Traveler's Diarrhea



  • Traveler’s diarrhea (TD) is the most common medical condition experienced in travelers from more developed to resource-limited countries.
  • TD is acute diarrhea that develops at travel destination and is defined as three or more unformed stools in a 24-hour period, plus one or more symptom such as abdominal cramping, bloating, nausea, vomiting, or fever.
  • TD occurrence decreases over time once at the travel destination.



  • Up to 70% of experienced travelers report having had TD at some point (1,2,3).
  • Due to improvements in infrastructure and hygiene, rates of TD have decreased in most destinations (4).
  • Cruise ships: 22 cases of acute gastroenteritis per 100,000 travel days (5)


  • High-risk regions (>20% of travelers): Middle East, much of Asia, Africa, Mexico, Central and South America
  • Intermediate-risk regions (8–20% of travelers): Eastern Europe, South Africa, parts of the Caribbean
  • Low-risk regions (<8% of travelers): Western and Northern Europe, Canada, Australia, New Zealand, Japan, United States
  • Risk of TD increases as economic resources of destination country decrease (4).

Etiology and Pathophysiology

  • TD results from disruption or invasion of the intestinal mucosa and/or environment by infectious organisms.
  • Bacteria cause 80–90% of TD.
    • Enterotoxigenic Escherichia coli
    • Enteroaggregative E. coli
    • Campylobacter jejuni (most common in South and Southeast Asia)
    • Salmonella and Shigella species
    • Vibrio (parahaemolyticus and cholerae)
    • Aeromonas hydrophila
    • Plesiomonas shigelloides
    • Yersinia enterocolitica
  • Viruses cause 5–8% of TD.
    • Noroviruses and rotaviruses
  • Parasites—protozoa uncommonly cause TD and may cause prolonged illness
    • Giardia intestinalis (lamblia, duodenalis)
    • Cryptosporidium parvum
    • Cyclospora cayetanensis
    • Microsporidia
    • Cystoisospora belli
    • Entamoeba histolytica
  • Infection by >1 organism is possible.
  • Repeat bouts of TD may occur during longer travels.
  • TD is typically self-limited (3 to 7 days) illness if untreated.
  • Dysentery: invasion of mucosa, may have fever, nausea and vomiting, abdominal pain, blood or mucus in stool
  • Cholera: About 1 in 10 develops severe illness, profuse diarrhea, dehydration, shock.


  • No specific genetic predisposition identified
  • HLA-B27 and TLR-2 polymorphism are associated with increased occurrence of postinfectious reactive arthritis (6).

Risk Factors

  • Traveler risk factors (1,2)
    • Infants and toddlers at increased risk for severe illness and hospitalization
    • Use of histamine H2 blockers and proton pump inhibitors may increase risk.
    • Immunosuppressive agents do not increase incidence, although may impact severity.
    • Inflammatory bowel disease increases TD incidence and illness duration.
  • Environmental risk factors (1,2,3,4,5)
    • Location of travel: high-, intermediate-, low-risk regions
    • Eating food from street vendors
    • Seasonal variation: more TD during warm and wet seasons
    • Risk directly linked to hygiene practices and sanitary conditions of food sources

General Prevention

  • “Boil it, cook it, peel it, or forget it”; sound advice, may not reduce TD risk
  • Proper hygiene practices and ensuring sanitary conditions of food sources decrease TD.
  • Use alcohol-based (≥60%) hand sanitizers.
  • Ice, freezing, and alcohol do not kill TD pathogens.
  • Heating food to 100°C kills pathogens, but heat-stable bacterial toxins persist—classic “food poisoning.”
  • Probiotics are not effective in preventing TD.
  • Oral vaccine for cholera is FDA-approved for adults 18 to 64 years traveling to active cholera area; other cholera vaccines available outside the United States (3)
  • Hepatitis A and typhoid vaccination indicated depending on travel destination
  • Consider pretravel health visit for risk stratification, medical advice, and medications for TD (1,2,3,4).

Commonly Associated Conditions

  • Irritable bowel syndrome
  • Dehydration
  • Acute gastroenteritis

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