The last thing you want when traveling is a major illness to derail the trip. Baylor College of Medicine infectious disease expert Dr. Stacey Rose explains the precautions you can take to prevent illness while away from home and what medications you can take with you in case you do get sick.
Before any trip, Rose recommends checking with your healthcare provider about your specific health needs. Be sure to pack all medications you take regularly, including extras in case you have an unanticipated travel delay. Some travel destinations may require you to get additional vaccines. Rose recommends consulting the Centers for Disease Control and Prevention website for guidance on which vaccines you may need. Don't forget about basic protective measures like sunscreen and insect repellent, as mosquitoes can carry infectious diseases.
Travelers' diarrhea
The CDC estimates that 30 to 70% of travelers will experience travelers' diarrhea during a two-week travel period. Most cases are caused by ingesting bacteria, but in some cases, the source may be a virus, such as norovirus or rotavirus, or a parasite, such as Giardia or Cryptosporidium. Symptoms brought on by bacteria or viruses may take days to present.
"It may be tricky to determine the cause because you might be thinking of what you ate or were exposed to yesterday, and actually it may be something you were exposed to several days prior," said Rose, associate professor of medicine - infectious diseases at Baylor. Bacterial-caused diarrhea typically lasts longer, and viral-caused diarrhea is more likely to be associated with vomiting as well.
Diarrhea also may be caused by ingesting toxins from food contaminated during preparation or food that has spoiled. Symptoms of toxin-related illness include vomiting and diarrhea appearing within hours and resolving within a day. Remember that not all gastrointestinal symptoms are caused by infection or toxins. An upset stomach also may result from a change in diet on vacation.
"When you travel, you may be eating foods that are outside of your normal routine, and your body may have trouble adjusting," Rose said.
As with any infectious disease, a key prevention method for travelers' diarrhea is practicing good hand hygiene. "Wash your hands before you eat every time," Rose said. "Wash your hands when you get back to your hotel after being out for the day. Sometimes the contamination doesn't come from your food, but from whatever you touched right before you put the food in your mouth."
Travelers also should be cautious about what food they eat. Raw fruits and vegetables have a higher risk of contamination if you don't know how well it has been washed. Fruits or vegetables that you peel yourself have less risk. Drinking only bottled water is advised if you don't know the source of tap water. Some people may avoid eating food from street vendors to lower their risk of eating contaminated food.
"When you're traveling you may want to engage in local cultural practices like eating local foods. That's the fun of traveling," Rose said. "Just know that it is a balance and be sure to use caution when you're choosing what to eat."
Two over-the-counter medications can help prevent and treat travelers' diarrhea. Pepto Bismol, or bismuth subsalicylate, has been shown to reduce incidence by 50%, according to the CDC. Travelers can take it as a preventative measure, but users should be aware that this medication can cause black stool or constipation. If you get travelers' diarrhea, Imodium, or loperamide, can help reduce the frequency and restore regular digestion. People who have bloody diarrhea or a fever accompanying diarrhea should not take Imodium and should see a doctor.
Rose does not generally recommend preventative antibiotics for travelers for two reasons: first, overuse of antibiotics can alter the normal bowel flora and increase risk for Clostridium difficile infection. Second, regular antibiotic use also increases risk for breeding resistant bacteria.
"If you do come down with traveler's diarrhea, consult with your healthcare provider for guidance on both testing and how to treat your symptoms; antibiotics are not always necessary for treatment," Rose said.
It's important for people with travelers' diarrhea to rehydrate as the body loses water. If you cannot stay hydrated or the diarrhea does not resolve on its own after a few days, see a doctor. Fever or bloody diarrhea are also signs of a more serious illness and should prompt you to seek medical attention.
Respiratory illnesses
Viral respiratory illnesses like the common cold, influenza, COVID-19, RSV and measles may be circulating where you are traveling. Rose reminds travelers to wash their hands regularly and make sure they are up to date on vaccinations before travel. Immunocompromised people may need to take extra precautions like wearing an N95 mask while traveling. Some immunocompromised people may be prescribed medications for these respiratory illnesses to be used if they develop symptoms or test positive on a trip.
Try to avoid crowded and enclosed spaces where you may be with people who are ill. During the COVID-19 pandemic, studies found airplanes had relatively low viral transmission rates due to frequent air recirculation and filtration with high-efficiency particulate air filters. However, it's important to be mindful in other spaces with less air circulation and filtration. If you know you have a respiratory illness, stay home until you get well. "Public health is a two-way street," Rose said. "Traveling with a known infectious disease is really not recommended."
Tropical diseases
People traveling to locations with tropical climates also should be aware of risk for mosquito-borne diseases like malaria and dengue. "Malaria is preventable with a combination of preventing exposure to mosquitos and prophylactic medication," Rose said. "Not all malaria prevention is the same. Talk to your doctor about the most effective agents for the area where you're traveling." Be sure to follow instructions for prophylaxis because some medications may require you to take doses after you return home. Dengue is another mosquito-borne illness that can present with fever and a rash and at times more serious symptoms. "With climate change, we are seeing dengue in more parts of the world."
In general, it's good practice to check the health advisories for the areas where you will be traveling. While not all infections are preventable, advanced preparation and reasonable precautions can help make the trip more safe and enjoyable.