Tropical Diseases Like Dengue Fever and Chikungunya Are on the Rise in Europe

In September 2024, a handful of patients showed up at the emergency room in the coastal city of Fano, Italy, with mysterious symptoms: a rash on their hands and feet, fever, nausea, and diarrhea. Doctors sent for various tests until one came back with a positive result for dengue, a viral infection spread by mosquitoes, usually in tropical regions of the world. They tested the other patients, and, sure enough, they had dengue too. The strange thing? None of the patients had recently traveled to a country where they might expect to pick up a dengue infection. The only thing they had in common w...