How to Avoid Food Poisoning on Vacation: What Actually Works

What actually causes traveler's diarrhea?

Traveler's diarrhea is by far the most common travel-related illness 1Ref 1Centers for Disease Control and Prevention (2023).Travelers' Diarrhea — CDC Yellow Book 2024.Causes of traveler's diarrhea, high-risk destinations, food and water safety rules (boil it/cook it/peel it), stand-by antibiotic guidance, and oral rehydration recommendations. It is usually caused by bacterial pathogens — most often strains of E. coli that are common in the local environment but unfamiliar to your immune system. Viral causes and parasites such as Giardia or Cryptosporidium account for a smaller share.

The illness typically begins within the first week of travel and causes loose or watery stools, cramping, nausea, and sometimes vomiting. Most cases resolve on their own within a few days with good hydration, though some require antibiotic treatment.

Higher-risk destinations include most of sub-Saharan Africa, South and Southeast Asia, Latin America, and parts of the Middle East. Lower-risk destinations include Western Europe, Australia, the US, Canada, Japan, and New Zealand 1Ref 1Centers for Disease Control and Prevention (2023).Travelers' Diarrhea — CDC Yellow Book 2024.Causes of traveler's diarrhea, high-risk destinations, food and water safety rules (boil it/cook it/peel it), stand-by antibiotic guidance, and oral rehydration recommendations.

What food and water rules genuinely work?

Water safety comes first. Drink only commercially bottled water (check the seal before opening), canned or bottled beverages, boiled water, or water treated with a reliable filter or purification tablets 1Ref 1Centers for Disease Control and Prevention (2023).Travelers' Diarrhea — CDC Yellow Book 2024.Causes of traveler's diarrhea, high-risk destinations, food and water safety rules (boil it/cook it/peel it), stand-by antibiotic guidance, and oral rehydration recommendations. Use bottled water for brushing your teeth. Avoid ice unless you are certain it was made from purified water.

Food choices matter almost as much. Cooked food served hot is generally safest. Avoid: - Raw or undercooked meat, fish, and shellfish - Raw salads and raw vegetables washed in tap water - Fruit you have not peeled yourself - Buffets where food sits at room temperature for extended periods

Street food cooked fresh and to order in front of you can be safer than cold buffet items that have been sitting out — even at a hotel that looks upscale.

Hand hygiene is critical. Wash with soap and water before eating. Use alcohol-based hand sanitizer when soap is not available 1Ref 1Centers for Disease Control and Prevention (2023).Travelers' Diarrhea — CDC Yellow Book 2024.Causes of traveler's diarrhea, high-risk destinations, food and water safety rules (boil it/cook it/peel it), stand-by antibiotic guidance, and oral rehydration recommendations.

Which vaccines help protect against foodborne illness when traveling?

Some foodborne illnesses are vaccine-preventable:

• Hepatitis A — strongly recommended for most travel to higher-risk regions. Spread through contaminated food and water; a single dose provides strong protection 2Ref 2Nelson NP, Link-Gelles R, Hofmeister MG, Romero JR, Moore KL, Ward JW, Schillie SF (2018).Update: Recommendations of the Advisory Committee on Immunization Practices for Use of Hepatitis A Vaccine for Postexposure Prophylaxis and for Preexposure Prophylaxis for International Travel.Hepatitis A vaccine recommendation for higher-risk travel destinations as a foodborne illness prevention measure.
• Typhoid — offers partial protection against typhoid fever, which is also transmitted through contaminated food and water 3Ref 3Jackson BR, Iqbal S, Mahon B; CDC (2015).Updated recommendations for the use of typhoid vaccine — Advisory Committee on Immunization Practices, United States, 2015.Typhoid vaccine recommendation for travelers to higher-risk regions as partial protection against a foodborne/waterborne illness.

Neither vaccine eliminates all food safety risk — they protect against specific pathogens. Other vaccines (for cholera, for example) may be relevant for specific itineraries. A travel medicine clinician can advise on which vaccines make sense for your destination 1Ref 1Centers for Disease Control and Prevention (2023).Travelers' Diarrhea — CDC Yellow Book 2024.Causes of traveler's diarrhea, high-risk destinations, food and water safety rules (boil it/cook it/peel it), stand-by antibiotic guidance, and oral rehydration recommendations.

What should you pack for food safety?

Before your trip, ask your clinician about a stand-by antibiotic prescription for traveler's diarrhea. This is commonly offered for travel to high-risk destinations 1Ref 1Centers for Disease Control and Prevention (2023).Travelers' Diarrhea — CDC Yellow Book 2024.Causes of traveler's diarrhea, high-risk destinations, food and water safety rules (boil it/cook it/peel it), stand-by antibiotic guidance, and oral rehydration recommendations. The idea is not to take it prophylactically but to start it promptly if moderate or severe diarrhea begins — which can shorten the duration significantly.

Other useful items: - Oral rehydration salts (ORS packets) — commercially available, these rehydrate more effectively than plain water if diarrhea hits. - A thermometer — useful for monitoring fever. - A water-purification device (filter straw, purification tablets, or UV pen) as a backup when bottled water is unavailable.

What should you do if you get sick while traveling?

For mild diarrhea without fever or blood: prioritize hydration with oral rehydration solution or diluted electrolyte drinks, rest, and bland foods. Most mild cases resolve within two to three days 1Ref 1Centers for Disease Control and Prevention (2023).Travelers' Diarrhea — CDC Yellow Book 2024.Causes of traveler's diarrhea, high-risk destinations, food and water safety rules (boil it/cook it/peel it), stand-by antibiotic guidance, and oral rehydration recommendations.

Anti-motility agents (such as loperamide) can reduce stool frequency and are sometimes used for convenience — for example, a long bus ride — but should generally not be used when there is blood in the stool, high fever, or in young children.

If you have a stand-by antibiotic prescription, use it per your clinician's instructions for moderate or severe illness. If symptoms include any of the red flags below, seek local medical care rather than managing on your own.