Most travelers have heard about dengue but don’t really know what it is or how bad it can be.  The nickname, breakbone fever, gives people a clue.  Dengue is a viral infection that is transmitted by infected mosquito bites and is endemic throughout the tropics and subtropics.  That means it is common in Mexico, Central and South America, Caribbean, South Asia, Southeast Asia, Africa, and northeastern Australia.  Over 100 countries have a risk of dengue.  According to the WHO, about half of the world’s population is now at risk for dengue.  Over the last few years, I’ve met many U.S. families returning from their trips worried about dengue or knew someone who recently got infected with dengue.  It is a leading cause of fever in returning travelers.

Dengue is a mean and smart virus.  It is more common in urban areas, as opposed to rural areas.  And the mosquitoes that carry dengue like to bite during the daytime as opposed to the nighttime.  There are 4 types of dengue viruses.  This means that many people who live in endemic country get infected with dengue more than once.  About 75% of people who get infected with dengue virus have no symptoms at all.  The rest, however, can develop a range of different symptoms, including fever, nausea/vomiting, abdominal pain, severe headache and eye pain, joint and bone pain, rash, and easy bleeding.  The incubation period ranges from 3-14 days.

Here’s the scary part.  As many as 5% of people who get dengue develop SEVERE DISEASE, which is called dengue hemorrhagic fever and dengue shock syndrome.  Children are more vulnerable to severe disease and more likely to die.  And people who had dengue in the past are more at risk for severe disease if they get infected with a different type of dengue virus a second time.  Dengue can cause leaky blood vessels which can lead to extra fluid in the lungs and abdomen and SHOCK.  Severe dengue also causes bleeding from GI tract, which shows up as bloody emesis or bloody/dark black stools.  Dengue can also cause hepatitis, pancreatitis, myocarditis, and encephalitis.

There are currently no licensed vaccines, prophylactic medications, or antivirals in the U.S. that protects us from dengue.  However, I learned at a recent international travel medicine conference that there are a few promising dengue vaccines in the pipeline.  The best way to prevent dengue currently is to AVOID MOSQUITO BITES by doing the following:

1. Use insect repellant, such as 20-30% DEET.

2. Wear loose clothing that covers exposed skin.  Clothing can also be pre-treated with permethrin, which will give extra protection.

3. Stay in places with window and door screens, bed netting, or air-conditioning.

4. Cover or avoid having standing or open water containers around the place you are staying in.  These are breeding grounds for mosquitoes.

What do you do if you or your child has a fever and develops other symptoms worrisome for dengue within 2 weeks after you return from your trip?  Go see your doctor right away.  There are blood tests available than can tell whether you have dengue. Many cases of dengue can be mild and be treated supportively at home.  But knowing the signs of severe dengue and getting EARLY appropriate treatment can be life-saving.