What is the most common cause of traveler's diarrhea?

Traveler's diarrhea is predominantly attributed to enterotoxigenic E. coli (ETEC), which is known to be highly prevalent among travelers consuming contaminated food and water in areas with poor sanitation. ETEC produces toxins that stimulate the intestines, leading to diarrhea, abdominal cramps, and sometimes nausea.

This bacterium is particularly notorious for causing illnesses in individuals visiting developing countries, where the risk of exposure to contaminated sources is significantly heightened. The ability of ETEC to produce heat-labile and heat-stable enterotoxins is a critical factor in its pathogenicity, leading to increased fluid secretion and causing the characteristic symptoms of traveler's diarrhea.

In contrast, while Shigella spp., Salmonella spp., and Campylobacter jejuni are also known to cause gastrointestinal infections, they are less frequently encountered in the context of traveler's diarrhea compared to ETEC. These pathogens typically result from different sources or modes of transmission. Therefore, the prevalence of ETEC makes it the most common cause of traveler's diarrhea.