In this week's Spotlight, we include the key findings from the recent Michigan-led study that tested the blood of farmworkers from two dairy farms that experienced an outbreak of highly pathogenic avian influenza A(H5N1) virus among cattle.

Four human cases of highly pathogenic avian influenza (HPAI) A(H5) ("H5 bird flu") virus infection in the state of Colorado have been confirmed by the Centers for Disease Control and Prevention (CDC). This includes all three presumptive-positive cases reported by that state on Friday, July 12 and a fourth specimen that was later found to be presumptive-positive by the state on Friday.

The state of Colorado has announced that three people have tested presumptive positive for highly pathogenic avian influenza (HPAI) A(H5) ("H5 bird flu") virus infection.

CDC has issued updated guidance to help prevent the spread of flu between animals and between animals and people at fairs.

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 Colorado.

CDC has reported this year's second and third U.S. human infections with influenza (flu) viruses that normally spread in pigs and not people.

Today, CDC recommended the updated 2024-2025 COVID-19 vaccines and the updated 2024-2025 flu vaccines to protect against severe COVID-19 and flu this fall and winter.

CDC has completed its initial study of the effects of the A(H5N1) bird flu virus from the human case in Texas on ferrets, a model used to assess potential impact on people.

CDC continues to respond to the public health challenge posed by a multistate outbreak of avian influenza A(H5N1) virus, or "A(H5N1) virus," in dairy cows and other animals in the United States.

CDC recommends that all persons exposed to highly pathogenic avian influenza (HPAI) A(H5N1) virus infected birds, cattle, or other animals be monitored for symptoms consistent with HPAI A(H5N1) virus infection starting the first day (day 0) of exposure and continuing until 10 days after the last exposure.

This report provides an update to the April 26, 2024, report to include three additional sporadic human cases (1 in Australia and 2 in the United States) and recent activity in wild birds, poultry, and other animals, including the multi-state outbreak in U.S. dairy cattle, and updated information on monitoring for human infections with highly pathogenic avian influenza A(H5N1) virus infections in the United States.

CDC continues to respond to the public health challenge posed by a multistate outbreak of avian influenza A(H5N1) virus, or "A(H5N1) virus," in dairy cows and other animals in the United States.

CDC has collaborating with STLT public health agencies to develop an enhanced summer influenza surveillance strategy.

CDC requests commercial laboratories continue to send influenza positive specimens to PHLs for further testing and characterization.

A second human case of highly pathogenic avian influenza (HPAI) A(H5) virus infection has been identified in the state of Michigan.

Influenza A(H5) virus infection was detected in two U.S. farm workers during a multistate outbreak of A(H5N1) viruses in dairy cows; these are the first known instances of presumed cow-to-human transmission of avian influenza A viruses.

A new CDC modeling study suggests that influenza testing in health care settings in the United States can serve as an effective warning system in the event of an outbreak of a novel (non-human) influenza virus with pandemic potential.

Technical Update: Summary Analysis of the Genetic Sequence of a Highly Pathogenic Avian Influenza A(H5N1) Virus Identified in a Human in Michigan

CDC A(H5N1) Bird Flu Response Update May 24, 2024

This fact sheet summarized current key public health prevention recommendations for HPAI A(H5N1) and provides links for additional information