Travelers' diarrhea is the most common health impairment in persons visiting developing countries, affecting 20% to ≥50% of tourists. Although it is usually benign, travelers' diarrhea represents a considerable socioeconomic burden for both the traveler and the host country. The most common enteropathogens are enterotoxigenic and enteroaggregative Escherichia coli. Travelers' compliance with dietary precautionary measures is poor. Despite the excellent protection rates provided by antibiotics, routine administration of prophylaxis is currently not recommended because of potential adverse reactions. Of the various antibiotics that have been tested, quinolones are considered to be the first choice worldwide; however, quinolone-resistant pathogens are increasingly being isolated. Because it is frequently administered and provides only moderate protection, bismuth subsalicylate is not considered a recommendable option for prophylaxis in Europe, where it is rarely available anyhow. To date, no probiotic has been able to demonstrate clinically relevant protection worldwide. In conclusion, there is no satisfactory prophylactic option, and worldwide monitoring of antimicrobial susceptibility patterns and the search for novel antimicrobial agents, such as nonabsorbed antibiotics, and nonantibiotic medications should continue.
