Leave home with a plan: What to pack in your medical kit and when to seek care for symptoms abroad

Before an international trip, vaccines are only part of the preparation, according to a travel medicine physician. The CDC estimates that 43% to 79% of travelers to low- and middle-income countries become ill during or after their journey, and many common problems—diarrhea, respiratory infections, motion sickness, and flares of existing conditions—can’t be prevented by a shot. The guidance emphasizes using a pretravel visit to plan for the specific risks of an itinerary: which illnesses are likely, what symptoms a traveler can manage, which medicines to carry, and which warning signs require medical care. Risks vary by destination and activities, such as freshwater swimming, caves, animal contact, hiking, and time in remote areas. The article cites shifting infectious threats since early 2025, including new yellow fever outbreaks in South America, a hantavirus cluster on a cruise ship, dengue growth worldwide, chikungunya flare-ups, and a fast-developing HIV outbreak in Fiji.