C Diff Flashcards

1
Q

C Difficile is defined as greater than or equal 3 unformed stools in 24 hours with:

A

A stool test positive for C diff toxins or detection of toxin C diff

OR

Colonoscopic or histopathologic findings revealing pseudomembranous colitis.
-Pseudomembranous colitis – severe inflammation of the inner lining of the bowel

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2
Q

Healthcare facility-onset (HO) CDI

A

laboratory identified event collected >3 days after admission to the facility

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3
Q

Community-onset, healthcare facility-associated (CO-HCFA) CDI

A

CDI that occurs within 28 days after discharge from health-care facility

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4
Q

Community-associated (CA) CDI

A

onset of symptoms within 48 hours of admission to hospital or more than 12 weeks after discharge

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5
Q

C-Diff can exist in spore and vegetative forms

A

Spore form – resistant to heat, acid, and antibiotic

Vegetative form – active, fully functional, toxin producing and become susceptible to killing antimicrobial agents

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6
Q

Spore C Diff

A

resistant to heat, acid, and antibiotic

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7
Q

Vegetative form

A

active, fully functional, toxin producing and become susceptible to killing antimicrobial agents

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8
Q

Produces two potent exotoxins, toxin A and toxin B

A

Toxin A – causes inflammation leading to interstitial fluid secretion and mucosal injury

Toxin B – 10 times more potent than toxin A

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9
Q

Pathogenesis of C Diff

A
  1. ) Antibiotic use
  2. ) Disruption of colonic microflora
  3. ) C diff exposure and colonization
  4. ) Release of toxin A and toxin B
  5. ) Mucosal injury and inflammation
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10
Q

Clinical Manifestation of C-Diff

A

new onset of ≥ 3 unformed stools in 24 hrs (May be associated with mucus or occult blood)

Low grade fever 
Nausea
Unexplained leukocytosis
Hypovolemia
Lactic acidosis
Hypoalbuminemia
Pseudomembranous colitis
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11
Q

Risk Factors

Mainly divided into 3 categories: advanced age, underlying illness and medical history, and immunosuppression

A

Significant risk factors: antibiotic use and age.
All antibiotics can be associated with CDI
Age: one study demonstrated that the risk of contracting CDI during an outbreak was 10x as high among persons older than 65 years of age as among younger inpatients.

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12
Q

Very common medications that Associated to C-Diff

A
**Clindamycin
Ampicillin
Amoxicillin
Cephalosporins
**Fluroquinolones
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13
Q

Somewhat common medications associated with C-Diff

A
Other Penicillins
Sulfonamides
Trimethoprim
Bactrim
Macrolides
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14
Q

Ticket to test

Lab Test Recommendations

A

Submit stool samples only from patients with unexplained and new onset > 3 unformed stool in 24 hrs

DO NOT submit stool samples on patients who have been receiving laxatives

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15
Q

Lab Test Recommendations

A

Nucleic acid amplification test (NAAT) alone OR with stool toxin test as part of a multiple step algorithm (GDH + toxin, GDH + toxin, arbitrated by NAAT, or NAAT + toxin) rather than toxin test alone

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16
Q

Glutamate dehydrogenase (GDH)

A

Sensitivity - High
Specificity - Low
Availability - Widely

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17
Q

Toxin A + B enzyme immunoassay (EIA)

A

Sensitivity - Low
Specificity - High
Availability - Widely

18
Q

Nucleic acid amplification test (NAAT)

A

Sensitivity - High
Specificity - High
Availability - Widely

19
Q

Multistep algorithm for C-Diff Diagnosis

A

Perform 2 rapid diagnostic stool tests in a symptomatic patient

Concordant results –> Final results

Discordant results –> Perform a third test on discordant samples –> Check results of the test –> Final results

20
Q

Detailed Diagnostic

A
  1. ) Perform Enzyme Immunoassay for Glutamate Dehydrogenase in stool sample
  2. ) Perform Enzyme Immunoassay for Toxin A and B in stool samples
21
Q
  1. ) Perform Enzyme Immunoassay for Glutamate Dehydrogenase in stool sample
  2. ) Perform Enzyme Immunoassay for Toxin A and B in stool samples
A

If GDH+a / toxin+ testing consistent with C-Diff

If GDH+ / Toxin-a OR If GDH- / Toxin+a perform PCR for tcbdB Gene (if + consistent with C-Diff / if - not consistent with c-diff)

GDH - / Toxin -1 not consistent with C-Diff

22
Q

Initial episode, non severe C-Diff diagnosis

A

Leukocytosis with a white blood cell count of ≤15,000 cells/mL
AND
Serum creatinine level <1.5 mg/dL

23
Q

Initial episode, severe C-Diff diagnosis

A

Leukocytosis with a white blood cell count ≥15,000 cells/mL
OR
Serum creatinine level >1.5 mg/dL

24
Q

Initial episode, fulminant

clinical presentation:

A

Hypotension or shock
Ileus
Toxic megacolon

25
Q

First recurrence

A

Reappearance of symptoms AND positive assay within 2-8 weeks after treatment has been stopped

26
Q

Second or subsequent recurrence

A

Reappearance of symptoms and positive assay within 2-8 weeks after treatment for the first recurrence has been stopped

27
Q

CDI recurrence defined by

A

resolution of CDI symptoms while on appropriate therapy, followed by reappearance of symptoms and positive assay within 2-8 weeks after treatment has been stopped

28
Q

Prevention of C-Diff

A
Improve antibiotic Prescribing
Use best test for accurate results
Rapidly identify
Wear gloves and gowns
Hand sanitizer does not kill C-Diff
Use EPA approved agents (spores)
29
Q

Treatment Medications

A
Metronidazole
Vancomycin
Fidaxomycin
Fecal microbiota
Bezlotuxumab
30
Q

Treatment of Non-severe C-Diff

A

Vancomycin 125 mg PO four times a day for 10 days

Fidaxomicin 200 mg PO twice a day for 10 days

Metronidazole 500 mg PO three times a day for 10 days

31
Q

Treatment of Severe C-Diff

A

Vancomycin 125 mg PO four days a week for 10 days

Fidaxomicin 200 mg PO twice a day for 10 days

32
Q

Treatment of fulminant C-Diff

A

Vancomycin 500 mg PO or via nasogastric tube four times a day

If ileus, consider adding vancomycin 500 mg in approximately 100 mL normal saline per rectum Q6H as a retention enema.

Present ileus, add metronidazole 500 mg IV Q8H with oral or rectal vancomycin

33
Q

Treatment of first recurrence C-Diff

A

If metronidazole was used for the initial episode, administer vancomycin 125 mg PO QID for 10 days

If vancomycin was used for initial episode, administer fidaxomicin 200 mg BID for 10 days

Prolonged tapered and pulsed vancomycin regimen

34
Q

Second or subsequent recurrence treatment

A

Vancomycin in tapered and pulsed regimen

Vancomycin 125 mg PO QID for 10 days followed by rifaximin 400 mg PO TID daily for 20 days

Fidaxomicin 200 PO BID for 10 days

Fecal microbiota transplantation (FMT)

35
Q

Metronidazole MOA and AE

A

After diffusing into the organism, interacts with DNA to cause a loss of helical DNA structure and strand breakage resulting in inhibition of protein synthesis and cell death in susceptible organisms

Metallic taste
“Furry” tongue
Nausea
Disulfiram reaction (vomiting, nausea, flushing, tachycardia, and dyspnea) when taken in combination with alcohol

36
Q

Vancomycin - MOA

A

Bactericidal
Binds to the D-Ala-D-Ala terminal of the nascent peptidoglycan pentapeptide side chain and inhibits transglycosylation, interfering with cross-linking and preventing the elongation of peptidoglycan chain

37
Q

Vancomycin Oral AE:

A

Hypokalemia (13%)
Abdominal Pain (15%)
Nausea (17%)

38
Q

Vancomycin hydrochloride (Firvanq®)

Oral solution

A

Indicated in adults and pediatric patients less than 18 years of age for:

C.difficile-associated diarrhea

Enterocolitis caused by Staphylococcus aureus (including methicillin-resistant strains)

39
Q

Vancomycin hydrochloride (Firvanq®)

Oral solution Dose for C.difficile – associated diarrhea:

A

Adults: 125 mg PO 4 times daily for 10 days

Pediatric (<18 years of age): 40 mg/kg in 3 or 4 divided doses for 7-10 days

40
Q

Fecal microbiota transplantation

A

Reintroduction of normal bacteria via donor feces will correct the imbalance of colon microbiota; thus restoring phylogenetic richness and colonization resistance

41
Q

Bezlotuxumab (Zinplava) is a human monoclonal antibody that binds to C.difficile toxin B
Indication:

A

Indicated to reduce recurrence of CDI in patients >18 years of age who are receiving antibacterial drug treatment of CDI and are at high risk for CDI recurrence
Should only be used in conjunction with antibacterial drug treatment of CDI