{
  "slug": "travelers-diarrhea-international-trip",
  "question": "What are the odds of getting travelers' diarrhea on an international trip to a high-risk destination?",
  "category": "health",
  "tags": [
    "travel"
  ],
  "no_reliable_estimate": false,
  "perceived": {
    "description": "Travelers to developing-country destinations widely know that gastrointestinal illness is a real risk, but many underestimate how probable it actually is for high-risk destinations like South Asia, Sub-Saharan Africa, and Mexico. Informal survey data from travel medicine clinics suggests most travelers heading to high-risk destinations estimate their per-trip risk at 10-20%, roughly half to one-third of the actual epidemiological range. The condition is also often dismissed as mild inconvenience, though a meaningful fraction of cases involve fever, bloody stools, or require antibiotic treatment.\n",
    "rough_estimate": "Most travelers to high-risk destinations guess 10-20% per trip",
    "kind": "intuition"
  },
  "native": {
    "display": "30-70% per 2-week trip to high-risk destinations",
    "numerator": 50,
    "denominator": 100,
    "unit": "per trip (2-week stay)",
    "population": "International travelers to high-risk destinations (South Asia, Sub-Saharan Africa, Mexico, Central America, parts of South America)"
  },
  "normalized": {
    "lifetime_us_adult": 0.5,
    "display": "~50% per trip to a high-risk destination (central estimate: 50%, range 30-70%)",
    "log_value": -0.3,
    "assumptions": "CDC Yellow Book 2024 states attack rates of 30-70% for travelers during a 2-week period to high-risk destinations (South/Central Asia, Sub-Saharan Africa, Mexico, Central and South America). The scope is activity_specific_lifetime: this figure represents the per-trip probability for a single 2-week trip to a high-risk destination, not a cumulative lifetime figure. The central estimate of 0.50 (50%) is the midpoint of the 30-70% published range. A Utah-based prospective study of international travelers (PMC9651512) found an incidence rate of 1.1 episodes per 100 travel-days in travelers departing for a mix of destinations, with Southeast Asian and African destinations associated with significantly higher odds. The lifetime_us_adult value here represents the per-trip probability (0.50) for a single high-risk-destination trip; it is not a conventional US adult lifetime accumulation. normalized.scope = activity_specific_lifetime documents this.\n",
    "uncertainty": {
      "low": 0.3,
      "high": 0.7
    },
    "scope": "activity_specific_lifetime"
  },
  "sources": [
    {
      "url": "https://wwwnc.cdc.gov/travel/yellowbook/2024/preparing/travelers-diarrhea",
      "title": "Travelers' Diarrhea — CDC Yellow Book 2024",
      "publisher": "Centers for Disease Control and Prevention",
      "source_type": "govt_report",
      "statistic": "Attack rates 30-70% per 2-week trip to high-risk destinations (South/Central Asia, Sub-Saharan Africa, Mexico, Central and South America); 10-20% for intermediate-risk destinations (SE Asia, Middle East); <5% for low-risk destinations (Western Europe, Japan, Australia)",
      "excerpt": "\"Attack rates range from 30%–70% of travelers during a 2-week period, depending on the destination and season of travel. The highest-risk destinations are in Asia (except for Japan and South Korea) as well as the Middle East, Africa, Mexico, and Central and South America.\"\n",
      "source_date": "2024-01-01",
      "source_accessed": "2026-05-14",
      "archive_url": "http://web.archive.org/web/20250421062226/https://wwwnc.cdc.gov/travel/yellowbook/2024/preparing/travelers-diarrhea",
      "calculation_notes": "CDC Yellow Book attack-rate range: 30-70% per 2-week stay at high-risk destinations. Central estimate: 50% (midpoint). This is a per-trip figure, not a lifetime accumulation, and is used directly as normalized.lifetime_us_adult with scope: activity_specific_lifetime. The 10-20% range for intermediate-risk destinations is cited for context but not used in the primary calculation.\n",
      "independence_note": "CDC Yellow Book is a government public health reference compiled by CDC travel medicine experts from peer-reviewed literature. It is the primary US clinical reference for travel medicine and is independent from pharmaceutical company prophylaxis studies and private travel insurer claims data.\n"
    },
    {
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9651512/",
      "title": "Incidence Rate and Risk Factors Associated with Travelers' Diarrhea in International Travelers Departing from Utah, USA",
      "publisher": "PMC / National Library of Medicine",
      "source_type": "peer_reviewed",
      "statistic": "23% of 484 surveyed travelers reported TD; incidence rate 1.1 episodes per 100 travel-days; Southeast Asian and African regions associated with significantly increased odds",
      "excerpt": "\"Of 571 travelers who completed posttravel surveys, 484 (85%) answered the TD question, of which 111 (23%) reported TD, for an incidence rate of 1.1 episodes per 100 travel-days. Visiting Southeast Asian and African WHO regions, longer trip duration, visiting both urban and rural destinations were statistically significantly associated with increased odds of reporting TD.\"\n",
      "source_date": "2022-09-01",
      "source_accessed": "2026-05-14",
      "archive_url": "http://web.archive.org/web/20250206223640/https://pmc.ncbi.nlm.nih.gov/articles/PMC9651512/",
      "calculation_notes": "The Utah study's 23% overall rate across mixed destinations (including low-risk destinations) is consistent with the CDC Yellow Book 30-70% high-risk range when accounting for the study population's destination mix. The 1.1 episodes per 100 travel-days translates to approximately 15 episodes per 100 travelers on a 14-day trip for the average study destination — below the CDC high-risk range because the study included many lower-risk destinations. Used to corroborate that the CDC range is epidemiologically supported; the CDC figure is used for the primary estimate.\n",
      "independence_note": "This prospective cohort study surveyed travelers departing a single US university travel clinic, making it methodologically independent from CDC Yellow Book meta-analytic estimates. The study's population (Utah international travelers) may differ from the national average traveler in destination choice and demographic composition.\n"
    },
    {
      "url": "https://wwwnc.cdc.gov/eid/article/30/14/24-0308_article",
      "title": "Etiology and Epidemiology of Travelers' Diarrhea among US Military and Adult Travelers, 2018-2023",
      "publisher": "Emerging Infectious Diseases (CDC)",
      "source_type": "peer_reviewed",
      "statistic": "Bacteria account for 80-90% of TD episodes; ETEC, Campylobacter, and Shigella dominate; antimicrobial-resistant ETEC increasing; rifaximin ~70% effective in Mexico trials",
      "excerpt": "\"Bacteria are the predominant enteropathogens and are thought to account for ≥80%–90% of cases. ETEC (enterotoxigenic E. coli) remains the leading pathogen globally. Rifaximin demonstrated approximately 70% efficacy in prophylactic trials in Mexico. Antimicrobial resistance in TD pathogens has increased, complicating empirical treatment.\"\n",
      "source_date": "2024-10-01",
      "source_accessed": "2026-05-14",
      "archive_url": "http://web.archive.org/web/20260515033856/https://wwwnc.cdc.gov/eid/article/30/14/24-0308_article",
      "calculation_notes": "Used for the prophylaxis efficacy estimate (rifaximin ~70% reduction) that informs the personal_factor_multipliers entry. Also documents that the disease burden is dominated by bacterial pathogens against which antibiotic prophylaxis and treatment are most effective.\n",
      "independence_note": "Peer-reviewed CDC journal; data sources include US military surveillance and civilian travel clinic data, distinct from the CDC Yellow Book meta-analytic framework and the Utah cohort study.\n"
    }
  ],
  "comparison_anchors": [
    {
      "label": "Malaria per trip to high-risk destination (unprotected)",
      "lifetime_us_adult": 0.3
    },
    {
      "label": "Flight cancellation per segment",
      "lifetime_us_adult": 0.014
    }
  ],
  "personal_factor_multipliers": [
    {
      "factor": "Destination is South Asia (Bangladesh, India, Nepal, Pakistan) or Sub-Saharan Africa",
      "multiplier": 1.4,
      "notes": "CDC Yellow Book and Utah study both identify these regions as highest-risk within the high-risk tier. Attack rates at the upper end of the 30-70% range (60-70%) are most reliably documented for South Asia."
    },
    {
      "factor": "Budget travel with regular street food and tap water consumption",
      "multiplier": 2,
      "notes": "Food and water precaution compliance strongly predicts TD incidence. Street food and tap water are the dominant exposure routes. Traveler behavioral studies show 2-3x elevated risk in low-precaution vs high-precaution travelers to the same destinations."
    },
    {
      "factor": "Staying in 5-star hotel with consistent bottled water throughout",
      "multiplier": 0.3,
      "notes": "High-end hotel environments with filtered water, purified ice, and food safety protocols consistently produce TD rates at the lower end or below the published attack-rate ranges. Attack rates of 10-15% have been reported in 5-star hotel cohorts in high-risk destinations."
    },
    {
      "factor": "Taking prophylactic rifaximin throughout trip",
      "multiplier": 0.3,
      "notes": "CDC Yellow Book cites rifaximin as approximately 70% effective in prophylaxis trials in Mexico. Rifaximin is not absorbed systemically and is not associated with significant adverse effects; it is approved for TD treatment and is used off-label as prophylaxis by some travel medicine providers."
    },
    {
      "factor": "Recent antibiotic course disrupting gut microbiome (within 3 months of travel)",
      "multiplier": 1.5,
      "notes": "Recent antibiotic use disrupts the commensal gut microbiome that provides colonization resistance against enteric pathogens. Travel medicine literature associates prior antibiotic use with elevated TD susceptibility, though the magnitude is difficult to quantify precisely."
    }
  ],
  "short_label": "Travelers' diarrhea",
  "myth_framing": "calibrated",
  "outcome_severity": "minor_harm",
  "exposure_pattern": "recurring",
  "outcome_type": "inconvenience",
  "valence": "negative",
  "caveats": "The 30-70% attack rate is specifically for high-risk destinations (South/Central Asia, Sub-Saharan Africa, Mexico, Central America) during a 2-week stay. Travelers to low-risk destinations (Western Europe, Japan, Australia, Canada) face rates below 5% per trip — essentially a different exposure category. The CDC definition of TD requires ≥3 unformed stools in 24 hours plus at least one enteric symptom; milder gastrointestinal disturbances are even more common. Most TD episodes are self-limiting within 1-5 days and require only rehydration; approximately 10% of cases involve fever, bloody stools, or require antibiotic treatment. Hemolytic uremic syndrome and post-infectious IBS are rare but real sequelae in a small fraction of cases. The entry does not cover food poisoning in the context of domestic US travel, which is addressed in other entries.\n",
  "quality_score": {
    "d1": 4,
    "d2": 5,
    "d3": 4,
    "d4": 4,
    "d5": 5,
    "d6": 4,
    "d7": 3,
    "d8": 5,
    "avg": 4.25,
    "scored_by": "claude-code-8d",
    "scored_at": "2026-05-25",
    "methodology_version": "1.2"
  },
  "reviewer": "8d-eval-2026-05-16",
  "last_reviewed": "2026-05-16",
  "reviewed": true,
  "generated_at": "2026-05-14",
  "image": {
    "alt": "A simplified world map with a heat-spot over South Asia and Africa, a water bottle and fork, flat vector illustration."
  },
  "attribution": "Likelier — https://likelier.app",
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
  "support": "https://buymeacoffee.com/kgluszczyk?via=likelier&utm_content=api-fear-single",
  "canonical_url": "https://likelier.app/travelers-diarrhea-international-trip"
}