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.
She woke that night in a sweat and spent the hours alternately burning up then freezing. In the morning, her eyes were sore and her lymph nodes were swollen. For the following week, there was nothing to do but sleep, stay hydrated and wait for the body aches that give the illness the moniker “break-bone fever” to pass.
Latin America is experiencing its worst dengue fever outbreak on record. Case numbers in the first 4 1⁄2 months of 2024 are already 238% higher than they were by this time last year, which itself ended with a record 4.1 million cases, according to the Pan American Health Organization .
Cases are more than 400% higher than the five-year average. An unusually wet and warm summer season brought by the El Niño weather pattern has created ideal conditions for the mosquitoes that spread dengue to hatch en masse and carry higher amounts of the virus. Experts warn this could be a preview of what dengue fever will look like in the future.
Climate change is creating unusually balmy conditions, which are already expanding the range of mosquito-borne diseases. “That’s concerning for places where dengue hasn’t occurred before in rece.
