Travel to Developing Countries - Traveler's Diarrhea

Highlights	Infectious Diseases	Resources
General Health Precautions	Travel Precautions	References
Traveler's Diarrhea	Traveling with Health Problems

Traveler's Diarrhea

Traveler's diarrhea (TD) is the most common health problem that a traveler encounters. It is almost always caused from ingesting certain organisms in contaminated food. (Diarrhea can also be caused--particularly in children--by anxiety, stress, allergies, fatigue and diet changes.)

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Symptoms and Course

Diarrhea frequently occurs within the first week of travel but may develop at any point, including after returning home. TD causes four or five loose or watery stools per day. Vomiting may also occur. It usually lasts 3 or 4 days, but about 14% of cases last longer. In rare cases, TD lasts more than 3 months. When TD does last a long time, it can cause postinfectious irritable bowel syndrome. TD is rarely life threatening, although it can be severely debilitating, especially in children. Any of the following symptoms require immediate medical attention, especially in children: Weakness, reduced urine output, lightheadedness, and mental changes. Life-threatening symptoms are reduced levels of consciousness, seizures, and coma.

Risk by Country

Traveler's diarrhea typically affects between 20 - 50% of all international tourists, with the highest risk occurring in travelers to developing countries:

High-risk destinations include most of the developing countries of Latin America, Africa, the Middle East, and Asia. The risk varies widely, however, in these countries. For example, in one study, 73% of children who traveled to Africa and 61% who went to India experience diarrhea. Only 40% who were in Southeast Asia, Latin American and other African countries had diarrhea.
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.

Infectious Causes

A number of infectious organisms, including bacteria, parasites, and viruses, can cause diarrhea in the traveler. These organisms are most often transmitted through contaminated food and water. Bacteria and viruses cause diarrhea within a few hours and up to 3 days, while diarrhea from parasites can occur 7 to 14 days after exposures. In about 10 - 50% of cases, the cause of TD is unknown.

The most common bacterial cause of traveler's diarrhea is Escherichia coli ( E. coli). It is an enterotoxigenic organism, which means it is toxic to the intestines. E. coli accounts for between 20 - 50% of cases. It is found in soil, water, and milk and occurs in major regions in the worlds, with the highest rates in Latin American and the lowest in Asia. Diarrhea caused by E.coli is generally explosive, non-bloody, and accompanied by nausea, vomiting, cramps, and fever.
Noroviruses, also called Norwalk-like viruses, are an increasingly common cause of traveler?s diarrhea in countries such as Mexico and Guatemala. Recent studies of travel in these destinations rank noroviruses second to E. coli for causing diarrhea.
Shigella is the bacterial cause of dysentery, affecting 15% of travelers. It is common in countries experiencing natural disasters, socioeconomic upheaval, or during other times when sanitary food and water are difficult to procure. Shigella causes bloody and mucus-laden diarrhea along with fever, cramps, and exhaustion.
Campylobacter is a very common bacterial cause of diarrhea in certain regions, notably Thailand and Morocco, during the winter.
Giardia is a parasite found in contaminated water in every country in the world. It can cause chronic diarrhea lasting for several weeks, causing vague pain, weight loss, excessive burping, bloating, and fatigue.
Entamoeba histolytica is a parasite that is prevalent Mexico, India, Africa, and Central and South America. It produces small stools that contain blood and mucus. If the condition becomes chronic, it can resemble inflammatory bowel disease (IBD). It is important to distinguish the two, since corticosteroids used to treat IBD can have dangerous effects in people carrying the parasite.
Additional common culprits are the bacteria Salmonella, parasites (Cryptosporidiosis, Cyclospora. mocrosporidia), and rotavirus (usually in Latin America).