United States

Dengue fever, once confined to the tropics, now threatens the U.S.

Climate change is expanding the habitat of the mosquitoes that carry the disease, allowing them to spread further north.

Meg Norris was traveling in Argentina in April when the first signs of dengue fever hit her. The weather in Salta, just south of the Bolivian border, was warm, but Norris, a 33-year-old from Boulder, Colorado, zipped a fleece sweatshirt around her body to stop herself from shivering.

“I thought it was sun poisoning,” she said.