The number of dengue fever cases is now more than double the total cases from last year, ABC News reported Oct. 31.
Here are four things to know:
1. In 2024, more than 6,800 cases of dengue were reported nationally, compared to 3,352 cases in 2023, the CDC found.
2. Currently, Puerto Rico has reported most of the cases at 4,200. The territory has declared a public health emergency amid the rise.
3. There are three possible reasons behind the rise in cases: warmer, wetter weather in 2024, more people traveling, and the fact that dengue is a cyclical virus that has large outbreaks every few years, federal officials said.
4. Of the 6,800 cases in 2024, 4,400 were acquired locally, meaning there was no history of travel to areas where dengue normally spreads.