Understanding the Infectious Disease Process:

Standard & Transmission Based Precautions

Russ OlmstedSJMHS, Ann Arbor, MIOlmstedr@trinity-health.org

Key Principles: It’s More Than Presence of the Microorganism

Historical Milestones in Development of Infection Prevention & Control Precautions, U.S. 1877: Separate facilities for the “Infectious Patient” 1910: Antisepsis and disinfection 1950-60: Closure of Infectious disease and TB hospitals 1970: CDC “Isolation Techniques for use in Hospitals” 1983: CDC Guideline for Isolation Precautions in

Hospitals (Disease-specific and category-based precautions including blood and body-fluids)

1985: Universal Precautions (Mostly focused on worker protection against bloodborne pathogens, e.g. HIV)”

1987 Body Substance Isolation (U WA team developed; concept was precursor to

Standard Precautions (SP) – used for all patients)

History of Infection Prevention & Control Precautions, U.S.

1996: Revised CDC Guidelines: Standard Precautions

2002: MSIPC Antimicrobial Resistant Organisms (ARO) Guidelines

2006: HICPAC, CDC; Management of Multidrug-resistant Organisms (MDROs) in Healthcare Facilities Dec. – Dec. 2007 issue of AJIC vol. 35:S165-S173

2007: HICPAC, CDC; Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Health Care Settings - Dec. 2007 issue of AJIC vol. 35:S65-S164

2006 MDRO & 2007 Isolation Precautions – must haves and full text available for all (non-subscribers too) at: http://www.ajicjournal.org

Just a Word About Standard Precautions (SP)Used for all patients – even those on trans.-based precautions

Assume that every person is potentially infected or colonized with an organism that could be transmitted in the health care setting

Hand hygiene PPE: gloves, gown, mouth-nose-eye protection, etc. Respiratory hygiene / cough etiquette Patient placement Environmental cleaning and disinfection, soiled linen Safe injection practices

SP: Precautions for Lumbar Puncture

Surgical Mask:placing a catheter or injecting material - spinal canal or subdural space (ie, myelo-grams, LP, & spinal or epidural anesth.)

Are providers at youraffiliate using a mask?Reason: 3 pts. S. salivarius meningitis; mask not used

by HCP

Chitnis AS, et al. Outbreak of bacterial meningitis among patients undergoing myelography at an outpatient radiology clinic. J Am Coll Radiol. 2012 Mar;9(3):185-90

Transmission-based PrecautionsUsed in addition to Standard Precautions Airborne

Contact

Droplet

Infection Prevention StrategiesHierarchy of Controls

Personal Protective Equipment

Administrative Controls: Respiratory Hygiene + cough etiquette

Environmental Controls: HVAC, AIIR#

# Heating, Ventilation and Air Conditioning ; Airborne Infection Isolation Room

Airborne Precautions For infections spread by particles that remain

suspended in the air (TB, measles, varicella [chickenpox])

Airborne Infection Isolation Room (AIIR) (a.k.a. “negative pressure room”)

Surgical mask on patient if necessary to leave room Respiratory protection for healthcare personnel (HCP)

in AIIR: N95 or more efficient respirator – e.g. patient with active TB

disease, SARS-CoV – 2007 Isol. Prec. Table For measles & chickenpox – only immune HCP should care for

patient; if immune no special resp protection needed AIIR exhaust should not be re-circulated in the building;

if filtered using HEPA media = OK

Contact Precautions For infections spread by direct or indirect contact with

patients or patient care environment (e.g., RSV, C. difficile, MRSA, VRE, CRE, MDR-A. baumannii).

Limit patient movement Private room preferred Cohort patients with the same infection status Don gown and gloves before entering the patient room –

Application ? Remove and discard gown and gloves inside the patient room Hand hygiene immediately after leaving the patient room Emphasis on cleaning, esp. frequently touched surfaces (bed

rails, bedside tables, lavatory surfaces, etc.). Dedicated equipment whenever possible (e.g., stethoscopes)

Does hand hygiene compliance change whenpatients are in contact precaution rooms in ICUs?; Gilbert J, et al. AJIC 2010

No! except for… MICU

RNs more likely (66.7%) with CP vs (51.6%) without

Droplet PrecautionsFor infections spread by large droplets

generated by coughs, sneezes, etc. (e.g., Neisseria meningitidis, pertussis, seasonal influenza).

Face shield or goggles, and a surgical mask are worn to prevent droplets reaching the mucous membranes of the eyes, nose and mouth when within ~6 feet of the patient

Patients should be separated by 3-6 feet, or be grouped with other patients with the same infection/colonization status

Patient should wear a surgical mask when outside of the patient room

AIIR is not needed

Coughing and Masks

Schlieren optics visualize the dispersion of expelled air during coughingBoth standard mask (A) and N95 respirator (B) prevent dispersion of cough plumeWithout any type of mask plume travels 1-2 m

Tang J W-T. N Engl J Med 2009;361;26

The Colonization “Iceberg” Effect

Infected and symptomatic

Colonized with Epidemiologically-significantmicrobe; no symptoms

Colonized or Infected: What is the difference? People who carry bacteria without

evidence of infection (e.g. fever, increased white blood cell count) are colonized

If an infection develops, it is usually from bacteria that colonize patients

Bacteria that colonize patients can be transmitted from one patient to another by the hands of healthcare workers

~ Bacteria can be transmitted even if the patient is not infected ~

Epidemiology of MDROs is NOT necessarily created equal nor the same across health care settings

…no evidence supports the use of stringent barrier precautions to decrease illness or death from MDROs in LTCFs …

Additional precautions are recommended for patients colonized …only when they are a documented source of transmission to others…e.g. MRSA in resident with extensive skin lesions that can’t be contained or VRE in lower GI tract + diarrhea/incontinence…”

Nicolle LE. Preventing Infections in non-hospitalSettings: long-term care. Emerg Infect Dis 2001;7(no.2):205-7.

Epidemiology of MDROs in LTCF- Are Contact Precautions Effective?

Setting: Residents in 122 bed skilled nursing facility in 667 bed hospital, IL

Study Interventions: Contact-Isolation (CI) phase =

gowns/gloves; not confined to room [+ for VRE, MRSA; no policy related to ESBL]

Routine glove (RG) use phase = gloves for care of all residents or their environment; no contact isolation even if culture +

Results: Frequency of acquisition of MDRO no

different between CI vs RG; During RG phase personnel more

likely to wear gloves, remove them, perform hand hygiene than during CI

Trick WE, et al. Comparison of Routine glove use and C-IPrecautions to prevent trans-Mission of MD bacteria in a LTCF. J Am Geriatr Soc 2004;52:2003-9.

Supply costs:Gowns (15/day) CI = $92,900/yrGloves with RG = $2,415/yr

Take home messages: RG preferred over CI, no incr. Risk, and more cost effective.

Contact Precautions (CP) & Patient Safety Paradox: Acute Care Setting Case Control Study: adult patients

on CP for MRSA; 2 large teaching hospitals

Care Process Results: Vital signs incomplete or absent

when on CP More days with no RN or MD

progress notes when on CP Outcomes & Satisfaction:

Freq. of adverse events 2x higher if on CP

Falls, pressure ulcers, fluid/electrolyte disorders = 8x higher among those on CP vs. controls

Patient dissatisfaction: 17-38% on CP vs 3-5% for controls

Stelfox HT. JAMA 2003;

290:1899-1905

Problematic Pathogens In the Healthcare Setting & Beyond

Vancomycin-resistant enterococci (VRE)1

Methicillin-resistant S. aureus (MRSA)2

C. difficile3

Norovirus4

12

3 4

12 Step Program for “Antibiotics Anonymous” http://www.mi-marr.org/LTC_toolkit.html

                  

MARR Long-term Care Tool Kit:PREVENT INFECTIONStep 1: Vaccinate Step 2: Prevent conditions that lead to infection Step 3: Get the unnecessary devices out DIAGNOSE AND TREAT INFECTION EFFECTIVELYStep 4: Use established criteria for diagnosis Step 5: Use local resources USE ANTIMICROBIALS WISELY Step 6: Know when to say "no"Step 7: Treat infection, not colonization/contaminationStep 8: Stop antimicrobial treatmentPREVENT TRANSMISSION Step 9. Isolate the pathogen Step 10. Break the chain of contagion Step 11. Perform hand hygiene Step 12. Identify resident with multidrug-resistant organisms (MDROs)

MDROs in LTCFs

The epidemiology of MDROs in LTCF differs from other settings such as acute care. This primarily reflects much less frequent use of invasive devices and severity of underlying illness.

Therefore while presence of MDROs among residents may be high, risk of cross transmission is low compared to acute care.

State of MI Bureau of Health Systems, MDCH, 10/03/2001 Guidelines for Care of Nursing Home

Residents with antimicrobial-resistant organisms (ARO) including MRSA & VRE Use Standard Precautions Communication of infection/colonization

when transferring or admitting a resident is essential

No regulation requires negative cultures as prerequisite for admission to LTCF, and federal/state rules prohibit same.

MI Society for Infection Prevention & Control. Guidelines for Prevention & Control of ARO. 2002

CDC Recommendations: MDRO in LTCFs; 2006

In LTCFs, consider the individual patient’s clinical situation and prevalence or incidence of MDRO in the facility when deciding whether to implement or modify Contact Precautions in addition to Standard Precautions for a patient infected or colonized with a target MDRO.

For relatively healthy residents (e.g., mainly independent and perhaps colonized with MDRO) follow Standard Precautions

CDC Recommendations: MDRO in LTCFs; 2006

For ill residents (e.g., those totally dependent upon healthcare personnel for healthcare and activities of daily living, ventilator-dependent) and for those residents whose infected secretions or drainage cannot be contained, use Contact Precautions in addition to Standard Precautions.

For MDRO colonized or infected patients without draining wounds, diarrhea, or uncontrolled secretions, establish ranges of permitted ambulation, socialization, and use of common areas based on your facility-based risk assessment

Step 6: Know when to say “no”

Minimize use of broad-spectrum antibiotics Avoid chronic or long-term antimicrobial

prophylaxis Develop a system to monitor

antibiotic use and provide feedback to appropriate personnel

Defining Epidemiologically Important Pathogens 2006 CDC/HICPAC MDRO Guide

Infectious agents that have one or more of

the following characteristics:

1) A propensity for transmission within healthcare facilities

2) Antimicrobial resistance implications

3) Associated with serious clinical disease increased morbidity and mortality

4) A newly discovered or reemerging pathogen

Why We Should Use Concept of Epidemiologically Important Pathogen?

Some bad pathogens in healthcare really are not multi-drug resistant:

– methicillin susceptible S. aureus (MSSA)

– Group A Streptococcus

– Clostridium difficile

Strategies described to control MDROs are often applied to control epidemiologically important organisms other than MDROs.

Pathogen Profile - Hospital A: Cent. Line-Assoc Bloodstream Infection (CLABSI), All Units 10/06-

09/07

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MRSA MSSA SSN Ents Gm neg Candida

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Figure 1: Rates of CDI HCF onset HCF assoc by Patient Care Unit, '08 & '09

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Clostridium difficile infection by Patient Care Unit, Hospital A

Active Sureillance Cultures – Look Before you Leap

Availability of private rooms Staffing needs: direct care & IPCS Monitoring adherence with contact

precautions by personnel Preventing unintended consequences

of placing patients in contact precautions

Decolonization therapy? Tracking of those positive for target

MDROs & electronic alert system for subsequent readmissions?

Diekema DJ, Edmond MB. Clin Infect Dis 2007;44 (April 15)

No significant difference in incidence of MDRO between intervention (ASD)& control ICUsHuskins WC, NEJM2011

Tale of Two Studies on Efficacy of Active Surveillance for MDROs

62% decrease in healthcare-assoc. MRSA infection in ICUs and 45% in non-ICUs, VAMCs withactive surveillance + CPJain R, et al. NEJM 2011