You may be able to prevent blastocystis or other gastrointestinal infection by taking a number of precautions while traveling in high-risk countries.

Watch what you eat

The general rule of thumb is this: If you can't boil it, cook it or peel it — forget it. Unfortunately, most travelers don't stick to these guidelines all of the time. Remember these tips:

  • Avoid food from street vendors.
  • Avoid unpasteurized milk and dairy products, including ice cream.
  • Avoid raw or undercooked meat, fish and shellfish.
  • Steer clear of moist food at room temperature, such as sauces and buffet offerings.
  • Eat foods that are well cooked and served hot.
  • Munch on dry foods — like breads — and foods high in sugar, such as jellies and syrups.
  • Stick to fruits and vegetables that you can peel yourself, such as bananas, oranges and avocados. Stay away from salads and unpeelable fruits, such as grapes and berries.

Don't drink the water

When visiting high-risk countries, keep the following tips in mind:

  • Avoid unsterilized water — from tap, well or stream. If you need to consume local water, boil it for at least three minutes and then let it cool to room temperature.
  • Avoid ice cubes or fruit juices made with tap water.
  • Beware of sliced fruit that may have been washed in contaminated water.
  • Don't swim in water that may be contaminated.
  • Keep your mouth closed while showering.
  • Feel free to drink canned or bottled drinks in their original containers — including water, carbonated beverages, beer or wine — as long as you break the seals on the containers yourself. Wipe off any can or bottle before drinking or pouring.
  • Use bottled water to brush your teeth.
  • Use bottled or boiled water to mix baby formula.
  • Make sure hot beverages, such as coffee or tea, are steaming hot.

If it's not possible to buy bottled water or boil your water, bring some means to purify water: Consider a water-filter pump with a microstrainer filter that can filter out small microorganisms. Look in camping stores for a filter that is certified by the National Science Foundation.

Another approach is to chemically disinfect water with iodine or chlorine. Iodine tends to be more effective, but reserve it for short trips, because too much iodine can be harmful to your body. You can purchase iodine tablets or crystals at camping stores and pharmacies. Be sure to carefully follow the directions.

Take precautions against passing a parasite to others

If you have blastocystis or another gastrointestinal infection, good personal hygiene will help keep you from spreading the infection to others:

  • Wash hands with soap and water frequently, especially after using the toilet and before handling food. Rub soapy, wet hands together for at least 20 seconds before rinsing. If soap and water aren't available, use an alcohol-based hand sanitizer.
  • Wash hands well after changing a diaper, especially if you work in a child care center, even if you wear gloves.
Jan. 25, 2013