Human Bird Flu Patient Had No Known Animal Contact

A Missouri adult who tested positive for H5 bird flu had no known contact with animals but has underlying medical conditions, according to a statement from the Centers for Disease Control and Prevention (CDC).

The case of avian influenza A (H5) was identified as part of Missouri's normal influenza surveillance testing program, which led to potential detection of the H5 subtype that was confirmed by the CDC, according to a press release from the Missouri State Department of Health and Senior Services. To ensure privacy, the state is not providing additional information on the patient other than that the individual has recovered and been discharged home. The state reports no increase in human influenza cases and no sign of unusual influenza activity in people, including influenza-related emergency room visits, according to the press release.

Although H5 occurs mainly in wild birds and poultry, it has been identified in other animals in the United States, including dairy cows.

According to the Missouri press release, "No H5 infection in dairy cattle has been reported in Missouri; some H5 cases in commercial or backyard flocks and wild birds have been reported." 

The case represents the 14th reported occurrence of H5 in humans in the United States in 2024 but is the first without a known occupational exposure to sick or infected animals, and additional testing to characterize the virus is underway, according to the CDC. Identification of the N (neuraminidase) in the specimen from the patient is pending; H1N1 has been identified in wild birds in Missouri in the past, but the CDC currently assesses the risk of H5N1 to the general public as low, according to the statement. 

"The main concern in these situations is that no onward transmission is occurring. Findings from the ongoing investigation will inform whether guidance changes are needed," noted the statement.