On Friday, the U.S. Centers for Disease Control and Prevention (CDC) confirmed a human case of avian influenza A reported by Missouri. Identified through the state’s seasonal flu surveillance system, the case was confirmed on Thursday, with an investigation into potential exposure still ongoing by the Missouri Department of Health and Senior Services.
The patient, who had underlying medical conditions and was hospitalized, was treated with antiviral medications and has since recovered. There is no known animal exposure or evidence of ongoing transmission among close contacts.
This case marks the 14th human instance of H5 avian influenza reported in the U.S. in 2024, and notably, it is the first without a known occupational exposure to infected animals.
Although the national flu surveillance system has detected other novel flu cases, this is the first instance of H5 identified through this system.
H5 bird flu is prevalent in wild birds globally and has caused outbreaks in U.S. poultry and dairy cows, with recent human cases primarily among those working with these animals.
In 2024, there have been outbreaks in both commercial and backyard poultry flocks, but Missouri has not reported any outbreaks in cattle.
Missouri last reported a bird flu case in a commercial poultry flock in February, according to the USDA. While H5N1 has been found in wild birds in the state before, no outbreaks in cattle have been reported in Missouri.
Fourteen states have reported H5N1 outbreaks in dairy cattle, raising concerns about the virus adapting to spread among humans. However, the CDC maintains that the risk to the general public from H5N1 remains low based on current data.
