Traveler's diarrhea refers to diarrheal disease caused by toxins produced by a number of different strains of Escherichia coli and other bacteria.
Traveler's diarrhea begins when a person swallows E. coli or other bacteria. This happens through close contact with feces from an infected person or animal. It can also come from ingesting food or water that has been contaminated with the bacteria. There have been numerous outbreaks of E. coli illness linked to unpasteurized contaminated cow's milk or undercooked hamburger meat. The disease can also pass from person to person, especially between children still in diapers.
Traveler's diarrhea is caused by certain bacteria, such as E. coli. Travelers generally come into contact with these bacteria by ingesting contaminated food or water. Travelers to the following countries are at particular risk:
Any raw food can be a source of these bacteria. However, the following foods and beverages pose the highest risk:
Traveler's diarrhea is more common in younger people but can occur at any age. People with immunodeficiency disorders, such as HIV, are at higher risk.
The type of bacteria causing the infection determines the symptoms of the disease. Symptoms of traveler's diarrhea may include:
Diagnosis of traveler's diarrhea begins with a medical history and physical exam. The bacteria can be cultured from an infected person's stool. A special test can be done to detect E.coli O157:H7.
The best way to prevent traveler's diarrhea is to pay very close attention to the foods and beverages ingested. Here are some guidelines to follow.
Traveler's diarrhea can be prevented by taking medicines while in areas where the risk is high. Such medicines include:
Certain strains of E. coli, like the O157:H7 strain, cause hemorrhagic colitis. This illness causes inflammation of the large intestine and bloody diarrhea in both adults and children. This strain can also cause a complication called hemolytic uremia syndrome (HUS). This disorder causes red blood cell destruction, a low platelet count, and loss of kidney function. HUS can range from a mild illness to a severe condition resulting in permanent kidney damage. HUS usually follows a case of bloody diarrhea.
A person who has been infected with E.coli and other bacteria can potentially pass them to others. There is a particular danger if the infected person does not wash his or her hands thoroughly.
Oral fluids, including rehydration solutions, are important to prevent dehydration. In most cases, antibiotics are not needed. However, they may be useful in the treatment of very young infants or with certain types of E.coli. They may also be recommended for immunocompromised individuals, or those with weak immune systems.
Medicines to control diarrhea should not be administered to children with diarrhea, especially if the diarrhea is bloody. They could cause the diarrhea to last longer or to make it worse.
Traveler's diarrhea may be treated with the same drugs used to prevent it. In addition to the medicines listed earlier, loperamide may reduce the diarrhea.
The medicines used to treat traveler's diarrhea can cause allergic reactions. They may also make the person more sensitive to sunlight and increase the risk of sunburn. Drugs for diarrhea may also cause nausea.
Traveler's diarrhea usually goes away, with or without treatment, within 1 week. Hemorrhagic colitis is more serious and lasts longer, especially if HUS develops. Kidney failure may develop in as many as 50% of children. Severe kidney failure can lead to high blood pressure. HUS may recur with repeated infections but not usually after the first year. Most children with HUS have a nearly complete recovery. Up to 1/3, though, have lasting evidence of some kidney damage.
Persons with severe diarrhea or HUS need to be monitored closely to be sure their blood chemicals remain in balance. Elderly people who are receiving fluid replacement are watched closely for congestive heart failure. If kidney failure develops, fluid intake and output must be measured carefully to keep them in balance. Tests are sometimes used to be sure the E. coli toxin is no longer in the stool. Any new or worsening symptoms should be reported to the healthcare provider.
Author:Danielle Zerr, MD
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:09/30/01
Reviewer:Eileen McLaughlin, RN, BSN
Date Reviewed:08/30/01
Scientific American Medicine 10(VII):6-7, 2000