Fact Sheet

CLINICAL FEATURES

• Sudden onset of fever, severe headache, myalgias and arthralgias, leukopenia, thrombocytopenia and hemorrhagic manifestations
• Occasionally produces shock and hemorrhage, leading to death

ETIOLOGIC AGENT

• Dengue viruses (DENV 1, DENV 2, DENV 3, and DENV 4) - flaviviruses

INCIDENCE

• Variable, depending on epidemic activity.
• Globally, there are an estimated 50 to 100 million cases of dengue fever (DF) and several hundred thousand cases of dengue hemorrhagic fever (DHF) per year
• Case fatality rate can be as high as 10%. Can be reduced to as low as 1% with early recognition and proper treatment.
• In 2007, 900,782 cases of DF and 26,413 cases of DHF reported in Americas. Outbreaks were reported in 11 countries.
• Between 100 to 200 suspected cases introduced into U.S. each year by travelers

SEQUELAE

• None

COSTS

• $250 million estimated in Puerto Rico in past 10 years

TRANSMISSION

• Mosquito-borne (Aedes Aegypti)

RISK GROUPS

• Residents of or visitors to tropical and subtropical environments, especially urban and suburban areas
• Increased severe and fatal disease in children under 15 years
• No cross-immunity from each serotype
• A person can potentially experience four dengue infections

SURVEILLANCE

• DF and DHF are designated as reportable disease by law in US
• Dengue Branch responsible for laboratory-based surveillance
• Laboratory-based surveillance in endemic areas outside of US and it territories  

TRENDS

• Resurgent disease in tropical and subtropical areas worldwide 
• Epidemics have increased in size and frequency
• Transmission in continental U.S. last reported in 2005 first since 1986
• Since first epidemic in 1981, DHF now reported from 18 countries in the Americas
• Evolution of disease pattern in Americas similar to SE Asia in 1950s and 1960s

CHALLENGES

• Increased incidence associated with increased urbanization
• More rapid dispersal of viruses via increased air travel
• Vector control methods used to respond to an epidemics have not  shown evidence of effectiveness
• Severe hemorrhagic disease poorly understood by physicians
• Need to increase effective epidemic prevention methods
• Need to increase community participation in prevention and control programs

RESEARCH OPPORTUNITIES and PRIORITIES

• Develop improved laboratory-based international surveillance
• Develop rapid, sensitive and specific diagnostic tests
• Develop more effective community-based prevention programs
• Develop tetravalent dengue vaccine
• Dengue Branch, designated WHO Reference Center
• Increased  medical community education