Which pathogens are the most common causes of traveler's diarrhea and what are their typical transmission routes?

Which pathogens are the most common causes of traveler's diarrhea and what are their typical transmission routes?

• A. Enterotoxigenic E. coli (ETEC) is most common; others include EAEC, Shigella, and Campylobacter; transmitted via contaminated food and water
• B. Enteropathogenic E. coli is most common; transmitted via airborne particles
• C. Salmonella is the most common; transmitted via contaminated food only
• D. Norovirus is the most common bacterial cause; transmitted via water

Answer: (A)

Traveler’s diarrhea is most often driven by ingestion of enteric bacteria acquired from contaminated food or water, especially in areas with poor sanitation. The leading offender is enterotoxigenic E. coli (ETEC), which produces toxins that trigger watery, nonbloody diarrhea by increasing fluid secretion in the small intestine. Other common bacterial culprits—enter aggregative E. coli (EAEC), Shigella, and Campylobacter—also spread mainly through the fecal-oral route via contaminated food or water and sometimes through contact with contaminated surfaces or people. The unifying idea is that these infections come from ingesting material contaminated with fecal matter, not from inhalation or other routes. Norovirus, while a frequent cause of gastroenteritis, is viral, not bacterial, so it isn’t categorized with bacterial traveler's diarrhea pathogens. Salmonella is a known cause of foodborne illness as well, but it isn’t the single most common cause of traveler's diarrhea.

Traveler’s diarrhea is most often driven by ingestion of enteric bacteria acquired from contaminated food or water, especially in areas with poor sanitation. The leading offender is enterotoxigenic E. coli (ETEC), which produces toxins that trigger watery, nonbloody diarrhea by increasing fluid secretion in the small intestine. Other common bacterial culprits—enter aggregative E. coli (EAEC), Shigella, and Campylobacter—also spread mainly through the fecal-oral route via contaminated food or water and sometimes through contact with contaminated surfaces or people. The unifying idea is that these infections come from ingesting material contaminated with fecal matter, not from inhalation or other routes. Norovirus, while a frequent cause of gastroenteritis, is viral, not bacterial, so it isn’t categorized with bacterial traveler's diarrhea pathogens. Salmonella is a known cause of foodborne illness as well, but it isn’t the single most common cause of traveler's diarrhea.