Download Disinfection and Sterilization: What`s New

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 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
Rapid Readout BIs for Steam Now Require
a 1-3h Readout Compared to 24-48h
Attest™ Super Rapid Readout Biological Indicators
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)
Washer/Disinfector
Rutala WA, Gergen MF, Weber DJ, ICHE. July 2014
• Five Chambers
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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/Disinfector
Removal/Inactivation of Inoculum (Exposed) on Instruments
Rutala et al. Infect Control Hosp Epidemiol. July 2014.
WD Conditions
Organism
Inoculum
Log Reduction
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
Positives
Washer/disinfectors are very effective (>7
log10 reduction) in removing/inactivating
microorganisms from instruments
Cleaning
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•
•
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


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
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 lowlevel disinfection
High-Level Disinfection of
“Semicritical Objects”
Exposure Time > 8m-45m (US), 20oC
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
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
TM
Resert
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High Level Disinfectant - Chemosterilant
2% hydrogen peroxide, in formulation
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pH stabilizers
Chelating agents
Corrosion inhibitors
Efficacy (claims need verification)
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HLD
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
•
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•
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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 crosstransmission
In the inanimate environment, although the incidence remains very
low, endoscopes represent a significant risk of disease
transmission
Transmission of Infection by Endoscopy
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 5
oscopy
Salmonella, HCV 14
6
Cleaning/Disinfection
ERCP
23
Pa
152
89
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.
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
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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 REPROCESSING
Multi-Society Guideline on Endoscope Reprocessing, 2011
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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 Methods
Ofstead , Wetzler, Snyder, Horton, Gastro Nursing 2010; 33:204
Endoscope Reprocessing Methods
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
Automated Endoscope Reprocessors (AER)
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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: CHALLENGES
NDM-Producing E. coli Associated ERCP
MMWR 2014;62:1051
NDM-producing E.coli recovered from elevator channel
ENDOSCOPE REPROCESSING: CHALLENGES
Complex [elevator
channel]-109
bacteria
Surgical instruments-<102 bacteria
ENDOSCOPE REPROCESSING: CHALLENGES
NDM-Producing E. coli Associated ERCP
MMWR 2014;62:1051
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March-July 2013, 9 patients with cultures for New Delhi Metallo-ßLactamase 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: CHALLENGES
NDM-Producing E. coli Associated ERCP
MMWR 2014;62:1051
•
Recommendations
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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
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>150 infections transmitted
Salmonella sp. and P. aeruginosa
Clinical spectrum ranged from colonization to death
• Bronchoscopy
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•
~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 Endoscopes
HLD-Narrow Margin of Safety
•
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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 Endoscopes
Establishing 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 Contamination
Rutala, Gergen, Weber. Unpublished 2014
ATP no correlation to microbes
Pathogen
Microbial Load
ATP
C. difficile
106
<100
Acinetobacter baumannii
~104
<100
MRSA
~104
<100
The Joint Commission
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Greater emphasis on infection prevention by The Joint
Commission
Sometimes do not use evidence-based guidelines for citations
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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 714 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 Days
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
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
Fecal Transplants for Refractory
C. difficile Infection
•
•
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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
Germicide
Exposure time > 1 min
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
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
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 Disinfection
CFU/5 Rodacs (#Path)
After Disinfection
CFU/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 Cleaning
Carling et al. ECCMID, Milan, Italy, May 2011
100
DAILY CLEANING
% Cleaned
80
TERMINAL CLEANING
>110,000
Objects
60
40
20
0
Mean =
32%
HEH
SG
IO W
OT H
OPE
NIC
EM
ICU
AM
MD
LO N
DIA
SV
BC
U
LYS
CLI
DAI
AH
ER
GT
RAT
E
H
N
IS
L
O
H
E
H
HO
EM
IC
ING
Y
RM
SP
OSP
ICL
SP
O
E
RO
S
OM
S
MONITORING THE EFFECTIVENESS OF CLEANING
Cooper et al. AJIC 2007;35:338
•
•
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•
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 Interventions
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
TECHNOLOGIES TO IMPROVE DISINFECTION OF
ENVIRONMENTAL SURFACES
•
New surface disinfectants


•
“No touch” terminal disinfection



•
Improved hydrogen peroxide
Electrochemically activated saline solution
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 iPads
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.
CONTACT TIMES FOR
SURFACE DISINFECTION
Most Prevalent Pathogens Causing
Healthcare-Associated Infections
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%)
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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
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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
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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
How About “Green” Products?
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Today, the definition of green is unregulated
It can mean:
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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
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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
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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
Kill Claims
Does the product kill the most prevalent healthcare pathogens
Kill Times and WetContact 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)
Score
(1-10)
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
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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
Decreasing Order of Resistance of
Microorganisms to Disinfectants/Sterilants
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, non-enveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)
Middle East Respiratory Syndrome-Coronavirus
MERS-CoV
MERS-CoV
Middle East Respiratory Syndrome
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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
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
 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
Decreasing Order of Resistance of
Microorganisms to Disinfectants/Sterilants
Most Resistant
Most Susceptible
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, non-enveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)
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)
Decreasing Order of Resistance of
Microorganisms to Disinfectants/Sterilants
Most Resistant
Most Susceptible
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, non-enveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)
C. difficile spores
DISINFECTANTS AND ANTISEPSIS
C. difficile spores at 10 and 20 min, Rutala et al, 2006
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~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
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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
Decreasing Order of Resistance of Microorganisms to
Disinfectants/Sterilants
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, non-enveloped viruses’
Gram-positive bacteria (MRSA, VRE)
Enveloped viruses (coronavirus)
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)
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
• New D/S technologies (new disinfectants, BIs) and practices (e.g., curtain
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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).
THANK YOU!
www.disinfectionandsterilization.org
PROPERTIES OF AN IDEAL DISINFECTANT
Rutala, 1995. Modified from Molinari 1987.
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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