Can You Capture Frozen Food’s Coronavirus? Experts say no.

In the middle of a flower of care on reports that frozen chicken wings imported to China from Brazil tested positive for the coronavirus, experts said on Thursday that the chances of the virus being caught from food – especially frozen, packaged foods – are extremely low.

“This means that someone probably treated those chicken wings that may have had the virus,” said Angela Rasmussen, a virologist at Columbia University. “But it does not mean, ‘Oh my god, no one buys chicken wings because they are contaminated.'”

Guidelines from the Centers for Disease Control and Prevention state that “there is no evidence to suggest that food handling or food consumption is linked to Covid-19.” The main route by which the virus is known from person to person is by spraying sneezing, coughing, talking or even breathing.

“I make no connection between this and any fear that this is the cause of any long-distance transmissions,” said C. Brandon Ogbunu, a disease ecologist at Yale University. When the virus crosses international borders, it is almost certainly chauffeured by humans, instead of the commercial products they ship.

The chicken wings were screened on Wednesday in Shenzhen’s Longgang district, where officials tested imports for the presence of coronavirus genetic material, such as RNA. Several samples taken from the outer packaging of frozen seabirds, some of which were shipped from Ecuador, have also recently tested positive for RNA virus in China’s Anhui, Shaanxi and Shandong provinces.

Laboratory procedures looking for RNA also form the basis of most of the coronavirus tests performed in humans. But RNA is only a proxy for the presence of the virus, which can leave behind bits of its genetic material, even after it has been destroyed, said Dr. Ogbunu. “This is just to detect from the signature that the virus has been there at some point,” he said.

To prove that a dangerous, viable virus persists on food as packaging, researchers would have to isolate the microbe and show in a lab that it can still replicate. These experiments are logistically challenging and require specially trained personnel, and are not part of the typical test pipeline.

After samples taken from the surface of the meat came up positively, officials conducted similar tests on several people they suspected came in contact with the product. They also test many other packaged goods. All samples analyzed so far have been negative for coronavirus RNA, according to a statement released by the Office Epidemic Office of Prevention and Control Headquarters.

But the same statement warned consumers about imported frozen products, and early reports of the news spoke alarm on social media.

Both Dr. Ogbunu as Dr. Rasmussen said an unusual series of events would have to occur before the virus could be transmitted through a frozen meat product. Depending on where the virus originated, it would have to undergo a potentially cross-continental journey in a frozen state – probably melting and resurfacing at least once en route – then find its way into someone’s bare hands, en route to the nose or mouth.

Even more unlikely is the scenario that a virus can pull on food after it has been heated, survived was dragged into the ultra-acidic human digestive tract, and then set up shop in the airway.

“The risks of that happening are incredibly small,” said Drs. Rasmussen.

Some viruses could heat up such a perishable pilgrimage route. But the coronavirus is probably not one of them, because it is a so-called enveloped virus, encased in a fragile outer shell that is vulnerable to all kinds of environmental disturbances, including extreme temperature changes.

Viruses are often frozen in laboratories that maintain supplies of pathogens for experiments. But virologists need to carefully monitor that process so as not to destroy the vulnerable bugs.

“The act of freezing and unfreezing is a kind of violent thermodynamic process,” said Drs. Ogbunu. “A virus is, for all its toughness and robustness, a very delicate instrument of infection.”

The CDC has noted that “it is possible” that the coronavirus could spread through contaminated surfaces, including food or food packaging. But that is not known among the main ways in which the virus is spread.

If you do not want to get infected, then direct contact with other people is likely to be a better use of your time, said Dr Ogbunu.

“Yes, we need to continue to wash our hands and think about surfaces where many individuals are,” he said. “But it’s close to others who can really facilitate the transfer.”