For months, scientists have said there’s no evidence that people can catch the virus through food or packaging. But that doesn’t mean it can’t happen.
Around the world, virtually all leading health agencies say the same thing: There is currently no evidence that people can catch Covid-19 from food. And experts beseech us: Stop wiping down your groceries. But just because there’s no evidence of transmission doesn’t mean it can’t happen.
For the next two years, researchers at Virginia Tech will thoroughly investigate that possibility, backed by a $1-million grant from the Department of Agriculture (USDA) to study how long the coronavirus that causes Covid-19 can live on food surfaces and packages, how it responds to different sanitizers, and its likelihood of survival as it travels along the food chain.
Food science and technology professor Reza Ovissipour, the primary investigator on the project, admits there isn’t much evidence that Covid-19 could be a foodborne illness. Nevertheless, he says it warrants further study: “I think this virus can survive on food material, but for how long, and under what conditions is unclear at this moment.”
In June and September, China suspended imports of American meat, over concerns that skyrocketing coronavirus cases would lead to infected poultry.
In the early days of the pandemic, Americans were petrified of catching the virus through food. News articles advised eaters on how to properly scrub their produce, and medical doctors said grocery shoppers could sanitize jars and containers if it made them “feel better.” Scientists discovered the virus lingering on packaging materials, like cardboard and plastic, for hours and days after exposure.
But since May, when the Centers for Disease Control changed its public guidance to state that surface-to-surface contact “isn’t thought to be the main way the virus spreads,” much of the hysteria has died down. There is some consensus that transmission from fomites, as surfaces are officially called, is highly unlikely. That could be because they require “unrealistically strong concentrations” to transmit the virus to people. Or it could simply be the case that fomite transmission is hard to prove, Angela Rasmussen, a Columbia University virologist, told The Washington Post.
“It’s not at all uncommon to not have strong epidemiological evidence,” she said, “but that doesn’t mean that fomite transmission doesn’t happen.”
At Virginia Tech, a team of seven virologists and food scientists will conduct their research in a biosafety lab on campus, where they will create droplets with the live virus, and spray them on foods, packaging materials, and handling surfaces. The goal is to see how long the virus survives under different environmental conditions—like low or high humidity, or at room temperature, refrigeration, or the freezing cold.
The group will mimic the food supply chain in the lab by inoculating gloves, and studying how the virus survives as it’s transferred from hand to food to contact surfaces.
Besides food contact surfaces, like stainless steel, plastics, and cardboard, the team will inoculate produce like avocados, tomatoes, spinach, and cantaloupe—selected for tactile variety. They will also test the virus on seafoods like oyster and salmon and meats such as steaks and chicken breasts. The meats have a range of proteins and fats, in addition to different surfaces, that could affect the survival of the virus, Ovissipour says.
Also on the list? The group will mimic the food supply chain in the lab by inoculating gloves, and studying how the virus survives as it’s transferred from hand to food to contact surfaces. It’s also going to test the efficacy of five different sanitizers, including bleach and peracetic acid, in killing the virus at all levels of the supply chain—from the farm to the processor to the grocery store.
“One drop of saliva from a person who is sick contains millions of particles of the virus,” Ovissipour pointed out. “Definitely, we need answers,” he said, when it comes to how long those particles can live in food and on its surfaces.
“We are not saying that this is a wholesale problem of foodborne outbreak with Covid. But it is a possibility.”
Indeed, as new studies show that the coronavirus that causes Covid-19 can potentially survive on surfaces for days and weeks, the Virginia Tech study, which looks at the entire food chain, could take on added importance, particularly when it comes to the sensitive issue of international trade. In June and September, China suspended imports of American meat, over concerns that skyrocketing coronavirus cases would lead to infected poultry. At the time, American authorities said the ban was “not consistent with the known science of transmission.”
Hamada Aboubakr and Sagar Goyal, food virologists at the University of Minnesota, point out several instances of Chinese authorities allegedly finding coronavirus on frozen food packaging, including the first discovery of live virus this week, and a baffling reemergence of Covid-19 in New Zealand linked to a frozen food worker. In an interview with The Counter, Aboubakr and Goyal say that the question of Covid-19 transmission through food isn’t settled science. In a September preprint article, they claim that this transmission is “more evident than previously thought possible.”
They also point out that the coronavirus that causes Covid-19 behaves similarly to the human norovirus, which transmits disease through food, often fresh produce. Both viruses remain infectious on surfaces for weeks, are highly contagious, and can survive in the GI tract.
“We have to take any eventuality into consideration,” said Goyal. “We are not saying that this is a wholesale problem of foodborne outbreak with Covid. But it is a possibility.”
The first batch of results from the Virginia Tech study will be released in February, and shared with industry trade groups and state agencies.