Outbreak Notice
Update: Dengue in Tropical and Subtropical Regions

This information is current as of today, February 23, 2012 at 03:18 EST

Updated: September 15, 2011

Situation Information

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 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 Dengue Map on the CDC website.

Africa and the Indian Ocean Islands

Dengue infection occurs throughout Africa and the Indian Ocean Islands. Dengue has been diagnosed in travelers returning from these areas, including countries where the disease has not been officially reported.

South Pacific

Dengue infection is endemic in the South Pacific, where cyclical epidemics also occur. Even outside the typical dengue transmission season, travelers are at risk for the disease.  The Philippines, Vietnam, and Thailand are among the countries reporting dengue activity in 2011. Australia also continues to report sporadic dengue activity in endemic areas of northern Queensland. For more information about dengue reports in Thailand and Vietnam, visit the Thailand Ministry of Public Health and WHO Western Pacific Regional Office (PDF) website.

The Americas and the Caribbean

As of August 5, 2011, more than 890,000 cases have been reported to the Pan American Health Organization (PAHO) during 2011, including 10,840 cases of dengue hemorrhagic fever (DHF) and/or dengue shock syndrome (DSS). Several countries across the region are reporting high incidence rates, including Brazil, Paraguay, Bolivia, the Bahamas, and Aruba.

Middle East

Dengue activity is reported sporadically throughout the Middle East, including areas popular with travelers, such as Jeddah in Saudi Arabia.

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 a repellent containing permethrin or another EPA-registered repellent. (Remember: don't use permethrin on skin.)

Symptoms and Treatment

Symptoms of dengue include:

• fever
• severe headache
• pain behind the eyes
• joint and muscle pain
• rash
• nausea/vomiting
• 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 right away. Be sure to tell the doctor or other health care provider about your recent travel.

Information for Health Care Providers

Proper diagnosis of dengue is important, as many other diseases may mimic dengue. Health care providers should consider dengue, malaria, (in south Asia and countries bordering the Indian Ocean,) chikungunya, and leptosporiasis depending on the itinerary and exposure in the differential diagnosis of patients who have fever and a history of travel to tropical areas during the 2 weeks before symptom onset.
See the Clinical & Laboratory Guidance on the CDC Dengue website for information about reporting dengue cases and instructions for specimen shipping. Serum samples obtained for viral identification and serologic diagnosis can be sent through state or territorial health departments to:
CDC Dengue Branch
Division of Vector-Borne Infectious Diseases
National Center for Emerging and Zoonotic Infectious Diseases (Proposed)
1324 Calle Cañada
San Juan, Puerto Rico 00920-3860
Telephone: 787-706-2399; fax, 787-706-2496

More Information

For more information about dengue and protection measures, see the following links:

• Dengue Fever in CDC Health Information for International Travel 2012
• Mosquito and Tick Protection
• Questions and Answers: Insect Repellent Use and Safety
• CDC Dengue website

For more information about dengue in travelers, see

• Epidemiological Alert: Update on Dengue Situation in the Americas (PDF) (PAHO, February 2, 2011)
• Epidemiological Alert: Update on Dengue Situation in the Americas (PDF) (PAHO, March 18, 2011)
• Epidemiological Alert: Update on Dengue Situation in the Americas (PDF)

(PAHO, August 19, 2011)

• French National Institute for Public Health Surveillance
• Travel-Associated Dengue Surveillance—United States, 2006–2008 [MMWR 2010, 59 (23)]
• Travel-Associated Dengue—United States, 2005 [MMWR 2006, 55 (25)].
• Travel-Associated Dengue Infections—United States, 2001-2004 [MMWR 2005, 54 (22)]

1Freedman DO, Weld LH, Kozarsky PE, Fisk T, Robins R, von Sonnenburg F, et al., for the GeoSentinel Surveillance Network. Spectrum of disease and relation to place of exposure among ill returned travelers. N Engl J Med 2006;354:119-130.