Key Facts

  • Approximately 500 million people in the Americas are today at risk of dengue.
  • Dengue incidence has increased in the Americas over the past three decades, from 16.4 cases per 100,000 in the 1980s to 218.3 per 100,000 during 2000 to 2010.
  • 2013 was an epidemic year in the Americas, with 2.3 million cases and an incidence of 455.9 per 100,000. There were 37,898 severe cases and 1,318 deaths in the hemisphere. However, in 2014 there was a 50% decrease in dengue cases compared with 2013,
  • The four dengue serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) circulate throughout the Americas, in some countries simultaneously.
  • Following infection with one serotype, subsequent infection with a different serotype increases a person's risk of severe dengue and death.
  • Ae. aegypti is widely distributed in the Americas. Only Canada and continental Chile are free from dengue and its vector. Uruguay has no dengue cases, but it does have Ae. aegypti.

What is Dengue?

Dengue is a febrile illness that affects infants, young children, and adults, with symptoms ranging from mild fever to incapacitating high fever, with severe headache, pain behind the eyes, muscle and joint pain, and rash. It is transmitted by the bite of a mosquito infected with one of the four dengue virus serotypes.

The illness can evolve to severe dengue, characterized by shock, respiratory distress, severe bleeding, and/or serious organ impairment. There is no vaccine or specific medicine to treat dengue. The disease has a seasonal pattern: most cases in the southern hemisphere occur in the first half of the year, and most cases in the northern hemisphere in the second half. In the Americas, Aedes aegypti is the mosquito vector for dengue. Prevention and control of dengue must involve the family, the community, and active intersectoral participation.

PAHO/WHO response

  • PAHO/WHO provides technical advice and support for dengue prevention and control based on a regional strategy adopted by PAHO/WHO Member States in 2003 (CD44.R9). A new model of this strategy is being developed within the framework of the WHO Global Strategy for dengue prevention and control 2012-2020.
  • In 2008, PAHO/WHO Member States established a Dengue Laboratory Network of the Americas (RELDA), made up of four PAHO/WHO Collaborating Centers and 22 national laboratories, to strengthen dengue diagnosis.
  • PAHO/WHO is supporting the development of an integrated dengue surveillance system model to generate standardized information for all the Americas. The model is being validated in several countries and territories. PAHO/WHO is also helping develop new standards for surveillance in the Americas.
  • PAHO/WHO adapted WHO's 2009 clinical guidelines on management of dengue patients for use in the Americas. After their implementation, the dengue case fatality rate declined from 0.07% to 0.05%, preventing approximately 3,300 deaths by dengue between 2011 and 2014. A second edition of the PAHO/WHO clinical guidelines will be published in 2015, incorporating new elements, including dengue in pregnancy, dengue in newborns, dengue in the elderly and preparedness and response for dengue outbreaks.

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(Last update: March 2015.)