Clostridium difficile (CDI)

1. Clostridium difficile (CDI) CIP Consulting LLC Michele Barr, RN, BSN, CIC Jennifer Perry, RN, BSN, CIC

2. Background • C. difficile is linked to about 14,000 U.S. deaths every year. Those most at risk are people who take antibiotics and also receive care in any medical setting. Almost half of infections occur in people younger than 65, but more than 90 percent of deaths occur in people 65 and older. • (CDI) Clostridium Difficile Infection, CDC Vital Signs; March 6, 2012

3. Background • Previously released estimates based on billing data show that the number of U.S. hospital stays related to C. difficile remains at historically high levels of about 337,000 annually, adding at least $1 billion in extra costs to the health care system. However, the Vital Signs report shows that these hospital estimates may only represent one part of C. difficile’s overall impact.

4. Background • HHS Prevention Targets • Case Rate per 10,000 patient-days as measured in NHSN. • National 5-year Prevention Target: 30% reduction • Because little baseline infection data exists, administrative data for ICD-9-CM coded C. difficile hospital discharges is also tracked • National 5-year prevention target: 30% reduction

5. Question #1 • Risk factors for CDI include: • Exposure to antibiotics • Hospitalization • Advanced age • All of the above

6. Background: Risk Factors • Antimicrobial exposure • Acquisition of C. difficile • Advanced Age • Underlying illness • Immunosuppression • Tube feeds • Gastric acid suppression Guide to the Elimination of Clostridium Difficile in Healthcare settings. APIC, pg 7.

7. CDI: Pathogenesis 1. Ingestion of spores transmitted from other patients via the hands of healthcare personnel and environment 3. Altered lower intestine flora (due to antimicrobial use) allows proliferation of C. difficile in colon 4. Toxin A & B Production leads to colon damage +/- pseudomembrane 2. Germination into growing (vegetative) form Sunenshine et al. Cleve Clin J Med. 2006;73:187-97.

8. Modes of Transmission • Survival of C. difficile in the Healthcare Environment • C. Difficile is a fastidious anaerobe and the vegetative cell dies rapidly outside the colon. • C. difficile spores can persist in the environment for many months and are highly resistant to cleaning and disinfection measures.

10. Modes of Transmission • Transmission of C. difficile to patients from the healthcare environment: • The two major reservoirs of C. difficile in the healthcare setting are infected humans and inanimate objects. • Patient care items such as electronic thermometers and commodes have been implicated in the transmission of CDI • Transmission via transient hand carriage on HCP is thought to be the most likely.

11. Question #2 • Clostridium difficile can be spread by providing oral care or oral suctioning. • True • False

12. Modes of Transmission • Transmission via Patient Care Activities • Sharing of electronic thermometers that have been used for obtaining rectal temperatures. • Oral care or oral suctioning when hands or items are contaminated • Administration of feedings or medications with contaminated hands, food or medication • Emergency procedures such as intubation Guide to the Elimination of Clostridium Difficile in Healthcare settings. APIC, pg 13.

13. Question #3 • Patients with CDI should be retested to ensure they have cleared the organism before discontinue isolation. • True • False

14. Diagnosis • Who should be tested and how frequently: • It is recommended to only test for C. difficile in patients who are suspected of having CDI, for example, patients experiencing diarrhea. • It is not recommended to test asymptomatic patients or to “test for cure” Guide to the Elimination of Clostridium Difficile in Healthcare settings. APIC, pg 15.

15. Diagnosis • Collection and transport of stool for testing: • Only watery or loose stool should be collected and tested. • Specimens should be submitted in a clean, watertight container • Specimens should be transported as soon as possible and stored at 2-8 degrees C until tested.

16. Diagnosis • Laboratory testing: • Stool culture for Clostridium difficile: While this is the most sensitive test available, it is the one most often associated with false-positive results due to presence nontoxigenic Clostridium difficile strains. • Molecular tests: FDA-approved PCR assays, which test for the gene encoding toxin B, are highly sensitive and specific for the presence of a toxin-producing Clostridium difficile organism.

17. Diagnosis • Antigen detection for Clostridium difficile: These are rapid tests (<1 hr) that detect the presence of Clostridium difficile antigen by latex agglutination or immunochromatographic assays. Because results of antigen testing alone are non-specific, antigen assays have been employed in combination with tests for toxin detection, PCR, or toxigenic culture in two-step testing algorithms.

18. Diagnosis • Toxin testing for Clostridium difficile • Tissue culture cytotoxicity assay detects toxin B only. This assay requires technical expertise to perform, is costly, and requires 24-48 hr for a final result. • Enzyme immunoassay detects toxin A, toxin B, or both A and B. Due to concerns overtoxin A-negative, B-positive strains causing disease, most laboratories employ a toxin B-only or A and B assay.

19. Prevention Strategies • Core Strategies • High level of scientific evidence • Demonstrated feasibility • Supplemental Strategies • Some scientific evidence • Variable levels of feasibility

20. Question #4 • Patient rooms should be cleaned with a hypochlorite solution after a patient with CDI is discharged. • True • False

21. Core Strategies • Perform Facility-wide surveillance for CDI • Contact Precautions for duration of diarrhea • Hand hygiene in compliance with CDC/WHO • Clean and disinfect equipment and environment • Lab-based alert system for immediate notification of positive test results • Use and EPA-approved germicide for routine disinfection.

22. Core Strategies • Implement a program that supports the judicious use of antimicrobial agents. • Educate about CDI: HCP, housekeeping, administration, patients, families

23. Supplemental Strategies • Extend use of Contact Precautions beyond duration of diarrhea. • Presumptive isolation for symptomatic patients pending confirmation of CDI • Evaluate and optimize testing for CDI • Implement soap and water for hand hygiene before exiting the room of a CDI patient

24. Supplemental Strategies • Implement universal glove use on units with high CDI rates. • Use sodium hypochlorite containing agents for environmental cleaning • Implement an antimicrobial stewardship program Guide to the Elimination of Clostridium Difficile in Healthcare settings. APIC, pg 41.

25. Supplemental Strategies • Consider presumptive isolation for patients with ≥ 3 unformed stools within 24 hours • Patients with CDI may contaminate environment and hands of HCP pending results of diagnostic testing • CDI responsible for only 30-40% of hospital-onset diarrhea • However, CDI is more likely among patients with ≥ 3 unformed stools within 24 hours.

26. Supplemental Strategies • Evaluate and optimize test-ordering practices and diagnostic methods • Most laboratories have relied on Toxin A/B enzyme immunoassays • Despite high specificity, poor test ordering practices may lead to many false positives • Consider more sensitive diagnostic strategies but apply these more judiciously.

27. Supplemental Strategies • Hand Hygiene- Soap vs. Alcohol • Alcohol is not effective in eradicating C. difficile spores • However, one hospital study found that from 2000-2003, despite increasing use of alcohol hand rub, there was not an increase in CDI rates • Discouraging alcohol hand rubs may undermine overall hand hygiene programs with untoward consequences overall

28. Supplemental Strategies • Hand Hygiene Methods • Since spores may be difficult to remove from hands even with hand washing, adherence to glove use, and Contact Precautions in general, should be emphasized for preventing C. difficile transmission via the hands of HCP.

29. Supplemental Strategies • Glove Use: • Although the magnitude of their contribution is uncertain, asymptomatic carriers have a role in transmission • Practical screening tests are not available • There may be a role for universal glove use as a special approach to reducing transmission on units with longer lengths of stay and high endemic CDI rates.

30. Supplemental Strategies • Environmental Cleaning • Bleach can kill spores, whereas other standard disinfectants cannot • Limited data suggests cleaning with bleach (1:10 dilution prepared fresh daily) reduces C. difficile transmission • Two before-after intervention studies demonstrated benefit of bleach cleaning in units with high endemic CDI rates

31. Supplemental Strategies • Assess adequacy of cleaning before changing to new cleaning products • Ensure that environmental cleaning is adequate and high-touch surfaces are not being overlooked • One study using a fluorescent environmental marker showed: • Only 47% of high touch surfaces were cleaned

32. Summary of Prevention Measures Contact Precautions for duration of illness Hand hygiene in compliance with CDC/WHO Cleaning and disinfection of equipment and environment Laboratory-based alert system CDI surveillance Education Prolonged duration of Contact Precautions Presumptive isolation Evaluate and optimize testing Soap and water for HH upon exiting CDI room Universal glove use on units with high CDI rates Bleach for environmental disinfection Antimicrobial stewardship program Core Measures Supplemental Measures

35. C-difficile LAB ID Event • LAB ID event reporting is the second surveillance option in NHSN, using this option allows laboratory testing data to be used without clinical evaluation of the patient. • Much less labor intensive method to track c-difficile. • Facility wide data to be collected. NHSN has the ability to collect overall facility wide inpatient and outpatient.

36. Three reporting choices • Method A – Report LabID event for the entire facility, but separately by each location requiring separate denominator submissions for each location. • Method B – Report LABID events for only selected locations • Method C – Overall facility wide (with only one denominator for the entire facility)(Options include overall facility wide inpatient – FacWideIN or overall facility wide outpatient – FacWideOUT)

37. Use NHSN CDAD Module

38. Measurement: Outcome Focus on Laboratory Identified (LabID) Events in NHSN

39. CDI Data AnalysisData can be stratified by time (month, quarter), incident or recurrent or even aggregated across the entire facility or stratified by patient care location!!! Based on data submitted to NHSN, CDI LabID Events are categorized as: • Incident: specimen obtained >8 weeks after the most recent LabID Event or a new incident. • Recurrent: specimen obtained >2 weeks and ≤ 8 weeks after most recent LabID Event

40. Data analysis Incident cases further characterized based on date of admission and date of specimen collection: • Healthcare Facility-Onset (HO): LabID Event collected >3 days after admission to facility (i.e., on or after day 4) • Community-Onset (CO): LabID Event collected as an outpatient or an inpatient ≤3 days after admission to the facility (i.e., days 1, 2, or 3 of admission) • Community-Onset Healthcare Facility-Associated (CO-HCFA): CO LabID Event collected from a patient who was discharged from the facility ≤4 weeks prior to date stool specimen collected

41. Measurement: OutcomeCategorize Cases by location and time of onset† Admission Discharge < 4weeks 4-12weeks > 12weeks 2 d HO CO-HCFA Indeterminate CA-CDI * Day 1 Day 4 Time HO: Hospital (Healthcare)-Onset CO-HCFA: Community-Onset , Healthcare Facility-Associated CA: Community -Associated *Depending upon whether patient was discharged within previous 4 weeks, CO-HCFA vs. CA † Onset defined in NHSN LabID Event by specimen collection date Modified from CDAD Surveillance Working Group.Infect Control Hosp Epidemiol2007;28:140-5.

42. Data AnalysisCalculating CDI Incidence Rates* • Healthcare Facility-Onset Incidence Rate = Number of all Incident HO CDI LabID Events per patient per month / Number of patient days for the facility x 10,000 • Combined Incidence Rate = Number of all Incident HO and CO-HCFA CDI LabID Events per patient per month / Number of patient days for the facility x 10,000 *For a given healthcare facility

43. Denominator data • NHSN will ask for your summary data each month so rates can be calculated. • You will need to have the following for inpatient locations; • Patient days • Admissions • You will need to have the following for outpatient locations; • Encounters • Counts from NICU, well baby nurseries and well baby clinics should not be included.

44. Evaluation Considerations • Assess baseline policies and procedures • Areas to consider • Surveillance • Prevention strategies • Measurement of effect of strategies • Coordinator should track new policies/practices implemented during collaboration