C. difficile Epidemiology





Epidemiology: Epidemic Strain

BI/NAP1/027, toxinotype III

First emerged in 2000 (1)

Associated with healthcare (2)

More resistant to fluoroquinolones (3)

Greater virulence
Associated with more severe disease and mortality (4).
Increased toxin A and B production (4,5)
Polymorphisms in binding domain of toxin B (5)

1. McDonald et al. N Engl J Med 2005; 353(23):2433-2441.
2. See et al. Clin Infect Dis 2014; 58(10):1394-1400.
3.Pepin et al.Clin Infect Dis 2005; 41(9):1254–1260
4. Stabler et al. J Med Micro 2008; 57(6):771-775.
5. Warny et al. Lancet 2005; 366(9491):1079-1084.


Epidemiology: Host Factors
Advanced age:
Incidence higher among females, whites, and persons > 65 years (1)
Death more common in persons > 65 years (5x greater risk) (2)
Underlying illness and medical history:
79% of 7421 patients with CDI had a comorbid condition 2
38% of 585 patients with NAP1 strain had ED visit in previous 12weeks (2)
Tube feeds (3)
Inflammatory bowel disease (2)
Immune-suppressive treatment (2)
Hematological malignancy/stem cell transplant (15-25x greater risk)
1. Lessa et al. N Engl J Med 2015; 372(9):825-834.
2. See et al. Clin Infect Dis 2014; 58(10):1394-1400.
3. Bliss et al. Ann Intern Med 1998; 129:1012-1019.
4. Kombuj et al. Infect Control Hosp Epidemiol 2016; 37:8-15
Epidemiology: Modifiable Risk Factors
Exposure to antibiotics:
High Risk:
 3rd and 4th generation
Exposure to C.difficile spores
Spores can remain viable for months (3)
Contamination is increased in rooms of patients with active CDI  (4,5)
Hands of patients and personnel are easily contaminated (5)
Gastric acid suppression
Data, though inconsistent, implicate proton pump inhibitor (PPI) use 1,4,6,7
More study is needed to link restriction of PPI use with decreased CDI
1. Pepin et al. ClinInfect Dis 2005; 41(9):1254 –1260.
2. Hensgens et al. J Antimicrob Chemother 2012; 67(3):742 -748.
3. Weber & Rutala. Infect Control Hosp Epidemiol 2011; 32: 207-209.
4.Dubberke et al. Am J Infect Control 2007; 35:315-318.
5.Shaugnessy et al. Infect Control Hosp Epidemiol 2011; 32;201-206.
6.Linney et al. Can J Hosp Pharm 2010; 63(1):31–37.
7.Buendgens et al. J Crit Care 2014; 696:e11-15.
8.Dubberke et al. Infect Control Hosp Epidemiol 2014; 35(6):628-645.
Defining Outbreaks and  Hyperendemic CDI
What is an outbreak?
Increase in CDI that is greater than expected by chance alone
Can be facility-wide, unit specific, or occurring within the community
What is hyperendemicity?
Persistently high rates of CDI compared to past rates or compared to
similar facilities/units
Example: Excess infections above a prevention goal as indicated by the
Cumulative Attributable Difference (CAD) metric in an NHSN Targeted
Assessment for Prevention ( TAP) report
Data for Action
Using the CDC Targeted Assessment for Prevention (TAP) Strategy
Target Units or Facilities with Excess Infections 
Assess Infection Prevention Practices
Training, auditing/feedback
Antibiotic stewardship
Early detection and isolation
Appropriate testing
Contact Precautions/hand hygiene
Environmental cleaning
Prevent Infections with Tailored Measures:
* Antibiotic Stewardship
* Early Detection, isolation, Appropriate Testing
To continue learning more about the Stewardship, Antibiotic – CDI Prevention Primer
please click on the following link to be re-directed: