Avoiding travel-related illness starts with this fact: Most germs come from food and water. The federal Centers for Disease Control and Prevention and the American College of Emergency Physicians give these tips:
Don't swim in stagnant or polluted water or after a heavy rainfall. Use goggles, nose plugs and ear plugs, and don't swallow water. Shower before and after, and wash cuts and scrapes with clean water and soap.
Drink only canned or bottled beverages or those made with boiled water. Don't use ice. Dry the outside of wet cans or bottles before drinking from them.
Use bottled water to brush your teeth and rinse your toothbrush.
Avoid raw food such as salads, uncooked vegetables, unpasteurized milk and milk products, such as cheese. Eat food that has been cooked and is still hot, and fruit that you have peeled. Don't eat undercooked or raw meat, fish or shellfish.
Don't buy food or drinks from street vendors.
Don't trust food and water on the plane home. It came from the country you visited, not where you are going.
Check your medical coverage. Most private insurers and Medicare don't cover hospital or medical costs outside the United States or pay for emergency medical evacuation. Consider travel insurance for this.
Get recommended vaccines far enough in advance. Information from the federal Centers for Disease Control and Prevention is at www.cdc.gov/travel.