Dengue epidemic in Puerto Rico 2012-2013: integration of passive and sentinel surveillance to characterize and differentiate dengue in the peri-vaccination era

Dengue represents an increasingly important global health challenge, as recent estimates suggest that nearly 2.5 billion people worldwide are at risk for infection1 and 390 million infections occurred in 2010.2 The four dengue virus-types (DENV-1–4) that cause dengue are single-stranded, positive-sense RNA viruses of the family Flaviviridae. Aedes aegypti and Ae. albopictus mosquitoes are endemic throughout the tropics and subtropics and serve as the primary vector for DENV transmission. DENV infection can result in a range of outcomes, from asymptomatic infection, to self-limited acute febrile illness (AFI), to potentially fatal severe dengue.