Traveler's diarrhea is a cosmopolitan illness, afflicting tourists in many developing countries. The disease has been most intensively studied in Mexico, principally because there is a huge volume of US visitors to Mexico, approximately 3 million per year, and the local authorities have been generous in allowing foreign scientists to investigate the problem in their country. Although the disease is known as "turista" and "Montezuma's revenge," it should be realized that traveler's diarrhea is at least as common, if not more so in certain Mediterranean countries and in parts of Africa, the Middle East, and Asia. Travelers to the Soviet Union are apt to acquire diarrheal disease, often caused by Giardia lamblia, ruefully known among its victims as the "Trotsky's."
The major causative agents in traveler's diarrhea in Mexico and other countries are enterotoxin-producing strains of a common intestinal bacterium, Escherichia coli.1,2 Based on statistics from Mexico, it seems