INTRODUCTION

International travel, which is increasing at a rapid rate, is a most rewarding way to experience different cultures, wonders of nature and the beauties of human inventiveness, and, of course, the culinary arts. Traveling to the developing world, however, where water and sanitation are less than adequate, becomes a significant obstacle when ingesting the wonderful cuisine of those countries. The traveler then often faces the challenge of dealing with the most common of travelers' diseases, acute diarrhea, or as it is usually referred to, travelers' diarrhea. Over the years, this illness has been given colorful names to describe its symptomatology, based on its location: Montezuma's Revenge, Delhi Belly, and Aztec two-step, to name a few. All of these very appropriate names refer to the same illness: travelers' diarrhea. This illness was first officially recognized and named in the 1950s by Kean (Kean, Waters, 1958) when it commonly occurred among students and vacationers traveling to Mexico and other developing countries. Initial studies for etiologic agents were all negative (using the available techniques at the time), and it was thought perhaps to be due to changes in the mineral concentrations of the drinking water, changes in gut flora, or even jet lag.

Our understanding of the disease changed remarkably in the mid-1970s, when it became clear that most cases of travelers' diarrhea were, indeed, due to infectious agents, the most common being enterotoxigenic E. coli (ETEC).