Most people with dengue will show no signs of infection or experience only mild symptoms, but in rare cases infections can become severe and potentially fatal.
Brazil looks to short-term and long-term strategies to fight a disease so painful it's known as "breakbone fever." The outbreak is part of a global wave of dengue triggered in part by climate change.
Researchers have found that certain viruses may have a trick up their sleeve that can make humans more attractive to mosquitoes. The study also revealed a possible remedy.