II. Epidemiology

  1. Incidence: 20-50% per short visit to endemic area (affects 10 million patients annually)
  2. Timing
    1. Peak Incidence for travelers from U.S. in October and June
  3. Ages affected
    1. Most common among younger patients (children, teens and young adults)
  4. Endemic Regions
    1. Developing countries in Africa, South Asia, Latin America, Middle East
    2. Highest risk countries
      1. Kenya
      2. Tunisia
      3. Morocco
      4. Egypt
      5. Mexico
      6. Honduras
      7. Thailand
      8. India

III. Risk Factors

  1. Lowered gastric pH from Antacid use (H2 Blocker, Proton Pump Inhibitor)
  2. Travel to endemic regions as above
  3. Younger age (children and young adults)
  4. Immunosuppression (e.g. Inflammatory Bowel Disease, Diabetes Mellitus)
  5. Participation in low-budget travel or adventure vacations
  6. Visiting family or friends in endemic regions
  7. Contaminated food exposure
    1. See Foodborne Illness
    2. Food washed in tap water (e.g. fresh fruit and raw vegetables)
    3. Food from street vendors (food storage without cooling, washed in tap water, unsafe hygiene)
    4. Salads and unpealed fruit or vegetables
    5. Raw seafood or meats
    6. Custard or cream dessert
  8. Contaminated water exposure
    1. See Waterborne Illness
    2. Tap water (including ice)
    3. Frozen drinks

IV. Course

  1. Onset in first two weeks of travel (usually first week)
  2. Duration: Short
    1. Diarrhea lasts <24 hours in 20% of cases
    2. Diarrhea lasts 2-7 days in 60% of cases
    3. Diarrhea lasts >1 week in <15% of cases
    4. Diarrhea lasts >4 weeks in <2% of cases
    5. Longer duration associated with age under 29 years
  3. Medical Care
    1. Local physician seen in 4% of Traveler's Diarrhea
    2. Hospitalization in <1% of Traveler's Diarrhea

V. Symptoms

  1. Three or more loose stools per day
  2. Abdominal cramping (20-60% cases)
  3. Bloody stools (15%)
  4. Fever (10%)
  5. Nausea or Vomiting (10%)
  6. Tenesmus

VI. Causes: Acute Diarrhea (<14 days)

  1. No cause is identified in up to 50% of Acute Diarrhea cases
  2. Incubation Periods
    1. Most are 1-3 days
    2. Shigella may incubate for up to 7 days, and Giardia up to 25 days after exposure
    3. Parasites also tend to incubate for at least 1 to 2 weeks
  3. Most common Bacteria
    1. Escherichia coli (most common)
      1. Enterotoxigenic E. coli (up to 36% in Latin america, Carribean and Africa)
      2. Enteroaggregative E. coli (Up to 25-35% in Latin america, Carribean and Africa)
      3. Enteroadherent E. coli (5%)
      4. Enteroinvasive E. coli (3%)
    2. Campylobacter jejuni (Up to 25-35% in Asia, <5% in Africa, Latin America)
    3. Shigella (5-15%)
  4. Other Bacterial and viral causes
    1. Nontyphoidal Salmonella (5%)
    2. Rotavirus (5-15%)
    3. Vibrio parahaemolyticus (seafood) (2%)
  5. Parasitic causes
    1. See Chronic Diarrhea causes below (which may present acutely)
    2. Entamoeba histolytica (2%)
    3. Giardia lamblia (<5%)
    4. Cryptosporidium
    5. Microsporidium species

VII. Causes: Chronic Diarrhea (>14 days)

VIII. Differential Diagnosis

IX. Labs

  1. Not indicated in most cases of Traveler's Diarrhea
  2. Lab Indications (red flag findings)
    1. Fever > 101.3 F (38.5 C)
      1. Suggestive of Shigella, Salmonella, Campylobacter, Norovirus
    2. Bloody Diarrhea or Dysentery
    3. Moderate to severe Dehydration (e.g. Cholera-like Diarrhea)
    4. Sepsis
    5. Chronic Diarrhea (>14 days)
  3. Labs when indicated
    1. Complete Blood Count
    2. Comprehensive metabolic panel
    3. Blood Cultures (indicated for fever)
    4. Stool Cultures (e.g. SSCE) or Stool Nucleic Acid (NAAT)

XIII. Prognosis: Course

  1. Most cases of Traveler's Diarrhea are self limited and last <5 days without antibiotics

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