Person infected with bird flu in Missouri had no contact with animals: What you should know

A person in Missouri has been infected with bird flu, the Centers for Disease Control and Prevention said Friday. The adult, who had no known contact with poultry or dairy cows, was hospitalized on Aug. 22 and has since recovered.

The case adds to growing concerns about the risk of bird flu spreading among humans, particularly because it is the first infection in the United States in a person who has not worked with poultry or dairy cows.

The CDC said the risk to the general population remains low.

Outbreaks of the H5 flu virus have been confirmed in at least 196 dairy herds in 14 states, according to the CDC. Outbreaks in poultry have been identified in 48 states. The Missouri patient is the 15th human case of H5 reported in the U.S. since 2022, according to CDC data. Fourteen poultry and dairy workers have been infected since the beginning of 2024. Most had mild flu-like symptoms, including fever or runny nose. Many had pink eye or conjunctivitis.

In Missouri, no H5 infection has been reported in dairy cattle. However, some cases have been reported in commercial or backyard poultry and in wild birds.

“The question now is: How did this patient acquire the infection?” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center in Nashville, Tennessee. “We need a very, very thorough investigation.”

There is no evidence that H5N1 – the H5 virus that spreads in dairy cows – has been transmitted from person to person. The Missouri patient's sample will need to be tested in the lab to determine whether the H5 virus may have acquired mutations that allow it to be transmitted more easily to humans, Schaffner said.

“This will be of enormous interest,” he said.

In a separate press release, Missouri health officials said there were no signs of unusual flu activity in the community, nor had there been an increase in emergency room visits or an increase in human flu cases in labs.

A sample from the patient was sent to the Missouri State Public Health Laboratory, Missouri health officials said in the news release. The sample was sent to the CDC for further testing.

The adult patient has underlying medical conditions and tested positive for influenza A, Missouri authorities said. No transmission of the virus was detected among the patient's close contacts.