CDI Epidemiology
-CDI accounts for 20-30% of antibiotic-associated diarrhea
-colonization in 1-3% healthy adults, 16-35% of hospital inpatients (only test pts w/ active symptoms b/c colonization is a thing)
-increases in incidence and virulence observed in the past few de
Pathogenesis of Cdiff
-Bowel Flora disruption
-Spore ingestion: fecal to oral
-Growth/vegetation
-Toxin production
Primary toxins
Toxin A (enterotoxin)
Toxin B (cytotoxin): allows creation of pseudomembrane
Binary toxin
Hypervirulent strain
epidemic strain: NAP1/BI/027
-toxin production --> more bowel inflammation
-tdcC gene deletion: used to keep toxin levels lower
-binary toxin
tx pts the same but outcome is worse
CDI Presentation
-acute, watery diarrhea
-? 3 loose (unformed) stools in a 24 hr period (in absence of bowel prep regimens or laxatives)
-abdominal pain, distension (bloating)
-dehydration
-low-grade fever
Diagnosis
-clinical signs and symptoms
-laboratory testing:in
--> stool culture (slowest and impractical)
--> Glutamate dehydrogenase (GDH) (+) in pathogenic toxigenic and non-toxigenic
--> Enzyme immunoassay (EIA) for toxin A and B (good positive predictive value)
Risk Factors
-all antibiotic use: long duration, multiple antibiotics worse; highest risk: Clindamycin, Fluoroquinolones, 3rd Gen Cephalosporins
-increasing age
-nonsurgical GI procedures
-receipt of stress ulcer prophylaxis (PPIs) (dec acid in GI tract, Cdif inc prop
Treatment Principles
-stop offending antibiotics (if possible)
-perform a severity assessment: WBC threshold of 15,000 cells/mm^3 (inflammation) and Scr threshold of 1.5 mg/dL (dehydration)
-guideline update: Vancomycin and fidaxomicin first line treatment options
-treat for
How to treat Cdiff?
Vancomycin 125 mg 4x daily for 10 days
Fidaxomycin 200 mg 2x daily for 10 days
How to treat fulminant Cdiff (hypotension or shock, ileus, megacolon)?
Vancomycin 500 mg 4x daily by mouth or nasogastric tube. If ileus, rectal instillation.
+
Metronidazole 500 mg q8h IV
How to treat recurrent Cdiff?
Use tapered and pulsed Vancomycin regimen if standard regimen was used or try Fidaxomycin or fecal transplant
rationale: allow normal flora to grow back
When do you use Metronidazole 500 mg PO?
if there's no resources to give oral Vancomycin
TS is a 68 yr old female hospitalized for the past 3 days for acute pancreatitis. She has received two doses of Ertapenem 1 g IV since admission and is now experiencing profuse diarrhea (6-8 loose stools/day). A stool sample analysis has identified toxige
A
TS is a 68 yr old female hospitalized for the past 3 days for acute pancreatitis. She has received two doses of Ertapenem 1 g IV since admission and is now experiencing profuse diarrhea (6-8 loose stools/day). A stool sample analysis has identified toxige
A, B, D
TS is a 68 yr old female hospitalized for the past 3 days for acute pancreatitis. She has received two doses of Ertapenem 1 g IV since admission and is now experiencing profuse diarrhea (6-8 loose stools/day). A stool sample analysis has identified toxige
B, C, D
Traveler's diarrhea symptoms
malaise, abdominal cramps followed by sudden onset diarrhea
What is travelers' diarrhea caused by?
contaminated food/water
Traveler's diarrhea: countries
S. America, Latin America, Africa, Asia
Most common bacteria for Travelers' Diarrhea
-enterotoxigenic E. coli
-salmonella
-shigella
-campylobacter
-viruses
How to treat mild cases of Traveler's diarrhea?
oral rehydration therapy
Treatment of choice for Traveler's diarrhea?
-Ciprofloxacin 500 mg PO for 1-3 days
-Azithromycin 1000 mg once: quinolone resistance among Campylobacter in Asia
Alternative treatment for Traveler's diarrhea?
Rifaximin 100 mg 3x daily for 3 days for noninvasive E. coli strains (Mexico, Latin America, Africa)
Supportive care and prevention for traveler's diarrhea
-fluid and electrolyte replacement essential
-loperamide: generally avoided in moderate/severe cases and with dysentery (can be more harmful b/c some bacteria must be passed in stool for symptom resolution)
-avoidance of high-risk foods and beverages
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