Dengue Fever

The Aëdes mosquito picks up the dengue virus by biting a person who has it and then transfers the virus to the next person it bites.

Who Gets Dengue?

Dengue (DENG-gee, English; DAIN-gay, Spanish) affects millions of people each year in tropical and subtropical regions. It is especially common in southeastern Asia and is also found in Latin America and the Caribbean, including Puerto Rico. Sometimes dengue may also appear in temperate climates in summer. Only very rarely does it occur in the United States.

Although dengue sometimes breaks out in epidemics, it is not spread directly from person to person. Instead, it is spread by the bite of a tropical mosquito whose scientific name is Aëdes (a-EE-dez). The Aedes mosquito picks up the dengue arbovirus^* by biting a person who has dengue (people are the main source of the virus), and when the mosquito bites someone else, it infects the next person with the virus. The virus then multiplies in the new person's body, causing the disease symptoms.

Does Dengue Cause Broken Bones?

Dengue does not cause broken bones, but the severe pain that often accompanies it may be the reason why it is called "breakbone fever." Its symptoms begin very abruptly, several days after infection. In addition to bone, joint, and muscle pain, there may be high fever, a rash, headache, and pain behind the eyes. The symptoms usually subside after five to seven days, return a few days later, and then go away entirely.

After recovery from dengue, people may feel weak and psychologically^* depressed. These feelings may last for days or weeks, but dengue is rarely fatal. In a small percentage of cases, people get a severe form of the disease, called dengue hemorrhagic^* fever, which causes internal bleeding. This sometimes turns into an even more dangerous condition called dengue shock syndrome. According to the World Health Organization, these severe forms of dengue kill approximately 24,000 children in tropical countries each year, although most people who get these diseases recover.

What Is the "Dengue Triad"?

In diagnosing dengue fever, doctors look for three main signs or symptoms called the "dengue triad": (1) fever, (2) rash, and (3) pain, including headache. Blood tests may be done to help in the diagnosis. In areas where dengue is uncommon, the physician may also ask if the patient has recently been in a tropical country.

How Do Doctors Treat Dengue?

There is no specific treatment for a typical case of dengue fever, which runs its course and clears up by itself. Doctors usually recommend bed rest and drinking plenty of fluids. They may also prescribe pain-relieving medications to ease symptoms.

How Is Dengue Prevented?

Prevention requires control or eradication of Aides mosquitoes, and protection against their bites. The Aedes mosquito also spreads other diseases, such as yellow fever, making public health improvements especially important. There is no available drug or vaccine that is effective against the dengue virus.

The U.S. and the World

• Dengue fever exists in more than 100 countries, but occurs mostly in tropical and subtropical areas of Asia, Africa, and Central and South America. Overall, as many as 2.5 billion people worldwide are at risk.
• Some cases have occurred in the United States, but most often in people who have traveled recently to other countries. The Aedes mosquito also can be found along the border between Texas and Mexico.
• The World Health Organization reports that approximately 500,000 people worldwide—almost 90 percent under age 15—are hospitalized every year with dengue fever. Millions more are infected but are not hospitalized.
• Approximately 24,000 people die from dengue each year, most of them children or young adults.