Dengue and Dengue Hemorrhagic Fever
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 AGENTS

  • Dengue viruses (DEN-1, DEN-2, DEN-3 and DEN-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.
  • Average case fatality rate of DHF is about 5%.
  • In 1995, 250,000 cases of DF and 7,000 cases of DHF reported in Americas.
  • Between 100 to 200 suspected cases introduced into U.S. each year by travelers .

COMPLICATIONS

  • Bleeding diathesis and end organ failure.

 

TRANSMISSION

  • Mosquito-borne (Aedes aegypti).

RISK GROUPS

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

 

TRENDS

  • Resurgent disease worldwide in the tropics .
  • Epidemics are larger and more frequent .
  • Transmission in continental U.S. in 1995; 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 .
  • Rapid dispersal of viruses via air travel .
  • Emergency control methods ineffective .
  • Severe hemorrhagic disease poorly understood by physicians in Americas .
  • Change emphasis from emergency response to prevention of epidemics .
  • Develop better government-based programs .
  • Encourage community participation in prevention and control programs .

OPPORTUNITIES

  • Dengue Branch, NCID, designated WHO Reference Center .
  • Improve laboratory-based international surveillance .
  • Educate medical community .
  • Develop community-based, integrated prevention programs .

RESEARCH 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.