Resurgence of avian influenza virus

Unprecedented outbreaks of the H5N1 highly pathogenic avian influenza virus raise concern Highly pathogenic avian influenza viruses (HPAIv) have recently been detected on the East coast of Canada (December 2021) and the United States (January 2022) and have been found in both wild birds and poultry ( 1 ). This comes after the same strain (known as H5N1) swept through Asia, Africa, and Europe in late 2021, replacing the previous HPAIv and causing widespread outbreaks and millions of deaths in poultry and wild birds. These HPAIv are of concern not only to birds but also to humans because they pose a potential pandemic risk. How has this virus emerged and spread so rapidly, and what does it mean for poultry, wild birds, and humans?