There is growing evidence that food packaging is transporting SARS-CoV-2 across international borders. Several countries are linked to either exported or imported frozen food that tested positive for traces of the virus, but experts say they believe the risk of developing COVID-19 from handling these products remains extremely low.
“The number of virus particles coming out a person’s mouth or nose is far greater than a few virus particles remaining on frozen foods, somebody touching it and then spreading it,” T. Jacob John, a retired virologist at Christian Medical College, tells Reuters. “Among all the risks, I think these are very low risks.”
China has reported the most cases of packaging contamination, according to NBC News, due in part to a massive screening effort targeting imported goods across the country. Last month, Chinese health officials found traces of the coronavirus on frozen goods imported into the cities of Dalian, Xiamen, and Pingxiang. In the last four days, similar findings have been reported in Wuhu and Shenzhen, linked to frozen shrimp and chicken wings imported from Ecuador and Brazil, respectively, and to frozen seafood of unnamed origins arriving in the port city of Yantai.
After New Zealand reported its first new cases of COVID-19 in more than three months, contact tracing revealed that one of the infected people worked in an import receiving facility, The Guardian reports. As a result, public officials are considering the possibility that the virus arrived in the country on freight. The facility is currently being tested to rule it out. “We can see the seriousness of the situation we are in,” Prime Minister Jacinda Ardern said in a news conference. “It’s being dealt with in an urgent but calm and methodical way.”
Previous research has shown that the virus can remain on packaging for hours or even days, depending on the type of material and the ambient conditions. For paper and plastic, the materials related to the most recent reports, that time varies between four to five days, Reuters reports, although other studies have given different ranges. Among the cases in China and New Zealand, it’s difficult to know just when the virus was introduced onto the contaminated surfaces. It could have happened at any point along the transport chain.
Both the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) dismiss the idea that disease transmission on packaging is a serious concern.
The WHO says it is “highly unlikely that people can contract Covid-19 from food or food packaging,” due to the fact that coronaviruses require a living host to multiply. Outside a body, they gradually become weaker and lose the ability to actively infect. In a June memo, the CDC similarly claimed that the risk of infection from food products or bags is “thought to be very low.” Remnants of dead virus have been known to cause false positive results in recovered patients, CNN reports.
Researchers have taken to scientific journals to downplay transmission by fomites, a term for the surfaces themselves. In a recent commentary in The Lancet, Emanuel Goldman, a microbiologist at Rutgers New Jersey Medical School, said, “the chance of transmission through inanimate surfaces is very small, and only in instances where an infected person coughs or sneezes on the surface, and someone else touches that surface soon after.”
Speaking to The Atlantic in July, Goldman stated his position more emphatically: “Surface transmission of COVID-19 is not justified at all by the science.”