Dr. Karatzios -- Diarrhea Flashcards
Definition of diarrhea (3)
- Stool weight > 200 g/day
- ≥ 3 loose or watery stools per day
- Decreased conmsistency and increased frequency from an individual baseline
3 types of diarrhea and their duration
- Acute: ≤ 14 days duration
- Persistent (subacute): > 14 days duration
- Chronic: > 30 days duration
7 effects of diarrhea
- Dehydration (water loss)
- Salt imbalances (esp Na+ or K+)
- Acidoses (bicarb losses)
- Hemorrhage (if dysentery)
- Chronic anemia (hematochezia)
- Malnutrition
- Sepsis (due to perforation or bacterial translocation into blood)
10 bacterial pathogens causing infectious diarrhea in the developed world
- E. coli**
- *Salmonella *spp.
- *Shigella *spp.
- Yersinia enterocolitica
- Campylobacterer jejuni
- Clostridium difficile
- Clostridium perfringens
- Listeria monocytogenes
- *Vibrio *spp.
- Bacillus cereus
2 types of E. coli causing diarrhea
- Enterohemorrhagic (EHEC)
- O157:H7
- Enterotoxin (ETEC)
2 types of Salmonella spp. causing diarrhea
- Non-typhi
- Typhi
7 viral causes of diarrhea in the developed world
- Calicivirus/Norovirus (Norwalk-like)
- Rotavirus
- Astrovirus
- Coronavirus (SARS)
- Adenovirus
- HIV
- Influenza virus (seen in pandemic 2009 strain)
8 protozoal causes of diarrhea in the developed world
- Giardia lamblia
- Cyclspora cayetansis
- Cryptosporidium **spp.**
- *Microsporidium *spp.
- Isospora belli
- Entamoeba histolytica
- Dientamoeba fragilis
- Blastocystis hominis
5 purely toxin-mediated bacterial pathogens causing diarrhea in the developed world
- Enterotoxigenic E. coli (Traveller’s diarrhea)
- *Staphylococcus aureus *enterotoxin
- *Bacillus cereus *enterotoxin, among others
- *Vibrio *spp
- C. difficile
5 bacterial causes of infectious diarrhea in the **developing **world (or “imported” diarrhea)
- Salmonella **typhi**
- *Shigella *spp.
- Entertoxigenic E. coli
- Vibrio parahaemolyticus
- Vibrio cholerae
4 viral causes of infectious diarrhea in the **developing **world (or “imported” diarrhea)
- Norovirus
- HIV
- Influenza virus (2009 pandemic)
- SARS Coronavirus
4 protozoal causes of infectious diarrhea in the **developing **world (i.e. “imported diarrhea)
- Giardia lamblia
- Entamoeba histolytica
- Microsporidium **spp.**
- Isospora belli
Usual origin of infectious diarrhea in North America
Viral
Visibly bloody stool in **North American **diarrhea is a good predictor for what kind of pathogen?
Bacterial (especially EHEC)
5 bacterial causes of dysentery
SSCYE
- *Shigella *spp.
- *Salmonella *spp.
- Campylobacter jejuni
- Yersinia enterocolitica
- E. coli O157
Viral causes of dysentery
None really, except perhaps adenovirus in immune suppressed patients (i.e. BMT)
Parasitic cause of dysentery
Entamoeba histolytica
EHEC: type of bacteria
Gram negative enteric rods containing a toxin created by a viral plasmis inside the cell
Reservoir of EHEC
Mammalian GIT
Most common cause of acute kidney failure in children
EHEC
Describe the progression of EHEC infection
- Enteritis about 1 - 2 days after infection
- Lasts for about 5 - 10 days
- Usually self-limiting
- 2 - 7% develop Hemolytic Uremic Syndrome (HUS)
3 symptoms of EHEC enteritis
- Severe cramps
- Very bloody diarrhea
- NO fever
Cause of HUS in EHEC
Shigatoxin
7 signs and symptoms of HUS in EHEC
- Renal failure
- Consumptive thrombocytopenia
- Vascular hemolysis (shearing of RBCs called schistocytes/schizocytes)
- Stupor
- Confusion
- Seizures
- Worsens with antibiotic therapy (release of toxin)
Type of bacteria: *Salmonella *spp
Gram negetive enteric rods
Resrvoirs of *Salmonella *spp.
Poultry and reptile GIT
Describe the progression and symptoms of *Salmonella *infection
- Need about 105 bacteria to cause disease
- Diarrhea (usually bloody), abdominal cramps, and fever 2 days after infection
- Lasts about 1 week
Most serious form of *Salmonella *infection
Typhoid fever
Cause of typhoid fever
*Salmonella enterica *serogroup typhi
9 signs and symptoms of typhoid fever
- Dissemination to various organs (i.e. blood, liver, etc)
- High fever
- Stupor
- Cramps
- Bloody diarrhea
- Blood sepsis
- Fleeting rose spots on skin
- Left shift leukopenia
- Bradycardia
What is *Salmonella *infection recurrence linked to?
Presence of biliary stones
*Shigella *spp: Type of bacteria
Gram negative enteric rods
Only reservoir of *Shigella *spp
Primates