When, where and how the H5N1 bird flu virus may evolve and its capacity to spark a pandemic is hard to predict — in part, some researchers say, because of federal restrictions on gain-of-function research.

The presence of highly pathogenic avian influenza, or H5N1 bird flu, has been confirmed after officials worked to quarantine a backyard flock in Franklin County last week. HPAI was confirmed in the 24-bird flock by Vermont’s Agency of Agriculture,

The first severe case of H5N1 bird flu was confirmed in Louisiana. Here is a map of other states that have been affected.

Public health officials have just reported the first known “severe” case of bird flu in the United States. There are now 61 confirmed cases across eight states. This week, the Centers for Disease Control and Prevention (CDC) announced that a person had been hospitalized with a “severe case” of bird flu.

Mississippi has confirmed H5N1 in a poultry flock. The birds are not part of food supply chain. What you need to know about bird flu symptoms, risk.

Los Angeles County health officials have identified three more cats with presumptive H5N1; the source of the virus has not yet determined, but experts suspect raw meat.

The United States has confirmed its first known severe human infection of H5N1 bird flu, in a person in Louisiana believed to have contracted the virus through contact with sick or dead birds in a backyard flock.

A chilling milestone in U.S. public health has been confirmed. The Centers for Disease Control and Prevention (CDC) recently announced the nation’s first severe case of avian