Photo: CDC- Dengue Map
With more than one-third of the world’s population living in areas at risk for transmission, dengue infection is a leading cause of illness and death in the tropics and subtropics. As many as 100 million people are infected yearly.
Dengue is caused by any one of four related viruses transmitted by mosquitoes. There are not yet any vaccines to prevent infection with dengue virus (DENV) and the most effective protective measures are those that avoid mosquito bites. When infected, early recognition and prompt supportive treatment can substantially lower the risk of developing severe disease.
Dengue has emerged as a worldwide problem only since the 1950s. Although dengue rarely occurs in the continental United States, it is endemic in Puerto Rico, and in many popular tourist destinations in Latin America and Southeast Asia; periodic outbreaks occur in Samoa and Guam.
Dengue fever is the most common cause of fever in travelers returning from the Caribbean, Central America, and South Central Asia.1 Dengue is reported commonly from most tropical and subtropical countries of Oceania, Asia, the Caribbean, the Americas, and occasionally from Africa. This disease is caused by four similar viruses (DENV-1, -2, -3, and -4) and is spread through the bites of infected mosquitoes.
Dengue virus (DENV) transmission occurs in both rural and urban areas; however, dengue infections are most often reported from urban settings. For the most up-to-date information on dengue worldwide, see the DengueMap on the CDC website.
The Americas and the Caribbean
Most countries in Central and South America, as well as in the Caribbean, are reporting dengue activity. As of September 8, 2010, 1,432,410 dengue cases have been reported throughout the Americas. Of these reported cases, 30,820 cases have been reported as severe dengue. Although dengue activity is reported every year in this region, circulation in parts of Central America and the Caribbean has been unusually high in 2010.
The parts of Central America and the Caribbean with unusually high activity are Brazil, Colombia, Costa Rica, Dominican Republic, El Salvador, French Guiana, Guadeloupe, Guatemala, Honduras, Martinique, Mexico, Nicaragua, Puerto Rico, and Venezuela.
In addition, a few dengue cases are being reported in the United States in Key West, Florida. Dengue has not typically been reported in this area. For more information about the situation, see the Local Dengue Transmission in Key West, Florida webpage on the CDC website.
Advice for Travelers
Travelers can reduce their risk of infection with dengue fever by protecting themselves from mosquito bites. The mosquitoes that spread dengue usually bite at dusk and dawn but may bite at any time during the day, especially indoors, in shady areas, or when the weather is cloudy.
Travelers should follow the steps below to protect themselves from mosquito bites:
Where possible, stay in hotels or resorts that are well screened or air conditioned and that take measures such as spraying with insecticide to reduce the mosquito population.
When outdoors or in a building that is not well screened, use insect repellent on uncovered skin. If sunscreen is needed, apply before applying insect repellent.
Look for a repellent that contains one of the following active ingredients: DEET, picaridin (KBR 3023), Oil of Lemon Eucalyptus/PMD, or IR3535. Always follow the instructions on the label when you use the repellent.
In general, repellents protect longer against mosquito bites when they have a higher concentration (percentage) of any of these active ingredients. However, concentrations above 50% do not offer a marked increase in protection time. Products with less than 10% of an active ingredient may offer only limited protection, often no longer than 1-2 hours.
The American Academy of Pediatrics approves the use of repellents with up to 30% DEET on children more than 2 months old.
Protect babies less than 2 months old by using a carrier draped with mosquito netting with an elastic edge for a tight fit. For more information about the use of repellent on infants and children, please see the “Insect and Other Arthropod Protection” section in Traveling Safely with Infants and Children and the “Children” section of CDC’s Frequently Asked Questions about Repellent Use.
For more information on the use of insect repellents, see the information on the Mosquito and Tick Protection webpage.
Wear loose, long-sleeved shirts and long pants when outdoors.
For greater protection, clothing may also be sprayed with repellent containing permethrin or another EPA-registered repellent. (Remember: don’t use permethrin on skin.)
Symptoms and Treatment
Symptoms of dengue include:
pain behind the eyes
joint and muscle pain
hemorrhagic (bleeding) manifestations
Usually dengue fever causes a mild illness, but it can be severe and lead to dengue hemorrhagic fever (DHF), which can be fatal if not treated. People who have previously been infected with dengue fever are more at risk of getting severe dengue.
No vaccine is available to prevent dengue, and there is no specific medicine to cure illness caused by dengue. Those who become ill with dengue fever can be given medicine to reduce fever, such as acetaminophen, and may need oral rehydration or intravenous fluids and, in severe cases, treatment to support their blood pressure. Aspirin (acetylsalicylic acid), aspirin-containing drugs, and other nonsteroidal anti-inflammatory drugs (e.g., ibuprofen) should be avoided because of the possibility of bleeding. Early recognition and treatment of severe dengue (e.g., signs and symptoms consistent with impending blood pressure failure) can reduce the risk of death.
If you return from a trip abroad and get sick with a fever, you should seek medical care. Be sure to tell the doctor or other health-care provider about your recent travel.