​Highly Pathogenic Avian Influenza (HPAI) viruses can spread from wild birds to domestic poultry and other avian and animal species. HPAIs are highly contagious and frequently cause fatal disease primarily affecting poultry. They may also be referred to as bird or avian flu. 

2024 HPAI H5N1 Outbreak (Dairy Cows) 

Since late March 2024, the US Department of Agriculture (USDA)US Centers for Disease Control and Prevention (CDC), and US Food and Drug Administration (FDA), and state veterinary and public health officials have been investigating outbreaks of influenza A (H5N1) in dairy cows and related exposures.

APHL is coordinating with these federal partners and public health laboratories to mitigate the impact of HPAI on both animal and public health. Public health laboratories in all 50 states are equipped for detecting the causative agent in this outbreak; influenza A (H5N1) viruses.

Situational update (as of June 28):

HPAI Testing and Surveillance Information

HPAI Frequently Asked​ Questions and Resources 

Federal Partners

From CDC's June 5, 2024 H5N1 Technical Report: CDC, along with state and local public health partners, continues to monitor people in the US who have been exposed to infected birds, poultry, dairy cattle or other animals for 10 days after their last exposure. To date, more than 9,000 people in 52 jurisdictions have been monitored since 2022.

Public Health Laboratories

Public health laboratories in all 50 states are equipped for detecting influenza A (H5N1) viruses, and 26 APHL member laboratories test milk under the Pasteurized Milk Ordinance.

Public health laboratories are likely to see an increase in summer influenza testing this season, particularly in areas of the country with active outbreaks. The following types of laboratories or laboratory departments should prepare for surge testing:  

  • National Incluenza Reference CentersVirology laboratories that perform influenza subtyping 

  • National Influenza Reference Centers 

  • Influenza Sequencing Centers 

  • National Animal Health Laboratory Network members 

  • Food safety laboratories

  • Veterinary diagnostic laboratories

HPAI Response Resources

Visit APHL’s Influenza site for more information about seasonal influenza surveillance and other influenza-related testing resources