C. diff- Morelli- (Morelli)

What is the BIGGEST risk factor for C.diff?

antibiotic use

What abx have the HIGHEST risk of causing C.diff?

1. CLINDAMYCIN

2. 3rd gen cephalosporins

3. fluoroquinolones

lower risk: SMX/TRM, tetracyclines, aminoglycosides

What’s another class of drugs, not abx, that have been associated with C.diff?

PPIs

Recurrent CDI generally occurs within __ weeks of initial treatment.

8

What is the clinical presentation of C.diff? in severe cases?

• nearly always limited to the colon

• symptoms range from asymptomatic—> life-threatening

• diarrheal illness

• in severe cases—> ileus, TOXIC megacolon, pseudomembranous colitis

What 2 toxins are produced by C.diff that are responsible for inflammation, fluid, and mucosal damage? Which is MORE potent?

• Toxin A and B

• Toxin B—> 1000 times more potent

For diagnosing CDI, who do we test?

a. asymptomatic

b. symptomatic

c. both

b

What LAB tests can diagnose CDI?

• Nucleic Acid Amplification Tests (NAAT)

• Enzyme immunoassay (EIA) for C. dif glutamate dehydrogenase

• Enzyme immunoassay (EIA) for C. dif toxins A and B

• anaerobic culture

Differentiate the following:

• NAAT

• EIA for GDH

• EIA for Toxins A and B

• anaerobic culture

(IDK HOW IMPORTANT!!!!!!!!)

• NAAT

  • highly sensitive

  • not capable of differentiating asymptomatic carriers

• EIA for GDH

  • not capable of differentiating toxic from nontoxic strains

  • useful initial screening step

• EIA for Toxins A and B

  • used with GDH and NAAT

• Anaerobic culture

  • too slow for clinical use

  • not capable of differentiating toxic from nontoxic strains

What are the infection Control Measures for CDI?

• HAND HYGIENE

  • soap and water

• CONTACT precautions

  • gloves AND gown must be worn when entering room

• use cleaning agents Cl^- or sporicidal

What are the severity classifications of CDI?

Classification	Clinical Presentation
Non-severe
Severe
Fulminant

MUST KNOW THIS—> MUST KNOW THIS !!!!!!!!!!!!!

Classification	Clinical Presentation
Non-severe	WBC ≤ 15,000 cells/ml AND SCr <1.5 mg/dL
Severe	WBC > 15,000 cells/ml OR SCr ≥ 1.5 mg/dL
Fulminant	Hypotension or shock Ileus megacolon

WHAT IS THE 1st LINE TREATMENT FOR CDI?

• FIDAXOMICIN

• VANCOMYCIN PO

WHAT is the treatment for CDI based on severity?

(sadly, MUST KNOW, said in lecture, “spend most of your time on this”)

• initial episode non-severe

• initial episode severe

• initial episode fulminant

• initial episode non-severe

  • Fidaxomicin 200mg PO BID, 10 days

  • Vancomycin 125mg PO QID, 10 days

  • Alternative: Metronidazole 500mg PO TID, 10 days

• initial episode severe

  • Fidaxomicin 200mg PO BID, 10 days

  • Vancomycin 125mg PO QID, 10 days

• initial episode fulminant

  • Vancomycin + Metronidazole IV ± Vancomycin PR (rectum)

    • Vancomycin 500mg PO QID, 10-14 days

    • Metronidazole 500mg IV q8h, 10-14 days

    • Vancomycin 500mg PR QID, 10-14 days

What is the treatment for CDI for recurrent severity?

• i wouldn’t memorize —> in lecture said “know all different options, just don’t do what you previously did”

Disadvantage of Fidaxomicin?

Expensive!!!

Vancomycin is the DOC in what?

• fulminant CDI

• pregnancy

True or False: IV vancomycin is effective against C. dif?

false

What are some alternative options for CDI? (only used in select circumstances)

• metronidazole

• rifaximin

• fecal microbiota transplant

• Live biotherapeutic products

• surgery

When is Metronidazole used PO v. IV?

ALTERNATIVE OPTION

• PO= non-severe infections

• IV= used in combo with PO vancomycin for fulminant infections

What is Fecal Microbiota Transplant (FMT)? When is it considered?

• transfer of fecal material from healthy donor to the infected individual to restore microbiome

• considered after at least 2 recurrences or refractory CDI

What are 2 live biotherapeutic products (LBPs) used as alternative options for CDI? (only in recurrent CDI, so $$)

Rebyota and Vowst

Is Bezlotoxumab indicated for treatment of CDI?

• NO!!!—> removed from the market janurary 2025

• was indicated to reduce recurrence of CDI in pts. 18 or older who are receiving antibacterial drug tx of CDI, and are at high risk of recurrence

  • AGAIN… REMOVED FROM THE MARKET

What product is associated with decreased CDI recurrences and can be used for prevention?

PROBIOTICS!!!—> S. boulardii

___________ is an OTC product that contains S. boulardii.

Florastor

“I was just discharged from the hospital and am finishing up medications for C. diff. Should I go back to my doctor to have my stool retested?”

How would you respond to this?

• once diagnosed—> no value in retesting stool

  • pt. continues to shed toxin

Should pts. with C.diff take anti-peristaltic agents like Loperamide or Diphenoxylate and atropine to help decreases diarrhea?

• NO!!!!!!!!!!!!!! AVOIDDDDDDDDD