Epidemiology:

Travelers diarrhea (TD) is a syndrome characterized by a twofold or greater increase in the frequency of unformed bowel movements. Commonly associated symptoms include abdominal cramps, nausea, bloating, urgency, fever, and malaise. Episodes of TD usually begin abruptly, occur during travel or soon after being home, and generally resolve without treatment. The most important determinant of risk is the destination of the traveler. Attack rates in the range of 20-50 percent are commonly reported. High-risk destinations include most of the developing countries of Latin America, Africa, the Middle East, and Asia. Intermediate risk destinations include most of the Southern European countries and a few Caribbean islands. Low risk destinations include Canada, Northern Europe, Australia, New Zealand, the United States, and a number of the Caribbean islands.

TD is acquired through the ingestion of contaminated food and/or water. Both cooked and uncooked foods may be implicated if improperly handled. Especially risky foods include raw meat, raw seafood, and raw fruits and vegetables. Tap water, ice, and unpasteurized milk and dairy products may be associated with increased risk of TD; safe beverages include bottled carbonated beverages, beer, wine, hot coffee or tea, or water boiled or appropriately treated.

The risk of acquiring TD appears related to where one eats with the greatest risk for street vendors and the least for private homes. Restaurants pose an intermediate risk for TD.

The onset of TD is usually within the first week, but may occur at any time during the visit, and even after returning home. TD typically results in 4-5 loose or watery stools per day. The median duration is 3-4 days, although 10% persist for more than one week, 2% for longer than one month, and less than 1% for longer than 3 months. Travelers may have more than one episode per trip.

Cause:

Bacteria are the most common causes of TD but viruses and parasites also cause diarrhea.

Prevention:

The best prevention is meticulous attention to food and beverage preparation and/or selection while away. However, this can be very difficult.

There is no vaccine available to prevent this problem. Several different types of medications have been evaluated as potential means to prevent TD. Lomotil or Imodium do not prevent TD, and in fact may increase the occurrence of it when used prophylactically. Pepto Bismol in large quantities has been shown to reduce the incidence of diarrhea by about 60% but the large quantity of aspirin in PeptoBismol may cause gastritis and tinnitus (ringing in the ears) in some people. Several antibiotics have been shown to reduce the incidence of TD by 50-80%. Again since there are seriously known risks of these antibiotics which outweigh the potential for reduction of TD, and because they select out resistant bacteria, they are not recommended for routine use.

Treatment

Travelers with diarrhea have two major complaints for which they request treatment, abdominal cramps and diarrhea. In addition, attention to the possibility of dehydration, especially in children, is important.

Cramps

Lomotil or Imodium are frequently used for the treatment of diarrhea and cramps. They do provide temporary relief by reducing the motility of the intestines. They may prolong the duration of the illness. They should not be used in the presence of high fever or blood in the stool. They should be stopped if symptoms persist for more than two days. Children under 2 should not use these preparations.

Antibiotics

Antibiotics can shorten a typical case of TD by 1-2 days. Nausea and vomiting without diarrhea is not treated with antibiotics. You may be provided with an appropriate antibiotic with instructions on its use if TD occurs. Generally, treatment is begun if diarrhea with 3 or more loose stools in an 8 hour period occurs, especially if associated with nausea, vomiting, abdominal cramps, fever or blood in the stool. Even if antibiotics are provided, medical attention should be sought if oral intake cannot keep pace with diarrheal stools, if shaking chills are noted, if there is no improvement (though not complete resolution) within 2-3 days, or if there is dehydration.

Oral Fluids

Since most episodes of TD resolve quickly on their own, simple replacement of fluids and salts can be accomplished by drinking potable fruit juices, soft drinks (caffeine-free), and salted crackers. Dairy products should be avoided.

You can prepare your own rehydration formula as follows:

Glass Number One: 8 ounces of fruit juice, ½ teaspoon of honey or corn syrup, and one pinch of salt.

Glass Number Two: 8 ounces of water and ¼ teaspoon of baking soda.

Drink alternately from each glass until thirst is quenched.

Infants with Diarrhea

Since infants and small children are at greatest danger of dehydration from TD they should be assessed by a medical professional familiar with signs of dehydration in infants.