Dengue virus is spread through mosquitoes, particularly, Aedes mosquitoes. Every year, approximately 390 million people are infected. Dengue outbreaks have taken place in parts of Southeast Asia, the Western Pacific, the Eastern Mediterranean, the Americas, the Caribbean, and Africa. However, almost all reported cases in the United States are travel associated. The majority of individuals infected with dengue develop mild symptoms or none at all. However, severe forms of the disease are possible which may be fatal. Treatment consists of supportive care. Preventing mosquito bites is the most important factor in reducing the likelihood of developing infection.