Proposed Framework for Environmental Infection

Control Research:

Focus on Non-critical Surfaces

Sujan Reddy, MD MSc

Division of Healthcare Quality Promotion, CDC

Emory University

July 17, 2015

Overview

� Background

� Objectives

� Conceptual models

� Proposed research agenda

� Feedback

BACKGROUND

Role of non-critical surfaces in transmitting pathogens

� In 1970s-1980s, transmission of nosocomial pathogens

via environmental surfaces was thought to be

negligible

� More recent studies suggest that non-critical surfaces

play a role in pathogen transmission

� Transmission related to prior occupants of the same room

� Suggests the surface environment may serve as a reservoir for

pathogens

� Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-

resistant enterococcus (VRE), Clostridium difficile

Changing landscape in environmental infection control

� Emerging technologies for reducing and preventing contamination� No-touch cleaning and disinfection modalities

� Enhanced wipes, mops and cloths

� Enhanced surface coatings

� Emerging technologies for monitoring cleaning and disinfection

� Limited evidence guiding facilities on how to minimize contamination

AHRQ Technical Brief on Environmental Cleaning (draft)

� Systematic review with key informant interviews

� Cleaning and monitoring practices

� Practice implementation

� Knowledge gaps

� Research challenges

� Conclusions:

� Limited evidence, weak study designs

� Reliance on non-clinical outcomes

� Lack of consensus around important concepts

• Cleanliness thresholds, delineation of high-touch surfaces

Agency for Healthcare Quality & Research Draft Technical Brief.

Environmental Cleaning for the Prevention of Healthcare-Associated Infections

AHRQ key areas for future research (draft)

1. Comparative effectiveness of emerging technologies

for cleaning and monitoring

2. Implementation and process research

3. Thresholds for cleanliness

4. Patient-centered outcomes

5. High-touch/high-risk surfaces

6. Controlling for confounders and multi-component

interventions

Agency for Healthcare Quality & Research Draft Technical Brief.

Environmental Cleaning for the Prevention of Healthcare-Associated Infections

OBJECTIVES AND AIMS

Research setting

� Who?� CDC and its partners

• Many ongoing and proposed projects relating to environmental infection control

• Goal of this research framework is to integrate these projects and guide future projects

� What? � Non-critical surfaces

• Defined by Spaulding criteria

� Contamination with potential pathogens• Including multidrug resistant pathogens (MDRO) and emerging pathogens such as Ebola

� Where?� Adult acute care facilities

� Intensive care units and wards > emergency rooms> operating rooms

� Single patient rooms

� Many of these findings may be applicable to other healthcare settings

Objectives

� Determine the public health significance of non-critical

environmental surface contamination

� Provide further guidance to healthcare facilities about

reducing the contamination of non-critical

environmental surfaces reliably in order to improve

patient safety

Specific Aims

1. Understand transmission dynamics of nosocomial pathogens in relation to non-critical environmental surface contamination in healthcare facilities

2. Determine bioburden levels on non-critical surfaces associated with decreased transmission of pathogens and healthcare-associated infections

3. Compare methods for reducing or preventing contamination as well as compare methods for monitoring cleaning and disinfection of non-critical surfaces

4. Understand the differences between healthcare settings in terms of transmission dynamics and bioburden levels

CONCEPTUAL FRAMEWORK

Conceptual Framework

1. Transmission of pathogens in healthcare settings

2. Surface exposure factors that may influence

transmission events

3. Focus on both bioburden and patient safety outcomes

The

Environment

Hospital Acquired

Infections

Healthcare

Workers

Transmission of pathogens in healthcare settings

Revised figure courtesy of Jon Otter

Infected and

Colonised

The

Environment

Hospital Acquired

Infections

Healthcare

Workers

Transmission of pathogens in healthcare settings

Revised figure courtesy of Jon Otter

Infected and

Colonised

Direct patient to patient

Air and water contamination

Nosocomial

transmission = Surface

exposure

Host

factorsConfounders

• Host factors: colonized patient and susceptible patient

• Confounders: hand hygiene, air and water contamination, direct patient-to-

patient contact

Surface

exposureBioburden

Transfer

efficiencyFrequency Time=

Nosocomial

transmission = Surface

exposure

Host

factorsConfounders

• Bioburden

• Total microbe level and composition of microbiota

• Transfer efficiency of pathogens between surfaces and patients (high-risk)

• Type of surface

• Type of pathogen

• Type of human exposure

• Frequency of exposure (high-touch)

• Time

• Survivability or persistence of pathogen

• Duration between cleaning

• Host factors: colonized patient and susceptible patient

• Confounders: hand hygiene, air and water contamination, direct patient-to-

patient contact

Bioburden levelsMethods of assessment

Association with pathogen levels

Reducing bioburden levels

Patient safety*Reduce HCW hand contamination

Reduce same room transmission

Reduce transmission events

Reduce healthcare-association infections

Focus on both bioburden and patient safety

*Close attention to research methodology

*Control for other key confounders

RESEARCH AGENDA

Aim 1: Understanding transmission dynamics

� What proportion of transmission events involve surface

contamination?

� How do environmental surfaces become

contaminated?

� Which non-critical surfaces are most important?

Aim 1: Understanding transmission dynamics

� What proportion of transmission events involve surface

contamination?

� How many hospital-acquired infections can be prevented by

decreasing surface contamination?

� Public health significance

� Guide to multiple studies

Aim 1: Understanding transmission dynamics

� How do environmental surfaces become

contaminated?

� Direct: patient, HCW, PPE � surface

� Indirect: short range particles, air handling, splash zone

� Microbial factors: persistence/survivability, matrix effects

Aim 1: Understanding transmission dynamics

� Which non-critical surfaces are most important?

� Frequency of touches

� Transfer efficiency

• By surface type

• By pathogen

• By human exposure

� Surface characteristics associated with:

• Contamination and microbial survivability or persistence

� Duration between cleaning

• Terminal and routine cleaning

• Re-contamination rates

Aim 2: Determine bioburden levels associated with outcomes

� What are the best methods for assessing bioburden?

� What influences the bioburden of surfaces in

healthcare settings?

� How do bioburden levels impact patient safety?

Aim 2: Determine bioburden levels –What are best methods for assessing bioburden?

� Sampling strategies� Performance characteristics

• Role of non-culture based methods

� Standardization of protocols for sampling

� Composite vs. multiple site sampling strategies

� Sampling a variety of surface types (hard vs soft surfaces)

� Feasibility of strategies in “real-world” settings

� Association of total bioburden levels with:� Microbial composition, particularly pathogen burden

� Surrogate markers

Aim 2: Determine bioburden levels–What influences bioburden in healthcare settings?

� How does microbiota of a room change over time?

� How well do pathogens survive or persist on surfaces?

� What influences non-pathogenic bioburden

distribution?

� Human- vs environmentally-derived (air and water contamination)

Aim 2: Determine bioburden levels–How do bioburden levels impact patient safety?

� What are the appropriate research methods to link bioburden to patient outcomes?

� How does one control for other elements that contribute to surface exposure in addition to bioburden? � Surface type, pathogen type, duration between cleaning, etc

� Are certain bioburden levels associated with clinical outcomes?� HCW hand contamination, patient colonization rates, patient infection

rates

� Does reducing bioburden reduce HAI?

� Can non-culture based approaches aid in evaluating risk?

Aim 3: Comparing methods

� What is the effectiveness of methods for reducing

contamination?

� Cleaning and disinfection

� Relative role of terminal vs. daily cleaning

� What is the effectiveness of methods for preventing

contamination?

� What are methods for monitoring cleaning and

disinfection?

� Assessing bioburden surrogates with outcomes

Aim 3: Comparing methods–Implementation and process research

� What is the current status of environmental surface hygiene in US hospitals?

� How long does it take to adequately clean and disinfect surfaces using currently available technologies?

� What factors effect “real-world” implementation?� Human factors

� Competency

� Education and training

� Which multi-component environmental surface cleaning interventions reduce transmission events?

Aim 4: Understand differences between healthcare settings in transmission dynamics and

bioburden levels

� Long term care facilities

� High-turnover ambulatory care settings

� Infusion centers, dialysis centers

� Inpatient radiology

� Pediatrics

� Multiple patient rooms

EXAMPLE OF CURRENT RESEARCH

Assessment of Overall and MDRO bioburden on Environmental surfaces

� 11 Hospitals or long term care facilities from four states � Georgia, Illinois, Maryland, Vermont

� MDRO Isolation Rooms:� Acinetobacter baumannii

� Clostridium difficile

� Klebsiella pneumoniae

� MRSA

� VRE

� 375 Composite samples collected from 170 rooms� Routine (daily) cleaned rooms (n=116)

� Terminal cleaned rooms (n=54)

� Different surfaces on one sponge stick

Shams A, Rose L, Noble-Wang J et al. 2014 ID Week, Philadelphia, PA

Factors associated with higher bioburden levels

� Routine cleaning > terminal

� Quaternary ammonium product > bleach

� Surfaces proximity to patient: closer > farther

� Bedrails, TV remote, telephone and call button

Shams A, Rose L, Noble-Wang J et al. 2014 ID Week, Philadelphia, PA

Factors associated with recovering a MDRO

� Room microbial burden > 103 CFU/100cm2

� MRSA, VRE, A. baumannii, K. pneumoniae, C. difficile

� Quaternary ammonium product > bleach

� The MDRO recovered was not always the same as the

MDRO for which patient was isolated

Shams A, Rose L, Noble-Wang J et al. 2014 ID Week, Philadelphia, PA

NEXT STEPS

Summary

� Many ongoing studies evaluating risk of pathogen transmission due to non-critical surfaces

� Objectives:� Describe public health significance of non-critical environmental

surface contamination

� Provide further guidance about reducing the contamination of non-critical surfaces reliably in order to improve patient safety

� This draft research agenda identifies areas for future studies to achieve these goals

Requesting feedback

� Conceptual models

� Transmission in healthcare settings

� Factors influencing surface exposure

� Focus on bioburden and patient safety

� Research aims/questions

� Transmission dynamics

� Assessment of bioburden levels and outcomes

� Comparing methods

� Assessing various healthcare settings

Thank you

Questions?

Sujan Reddy

scredd2@emory.edu

For more information please contact Centers for Disease Control and Prevention

1600 Clifton Road NE, Atlanta, GA 30333

Telephone: 1-800-CDC-INFO (232-4636)/TTY: 1-888-232-6348

Visit: www.cdc.gov | Contact CDC at: 1-800-CDC-INFO or www.cdc.gov/info

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the

Centers for Disease Control and Prevention.