Missouri officials are under growing pressure from national public health experts to pinpoint the source of the state’s first human bird flu infection.

Chances are low that human-to-human spread of bird flu occurred in a group of people who were exposed to a patient infected with the virus in Missouri, US health authorities said.

U.S. health officials have run into obstacles in their efforts to determine whether a Missouri person infected with H5N1 bird flu passed the virus on to others.

The United States is in the middle of an unprecedented bout of bird flu, also known as H5N1. Since 2022, the virus has killed millions of birds and spread to mammals, including co

As of Monday evening, there is only one confirmed human case of bird flu in Missouri. The single case is one of 15 reported nationwide since 2022. However, the recent Missouri case is unusual... because there is no known animal link to that case.