Clostridium difficile: Clean DifferentlyInfection control measures to prevent transmission in inpatient settings
Outline • C. difficileoverview • Pathogenesis • Brief description of various tests • Transmission of C. difficile • Identifying high-touch surfaces • Daily cleaning vs. terminal cleaning • Proper use of bleach • Brief intro to alternative cleaning products
Historical Perspective • Bacillus difficilis(now C. difficile) was cultured from healthy neonates in 1935 • In the 1960’s it was noted that patients on antibiotics developed diarrhea • “Staphylococcal Colitis” • Originally thought to be caused by S. aureus and treated with oral bacitracin • Stool cultures routinely ordered for S. aureus • Early 1970’s, a new explanation • “Clindamycin Colitis” • Severe diarrhea, pseudomembrane colitis, and occasional deaths documented in patients on clindamycin
CDI Overview • Spore-forming, anaerobic, gram-positive bacterium • Causes gastrointestinal infections resulting in diarrhea and colitis • – Severity ranges from mild colitis to toxic megacolon and death • Leading cause of healthcare-associated infectious diarrhea in US • Rivals methicillin-resistant Staphylococcus aureus (MRSA) as the most common organism to cause healthcare-associated infections in US
Prevalence • C. difficile causes about 500,000 illnesses in the United States every year (Kuchn, 2011). • In the United States, estimated 15000-20000 patients die from the illness each year (Barbut, Jones, & Eckert, 2011). • In the general population, one to three percent of adults are colonized with the organism (Barbut et al., 2011). However, about 20 percent of hospitalized adults are C. difficile carriers (LaMont, 2009).
Strains of C. difficile • Anaerobic, gram-positive, spore-forming, bacillus • Non-toxin producing C. difficile • Toxin A (tcdA) • Toxin B (tcdB) • NAP1/BI/027 (deletion tcdC) • Down regulation of toxin production • Enhance capability for production of toxin A and B.
Two forms of C. difficile Vegetative Spore
Clinical Symptoms • Watery diarrhea is the cardinal clinical symptoms • Diarrhea can be up to 15 times per day • Fever, cramping, abdominal discomfort, and peripheral leukocytosis (cohen, 2010) • Colonic ileus or toxic dilatation may present with no or minimal diarrhea.
Methods of testing C. difficile • Culture • Cell cytotoxicity neutralization assay • Enzyme immunoassays (EIA) C. difficiletoxin A (Tcd A) • EIA TcdB or TcdA/B • EIA, glutamate dehydrogenase (GDH) • Nucleic acid amplification tests
Culture • Target: organism • Advantages: • High sensitivity (often considered as the gold standard) • Disadvantages: • Turn-around time >7 days • Labor intensive • Lacks specificity • Isolates must be further tested for the presence of toxins
Cell cytotoxinneutrlization assay • Functional assay for C. difficiletoxin B (TcdB) • Advantages: • Moderate-to-high sensitivity • High specificity • Disadvantages: • 48-72 hrs turn-around time • Subjective interpretation • Labor intensive
Enzyme immunoassays (EIA) C. difficiletoxin A (Tcd A) • Target: Toxin A detection • Advantages: • Easy to perform • Rapid turn-around time • Inexpensive • High specificity • Disadvantages: • Low sensitivity • MissessTcdA-/TcdB+ isolates
EIA TcdB or TcdA/B • Target: Toxin A or B detection • Advantages: • Easy to perform • Rapid turn-around time • Inexpensive • High specificity • Disadvantages: • Low sensitivity
EIA, glutamate dehydrogenase (GDH) • Method: common antigen detection • Advantages: • High sensitivity • Good screening test • Disadvantages: • Low specificity • Must test further
Nucleic acid amplification tests • Method: Toxin gene detection • Advantages: • High sensitivity • High specificity • Short-turn around time • Easy to perform, minimal hands on • Disadvantages: • Expensive • Detection of asymptomatic colonization
Combination method and algorithm Report as negative Report as positive Need further testing
Combination method and algorithm Report as positive Report as negative
46 Consequences of Bad Tests • Repeat testing • Low sensitivity • – False negative patients don’t get treated and spread the organism • Low specificity • – False positive patients get costly treatments and IC protocols
Practice change • Send stool to lab right away or refrigerate If GDH and EIA method are used • Test only symptomatic patient (3 loose stools in 24 hours) • Test only loose stool (stick or conform) • Test only one stool per patient per week • Do not test for cure • Assess patient for other reasons for the diarrhea
Clinical Practice Guidelines 2010 SHEA and IDSA Summary • Test only unformed stool (exception: ileus) • Do not perform a test of cure • Stool cultures sensitive but not practical except for epidemiological studies • EIA is rapid, not very sensitive and is sub-optimal • 2 step GDH and EIA is a interim recommendation • More data needed on PCR before they can recommend • Repeat testing discouraged Cohen, S.H. et al. 2010. ICHE. 31: 431-455
Transmission of C. difficile • Person to person by swallowing fecal matter. • Periods between exposure C. difficileand the occurrences 2- 3 days (cohen, 2010) • Culprits in healthcare: • Contaminated hands of healthcare worker • Electronic rectal thermometers • Inadequately cleaned commodes or bedpans
Germs (skin bacteria) Culture plate showing growth of germs 24 hours after a nurse placed her hand on the plate
Before entering the room,Clean your hands with: OR Soap and Water Hand Sanitizer
Environmental source • Acquisition of spores on gloved hands occurred as frequently after contact with environmental surfaces as after contact with skin sites (50% vs50%)
Portable equipment • Electronic thermometers • Blood pressure cuffs • Bedside commodes • Stethoscopes Cohen SH, et al. ICHE 2010;31:31:431-55
Confusing products • Omit confusing products
Confusion about who cleans what • House keeping ? • Nurses? • Central supply? • Nobody?
Sufficient contact time is necessary Barbut F, et al. Infect Control HospEpidemiol 2009;30:507-14
Stopping the spread: Cleaning and Disinfection Cleaning: Removal of organic matter and visible dirt Disinfection: Killing of microorganisms
Reducing contamination of cleaning solution and cleaning tools • Laundering microfiber/swiffer after each room cleaning. • Replace soiled microfiber/swiffer with clean item each time a bucket or detergent/disinfectant is emptied or replaced. • Keeping microfibers/swiffers in solutions do not kill all the bugs, some bugs can grow in the solution. • Make sufficient cleaning solution for the day, emptying the solution and drying out the container minimize contamination. Clostridium difficile Excerpt: Guideline for Environmental Infection Control in Health-Care Facilities, 2003
High-touch surfaces Huslage K, et al. A quantitative approach to defining high-touch surfaces in hospitals. Infect Control HospEpidemiol 2010;31:850-3.
Daily Cleaning • Wipe all high-touch surface daily • Two wipe system, Clean and Disinfect • Minimizing mist and aerosol dispersion
Terminal/ Dischrage Cleaning • Clean all high-touch surfaces and all other area including wall with quaternary solution • Then disinfect with bleach wipe or bleach solution. • Stay wet for 10 minutes
Diluted bleach Diluted bleach only stable only for 24 hrs
Peroxyacetic acid/ hydrogen peroxide/ Octanoic acid combination • One- Step detergent disinfectant • Components: • Peroxyacetic acid 0.05% • Hydrogen peroxide 3.13% • Octanoic acid 0.099% • Kills C. difficilespores in 10 minutes • Effective with 5% organic load (peracetic acid is not affected as much as bleech by organic load) • Compatible with materials
Peroxyacetic acid/ hydrogen peroxide/ Octanoic acid combination • Precautionary Statement: • Danger: Causes irreversible eye damage. Do not get in eyes or on clothing. Wear goggles, face shield, or shielded safety glasses.