乌鸦传媒

The U.S. Department of Agriculture (USDA) has good news for meat eaters: cooking ground beef at the currently recommended temperatures would likely kill any avian flu virus if it should ever get into the meat supply.

"The USDA is confident that the meat supply is safe, and we have a rigorous meat inspection process in place," Eric Deeble, the USDA's acting advisor for highly pathogenic avian influenza (HPAI), said Thursday on a call with reporters. Although testing results announced on May 1 found no virus particles in any retail ground beef samples tested, "in the interest of scientific inquiry and to further reaffirm consumer confidence, USDA scientists initiated a series of studies on ground beef and beef muscle samples," he said.

In the latest test, USDA researchers inoculated a very high level of an HPAI virus surrogate into 300-gram (10.6-oz.) ground beef patties, and then cooked the patties at different temperatures. "Researchers found that there was no virus present in the burgers cooked to 145° [F.] internal temperature -- or roughly 'medium' -- or 160° [F.], which equates with a 'well done' burger, which is the recommended cooking temperature," said Deeble. Asked during a question-and-answer session about whether the virus was found in samples cooked at lower temperatures, he said that "cooking to -- I believe it was 120° [F.] -- showed that there was virus still in the cooked hamburger patty, but at much, much reduced levels."

Should consumers change the way they cook meat based on these results? Deeble said he didn't think so. "I would refer everyone to the [USDA's] FSIS [Food Safety and Inspection Service] webpage, which has a for a variety of different meat products. And I believe that the recommended temperature for burgers is 160° internal temperature, but I don't think that anybody needs to change any of the safe meat handling or safe cooking practices that are already recommended."

The agency is also collecting beef muscle samples from dairy cows that were found after slaughter to have indications of a possible respiratory virus. The USDA is using a polymerase chain reaction test to determine whether any viral particles are present in those samples, "and these results are forthcoming and we'll share them as soon as they're available," Deeble said.

In addition to the ground beef and beef muscle tests, the USDA's Animal and Plant Health Inspection Service is awarding more than $22.2 million to enhance prevention, preparedness, early detection, and rapid response to the most damaging diseases that threaten U.S. livestock, the agency .

This includes $16.2 million to help states develop and practice plans to control disease outbreaks, train responders and producers to respond to animal disease outbreaks, increase use of biosecurity measures, educate livestock owners on outbreaks and disease prevention, and support animal movement decisions during outbreaks. The funding also includes $5 million awarded directly to laboratories in the National Animal Health Laboratory Network for infrastructure needs.

During the call, Deeble also addressed reports of people drinking raw milk in hopes of developing an immunity to the H5N1 virus. "We've read those reports as well," he said. "Suffice it to say that our long-standing recommendation against consumption of raw milk remains in place. It is even more important in the context of individuals who might be seeking raw milk under the mistaken belief that it may provide some degree of protection against [H5N1]. Just the opposite is true -- raw milk is unsafe at any speed, and the notion that you could protect yourself against H5 infection by consuming it is erroneous. There are much safer ways to protect oneself."

He added that the USDA "has been in communication with all of the affected known herds, and we are not aware of any raw milk being sold from any of those premises." The number of currently affected herds now stands at 49, up from 42 reported by USDA officials on a press call last week. "We think part of the reason that we are seeing an increase in the number of herds within states ... is because of the ongoing testing that is happening," Deeble said. States that haven't previously had affected herds seem to be staying unaffected, which Deeble said he attributed "at least in part [to] the federal order that restricts the movement of lactating dairy cattle without having confirmatory negative testing done prior to shipping."

As to when the current outbreak started, "the information that we have about the epidemiology indicate[s] that the spillover event from wild birds into dairy cattle was likely somewhere in the late 2023 timeframe," said Rosemary Sifford, deputy administrator for veterinary services and chief veterinary officer at USDA. "The virus probably started to circulate in cattle shortly after that. All the evidence points to the fact that after that spillover event -- in the Texas panhandle region -- the movement to other herds since that time has been through contacts between those herds, whether that be movement of cattle or equipment or other items."

Comment