Outbreak Notice
Update: Dengue, Tropical and Subtropical Regions
This information is current as of today, May 05, 2009 at 19:32 EDT
Updated: April 02, 2009
Situation Information
Dengue fever is the most common cause of fever in travelers returning from the Caribbean, Central America, and South Central Asia.1 This disease is caused by four similar viruses (DENV-1, -2, -3, and -4) spread through the bites of infected mosquitoes.
Many countries reported high numbers of dengue infections during 2007 and this trend continued in 2008. Dengue infections are frequently reported from most tropical countries of the South Pacific, Asia, the Caribbean, the Americas, and Africa. See the Distribution of Dengue maps for areas where cases have been reported in previous years. Some of the recent outbreaks of dengue include the following reports:
- Since the beginning of 2009, dengue fever cases have been rising in several areas of South America. In the northern provinces of Argentina, approximately 2,000 people have reportedly become ill with dengue fever during the first 2 months of 2009. Additionally, 5,000 cases of dengue fever have been reported in the Tumbes region in northwest Peru, while in Paraguay, 542 confirmed cases and 728 suspected cases of dengue fever have been reported.
- In January 2009 health officials in Bolivia declared a health emergency due to increasing cases of dengue fever. As of 16 March 2009, the Bolivian Ministry of Health reports 5,261 confirmed cases of dengue fever and 127 cases of dengue hemorrhagic fever (DHF). An additional 46,381 suspected cases of dengue fever were also reported. For the most current update on number of cases, please see the Bolivian Ministry of Health. For more information on this outbreak, listen to this podcast from the World Health Organization (WHO).
- The Brazilian Ministry of Health reported increasing dengue fever activity in 2008. The State of Rio de Janeiro in particular reported significant activity, with 248,609 cases, including 106 deaths, reported during 2008.
- Health officials in the Netherlands Antilles reported an increase in dengue cases on the islands of St. Maarten, Saba, and Curaçao in late 2008. More than 500 cases of dengue fever have been confirmed on St. Maarten and nine cases of dengue fever have been recorded in Saba. Saba officials say this is the largest number of dengue cases reported on the island in the past 30 years.
- Health authorities in Malaysia have issued a dengue fever alert following increasing dengue fever activity throughout the country. During the first 3 weeks of January 2009, 4,200 cases and 12 deaths from dengue fever were reported. Kuala Lumpur has been particularly hard hit, reporting over 400 cases and 2 deaths during this time period.
- As of March 13, 2009, Queensland (Australia) Health has reported 749 confirmed cases of dengue fever in the northern part of the state of Queensland, which is located in northeastern Australia. Additionally, it was reported on March 4, 2009, that an elderly woman in the city of Cairns became the first dengue-associated death in the current outbreak.
Dengue is transmitted in regions throughout the tropics and subtropics. Although dengue transmission often occurs in both rural and urban areas, dengue infections are most frequently reported from urban settings. See Dengue Fever from CDC’s Division of Vector-Borne Infectious Diseases and the World Health Organization’s (WHO) Dengue webpage for more information on dengue and updates on worldwide activity.
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 had dengue fever before are more at risk of getting DHF.
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. Early recognition and treatment of severe dengue 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.
Prevention Measures for Travelers
Travelers can reduce their risk of getting 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 to reduce the mosquito population. If the hotel is not well screened, sleep under bed nets to prevent mosquito bites.
- When outdoors or in a building that is not well screened, use insect repellent on uncovered skin. If sunscreen is needed, apply before 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 of the use of repellents with up to 30% DEET on children over 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, visit Insect and Arthropod Protection in the CDC Health Information for International Travel 2008.
- Wear loose, long-sleeved shirts and long pants when outdoors.
- Clothing may also be sprayed with repellent containing permethrin or another EPA-registered repellent for greater protection. (Remember: don't use permethrin on skin.)
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, and (in south Asia and countries bordering the Indian Ocean) chikungunya 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 Dengue and Dengue Hemorrhagic Fever: Information for Health-Care Practitioners for information regarding 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 Zoonotic, Vector-Borne and Enteric Diseases
1324 Calle Cañada
San Juan, Puerto Rico 00920-3860
Telephone: 787-706-2399; fax, 787-706-2496.
For more information about dengue and protection measures, see the following links:
For more information about dengue in travelers, see
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.
