C. Diff Infections

What is C. diff?

A spore-forming gram positive anaerobe that can produce a toxin.

T/F: NON-toxigenic C. diff is just as bad as toxigenic C. diff

False, actually being colonized with non-tox is protective against c. diff that is toxigenic

How is C. diff transmitted?

It is shed by the feces and transmitted via fecal oral route.

T/F: Spores in C. diff are heat stable and hard to get rid of (live super long on surfaces)

True

What are two major propogaters of C. diff infections?

Frequent hospitalization/exposure and overuse of antibiotics killing off normal flora

Is C. diff relapse common?

Yes typically and its due to the persistence of spores in the gut despite therapy.

Do we currently have a sporicidal C. diff treatment?

No

What are the risk factors for developing CDI?

• current or recent antibiotic use especially if within last 3 months

• Cephalosporins (3rd gen have highest), Clindamycin or Fluoroquinolones specifically

• Inappropriate PPI or H2RA use

• Hospitalization or in long-term facility within 30 days

• exposure to an infected person

• inflammatory bowel disease

• serious underlying illnesses

• immunocompromised

• advanced age >65 or more

• repeated enemas

• prolonged NG insertions

• GI surgeries

• feeding tubes

What is the most significant yet most modifiable risk factor for CDI?

Antibiotic use and choosing our antibiotics wisely. It also increases risk with higher duration (>7 days)

What are the complications that can result from CDI?

• prolonged ileus or blockage

• pseudomembranous colitis

• toxic megacolon

• colon perforation

• sepsis

• death (rare)

How do we diagnose CDI?

1. A positive laboratory resuslt for presence of toxigenic C. diff in the stool (GDH + toxin or NAAT + toxin) AND:

2. Any of the following

   1. New onset diarrhea as >/= 3 unformed stools in a 24 hour period without alternative explanation

   2. Radiographic evidence of ileus/blockage without alternative explanation (especially if WBC > 15000)

   3. Abdominal pain with radiographic evidence of bowel thickening

   4. radiographic evidence of toxic megacolon

OR

1. Colonoscopic or histopathologic evidence of pseudomembranous colitis

T/F: A positive test result can be used alone to confirm CDI

FALSE we MUST have symptoms and a positive test

What happens if we just have a positive test only?

This is more likely c. diff colonization which is asymptomatic and more common.

Should we treat C. diff colonization?

NO treatment can provoke infection and disturb normal bowel flora.

What is considered non-severe CDI?

Diagnosis of CDI with none of the criteria for severe or fulminant disease

What is considered severe CDI?

Diagnosis of CDI AND systemic signs of infection AND WBC >/= 15000 OR SCr >1.5 mg/dL w/ previous normal renal function

What is considered fulminant CDI?

Diagnosis of CDI AND systemic signs of infection AND any of the following:

• Hypotension

• ileus

• toxic megacolon

What is considered recurrent CDI?

Recurrence within 8 weeks of successfully completing treatment for CDI

How can we prevent CDI?

• minimize our antibiotic use or change to those with less CDI risk

• avoid PPI/H2RA if appropriate

• Proper infection control:

  • Isolation gowns + gloves if assisting CDI patient in room

  • Disinfecting surfaces with a SPORICIDAL solution such as BLEACH

  • Mechanical handwashing to remove spores with soap and water

• Potential oral vanco prophylaxis if we need in patients that had a first or greater recurrence of CDI or fulminant disease in past 90 days

Are probiotics good preventative measures in CDI?

NO because they are not regulated by the FDA, there is no consensus from the literature and there are some safety concerns in hospitalized patients and no way to confirm product integrity of what you actually get.

How long do we treat C. diff with antibiotics for?

10 days

Can we extend antibiotic treatment duration?

Yes to 14 days if symptoms don’t resolve by day 10.

What is failure to treatment defined by?

No improvement or worsening in symptoms or lab markers such as WBC or hypotension after 48-96 HOURS of primary therapy.

Should we repeat test after treating a patient with CDI?

NO because the patient can still be colonized and residual spores can still germinate periodically; we would only propogate disease.

How do we treat non-severe CDI?

1. Vanco 125 mg PO QID for 10 days first line

2. Fidaxomicin 200 mg PO BID for 10 days

Can also consider metronidazole if the other therapies are unavailable

How do we treat severe CDI?

• Vancomycin 125 mg PO QID for 10 days 1st line

• Fidaxomicin 200 mg PO BID for 10 days

  • Especially if at higher risk for recurrence then fidaxo

How do we treat fulminant CDI?

Vancomycin 500 mg PO QID AND Metronidazole IV 500 mg Q8H

Can also consider fecal microbiota transplant if refractory to therapy

If a patient has fulminant disease, specifically with an ileus, bowel obstruction or toxic megacolon present, what MUSt we add?

ADD vancomycin ENEMA

How do we treat a first recurrent CDI?

1. Tapered/pulsed vancomycin PO 1st line

2. Extended course of fidaxomicin PO

How do we treat a second or subsequent recurrence of CDI?

1. Vancomycin PO tapered and pulsed

2. Fidaxomicin PO extended

3. Vanco 125 mg for 10 days then RIFAMIXIN 400 TID for 20 days

4. fecal microbiota transplant

How do we treat any recurrence that presents as fulminant disease?

Initially we treat as fulminant, then can treat any other recurrences based on chart.

What is the most effective treatment option in patients with multiple CDI recurrences despite appropriate CDI treatment?

Fecal microbiota transplant (poop pill!)

When do we exclude patients from FMT?

If they have primary CDI or only 1 reccurence

Can we give IV metronidazole as a solo monotherapy for CDI?

NO because it has poor intraluminal penetration

What are some common AE associated with metronidazole?

• metallic taste

• nausea

• reversible peripheral neuropathy with prolonged courses

• DDI with alcohol due to potential disulfiram-like reaction

Is IV vanco effective for CDI?

NO

Is oral vanco okay to use in renal disease?

For the most part yes but if we use very high doses and longer durations we can start to see accumulation systemically.

Why is fidaxomicin super great?

Less disruption of normal colonic microflora because it is highly specific for only c. diff.

What is the major downside of using fidaxomicin?

Its cost (expensive)

What is the AE associated with fidaxomicin?

GI effects

What are some warnings and precautions for Fidaxomicin?

• hypersensitivity reactions

• macrolide allergy potential caution

• DO NOT use for systemic infection—→ will not work

• Pregnancy risk factor (potential mutagen)

Can we use vanco enemas alone?

NO they must be an add on, especially if we are concerned our oral vanco can’t reach the colon (i.e ileus or toxic megacolon)

Whats another sign our patient has a blockage?

Usually C. diff presents with major diarrhea. If we start to see nothing coming out we should be concerned.

Can we treat peds patients w/ C. diff?

Yes metro or vanco in nonsevere disease but usually its colonization and not actual disease in this population.