Dengue (DENG-gey) fever is a mosquito-borne disease that occurs in tropical and subtropical areas of the world. Mild dengue fever causes high fever, rash, and muscle and joint pain. A severe form of dengue fever, also called dengue hemorrhagic fever, can cause severe bleeding, a sudden drop in blood pressure (shock) and death.
Millions of cases of dengue infection occur worldwide each year. Dengue fever is most common in Southeast Asia and the western Pacific islands, but the disease has been increasing rapidly in Latin America and the Caribbean.
Researchers are working on dengue fever vaccines. For now the best prevention is to reduce mosquito habitat in areas where dengue fever is common.
Symptoms
Many people, especially children and teens, may experience no signs or symptoms during a mild case of dengue fever. When symptoms do occur, they usually begin four to 10 days after you are bitten by an infected mosquito. Signs and symptoms of dengue fever most commonly include:
- Fever, as high as 106 F (41 C)
- Headaches
- Muscle, bone and joint pain
- Pain behind your eyes
You might also experience:
- Widespread rash
- Nausea and vomiting
- Rarely, minor bleeding from your gums or nose
Most people recover within a week or so. In some cases, symptoms worsen and can become life-threatening. Blood vessels often become damaged and leaky. And the number of clot-forming cells (platelets) in your bloodstream drops. This can cause:
- Bleeding from your nose and mouth
- Severe abdominal pain
- Persistent vomiting
- Bleeding under the skin, which might look like bruising
- Problems with your lungs, liver and heart
When to see a doctor
If you’ve recently visited a region in which dengue fever is known to occur and you suddenly develop a fever, see your doctor.
Causes
Dengue fever is caused by any one of four dengue viruses spread by mosquitoes that thrive in and near human lodgings. When a mosquito bites a person infected with a dengue virus, the virus enters the mosquito. When the infected mosquito then bites another person, the virus enters that person’s bloodstream.
After you’ve recovered from dengue fever, you have immunity to the virus that infected you — but not to the other three dengue fever viruses. The risk of developing severe dengue fever, also known as dengue hemorrhagic fever, actually increases if you’re infected a second, third or fourth time.
Risk factors
Factors that put you at greater risk of developing dengue fever or a more severe form of the disease include:
- Living or traveling in tropical areas.Being in tropical and subtropical areas increases your risk of exposure to the virus that causes dengue fever. Especially high-risk areas are Southeast Asia, the western Pacific islands, Latin America and the Caribbean.
- Prior infection with a dengue fever virus.Previous infection with a dengue fever virus increases your risk of having severe symptoms if you’re infected again.
Complications
If severe, dengue fever can damage the lungs, liver or heart. Blood pressure can drop to dangerous levels, causing shock and, in some cases, death.