Table of contents
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Definitions
- "Diarrhea"
- Increase in water content, volume or frequency of stools.
- Typically ≥3 stools/day (defined epidemiologically)
- "Infectious Diarrhea"
- Diarrhea due to infectious etiology.
- Often accompanied by nausea, vomiting, abdo cramps.
- "Acute Diarrhea"
- ≤14 days
- "Chronic Diarrhea"
- >14 days (Sometimes >30)
Food-Related Diarrheal Illnesses
- Questions on history:
- Characterize Symptoms:
- Onset
- abrupt? gradual? duration?)
- Stool Characteristics
- Watery, bloody, mucous, purulent, greasy etc..
- Frequency of BM + quanity of stool
- Dysenteric symptoms
- fever, tenesmus (feeling need to passing stools, despite empty colon), blood and/or pus in stool
- Volume Status
- Thirst, tachycardia, orthostasis, decreased urination, lethargy, skin turgor
- Associated Sx:
- Nausea, vomiting, abdo pain, cramps, headache, myalgias, sensorium
- Onset
- Epidemiological Risk Factors
- Travel to developing area
- Day care
- Unsafe foods (raw meats, eggs, shellfish, unpasteurized milk)
- Swimming in or drinking untreated fresh surface water (lake/stream)
- Sick contacts
- Medications (antibiotics, antacids, anti-motility agents)
- Medical Conditions (AIDS, immunosuppression)
- Receptive anal intercourse
- Characterize Symptoms:
Common Enteric Pathogens
- Escherichia coli (STEC) (Shinga toxin-producing Escherichia coli)
- Symptoms - Develop several days after exposure (toxin formed by growing bacterial contamination)
- Bloody diarrhea (90% of pts) - hemorrhagic colitis.
- Abdominal tenderness
- Leukocytosis
- Fever - uncommon (1/3 of pts)
- Strain O157:H7 and O104:H4 is the most common in US.
- Producing shinga toxin --> cause vascular damage --> Hemorrhagic colitis.
- Symptoms - Develop several days after exposure (toxin formed by growing bacterial contamination)
- Bacillus cereus, Staphylococcus aureus
- Also foodborne GI disease.
- Symptom onset in <24hrs --> Caused by pre-formed toxin.
- Nausea and vomiting (less commonly diarrhea).
- Campylobacter jejuni and Yersinia enterocolitica
- Also foodborne GI disease.
- Bloody diarrhea UNCOMMON.
- Fever in most patients.
Overview Enteric Pathogens
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Campylobacter jejuni
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Raw or undercooked poultry, raw dairy products, and contaminated produce.
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Sometimes bloody, usually not.
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<1% get Guillain-Barre Syndrome
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E.coli
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Shinga Toxin-Producing E. coli (STEC) (aka. enterohemorrhagic E. coli infection - EHEC)
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Classically R-sided abdo pain without high fever (bloody or non-bloody diarrhea).
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Risk of hemolytic Uremic Syndrome, Renal Failure
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Shunga Toxin-Producing E. coli O157 (STEC O157)
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Test for shinga toxin and E.coli O157 strain analysis.
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Enteroaggregative E.coli
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Malnutrition with/without diarrhea.
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Salmonella
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Can cause aortitis --> bacteria bind to vessels with lots of atherosclerosis or grafts.
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Reactive arthritis can occur. (if HLA-B27 positive)
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Shigella
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Reactive arthritis can occur. (if HLA-B27 positive)
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Yersinia enterocolitica
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Persistent abdo pain and fever in Asian-Americans in California and African-American infants
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Perform cultures in fall/winter seasons.
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Causes swelling of mesenteric lymph node, can mimic appendicitis.
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Reactive arthritis can occur. (if HLA-B27 positive)
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Cyclospora
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Cryptosporidium
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Malnutrition
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Giardia
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Vibrio
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Seafood/sea coast exposure
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Culture
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Clostridium difficile
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Caliciviruses
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Other Enteric Viruses
Management
- SECTION UNDER CONSTRUCTION
- TREAT DEHYDRATION
- Oral Glucose or Starch containing electrolyte solution.
- (See WHO recommended rehydration solutions)
- Report Suspected Outbreak
- Stool culture (yield extremely low)
- 5.8% positive for enteric pathogens:
- Of all stool cultures: 1.4% Campylobacter, 0.9% salmonella, 0.6% shingella, 0.3%E.coli O157.
- Recommendation: Test in all bloody diarrhea cases. Other testing is controversial.
- Treatments:
- Controversial
- Risks: resistance, suprainfection, induction of disease-producing phage
- Empiric Therapy Recommended in:
- Traveller's diarrhea (ifETEC and other bacterial causes are likely)
- Fluoroquinolone (Septra in children)
- Reduces duration of illness from 3-5d to 1-2d.
- Diarrhea >10-14d with suspected giardia (negative tests, hx of water exposure)
- Moderate to severe invasive diarrhea (consider treating) - fluoroquinolone or TMP/SMZ in children.
- Traveller's diarrhea (ifETEC and other bacterial causes are likely)
- Concern about resistant Campylobacter infections (10% in Minnesota)
- Patients get worse as quinolones eradicate other flora.
- If bloody diarrhea or HUS
- Stool culture
- Stool E.coli O157 detection
- Stool Shinga toxin detection
- Don'ts:
- DO NOT send stool culture if diarrhea develops >3 days of hospitalization. (15-50% of all stool cultures)
- Known as the "3-day-rule"
- DO NOT repeat stool for Ova/Parasites.
- DO NOT send stool culture if diarrhea develops >3 days of hospitalization. (15-50% of all stool cultures)
Reference:
- Guerrant RL, Van Gilder T, Steiner TS, et al; Infectious Diseases Society of America. Practice guidelines for the management of infectious diarrhea. Clin Infect Dis. 2001;32(3):331-351. PMID: 11170940
Clostridium Difficile
Source: "A woman with community-acquired Clostridium difficile infection" by Christopher Kandel, et al (2012) CMAJ
Source: Orange book
source: NEJM+ Knowledge
Click here for 2010 guidelines.
- Risk Factors
- Antibiotic use in last 3 months (most modifiable)
- Clindamycin
- Fluoroquinolones
- Broad-spectrum penicillins
- Cephalosporins
- PPIs
- Previous abdo sugery
- Age ≥65
- IBD
- Recent hospital stays
- Antibiotic use in last 3 months (most modifiable)
- Symptoms:
- ACUTE non-bloody watery diarrhea (occasionally bloody).
- Lower abdominal pain
- Clinical Features:
- Fever, High WBC count
- Complications:
- Fulminant colitis (2-3%)
- Toxic megacolon (triad: colon dilation ≥ 6cm on KUB, colonic atony, systemic toxicity)
- Bowel Perforation
- Diagnosis:
- Stool PCR -many false negatives of colonization
- (OR toxin assay EIA detects toxin B or A, fast, more specific)
- Treatment
- Stop offending abx (or shorten course)
- Stop anti-motility agents
- Determine if Severe or Non-Severe
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Severe Vs. Non-Severe C.diff infection
ANY of the following:
1. Leukocytosis WBC ≥ 15,000 /uL
2. Creat 1.5x patient's baseline
For Severe, differentiate by:
Complicated Vs. Uncomplicated
ANY of following
1. Hypotension
2. Shock
3. Ileus
4. Megacolon
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- If NON-SEVERE (mild-to-mod)
- Metronidazole 500mg po q8h x10-14d
- (new evidence, but not in guidelines, to start with OR Vancomycin 125mg PO q6h)
- (NEJM paper: equal cure rates, MTZ less well tolerated)
- (new evidence, but not in guidelines, to start with OR Vancomycin 125mg PO q6h)
- Treat for 10-14d
- Metronidazole 500mg po q8h x10-14d
- If SEVERE:
- Vancomycin 125mg po q6h x 10-14d (+/- Metronidazole)
- If SEVERE + COMPLICATED
- Vancomycin 500mg QID PO/NG + metronidazole 500mg IV q8h
- (If Ileus, add PR vanco)
- If worsening (ileus, rising WBC, rising lactate, shock, toxic megacolon, peritonitis)
- Abdo CT
- Urgent SURGERY CONSULT (subtotal colectomy (?diverting loop ileostomy or colonic lavage)
- Consider PR vanco
- NOTES
- if cannot discontinue offending abx... continue C.diff therapy until ≥7d abx stopped.
- Stools may continue to be C.diff positive (do not retreat unless symptoms)
- Recurrence:
- 15-30% risk (usually in 2w of stopping abx therapy)
- 1st Recurrence: Same as initial episode
- 2nd Recurrence: Vancomycin PO pulse + taper.
- Consider ID, consider fecal transplant (NEJM 2013, JAMA 2016), or fidaxomicin 200mg BID x10d.
- Probiotics Saccharomyces boulardii - reduce recurrence risk. (avoid in immunosuppression).
- Studies controversial.
- Most antibiotics not helpful (Lancet 2013)
- Monitor Treatment
- Watch complications: Ileus, Peritonitis
- Typically diarrhea x3-4 days resolves by day 7.
- Do not re-test stool (toxin persists for up to 6 weeks (40%))
- Prevent Spread
- Contact precautions!!
- Two factors in prevention:
- 1. Limiting Transmission
- 2. Minimizing abx exposure
- Hand hygeine important!
- Use Soap & Water. C. diff spores are resistant to EtOH-based hand sanitizers.
- All eqiupment wash with hypochloride-based solution.
- Future Research:
- Fidaxomicin vs. vancomycin --> similar cure rates.
- Fidaxomicin had lower recurrence than vanco.
- Monoclonal antibodies to C.diff toxin A and B reduce recurrence.
- Rifaximin (minimally-absorbed macrolide) - given for two weeks after course of vanco decreased recurrence.
- Fecal transplant - Observational studies --> effective to prevent recurrence.
- No standardized regimens and no RCTs.
- Fidaxomicin vs. vancomycin --> similar cure rates.
Liver Abscesses / Cholangitis
- Sources:
1. Biliary tract infection
2. Portal vein bacteremia (Appendicitis, diverticulitis, IBD)
3. Direct extension (perfed duodenal ulcer, perfed gall bladder, or perinephrin/pancreatic/subphrenic abscess).
4. Skin (Penetrating wounds, surgical)
5. Bactermia (any cause, via hepatic artery and multiple abscesses)
6. Unidentified (25% of cases)
- Organisms:
- 1. Gram negatives + (Enterococcus) + anaerobes.!!!! (MOST COMMON)
- 2. Skin organisms (S. aureus, GAS)
- 3. Bacteremia (S.aureus, Strep angionus?, Klebsiella, Odd things)
- Organisms (approach #2)
- By site of primary infection
- Peritonitis
- Usually polymicrobial
- Anaerobes (Bacteroides, Fusobacterium Peptostreptococcus, Actinomyces, and microaerophilic streptococci (S. milleri)
- Gram-negatives (K. pneumoniae - esp the K1 serotype)
- Usually polymicrobial
- Candida (if immunocompromised)
- Amoebic liver abscess
- Peritonitis
- By site of primary infection
- Treat with Amox-Clav for 3-4-6 weeks (esp longer if cannot drain abscesses)
- If allergic to amox clav then treat with Cipro-flagyl (ignore Enterococcus).
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