What is Dengue Fever?
Dengue 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.
What are the Symptoms of Dengue Fever?
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)
- 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
What Causes Dengue Fever?
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 associated with Dengue Fever
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.
Tests and diagnosis for Dengue Fever
Diagnosing dengue fever can be difficult, because its signs and symptoms can be easily confused with those of other diseases — such as malaria, leptospirosis and typhoid fever. Your doctor will likely ask about your medical and travel history. Be sure to describe international trips in detail, including the countries you visited and the dates, as well as any contact you may have had with mosquitoes. Certain laboratory tests can detect evidence of the dengue viruses, but test results usually come back too late to help direct treatment decisions.
If you're living or traveling in an area where dengue fever is known to be, the best way to avoid dengue fever is to avoid being bitten by mosquitoes that carry the disease.