Travel gives you stories to tell, photos to post, food to obsess over and, if you’re lucky, a tan that lasts longer than your vacation.

But there is another souvenir you don’t want – An infection.

Yes, it is fun and exciting to travel. You want to chase waterfalls, walk through crowded markets, sleep in beach resorts, eat street food and explore places you’ve never seen before.

You should.

But you also need to remember that travel can expose you to diseases that may be uncommon where you live.

Some arrive through a mosquito bite. Others spread through contaminated food and water. Some travel through the air from an infected person. A few can become life-threatening.

A new Medscape review published in August 2026 highlights six high-consequence infections associated with travel: malaria, dengue, tuberculosis, measles, yellow fever and Ebola disease.

That doesn’t mean you should cancel your holiday.

It means you should pack something besides your passport.

Here are the diseases travelers should know about, and the practical steps that can lower your risk.

(This article is for general travel-health information and does not replace advice from a qualified healthcare professional.)

1. Malaria: The mosquito bite you really don’t want

Let’s start with the tiny flying menace.

Malaria is caused by Plasmodium parasites and is mainly transmitted through bites from infected female Anopheles mosquitoes. It can cause fever, chills, headache, vomiting, muscle aches and anemia.

And this isn’t a case of simply feeling miserable for a few days.

The Medscape review reports an estimated 282 million malaria cases and 610,000 deaths globally in 2024. The African region accounted for the overwhelming majority of cases and deaths.

One particularly dangerous form, P. falciparum malaria, can progress rapidly after symptoms begin.

Here’s the traveler’s problem.

You might already be home when malaria starts showing itself. The incubation period can range from about seven to 30 days, and symptoms can sometimes appear months after exposure.

How travelers can reduce the risk

If you’re heading to a malaria-risk destination, talk to a doctor or travel-health professional before leaving.

Depending on your destination, you may be advised to take preventive antimalarial medication.

You should also:

• Use insect repellent.
• Wear long sleeves and long trousers when practical.
• Sleep under an insecticide-treated bed net in areas where this is recommended.
• Choose screened or air-conditioned accommodation.
• Follow destination-specific malaria advice.

CDC guidance also stresses that the choice of malaria medication depends on the destination and local drug-resistance patterns.

And here’s a rule worth remembering.

If you develop a fever after visiting a malaria-risk area, tell the doctor where you’ve been.

Don’t simply say, “I think I caught the flu.”

Your passport stamps may be medically useful.

2. Dengue: Four chances to meet the same problem

Dengue is another mosquito-borne disease, but this time the culprits are Aedes mosquitoes.

The interesting part? There are four dengue virus serotypes.

That means getting dengue once doesn’t automatically mean you’re done with it. A person can be infected multiple times, and subsequent infections can carry a greater risk of severe disease.

Dengue is also widespread, noting the urban areas of the Philippines. The Medscape review notes that roughly 4 billion people live in areas at risk of dengue, with around 400 million infections estimated annually.

Most infections don’t become severe – but some do.

Symptoms commonly include high fever, headache, nausea, vomiting, rash and muscle or joint pain. Severe dengue can involve bleeding, intense abdominal pain, persistent vomiting, breathing problems and shock.

How do you avoid it?

Here’s the frustrating part.

Your best defense while traveling is still the humble mosquito strategy.

Aedes mosquitoes can live around populated areas.

That means your tropical vacation villa may be Instagram-worthy and still have mosquitoes.

3. Tuberculosis: You can’t always see the exposure coming

TB is different.

You won’t necessarily see the mosquito.

You won’t necessarily taste contaminated food.

You could simply be sharing air with someone who has active tuberculosis.

Tuberculosis is caused by Mycobacterium tuberculosis and primarily spreads through the air when someone with active disease coughs, sneezes or spits.

The disease mainly affects the lungs, although it can affect other parts of the body.

Symptoms of active pulmonary TB can include:

• Persistent cough
• Coughing up sputum or blood
• Chest pain
• Weakness
• Weight loss
• Fever or chills
• Night sweats

Here’s something travelers should understand.

Latent TB infection can have no symptoms and isn’t contagious. Active TB is different.

The Medscape review notes that Southeast Asia accounted for the largest share of new TB cases in 2023, followed by Africa and the Western Pacific.

How can travelers reduce their risk?

Avoid prolonged exposure to people known to have active TB, particularly in crowded and poorly ventilated indoor environments.

For travelers who expect significant exposure, medical advice before and after travel may include TB testing.

And if you return from a trip with a persistent cough, unexplained weight loss, fever or night sweats, don’t leave your travel history out of the conversation with your doctor.

Your vacation destination can be a useful clue.

4. Measles: The disease many travelers think they’ve forgotten about

Remember measles?

You should.

Measles is an extremely contagious airborne viral disease. It can cause high fever, cough, runny nose, red eyes and a characteristic rash.

The problem isn’t simply feeling sick for several days.

Measles can lead to complications such as pneumonia, severe diarrhea and dehydration, blindness and encephalitis.

And international travel matters because travelers can acquire measles in places where transmission is occurring and bring the virus home.

The good news?

There is an effective vaccine.

Before you fly

Check your vaccination status.

CDC travel guidance recommends reviewing routine vaccines before international travel, including measles, mumps and rubella vaccination.

If you’re unsure about your vaccination history, talk to your healthcare provider before your trip.

This is one disease where “I’ll deal with it if I catch it” is a poor travel strategy.

Vaccination is far easier than spending your vacation coughing behind a hotel-room door.

5. Yellow fever: A mosquito-borne disease with a dangerous second act

Yellow fever gets its name from jaundice, which can occur in people who develop severe disease.

It is caused by a virus transmitted by infected mosquitoes and occurs mainly in parts of sub-Saharan Africa and tropical South America.

Early symptoms can look deceptively ordinary.

Fever.

Chills.

Headache.

Muscle aches.

Nausea.

Vomiting.

Fatigue.

Then comes the part you don’t want.

According to the Medscape review, around 12% of infected people can progress to a severe phase involving high fever, jaundice, bleeding and potentially shock and multiple-organ failure. About half of those who develop this severe form die within seven to 10 days.

The good news

There is a highly effective vaccine.

CDC guidance recommends vaccination for travelers heading to certain areas where yellow fever occurs, with vaccination generally given at least 10 days before travel. Some countries also require proof of vaccination for entry.

So before booking that dream trip, check the health requirements for your destination.

A vaccine certificate is a much nicer thing to carry than a medical emergency.

6. Ebola: The one you shouldn’t treat like ordinary traveler’s diarrhea

Ebola disease is rare compared with many other travel-associated infections, but it belongs on this list because of its potential severity and the importance of outbreak-specific precautions.

The Medscape review discusses the 2026 Ebola situation and notes that different orthoebolaviruses can cause human disease. The clinical picture can begin with nonspecific symptoms such as fever, fatigue, headache, muscle aches and sore throat. Later illness can involve vomiting, diarrhea, abdominal pain and bleeding.

The incubation period can range from two to 21 days.

Treatment has improved, with supportive care and targeted therapies available for certain forms of Ebola disease. Vaccination is also used for specific Ebola virus outbreaks, although vaccines do not cover every orthoebolavirus.

What should travelers do?

Check official travel health advisories before visiting an area experiencing an outbreak.

Avoid contact with people who are sick when an outbreak is occurring.

Follow local public-health instructions.

Do not handle bodies of people who have died from suspected or confirmed Ebola disease.

And if you become seriously ill after visiting an outbreak area, tell healthcare workers about your travel history immediately.

This is not the time to be shy about showing your itinerary.

The Other Travel Threat Sitting on Your Plate

The six diseases above get the headline, but travelers should also think about something much more ordinary.

Food.

And water.

A questionable buffet can turn your five-day vacation into a five-day relationship with the hotel bathroom.

Contaminated food and water can carry bacteria, viruses, parasites and toxins. Raw or undercooked meat, seafood, eggs and produce can pose risks, while untreated water can cause gastrointestinal and other infections.

CDC travel guidance recommends choosing food that is fully cooked and served hot, being careful with raw foods, and drinking water that you know is safe.

When you’re unsure about the water, don’t casually assume that the ice is safe.

Ice is water wearing a disguise.

Your Travel Health Checklist

Before you leave, spend a few minutes thinking beyond flights and hotels.

Before your trip

Check the destination.

Disease risks vary by country, region, season and type of travel.

Review your vaccines.

Routine vaccines matter, and some destinations require or recommend additional vaccines.

Talk to a healthcare professional early.

CDC recommends considering a travel-health consultation around four to six weeks before international travel, particularly when vaccines or preventive medication may be needed.

Pack mosquito protection.

Bring repellent and appropriate clothing. Consider mosquito nets or treated clothing when relevant.

Think about food and water.

Cooked food, safe drinking water and good hand hygiene can prevent a miserable vacation.

During your trip

After you return

This part gets forgotten.

A fever that appears after your trip may have nothing to do with travel.

Or it could.

Some travel-associated infections can appear days or even weeks after exposure. Malaria symptoms, for example, can be delayed.

If you become sick after traveling, tell your healthcare provider where you went, when you went and what you did there.

Travel Smart, Not Scared

None of this means you should stop traveling.

Quite the opposite.

Travel is one of life’s great pleasures. Eat the local food. Walk the old streets. Swim in the sea. Take the train. Wake up before sunrise for that view.

Just give your health a seat on the itinerary.

The biggest lesson from the latest Medscape review isn’t that travelers should be frightened of every mosquito, buffet or crowded street.

It’s that travel health starts before you board the plane.

Know the diseases associated with your destination.

Know how they spread.

Know which vaccines or preventive medicines may apply.

Pack the right protection.

And know when a post-travel fever deserves medical attention.

Because the best souvenir from your vacation should be a ridiculous number of photos, a few great stories and the desire to plan the next trip.

Not a parasite.

Not a virus.

And definitely not a hospital bill.