What is the most common illness travelers experience in developing countries what causes it?

The most common illness travelers experience in developing countries is traveler’s diarrhea, often caused by consuming contaminated food or water. Bacterial pathogens such as Escherichia coli, viruses like norovirus, and parasites are typical culprits. Poor sanitation, inadequate food handling practices, and a lack of clean drinking water contribute significantly to the risk of infection. Preventive measures include practicing good hygiene and being cautious about what and where to eat and drink.