Dengue fever is a serious viral disease that is transmitted through the bite of infected Aedes aegypti mosquitoes. Many countries in South and Central America and other tropical and subtropical regions of the world are reporting increased dengue activity. Although the risk of dengue infection for the international traveler is low, it is possible that travelers may become infected with dengue during visits to countries in Asia, the Pacific Islands, the Caribbean Islands, Mexico, Central and South America, and Africa, especially if an outbreak is in progress. The risk of contracting dengue is greater in urban areas and there is less risk in rural and areas of high altitude, above 4500 feet (1500 meters).

The mosquito's biting activity is greatest in the morning for several hours after daybreak and in the late afternoon for several hours before dark. However, this mosquito sometimes feeds throughout the entire day indoors, or in nearby areas protected from direct sunlight. In addition, Aedes aegypti sometimes feeds indoors during the night if lights are turned on. This mosquito breeds in manmade containers that can collect or hold water, such as cans, tires, barrels, etc.


Dengue fever may begin suddenly. The symptoms usually include high fever, severe headache, and joint and muscle pain. Nausea, vomiting, and loss of appetite are common. A rash may appear 3 to 4 days after the fever begins and may spread from the torso to the arms, legs, and face. These early symptoms do not usually last more than 7 days. In general there are no long-term effects of dengue infection. On rare occasions, dengue may also appear as a severe and potentially fatal disease called dengue hemorrhagic fever (DHF).

There is no vaccine to prevent dengue and no medication to cure it. Travelers should advise their physicians of any illness with fever occurring within weeks of leaving a tropical area. If you think you may have dengue, you should:

  1. Treat fever and discomfort using a pain reliever with acetaminophen (Tylenol) Avoid pain relievers that contain aspirin.

  2. Rest and drink plenty of fluids.

  3. Consult a physician.