Last Modified: May 16, 2024

What's New

May 16, 2024

USDA’s Food Safety and Inspection Service (FSIS) and Agricultural Research Service (ARS) are announcing results from the ground beef cooking study. The study was conducted to determine the effectiveness of cooking related to H5N1 and beef. Ground beef patties were inoculated with a very high concentration of an H5N1 virus surrogate. The ground beef patties did not previously contain any virus particles prior to inoculation for the purposes of the study. No virus remained in burgers cooked to 145 and 160 degrees Fahrenheit. These results validate that FSIS’ recommended cooking temperatures are sufficient to kill H5N1 in meat. 

May 1, 2024: USDA’s Food Safety and Inspection Service (FSIS) announced results from its testing of retail ground beef. FSIS collected 30 samples of ground beef from retail outlets in the states with dairy cattle herds that had tested positive for the H5N1 influenza virus at the time of sample collection. The samples were sent to APHIS’ National Veterinary Services Laboratories (NVSL) for PCR testing. On May 1, NVSL reported that all samples tested negative for H5N1. These results reaffirm that the meat supply is safe.


USDA is confident that the meat supply is safe. USDA has a rigorous meat inspection process, where USDA’s Food Safety and Inspection Service (FSIS) veterinarians are present at all federal livestock slaughter facilities. FSIS inspects each animal before slaughter, and all cattle carcasses must pass inspection after slaughter and be determined to be fit to enter the human food supply. 

While we have multiple safeguards in place to protect consumers, we recommend consumers properly handle raw meats and cook to a safe internal temperature. Cooking to a safe internal temperature kills bacteria and viruses in meat. Specific recommendations are available online at: Safe Minimum Internal Temperature Chart | Food Safety and Inspection Service (

Ongoing Research

To verify the safety of the meat supply in the context of H5N1, USDA’s FSIS, APHIS, and Agricultural Research Service (ARS) are working on three separate beef safety studies related to avian influenza in meat from dairy cattle. These studies are taking place in the interest of scientific inquiry and reaffirm consumer confidence. 

  1. Samples of ground beef obtained at retail in the affected States: Final results were posted on May 1, 2024. Samples were collected at retail outlets in the States in which dairy cattle herds have tested positive for H5N1 influenza virus. The samples were analyzed by APHIS using polymerase chain reaction (PCR), to indicate whether any viral particles were present. No virus particles were found to be present.
  2. Beef muscle sampling of cull dairy cows condemned at select FSIS-inspected slaughter facilities: FSIS has completed collection of muscle samples at FSIS-inspected slaughter facilities from cull dairy cattle that have been condemned for systemic pathologies. The samples are currently being analyzed by APHIS using PCR to determine presence of viral particles. The results are forthcoming and will be posted as soon as they become available. 
  3. Ground beef cooking study: Final results were posted on May 16, 2024. ARS inoculated a very high level of a HPAI virus surrogate into 300 grams ground beef patties (burger patties are usually 113 grams) to determine whether FSIS recommended cooking temperatures are effective in inactivating H5N1 virus The burger patties were then cooked to three different temperatures (120, 145 and 160 degrees Fahrenheit), and virus presence was measured after cooking. There was no virus present in the burgers cooked to 145 (medium) or 160 (well done) degrees, which is FSIS’ recommended cooking temperature. Even cooking burgers to 120 (rare) degrees, which is well below the recommended temperature, substantially inactivated the virus.