There have been 67 human cases of bird flu nationwide since 2024, 38 of which occurred in California, the most out of any state.

How deadly is the bird flu? The US has reported its first death from avian influenza, H5N1. Here's what to know about bird flu mortality rate and who is at risk.

Two months shy of the fifth anniversary of COVID-19 being declared a global pandemic, the US has recorded its first human death as a result of avian influenza H5N1 infection. The unidentified Louisiana man contracted the virus through contact with infected wild and domestic birds on his property

For influenza viruses, imperfection is a strength. They constantly mutate, producing new strains that challenge immune systems primed to fight earlier varieties. That’s what makes flu a life-long threat to humans and the animal species — mainly birds — that are vulnerable to it.

NBC News Medical Contributor Dr. Kavita Patel speaks with Gadi Schwartz about the difference in symptoms between a cold and the flu and explains the CDC's urge for faster testing to find human bird flu cases.

The risk to the general public from bird flu is low, and there has been no further evidence of person to person spread, the agency said. Influenza A-positive patients, particularly those in an intensive care unit,

CDC officials say they extended the guidance now because they are seeing more H5N1 patients whose illness they cannot track back to an infected bird or cow.