What is dengue fever? You'll survive if you get it, but your trip probably won't.
Now endemic throughout Asia, Africa, and Latin America, dengue fever is a mosquito-borne illness that is a leading cause of death and hospitalization of children in tropical and sub-tropical countries. Dengue has risen dramatically in the last decade, even making appearances in the U.S. and Europe. The World Health Organization estimates that around half of the world's population is now at risk and that there are between 50 - 100 million dengue infections each year.
As a traveler in Asia, particularly Southeast Asia, you are at risk for contracting dengue fever.
What Is Dengue Fever?
First understand the basics:
- Dengue fever is typically spread through daytime mosquito bites.
- There is currently no vaccination to prevent dengue fever, but one is in trials.
- Dengue is typically not fatal, however, you could be hospitalized or sick for weeks.
- Dengue fever is much more risky the second time you contract it.
- Although you'll hear several variants for pronouncing dengue fever, the correct way sounds like "den-gay."
Dengue fever, also known as breakbone fever, is a mosquito-borne illness caused by bites from the Aedes aegypti mosquito. When an infected mosquito bites someone whom is already suffering from dengue fever, she carries the virus on to her next victim.
Dengue fever is not transmitted from human to human, however, one mosquito can infect many people within her life cycle (only the female mosquitoes bite).
You are more at risk for contracting dengue when other people infected with dengue are present. Blood transfusions have been known to spread dengue in rare instances.
Although typically survivable, dengue fever can put you out of commission for a month or longer, certainly putting a damper on your visit to Asia!
How to Limit Your Risk
Only female mosquitoes from the genus Aedes can transmit dengue fever. The main culprit is the Aedes aegypti mosquito or "tiger mosquito" which is larger than other mosquitoes and has white spots/markings. These mosquitoes mostly breed in man-made containers (e.g., empty flower pots and buckets) in urban environments. The aedes aegypti mosquito prefers to feed off of humans and thrives more around human settlements rather than in the jungles.
Unlike the mosquitoes that transmit malaria, dengue-infected mosquitoes typically bite during the day. Protecting yourself from bites in the early morning and late evening just before dusk is essential to avoid potential exposure to dengue fever.
- See proven methods and tricks for how to avoid mosquito bites.
- Read 10 interesting facts about mosquitoes.
Symptoms of Dengue Fever
The first symptoms of dengue fever start to appear from 4 - 10 days after a bite from an infected mosquito.
As with many viruses, early symptoms of dengue fever begin with flu-like aches and pains -- particularly in the joints -- with a severe headache and high fever (104 degrees Fahrenheit / 40 degrees Celsius).
The aches and pains are usually followed by swollen glands, nausea, and vomiting. Even when dengue doesn't turn severe, it can produce fatigue for weeks after exposure. Sometimes patients report severe eye pain.
Because dengue fever symptoms are flu-like and fairly common, a combination of two or more (the rash is often an indicator) are needed to make a potential diagnoses:
- High fever (104 degrees Fahrenheit / 40 degrees Celsius)
- Severe joint pain (hence the name breakbone fever)
- Muscle stiffness / swollen glands
- Severe eye pain
- Rash, red spots, blotches on skin. The discolored skin blanches when pressed during the acute stage. White spots surrounded by red skin are common.
- Bleeding from nose, gums, or other membranes
Dengue Fever Complications
Signs that dengue fever has produced complications and may have become potentially life threatening include: severe abdominal pain, vomiting blood, bleeding from mucous membranes, and rapid/shallow breathing.
People with asthma and diabetes are at a higher risk for developing dangerous complications from dengue.
Around half a million people require hospitalization from severe dengue each year and about 2.5% of those cases prove fatal. Young children in developing countries are most often the victims of dengue fever.
If you are unlucky enough to get dengue fever a second time, you have a much higher risk for complications and dangerous health implications.
Dengue Fever Treatment
Unfortunately, there is no official or sure-fire way to treat dengue fever; you simply have to ride it out over time. Treatment includes basics such as giving over-the-counter medications to control fever, fluids to stop dehydration, and close monitoring to ensure the virus does not cause hemorrhaging.
Important: People who think they have dengue should never take ibuprofen, naproxin, or aspirin-containing drugs; these can cause additional bleeding. The CDC recommends taking only acetaminophen (Tylenol in the U.S.) for pain and fever control.
- The risk of dengue fever is another reason to get travel insurance before going to Asia.
Dengue Fever in Thailand and Southeast Asia
Dengue hemorrhagic fever first made an appearance in Thailand and the Philippines during the 1950s. Only nine countries were thought to have dengue epidemics before 1970. Today, dengue is considered endemic in more than 100 countries with Southeast Asia being the worst affected region.
Unlike Japanese encephalitis and malaria, you have more risk for for contracting dengue fever in urban areas such as Pai and Chiang Mai, although dengue is also a real problem in the Thai islands. Places such as Railay, Thailand, have plenty of porous rocks and wet areas where mosquitoes can breed uninhibited.
Dengue Fever in the United States
Much of the Southeast United States is now at risk for dengue fever; 24 cases were reported in Florida during a 2010 outbreak. Dengue has also been prevalent in Oklahoma and along the border with Mexico in southern parts of Texas.
Climate change has been blamed for the jump in dengue cases as well as the mosquitoes' ability to adapt. Some varieties of the Aedes aegypti mosquito have adapted to the cooler climates found in Europe and the US.
- See what the World Health Organization says about dengue fever.
- See some dengue fever symptoms listed by the CDC.
The Dengue Fever Vaccination
Researchers at Chiang Mai University in Thailand -- one of the worst-affected countries -- made a breakthrough in 2011 on what could become the world's first dengue fever vaccination. Mexico approved the vaccination in December 2015.
Although developing a live attenuated vaccine against dengue in the laboratory was a giant step forward, getting the vaccination tested, approved, and to market is estimated to take years.
Despite the fact that there is no widespread vaccination -- yet -- against dengue fever, you should take advantage of the vaccinations against other threats that are available before leaving home. Learn more about travel vaccinations for Asia.