We didn’t face a new global pandemic in 2024, but the year was filled with reminders that zoonotic diseases—diseases that people get from animals—are a constant and evolving challenge. Here’s a rundown of some of the events of 2024.
The H5N1 avian influenza virus continued its global spread, notably infecting several new mammal species, which wasn’t unheard of before, but has now become much more common. In the U.S., the virus moved into dairy cattle in at least 16 states. Cats consuming unpasteurized milk from infected cows were also infected, raising concerns about its adaptability and the potential for an additional chain of transmission to humans. Human infections, though sporadic, were reported in Cambodia, Vietnam, and the U.S. with some cases resulting in fatalities. These incidents highlight the ongoing risk of zoonotic influenza, especially to people in contact with poultry and cattle.
