H5 Bird Flu: Current Situation

What to know

  • H5 bird flu is widespread in wild birds worldwide and is causing outbreaks in poultry and U.S. dairy cows with several recent human cases in U.S. dairy and poultry workers.
  • While the current public health risk is low, CDC is watching the situation carefully and working with states to monitor people with animal exposures.
  • CDC is using its flu surveillance systems to monitor for H5 bird flu activity in people.
H5N1 Bird Flu How is it Spreading?

Current situation

H5 Bird Flu Detections in USA‎

• Dairy cattle: Ongoing multi-state outbreak



• Wild Birds: Widespread

• Poultry Flocks: Sporadic outbreaks

• Mammals: Sporadic infections

• Person-to-person spread: None

• Current public health risk: Low

Confirmed human case summary during the 2024 outbreak, by state and exposure source

Exposure Source

Exposure Source
State Cattle Poultry Unknown State Total
California 31 0 1 32
Colorado 1 9 0 10
Michigan 2 0 0 2
Missouri 0 0 1 1
Oregon 0 1 0 1
Texas 1 0 0 1
Washington 0 11 0 11
Source Total 35 21 2 58

NOTE: One additional case was previously detected in a poultry worker in Colorado in 2022.

Additional cases meeting the Council of State and Territorial Epidemiologists (CSTE) probable case definition have been reported by states: 1 case with dairy cow exposure (CA), 3 cases with poultry exposure (WA), and 2 cases with poultry exposure (AZ). Confirmatory testing at CDC for these cases was negative.

This table is typically updated by 5 PM EST on Mondays (for cases confirmed by CDC on Friday, Saturday, or Sunday), Wednesdays (for cases confirmed by CDC on Monday or Tuesday), and Fridays (for cases confirmed by CDC on Wednesday and Thursday). Affected states may report cases more frequently.

H5 Monitoring in People‎

CDC influenza (flu) surveillance systems show no indicators of unusual influenza activity in people, including avian influenza A(H5).

National flu surveillance (since February 25, 2024)

Targeted H5 surveillance (since March 24, 2024)

Detections in Animals

  • 10,718 wild birds detected as of 12/10/2024 | Full Report
  • 51 jurisdictions with bird flu in wild birds
  • 120,572,146 poultry affected as of 12/10/2024 | Full Report
  • 49 states with outbreaks in poultry
  • 742 dairy herds affected as of 12/10/2024 | Full Report
  • 16 states with outbreaks in dairy cows

These data will be updated daily, Monday through Friday, after 4 p.m. to reflect any new data.

Cumulative data on wild birds have been collected since January 20, 2022. Cumulative data on poultry have been collected since February 8, 2022. Cumulative data on humans in the U.S. have been collected since April 28, 2022. Cumulative data on dairy cattle have been collected since March 25, 2024.

What CDC is doing

Protective Actions for People