The Centers for Disease Control and Prevention (CDC) has confirmed Missouri’s first human case of avian influenza A (H5), also known as “H5 bird flu.” The Missouri Department of Health and Senior Services (DHSS) identified the case through their ongoing influenza surveillance program. Despite this confirmation, the risk of sustained transmission or infection among the general public remains low, according to health officials.
The patient, an adult with underlying medical conditions, was hospitalized on Aug. 22 and tested positive for influenza A. There was no reported exposure to animals, and the patient has since recovered and been discharged. To protect privacy, no further details regarding the patient will be released.
The Missouri State Public Health Laboratory received a specimen from the patient, and as part of routine testing, they conducted additional analysis to determine the influenza subtype. This resulted in the presumptive detection of the H5 subtype. The specimen was forwarded to the CDC for further testing, which confirmed the presence of the H5 avian flu virus. The CDC is conducting additional virus characterization to understand more about this specific case.
While H5 is primarily found in wild birds and poultry, it can occasionally infect humans through close contact with infected animals or contaminated environments. There have been 15 human cases of H5 reported in the U.S. since 2022 (14 cases this year), including this one in Missouri. No reports of H5 infections in dairy cattle have been made in Missouri, although the state has seen some cases in commercial or backyard flocks and wild birds.
