Living in Costa Rica, we are well aware of the risk of dengue fever and we take precautions to not attract the mosquitoes. Luckily, we have very few of those little buggers come to visit where we are located, far enough away from the river and on top of the hill where there is more breeze than the insects like.

Personally, I know one gringa who has lived here for lots of years and got the dengue, all other cases I have heard about are local people who live close to the rivers and are less diligent about cleaning up around their houses.

The biggest risk for getting bit is during rainy season, the part of the year when we have the fewest tourists visiting. Granted, there is still a risk the rest of the year, if there is clean standing water around where you are, but dengue is not rampant among the tourists.