6
<4.3
NT
>6.5
>6.1
>6.7
>6.7
<4.0
<3.6
<4.3
NT
<4.0
<3.6
<4.3
<4.2
5.5
4.6
>6.8
<4.2
VRE, FCS
MDR-Ab,
FCS
>6.3
>6.6
NT
NT
>6.3
>6.6
NT
NT
<3.8
<4.1
<3.8
>6.6

(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)

Rutala, Gergen, Weber. Am J Infect Control. 2014;42:426-428
CP for: Before Disinfection
CFU/5 Rodacs (#Path)
After Disinfection
CFU/5 Rodacs (#Path)
% Reduction
MRSA
MRSA
MRSA
VRE
VRE
VRE
MRSA
MRSA
330 (10 MRSA)
186 (24 VRE)
108 (10 VRE)
75 (4 VRE)
68 (2 MRSA)
98 (40 VRE)
618 (341 MRSA)
55 (1 VRE)
21*(0 MRSA)
4* (0 VRE)
2* (0 VRE)
0 (0 VRE)
2* (0 MRSA)
1* (0 VRE)
1* (0 MRSA)
0 (0 MRSA)
93.6%
97.9%
98.2%
100%
97.1%
99.0%
99.8%
100%
MRSA, VRE
MRSA
320 (0 MRSA, 0 VRE)
288 (0 MRSA)
1* (0 MRSA, 0 VRE)
1* (0 MRSA)
99.7%
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

100
80
60
40
20
0
Carling et al. ECCMID, Milan, Italy, May 2011
DAILY CLEANING
TERMINAL CLEANING
>110,000
Objects
Mean =
32%
HEH
SG
IOW
HOSP
A HO
OTHER
SP
OPE
HOSP
RATIN
NICU
G RO
OMS
EM
S VE
ICU D
HICL
ES
AILY
AMB
CHEM
MD
O
CLIN
IC
LONG
TER
DIAL
M
YSIS

MONITORING THE EFFECTIVENESS OF CLEANING
Cooper 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/cm 2 -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)

“
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

Donskey 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

• 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

• 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

Howell 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.

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

• 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

• 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

• 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”

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

Cadnum et al. ICHE 2013;34:441-2
• Detergent/nondisinfectant-nonsporicidal wipes transfer or spread microbes/spores to adjacent surfaces; disinfectants inactivate microbes

Rutala, Weber. Infect Control Hosp Epidemiol. July 2014.
Consideration Question to Ask Score
(1-10)
Kill Claims
Kill Times and Wet-
Contact Times
Safety
Ease-of-Use
Other factors
Does the product kill the most prevalent healthcare pathogens
How quickly does the product kill the prevalent healthcare pathogens.
Ideally, contact time greater than or equal to the kill claim.
Does the product have an acceptable toxicity rating, flammability rating
Odor acceptable, shelf-life, in convenient forms (wipes, spray), water soluble, works in organic matter, one-step (cleans/disinfects)
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).

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

Most Resistant
Most Susceptible
Prions (CJD)
Bacterial spores (C. difficile)
Protozoal oocysts
Helminth eggs
Mycobacteria
Small, non-enveloped viruses (norovirus)
Protozoal cysts
Fungal spores
Gram-negative bacilli (Acinetobacter)
Vegetative fungi and algae
Large, nonenveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)

Middle East Respiratory Syndrome-Coronavirus
MERS-CoV

MERS-CoV
• History and Epidemiology
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First reported in Saudi Arabia in 2012.
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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)
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Two non-linked, imported cases in US (MMWR; May 14, 2014)
• Symptoms

Fever, cough, shortness of breath

Disinfectants and antiseptics (e.g., ethanol) effective in 1m; survives on PPE (hours) and surfaces (days)
• Sattar, Springthorpe, Karim, Loro. Epidemiol Infect 1989;102:493
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3 log
10 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
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2 log
10 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
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2-3 log
10 reduction in 4-24h on gloves, gowns, N95, scrub fabric; 1 log reduction at 2h
10
• Casanova, Jeon, Rutala, Weber, Sobsey Appl Env Micro. 2010;76:2712
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4-5 logs persisted for 3 days at 50% RH and 28 days at 20% RH

Most Resistant
Prions (CJD)
Bacterial spores (C. difficile)
Protozoal oocysts
Helminth eggs
Mycobacteria
Small, non-enveloped viruses ( papillomavirus, polio)
Protozoal cysts
Fungal spores
Gram-negative bacilli (Acinetobacter)
Vegetative fungi and algae
Large, nonenveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)
Most Susceptible

ENDOSCOPE REPROCESSING: CHALLENGES
Susceptibility of Human Papillomavirus
J Meyers et al. J Antimicrob Chemother, Epub Feb 2014
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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 FDAcleared instructions (no alterations)

Most Resistant
Prions (CJD)
Bacterial spores ( C. difficile )
Protozoal oocysts
Helminth eggs
Mycobacteria
Small, non-enveloped viruses (papillomavirus, polio)
Protozoal cysts
Fungal spores
Gram-negative bacilli (Acinetobacter)
Vegetative fungi and algae
Large, nonenveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)
Most Susceptible

C. difficile spores

C. difficile spores at 10 and 20 min, Rutala et al, 2006
• ~4 log
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10 reduction (3 C. difficile strains including BI-9
Bleach, 1:10, ~6,000 ppm chlorine (but not 1:50)
)
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Chlorine, ~19,100 ppm chlorine
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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

• 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

Most Resistant
Most Susceptible
Prions (CJD)
Bacterial spores (C. difficile)
Protozoal oocysts
Helminth eggs
Mycobacteria
Small, non-enveloped viruses (norovirus)
Protozoal cysts
Fungal spores
Gram-negative bacilli (Acinetobacter)
Vegetative fungi and algae
Large, nonenveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)

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)

Disinfection and Sterilization:
What’s New
• Current Issues and New Technologies

Sterilization of critical items
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Biological indicators, cleaning indicators, washer disinfectors
High-level disinfection for semi-critical items
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Endoscope reprocessing issues, new high-level disinfectants
Low-level disinfection of non-critical items
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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

• 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).

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