CDC reports second human case of H5 bird flu tied to dairy cow outbreak

May 24, 2024
CDC’s risk assessment for the general public remains low.

A human case of highly pathogenic avian influenza (HPAI) A(H5) (“H5 bird flu”) virus infection in the United States has been identified in the state of Michigan.

This is the second case associated with an ongoing multistate outbreak of A(H5N1) in dairy cows. As with the case in Texas, the individual is a worker on a dairy farm where H5N1 virus has been identified in cows. While a nasal swab from the person tested negative for influenza in Michigan, an eye swab from the patient was shipped to the Centers for Disease Control and Prevention (CDC) and tested positive for influenza A(H5) virus, indicating an eye infection. Similar to the Texas case, the patient only reported eye symptoms. CDC has been watching influenza surveillance systems closely, particularly in affected states, and there has been no sign of unusual influenza activity in people, including in syndromic surveillance.

Based on the information available, this infection does not change CDC’s current H5N1 bird flu human health risk assessment for the U.S. general public, which the agency considers to be low. However, this development underscores the importance of recommended precautions in people with exposure to infected or potentially infected animals. People with close or prolonged, unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection.

More information is available on the CDC website at

CDC release