Antibiotic associated diarrhea and C diff

Question 1

antibiotic associated diarrhea

Answer 1

-common
-during period of antibiotic exposure
-dose related
-self limited- usually stops after use
-azithromycin- increases motility
-resolves after discontinuation of antibiotic
-mild, self limited, not requiring any specific lab eval or tx
-most cases are due to changes in colonic bacterial fermentation of carbs

Question 2

antibiotic associated colitis

Answer 2

-almost always caused by C. difficile infection (CDI)

Question 3

C. difficile incidence

Answer 3

-Clostridioides difficile is spore-forming, toxin-producing, gram-positive anaerobic bacterium
-Incidence has doubled -> 500,000 cases/yr in US (as well as virulence)
-strong, can live through many conditions
-C. diffis major health threat
-In 2017 -> 223,900 cases in hospitalized pts and 12,800 deaths in US

Question 4

who is at risk for C. diff

Answer 4

-most susceptible:
-Severely ill/malnourished
-Chemotherapy
-Multiple antibiotics
-Tube feeds
-PPI* - long term bc your raising pH of stomach
-Surgery
-IBD- flora is not as strong

-other risks:
-Advanced age
-Contact with infected pts
-Health care providers
-Impaired immune function

Question 5

virulance of C. diff

Answer 5

-can cause spectrum of manifestations ranging from asymptomatic to fulminant disease with toxic megacolon
-becoming more virulent - even non immunodifficient pts can get
-Hyper-virulent strains:
-Severe ds and recurrence
-Community acquired infection without antibiotics
-Young healthy individuals

Question 6

almost all antibiotics can cause C. diff

Answer 6

-Ampicillin
-Clindamycin* - most at risk (dentists use this)
-Third-generation cephalosporins
-Fluoroquinolones

-Symptoms begin during/shortly after antibiotic rx but can be up to 10 weeks later
-if someone is coming in for diarrhea ask ab recent antibiotic use

Question 7

c. diff transmission

Answer 7

-Normal flora is disrupted and person ingests C. diff -> Fecal-oral transmission
-hand sanitizer does not kill this!!!
-Vegetative and Spore forms
-Spores are found throughout hospitals, pt rooms and bathrooms -> transmitted by hospital personnel
-Hand washing, gloves, isolation are helpful in minimizing transmission
-Colonizes the colon of 3% of healthy adults -> carry (non toxic disease)

Question 8

clinical manifestation of C. diff: diarrhea with colitis (chart)

Answer 8

-CC
-multiple loose bowel movements per day
-fecal leukocytes (50%)
-occult bleeding may be seen
-hematochezia rare
-nausea, anorexia, fever, malaise, dehydration, leukocytosis*
-abdominal distention
-stool specimen
-sigmoidoscopic exam- diffuse or patchy nonspecific colitis (not necessary anymore)

Question 9

clinical manifestation of C. diff: fulminant colitis (Chart)

Answer 9

-just a more extreme diarrhea with collitis from c diff
-diarrhea may be severe or diminshed
-paralytic ileus and colonic dilatation
-colectomy can be life saving
-lethargy, fever, tachycardia, abdominal pain, dilated colon/paralytic ileus
-sigmoidscopy and colonoscopy contraindicated!
-flexible proctoscopy with minial air insufflation may be dx

Question 10

diagnosis: stool studies for c diff

Answer 10

-c. diff produce 2 toxins: Toxin A (enterotoxin) and toxin B (cytotoxin)
-> 90% with two specimens
-PCR Assay:
-Tests for toxin B gene
->93% sensitive, >95% specific
-One sample needed

Question 11

approach to dx of c. diff (chart)*****

Answer 11

-GDH antigen test and Toxin A and B tests differentiate who is carrier and who is sick
-pt with diarrhea and risk factor for c. diff
-send for stool- GDH antigen test (EIA) and toxin A and B test (EIA)
-GDH + and toxin + -> testing consistent with C. diff
-ONE IS + AND ONE IS NEG -> GDH + and toxin - OR GDH - and toxin + -> do PCR for tcdB and tcdC genes -> + -> consistent with c. diff

Question 12

sigmoidoscopy

Answer 12

-you dont do this for c. diff anymore (stool specimen is enough) -> do this to look for other reasons of sickness
-Not warranted in pts with typical clinical manifestations, a + lab test, and/or clinical response to empiric tx
-May be pursued if seeking an alternative dx
-Mild to moderate symptoms: No abnormalities or patchy or diffuse, nonspecific colitis indistinguishable from other causes
-Severe illness:
-True pseudomembranous colitis seen
-Yellow adherent plaques 2–10 mm in diameter scattered over colonic mucosa interspersed with hyperemic mucosa

Question 13

Endoscopic appearance ofClostridioides(formerlyClostridium)difficile-induced pseudomembranous colitis

Answer 13

-Scattered pseudomembranes are visible on top of the mucosa, being separated by areas of relatively normal mucosa
-Some of lesions have a red halo
-Yellow pseudomembrane circumferentially covering the entire colonic mucosa

Question 14

imaging

Answer 14

-Abdominal radiograph or CT
-CT can show thickening of wall of sigmoid colon in pseudomembrane colitis (but also can be seen with any colitis)
-If fulminant symptoms present to look for evidence of toxic dilation or megacolon
-Mucosal edema or “thumbprinting”

Question 15

differential diagnosis

Answer 15

-Simple antibiotic-associated diarrhea (not related to C difficile)
-Ileus
-Enteral feedings
-Medications
-Ischemic colitis
-Infectious diarrhea
-IBS
-IBD
-Microscopic colitis
-Celiac disease

Question 16

complications

Answer 16

-Dehydration
-Electrolyte imbalance
-Wt loss
-Malnutrition
-Toxic megacolon
-Perforation
-Death

Question 17

recurrent CDI

Answer 17

-Recurrent CDI is defined by resolution of CDI symptoms while on appropriate therapy, followed by reappearance of symptoms within 2-8 weeks after treatment has been stopped
-Up to 25% of pts experience recurrentC. difficilewithin 30 days of completing tx
-Less commonly, recurrent CDI can occur as late as 2 months after discontinuation of tx
-Once patients have experienced one recurrence, they are at significantly increased risk for further recurrences

Question 18

fecal microbiota transplantation (FMT)

Answer 18

-For pts with multiple recurrences of CDI who have received appropriate antibiotic treatment for at least 3 CDI episodes (ie, initial episode plus two recurrences)
-FMT consists of instillation of processed stool collected from a healthy donor into the intestinal tract of a patient with recurrent CDI
-flora of donor takes over sick pts GI
-colonoscopy (MC), sigmoidoscopy, NG tube, capsules, enema
-90% success

Question 19

C. diff treatment

Answer 19

-fidaxomicin
-vancomycin
-metronidazole (not used anymore)
-25% of pts treated with fidaxomicin or vanco are likely to reoccur
-1st recurrence- same drugs with altered course (longer) w/ biologic
-taper
-after first recurrence 60% likely to reoccur
-3rd recurrence- fecal transplant

Question 20

some probiotics with some studies behind it

Answer 20

-florastor
-align
-VSL

Question 21

c diff levels

Answer 21

-C diff. with diarrhea
-severe c diff- thumbprinting, pseudomembranous colitis, leukocytosis -> sigmoidoscopy/colonoscopy
-fulminant- toxic megacolon, perforation, paralytic ileus and colonic dilatation-> -flexible proctoscopy with minimal insufflation
-Abdominal radiograph or CT*