The World Health Organization is warning a highly pathogenic variant of avian influenza is increasingly spreading among mammals — raising the prospect it could trigger a pandemic in humans. The H5N1 flu outbreak has killed countless wild birds and millions of farmed poultry, driving up the cost of eggs worldwide. In October, the virus was found circulating among mink on a fur farm in Spain, and recently it’s been detected in wild mammals including foxes, coyotes, skunks, bears, mountain lions, and even seals and dolphins. Last week, World Health Organization Director-General Tedros Adhanom Ghebreyesus warned health agencies to prepare for the possibility of community spread in humans.

Tedros Adhanom Ghebreyesus: “Since H5N1 first emerged in 1996, we have only seen rare and nonsustained transmission of H5N1 to and between humans, but we cannot assume that will remain the case, and we must prepare for any change in the status quo. As always, people are advised not to touch or collect dead or sick wild animals, but to report them to the local authorities.”