Gastrointestinal symptoms in travellers.

Area of Science:

• Infectious Diseases
• Travel Medicine
• Microbiology

Background:

• Diarrhoea is the most common medical complaint among returning travellers.
• Key bacterial pathogens include entero-toxigenic Escherichia coli, Shigella, Salmonella, and Campylobacter.
• Viral, other bacterial, and parasitic causes are increasingly identified but often not tested.

Purpose of the Study:

• To review the common causes of traveller's diarrhoea.
• To highlight the diagnostic challenges and emerging pathogens.
• To discuss the implications of empiric antibiotic use.

Main Methods:

• Literature review of common pathogens causing diarrhoea in travellers.
• Analysis of diagnostic limitations and emerging infectious agents.
• Discussion of treatment strategies, including antibiotic use and resistance.

Main Results:

• Entero-toxigenic Escherichia coli, Shigella, Salmonella, and Campylobacter are the most frequent bacterial causes.
• Viruses, toxigenic Arcobacter, Bacteroides fragilis, and parasites like Cryptosporidium are increasingly recognized.
• Blood in stools warrants exclusion of invasive amoebic disease.

Conclusions:

• Traveller's diarrhoea has diverse causes, with bacterial pathogens being most common.
• Diagnostic testing often misses viral and parasitic etiologies.
• Empiric antibiotic treatment is complex due to pathogen diversity and antimicrobial resistance.