The Costa Rican Minister of Health declared a health alert for Dengue fever due to the increased number of cases. The article states the areas most affected are Parrita, Quepos, Puntarenas, and Perez Zeledon.
In contrast the CDC has NOT issued a travel alert for Costa Rica although they do talk about the "especially potent outbreak of Dengue fever" in Central America that has sickened 40,000 people and killed 26 as of July 25, 2013.
So, my family is going to spend several weeks in the Tamarindo and Playa Flamingo area in August. The forecast is for lots of rain, therefore mosquitos. Usually I just spray myself with bug spray in the evening and don't worry.
Have you been seeing Dengue in Tamarindo and Flamingo?
How much of a concern is it locally?