We just returned from 10 days in Costa Rica -- San Jose, Arenal, Monteverde, and Playa Samara. Upon returning home, one of the people who had traveled with us developed severe joint pain and high fevers. Ultimately, he was hospitalized and found to have Dengue Fever.
Our trip to Costa Rica was amazing and I would not hesitate to return to this wonderful country! But please take precautions to prevent Dengue Fever when traveling to Costa Rica. It is a virus transmitted by mosquitoes, so wear long sleeves when possible, and lots of insect repellent! Our friend is a very healthy 29 year old, so it was scary how sick he became -- it can happen to anyone. But we definitely were not as careful as we could have been to prevent mosquito bites.