Infections of the GI tract (Schoenwald) Flashcards
Is infectious diarrhea acute or chronic in onset?
Acute
How long does infectious diarrhea last for?
Lasts less than 2 weeks
What should be part of the history in patients with infectious diarrhea?
Travel history
What suggests a viral etiology of infectious diarrhea?
Community outbreaks in nursing homes, schools, cruise ships, or common food source
Watery, non-bloody diarrhea is characteristic of what kind of diarrhea?
Non-inflammatory
What are the sxs of non inflammatory diarrhea?
Cramping, bloating, nausea, vomiting- disrupts normal absorption in the small bowel
Will you see fecal leukocytes on a smear in non-inflammatory diarrhea?
No, no fecal leukocytes will appear on the smear because tissue invasion does not occur in non inflammatory diarrhea
What types of diarrhea accompanies fever and bloody diarrhea
Inflammatory
What type of diarrhea will you have colonic tissue damage from invasion of bacteria or toxin?
Inflammatory diarrhea, which is why it is bloody
What part of the colon is primarily involved in inflammatory diarrhea?
Lower colon
What sxs will you see in inflammatory diarrhea?
Lower quadrant cramping, urgency
Will there be fecal leukocytes present in inflammatory diarrhea?
Yes, because of invasion of mucosa
What should your differential include when diagnosing inflammatory diarrhea?
Ulcerative colitis
Diarrhea lasting longer than 14 days is most likely…
NOT due to an infectious agent (except c diff!)
What is the major difference between inflammatory and non inflammatory diarrhea?
Colonic tissue invasion by the organism and/ or toxin
Why is it important to classify the diarrhea as inflammatory vs non inflammatory?
Helps to differentiate when it is “okay” to use anti motility agents such as Imodium
What is Imodium?
Anti motility agent- helps with diarrhea
When should you absolutely not use antimotility agents?
In inflammatory diarrhea- this traps the organism in the colon, causing more damage, perpetuating the sxs, and prolonging the infection
What are some typical stool pathogens?
Salmonella Shigella Campylobacter Vibrio E Coli O157:H7 Clostridium difficile Norovius Enterovirus Parasites- giardia, amoeba, cryptosporidium
What organism should you suspect with previous antibiotic usage?
Cdiff
What causes non inflammatory diarrhea?
Enterotoxin production- Staph aureus B cereus Enterotoxigenic E. coli Vibrio cholerae
& Norovirus Rotavirus Giardia Cryptosporidium Listeria monocytogenes
What causes inflammatory diarrhea?
Cytotoxin production... Enterohemorrhagic E. coli 0157:h7 C diff Mucosal invasion... Campylobacter Shigella Salmonella
Cytomegalovirus
Entamoeba histolytica
What agents cause enterotoxin production in non-inflammatory diarrhea?
Staph aureus
Bacillus cereus
Enterotoxigenic E. coli
Vibrio cholerae
What agents cause cytotoxin production in inflammatory diarrhea?
Enterohemorrhagic E. coli 0157:H7
C diff
What agents cause mucosal invasion in inflammatory diarrhea?
Campylobacter
Shigella
Salmonella
What is the new name for C diff?
Clostridioides difficile
Previously clostridium difficile
What agents cause inflammatory diarrhea?
C diff Salmonella Shigella Campylobacter E. coli 0157:h7
What is the main symptom in a c diff infection?
Diarrhea
What are the major risk factors to an infection with c diff
Previous antibiotic usage
Advanced age
Previous hospitalization
Nursing home resident
What antibiotics are known for causing a c diff infection
Clindamycin
Penicillins
Cephalosporins
Fluroquinolones
What makes the diagnosis under the new guidelines for c diff?
Presence of symptoms in the form of three or more unformed stool over 24 hours for 2 consecutive days in conjunction with positive stools for pseudomembranes
Prior antibiotic usage in not included in making the diagnosis with the new guidelines
What are the clinical findings in a c diff infection?
Water diarrhea 15-30 bowel movements per day Abdominal pain or cramps Low grade fever Can lead to toxic mega colon and Colectomy
What are the lab findings in c diff?
Leukocytosis- often with bandemia (left shift)
Hypoalbuminemia
Positive stool c diff test
What are the lab tests for c diff?
Molecular test- PCR
Antigen detection
Toxin testing
What lab test for c diff is highly sensitive and specific and can be positive in asymptomatic patients?
Molecular test PCR
Which lab test for c diff is nonspecific?
Antigen detection
Which lab test for c diff is associated with high rates of false negatives?
Toxin A and B testing, used for screening
For an initial episode of c diff that is mild/moderate what do you expect to see on labs?
Leukocytosis <15,000, creatinine <1.5
For an initial episode of c diff with mild to moderate symptoms, what should you use to treat?
Vancomycin 125mg po qid X 10 days OR
Fidaxamin 200 mg po bid X 10 days
For an initial episode of c diff that is severe, what labs would you expect to see?
Leukocytosis >15,000, creatine >1.5 prior to CDI
For an initial episode of c diff with complications, what clinical signs will you see?
Hypotension
Shock
Perforation
Megacolon
What should you use to treat an initial episode of c diff that is complicated?
Vancomycin 500mg po qid or via NG tube and or metronidazole 500-750 mg IV q 8 hours
What should you use to treat the 1st recurrence of c diff?
Vancomycin oral taper or Fidaxamin 125mg po qid
What should you use to treat a 2nd recurrence of c diff?
Vancomycin oral taper or Fidaxamin
Fecal mircobiota transplant
What can be done to prevent c diff infections?
Antibiotic stewardship
Environmental control, hand hygiene
When wanting to prevent c diff, it is important to remember that spores can live up to ___ months on a surface
5
When thinking about preventing a c diff infection, it is important to remember that _____ can be a vector
Health care workers
Are alcohol hand preps effective for preventing c diff?
No
What should be used on surfaces to prevent the transmission of c diff?
Chlorine based disinfectants
Salmonella is a gram negative/ positive rod
Gram negative rod
Salmonella is carried in the GI tract of….
Reptiles and birds
How many cases of salmonella infections yearly in the US?
3.7 million
How do most cases of salmonella occur?
From eating contaminated meat or eggs or from infected food handlers
Also associated with handling reptiles
Patients with a salmonella infection can remain culture positive for ___ months after treatment, making them a long term carrier
1 month