WASHINGTON — The US Department of Agriculture determined that when cooking ground beef to the proper internal temperature, the H5N1 virus would be killed.

The agency’s Food Safety and Inspection Service (FSIS) and Agricultural Research Service (ARS) released the results of a study on May 16 that sought to determine the effectiveness of cooking related to H5N1 and beef.

To carry out the study, ARS inoculated a very high level of an H5N1 virus surrogate into 300 grams ground beef patties — roughly three times larger than the average burger patty. The patties were cooked to three different temperatures: 120°F, 145°F and 160°F. After cooking, the presence of the virus was measured. 

The results indicated no virus was present in the burgers cooked to 145°F (medium) or 160°F (well done) degrees. USDA noted that even when cooking burgers to 120°F (rare) degrees, which is well below the recommended temperature, the virus was substantially inactivated.

“These results validate that FSIS’ recommended cooking temperatures are sufficient to kill H5N1 in meat,” the agency concluded.

The USDA posted the results of another H5N1 and ground beef related study earlier this month, indicating no virus particles were present at retail stores located in states that have tested positive for H5N1.

Currently, the agency is conducting a study on beef muscle samples of cull dairy cows condemned at select FSIS-inspected slaughter facilities. The results will be posted as soon as they become available, USDA said.