‘Decontamination of RIMD –

It ain't what you do, it's the way that you do it’

Microbial Surveillance of

Reusable Invasive Medical Devices

‘It is what you do and the way that you do it’

C Herra PhD, School of Biological and Health Sciences, DIT

2018 IDI Annual Conference, Dublin

Microbial Surveillance of RIMD

Methods

Feasibility

Alternatives

Need

Quarantine

Role of RIMD in Healthcare-Associated Infection (HCAI)

Microbial Surveillance-Need?

Indirect contact with the environmentDirect-contact

HCAIs- contracted in a hospital, long-term care or other healthcare facilities

Prevalence of HCAI in Ireland

37%

15%

11%9% 8% 7% 6%

0%

5%

10%

15%

20%

25%

30%

35%

40%

Distribution of HCAI pathogens in Ireland

% HCAI

In Ireland HCAI affects 6.1% of hospitalised patients and 4.4% of patients in long-term care facilities

Point Prevalence Survey of Hospital‐Acquired Infection, Irish Acute Care Hospitals, 2017

EARS-Net data on Antimicrobial Resistance in Ireland, 2017

Summary of Antimicrobial Resistance Trends

Distribution of VRE in EARS-Net countries in 2016

2016 trends

7 countries

2 countries

IE 44%

EU/EEA: 12%

• Ireland had the 2nd highest proportion of VREfm in Europe after Cyprus

in 2016 and the highest for the previous 8 successive years

Distribution of MDR K. pneumoniaein EARS-Net countries in 2016

Note: MDR defined as

combined resistance to

3GCs, fluoroquinolones

and aminoglycosides

EU/EEA: 16%

2008 data

downloaded

from TESSy,

31/03/2016

2016 trends

4 countries

3 countries

Map downloaded from ECDC’s TESSy database on 20/10/2017: https://ecdc.europa.eu/en/antimicrobial-resistance/surveillance-and-disease-data/data-ecdc

EU/EEA: 6%

2016 trends

2 countries

3 countries

Map downloaded from ECDC’s TESSy database on 20/10/2017: https://ecdc.europa.eu/en/antimicrobial-resistance/surveillance-and-disease-data/data-ecdc

Distribution of Carbapenem-Resistant Enterobacteriaceae (CRE) in EARS-Net in 2016

Impact of HCAI

Real problem- HCAI with MDR strains

HCAI significant cost in terms of

1. Increased morbidity and mortality

Pt with HAI X 7 more likely to die in hospital

2. Extra hospital days

HCAI delays pt discharge by average of 11 days

3. Financial cost

Cost an average HCAI ~ €9000/episode

Risk Factors for HCAI- Medical Devices

Risk factors for HCAI

Intravascular and urinary catheterization

Mechanical ventilation of the respiratory tract

Operative surgery

Invasive procedures – endoscopy, bronchoscopy

Immuno-suppression and existing disease

Prolonged hospital stay/antimicrobial treatment

HCAIs most commonly associated with the use of invasive

procedures and devices

Collectively, these account >80% of all HCAIs

HCAI- Device-Associated Infection

Catheter-associated

(CAUTI)

Ventilator-associated

(VAP)

Central line-associated (CLABSI)

Device-associated infections

PneumoniaUrinary tract

infectionBloodstream

infectionSurgical Site

InfectionHCAI

Bronchoscopes

Endoscopes,Surgical/

Dental devices

Surgical/Dental Devices

RIMD -associated infection

Semi-critical CriticalMedical Non critical Devices

Devices

RMD: Spaulding classificationCritical Devices Semi-critical Devices Non-critical Devices

Enter the vascular system and

sterile tissues

Come in contact with mucous membrane

IIb Instrument IIa contact only

Come into contact

with intact skin

Surgical instruments

Laparoscopes Arthroscopes

Dental forceps flap retractors,

burs, abscess drains

Flexible Endoscopes Thermometers

Colonoscopes

Duodenoscopes,

Gastroscopes,

Sigmoidoscopes

Brochoscopes

Dental probes Mouth mirrors,

Dental hand-piece Impression

trays

Stethoscopes

Blood pressure cuffs

Prosthetic gauges, bib

chains. air/water

syringe

High level infection risk Moderate level infection risk Low level infection

risk

Require sterilisation-

destruction of all microbial life

IIb Require cleaning followed by high-

level disinfection-destruction of all veg

orgs, tb, viruses, fungal spores, and

some bacterial spores. IIa Intermediate

disinfection- most veg org not kill spore

Require low-level

disinfection or simple

cleaning with

detergent & water

Flexible Endoscopes

High speed

Dental hand-pieces Low Risk

High Risk

But

Effective

Sterilisation

Flexible Endoscopes- HCAI Risk?

RIMD- flexible endoscopes most frequently associated with

outbreaks of HCAI

Duodenoscopes (used for ERCP)- highest risk

Unique challenge to infection control

1. Heavily contaminated- Bioburden of GI endoscopes 105 -

1010 CFU/ml after use

2. Thermolabile- cannot be heat sterilized

3. Complex design- multiple narrow lumens, elevator levers

4. Biofilms formation in the endoscope channels

Report Time

Period

No. transmission

events

No.

significant

Infections

Cause of Transmission

Meta- Analysis

Kovaleva et al

2016

1970-

2015

500 345- 2 peaks 1991-95

140 - defective AERs

2010-15

158 MDR GNB- 103 CRE

26- Defect endoscope

41- Improper cleaning

90- No breach reprocessing

Meta- Analysis

McCafferty et

al 2018

2008-

2018

18 GI outbreaks

16 duodenoscope

NA 14 outbreaks MDR agents-CRE

9 reprocessing failures

7 No breach in reprocessing

❑ Despite large number of endoscopic procedures, when all decontamination steps followed- rate of proven exogenous HCAI was considered rare 1/1.8million (Barakat, Gastro. Endoscopy, 2018)

Reported Episodes of Exogenous

Microbial transmission in GI endoscopy?

Reported Episodes of Microbial

Transmission in GI endoscopy

First CRE outbreaks

FDA 2010-15- Endoscopy-related Reports from Reprocessed Duodenoscopes

Exogenous Endoscopy-related HCAI-

MDR CRE pathogens

Duodenoscope-associated MDR infections reported in Canada and

the United States, Europe- UK

Worldwide Duodenoscope-associated MDR outbreaks-25 hospitals

involving at least 250 pts

Duodenoscope-associated MDR infections pose significant threat to

patients – public health concern

Exogenous endoscopy-related HCAI

True rate transmission during endoscopy may unrecognized

inadequate/no surveillance

absence of clinical symptoms- colonisation not infection

Recent studies indicate

> 2% bacterial contamination rate of patient-ready

endoscopes

25-38% infection rate post ERCP- CRE outbreak

Endoscopy-potential significant risk for HCAI transmission

Need to validate endoscope reprocessing by

microbiological surveillance increasingly recognised

Professional Guidelines

Microbial Surveillance

Settle/Contact Nasal/Rectal swab Channel/elevator flush

Plate AER Rinse water

Environmental Screening in Healthcare Healthcare environment Patient screening RIMD- Endoscopes

Conventional

Culture Detect Total Viable Count

Colony count- CFU/ml

Microbiological Surveillance of

Endoscope Reprocessing

Microbial Surveillance promoted by Professional bodies

Formal guidelines for endoscope surveillance published by

• FDA/CDC- Surveillance Sampling& Culturing Protocols

• Gastroenterological Society of Australia (GESA)

• European Society of Gastroenterology (ESGE)

• European Soc. Gastro and Endoscopy Nurses (ESGENA)

• British Society of Gastroenterology (BSG)

• HSE-Standards and Recommended Practices for

Endoscope Reprocessing

International Guidelines on Microbial Surveillance of Endoscopes

No Agreement

❑ Sampling- Frequency, Sites, Techniques?

❑ Culture- Process Volume, Culture conditions, Target organisms?

❑ Result- Acceptance criteria, Interpretation, Action?

Cattoir et al Infect Control Hosp Epidemiol, 2017

Site Frequency Sampling site Sampling Mtd. Sample Process Interpretation

Sample

Reprocessed

Endoscope

(Process &

Endoscope)

Microbial

Quality of

Water

Quarterly-

Annually

(no. endoscopes

in same family)

Weakly EWD

Quarterly for

RO main

Lumen

(all channels)

Final Rinse

water

Wet

Brush re-suspend

tip in 10ml neut.

Dry

Flush 10ml neut.

100mls

Sonicate - Filter

10ml on R2A

5 days incubation

Filter 10 ml on

R₂A, TSA or YEA

5 days incubation

Filter 100ml on

R2A media

5 days incubation

TVC <10/10mls

TVC <10/100mls

Actions

10-100- Recycle

>100- Remove

from service

Nuet- Neutralising solution, Agar- R2A- Low nut med, TSA- Tryptic Soya Agar, YEA- Yeast Extract Agar

Microbial Surveillance- HSE Standards for Commissioning, Validation & Testing in EDU, 2018

Wet

Dry

Performance of Conventional Culture

Culture and Quarantine

Culture Surveillance- Feasible

Culture Surveillance- does it work?

Specificity Sensitivity TAT Cost Quality Report

81% 75% 3-5 days Labour intensive ? Patient impact

Satisfactory Borderline Very slow ? Cost effective ? Actions/Alert

Poor sampling-

Complex design

ERCP-CRE outbreaks

culture negative

inaccessibility of

bacteria in elevator

channel

Routine

TVC 2 days

Id + 1 day

AST +1 day

5 days

Fastidious

TB 28 days

Materials cheap

but labour

intensive

Culture & Quarantine

may not be feasible

Systematic culture programme to monitor endoscope reprocessing

Ma et al Gastrointest Endosc 2018

❑ Implemented 16-mth program to systematically culture elevator

lever-equipped endoscopes using a modified CDC culture mtd.

❑ Each week 25% endoscopes selected for culture and quarantine

Results- Programme Feasible

Id low rate of positive cultures- 1%- 3 pos/285 cultures

3 quarantined scopes reprocessed, repeat cultures were negative

Modest cost 20 endoscopes €25,000/year €1,300/scope

(cost of ERCP outbreak – 6 pts with BSI - €170,000)

New Approaches

Bioburden assays

ATP

Non-Culture Alternatives

Bioburden Assays- do they work?

Specificity Sensitivity TAT Cost Quality Report

NA NA 90 sec Easy to use NA

Not specific ? Very quick Cost effective Defined criteria

Proposed Interpretation

❑ Rapid audit tool to assess compliance with manual cleaning

(Alfa et al. American Journal of Infection Control 2012)

Endoscope Bioburden assays detect

protein on surface of endoscopes

protein and blood within the biopsy channel and

protein, blood, and carbohydrates within channel

Estimate of all biological contamination- not just bacterial

ATP Assays- do they work?Specificity Sensitivity TAT Cost Quality Report

43-81% 46-75% 2 mins Easy to use NA

Not specific Not sensitive Very quick Cost effective Defined criteria

Proposed Interpretation

❑ Not specific- all cells + false pos from dead cells

❑ Not sensitive- bacteria low ATP- 104-105 viable bacteria but

negative ATP result (Humphries Jrn Clin Micro 2015)

❑ ATP testing convenient assessment of endoscopy hygiene

(Gillespie Jrn of Hosp. Infect 2017)

❑ Rapid indicator for endoscope contamination before HDL-

cannot act as a screening tool before patient use

(McCafferty Jrn of Hosp. Infect 2018)

❑ CDC- not sufficiently sensitive marker for adequacy of HLD

Non-culture methods – jury is out!

While individual facilities might choose to use non-culture

assays, more work is needed to interpret results

Non-culture methods lack consistent correlation to bacterial

concentrations

Methods indicate biological contamination- not intended

replace Microbial surveillance

Olafsdottir et al Infect Control Hosp Epidemiol 2017

Washburn et al. Am Jrn of Infection Control 2017

Reliable, rapid alternatives for microbial surveillance?

Phenotype Vs Genotype

Molecular Detection

Diagnostic Microbiology

Day 2

Day 1

Isolation

Identify

AST

Conventional culture Molecular Detection

Isolate pathogen Direct detection

Identify & Sensitivity DNA from specimen

Overnight

incubation

Day 1

Day 3 Result Day 1 Result

Overnight

incubation

Real Time PCR

Real time PCR used extensively diagnostic micro lab

Direct microbial investigation of clinical sample

Exquisite sensitivity

Excellent specificity

Rapid- automated systems result 3h TAT

Expensive- but cost effective

Largely replaced culture- Gold standard for detection of

Non-culturable organisms- viruses

Slow growing organisms- Mycobacteria

Important HCAI pathogens- MRSA, CRE, VRE

New approaches- Molecular Detection

Microbial Surveillance of Endoscopes-Role of Molecular detection

Real-Time

PCR

platform

Automated 3hr TAT

Amplification plot

❑ Role in microbial surveillance of Endoscopes- recognised

❑ Expense and Access- limited investigation

❑ Multicenter study111endoscope samples 98% accuracy 4hr TAT (Valeriani et al Am Jrn Infection Control 2018)

Detect target nucleotide sequence- unique to the pathogen

Amplify target sequence more than million fold

Detect amplified sequence using fluorescent probes-sensitivity

Test using

Real-Time PCR

3hr TAT

Clinical

sample

Positive

Report

Culture Confirm AST

Release

Scope

Back into use

Quarantine

Scope

Reprocess and resample

Diagnostic Algorithm for Microbial Surveillance