Infectious Diarrhea - Schoenwald (Exam 3) Flashcards
Infectious diarrhea is (acute/chronic) in onset and lasting ___ wks.
Infectious diarrhea is acute in onset and lasting <2 wks.
Noninflammatory diarrhea is describes as ______ and _________ and is associated with ________, ________, ______, and ________.
Noninflammatory diarrhea is described as water and nonbloody and is associated with cramping, bloating, nausea, and vomiting
T/F: In noninflammatory diarrhea, tissue invasion of colonic mucosa does not occur and there are no fecal leukocytes on smear.
True.
T/F: Inflammatory diarrhea does not involve fever or bloody diarrhea
False. Fever and bloody diarrhea.
Noninflammatory diarrhea disrupts normal absorption in the ___________, whereas inflammatory diarrhea involves primarily the ___________.
Small bowel; lower colon.
T/F: Inflammatory diarrhea is usually negative for fecal leukocytes because there is no invasion of the mucosa
False.
Will be positive for fecal leukocytes because there is invasion of the mucosa. This results in colonic tissue dammage.
Diarrhea >14 days most likely not due to infectious agent. What’s the exception to this?
C. diff
Do not use anti diarrheal meds or antimotility meds in (inflammatory/noninflammatory) diarrhea
Inflammatory
Which type of E. coli causes inflammatory vs noninflammatory diarrhea?
- Inflammatory: Enterohemorrhagic E. coli 0157:H7
- Non-inflammatory: Enterotoxigenic E. coli
Campylobacter, shigella, and salmonella are causes of (noninflammatory/inflammatory) diarrhea.
Inflammatory. They invade the mucosal tissue.
Norovirus, rotavirus, giardia, cryptosporidium, and listeria are all causes of (inflammatory/noninflammatory) diarrhea.
Noninflammatory
Enterotoxin producers, such as staph aureus, bacillus cereus, enterotoxigenic E coli, and vibrio cholerae are all causes of (inflammatory/noninflammatory) diarrhea.
Noninflammatory
Cytomegalovirus cause (inflammatory/noninflammatory) diarrhea
Inflammatory
Entamoeba histolytica causes (inflammatory/noninflammatory) diarrhea
Inflammatory
C. diff causes (inflammatory/noninflammatory) diarrhea.
Inflammatory.
What is the definition of C diff?
- Presence of sx in the form of 3 or more unformed stool over 24 hrs for 2 consecutive days in conjunction with positive stools for pseudomembranes.
- However, pts usually have profuse diarrhea (20-30 stools/day)
- Prior abx use is not included in the new guidelines
What are some major risk factors for C diff?
- Previous abx usage (Clindamycin is highest risk, but really any abx and mostly broad spectrum)
- Advanced age
- Previous hospitalization
- Nursing home resident
C diff presents with watery diarrhea (15-30 stools/day), abd pain/cramps, and fever. It can lead to _________ and _________.
Megacolon (very large colon, can burst and kill you) and colectomy.
What will lab findings look like for C diff?
- Leukocytosis often with bandemia (left shift)
- Hypoalbuminemia
- Positive stool C diff
- Molecular test-PCR (highly sensitive & specific)
- Can be positive in asymptomatic pts
- Antigen detection (nonspecific)
- Toxin A & B testing
- High rate of false negatives
- A lot of hospitals will do toxin testing 1st - if negative but pt symptomatic, then do PCR.
How do you treat initial episode of mild/moderate C diff?
Vancomycin PO or Fidaxamin PO
T/F: Alcohol hand preps are effective against C diff
False. Need soap and water. For surfaces, chlorine based disinfectants effective.
__________ is a gram negative rod carried in the GI tract of reptiles and birds and most cases occur from eating contaminated meat or eggs or from infected food handlers.
Salmonella
T/F: Bloody stools are uncommon with Salmonella enteriditis
True
T/F: Metastatic spread to vascular grafts, joints, kidneys, and liver common in bacteremic pts with salmonella enteriditis
True
Salmonella enteriditis treatment for…
- Uncomplicated cases?
- Complicated cases?
- Uncomplicated: self-limiting
- Complicated: Ciprofloxacin, or Bactrim (alternate)
Typhoid fever is caused by which bug?
Salmonella typhi
T/F: Typhoid fever is endemic to the US and is transmitted by contaminated food, sewage, and infected food handlers.
False. NOT endemic to US - travel hx vital for diagnosis! High risk areas: India, Pakistan, Carribean, Mexico.
Common sx of typhoid fever?
- Diarrhea OR constipation
- Rose-colored rash on torso and back
- Fever
- Abd pain
- Weakness
- Can be fatal
Resistance to abx is an issue with typhoid fever. The current recommendation is _______________ for mild cases and ________________ for more severe cases especially with hx of travel to SE Asia.
Azithromycin (mild) and Carbapenems (severe)
___________ is a gram negative rod responsible for dysentary.
Shigella
How is Shigella spread?
- Fecal oral spread
- Often spreads in daycare setting (not washings hands b/w washing diapers)
- Also flies and inanimate objects
- Incubation 12 hrs - 4 days.
Describe the diarrhea associated with shigella. This is a fun one!
Bloody, watery, pus and mucus (secretory). Pt also has fever, stomach cramps, n/v, dehydration
How do you tx shigella?
- Rehydration
- Ciprofloxacin
- Bactrim or Azithromycin (alternates)
- Recent strains show high rates of resistence
___________ is a gram negative rod that you can get from sausage, hard meats, or undercooked chicken
Campylobacter
T/F: Campylobacter sx are often highly severe
False. Often low grade sx.
Drug of choice for campylobacter?
- Ciprofloxacin
- Azithromycin (alternate)
What are 3 complications of campylobacter?
- Bacteremia in <1%
- Guillain Barre
- Reactive arthritis
80% of traveler’s diarrhea is caused by ________________
Enterotoxigenic-shiga toxin from pathogenic E coli infections
What is the main cause of hemolytic uremic syndrome in the US?
E coli 0157:H7
Which bug is linked to undercooked ground beef, drinking of unpasteurized juices and milk, working with cattle (1% of cattle in US carry)
E coli 0157:H7
Which test differentiates HUS from TTP?
ADAMTS 13 (positive in TTP)
HUS triad?
- Acute renal insufficiency
- Hemolytic anemia
- Thrombocytopenia
What will labs look like with E coli 0157:H7 infection?
- Culture often negative
- Anemia and thrombocytopenia
- Decreased haptoglobin and increased LDH
- Negative coomb’s
- Elevated creatinine
- Hematuria and proteinuria
Tx for E coli 0157:H7?
Supportive. Abx use controversial.
Staph food poisoning usually onsets within ___ to ___ hrs.
4-8 hrs
Tx for staph food poisoning?
Usually self-limiting. Abx not indicated.
How is listeria typically spread?
Foodborne.
__________ is a gram positive bacillus. Previous corticosteroid use is a predisposing risk factor.
Listeria
Tx of choice for listeria?
Ampicillin. Crosses blood brain barrier to tx meningitis.
What is the main cause of traveler’s diarrhea?
Enterotoxigenic E coli
Tx options for enterotoxigenic E coli?
- Ciprofloxacin
- Bactrim
- Azithromycin
__________ is waterborne and can also be in shellfish. It results in massive secretion from small bowel.
Virbrio cholera
__________ causes rapid dehydration - profuse watery diarrhea - lose 1-3 L per day, up to 20 L per day.
Vibrio cholera
“Rice water stools” = ______________
Vibrio cholera
Tx for Vibrio cholera?
- HYDRATION, HYDRATION, HYDRATION
- Doxycycline or Ciprofloxacin
- Can limit duration of dz, but dehydration is main issue
Inflammation of the stomach and intestinal tract with sudden onset and rapid resolution: ________________
Viral gastroenteritis
Most common cause for nonbacterial acute gastroenteritis?
Norovirus (aka “Cruiseship virus”)
T/F: Norovirus is contagious even after sx resolve, may shed in stool up to several weeks
True
How is norovirus spread?
Person to person contact, contaminated food and water, airborne
With norovirus, kiddos usually have more (vomiting/diarrhea), whereas adults usually have more (vomiting/diarrhea).
Vomiting (kiddos)
Diarrhea (adults)
Tx for norovirus?
Self-limiting. Supportive tx.
Gold standard test for norovirus?
Stool culture; however, turnaround is 48-72 hrs, so sx will likely be gone anyway.
Have you done the H&P nutrition assignment yet?
Slacker
