Recommendations have been expanded to include/define certain additional job tasks that may put workers at risk for avian influenza A virus infection.

CDC continues to respond to the public health challenge posed by the outbreak of avian influenza A(H5N1) virus, or "H5N1 bird flu" in dairy cows and other animals in the U.S. CDC is collaborating with partners including the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), and state public health and animal health officials to address this emerging infectious disease using a One Health approach.

CDC is working with USDA and state partners to monitor for infections in exposed persons in the states where detections in poultry, backyard flocks, or other animals have occurred.

H5N1 is a bird u virus that could make you sick. Wear recommended personal protective equipment (PPE) when working directly or closely with sick or dead animals, animal feces, litter, raw milk, and other materials that might have the virus.

Any person working with or exposed to animals such as poultry and livestock farmers and workers, backyard bird flock owners, veterinarians and veterinary staff, and responders should take steps to reduce the risk of infection with avian influenza A viruses associated with severe disease when working with animals or materials potentially infected or confirmed to be infected with these viruses.

Highly pathogenic avian influenza (HPAI) A(H5N1) virus is an influenza virus that causes what is known as "bird flu." Although bird flu viruses mainly infect and spread among wild migratory water birds and domestic poultry, bird flu viruses have been shown to spread, although inefficiently, to mammals, including humans.

These recommendations are based on information available as of March 2024 and will be updated as needed when new information becomes available.

Vietnam has reported the country's first human infection with a low pathogenic avian influenza (LPAI) A(H9N2) virus.

On April 1, 2024, Texas reported a human infection with highly pathogenic avian influenza (HPAI) A(H5N1) virus (H5N1 bird flu) after confirmation by CDC. This is the first time this virus has been found in a cow and the second human case of H5N1 bird flu reported in the United States.

The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to inform clinicians, state health departments, and the public of a recently confirmed human infection with highly pathogenic avian influenza (HPAI) A(H5N1) virus in the United States following exposure to presumably infected dairy cattle.

On March 29, 2024, CDC reported this year's first U.S. human infection with an influenza (flu) virus that normally spreads in pigs and not people.

Avian Influenza Current Situation Summary

This is a technical summary of an analysis of the genomic sequences of viruses associated with an outbreak of highly pathogenic avian influenza (HPAI) A(H5N1) viruses in Texas.

CDC's Risk Assessment for the General Public Remains Low

All flu vaccines for the 2024-2025 season are anticipated to be trivalent in the United States. Both trivalent and quadrivalent flu vaccines are expected to offer similar protection against the flu viruses they protect against.

Trivalent flu vaccines protect against three different influenza viruses.

On March 5, 2024, the FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) met to discuss and make recommendations on the vaccine viruses for U.S. influenza vaccines for the 2024-2025 influenza season.

CDC reported 10 new flu-related pediatric deaths this week, bringing the total for the season to 103.

Interim flu vaccine effectiveness estimates show that so far during the 2023-2024 flu season, flu vaccines have worked, substantially reducing the risk of flu-related medical visits and hospitalizations across all age groups, with some estimates higher than have been previously observed, even during well-matched seasons.

Heart disease is a known risk factor for developing serious flu complications. But a growing body of research suggests that influenza virus infection itself could put people at increased risk for acute cardiovascular events, like heart attack and stroke.