Dengue fever, the most prevalent virus spread by mosquitoes globally, poses a growing threat across the world's tropical zones, from Southeast Asia to Central America—and now, Florida. Dengue virus is showing up in the Florida Keys, the CDC reported yesterday, with 5 percent of Key West residents exposed to the virus last year and 12 confirmed cases of the fever so far this year, CNN reports.
"We are concerned that if dengue gains a foothold in Key West, it will travel to other Southern cities like Miami," said a CDC official. Dengue fever, which was last seen in Florida in 1934, causes about 100 million infections a year, killing 25,000 people worldwide. There is no vaccine against the disease, which typically causes high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain. (Read more Dengue Fever stories.)