CLEVELAND, Ohio – Infectious disease experts are downplaying a report out of Singapore that suggests the coronavirus can be transmitted by food because the virus was found living on salmon, pork and chicken three weeks after the meat had been frozen or refrigerated.
While the study showed it’s biologically possible for the virus to survive on salmon, pork and chicken for three weeks, that’s not news, said Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security and one of three experts contacted by cleveland.com and The Plain Dealer.
The question is whether the coronavirus can be transmitted by food, Adalja said, and that’s not very likely
Researchers in Singapore tested the survivability of the coronavirus under lab conditions in an effort to explain how the virus might have reemerged in places such as New Zealand, Vietnam and parts of China, where it had appeared to have been eradicated.
Their report attempts to piece together information to suggest food borne transmission could be to blame. They quote the World Health Organization as believing it is “very unlikely that people can contract COVID-19 from food or food packaging.” But they also describe the possibility that “contaminated items” can lead to an outbreak as an “important hypothesis.”
The report, however, has not been peer reviewed and was posted on a website, biorxiv.org, with a disclaimer stating coronavirus-related papers posted there “should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information.”
Adalja at Johns Hopkins noted that the primary means of transmission of the coronavirus is through respiratory droplets passed along through close contact, unlike other viruses such as the norovirus and hepatitis A that are considered food borne diseases.
The research out of Singapore is getting media attention simply because it’s about the coronavirus, he said, and while worth conducting, is not a big deal
“I mean nobody is reporting on the big salmonella outbreak in peaches right now,” he said. Salmonella is a food-borne bacteria.
Dr. Claudia Hoyen, director of pediatric infection control at University Hospital’s Rainbow Babies & Children’s Hospital, said she knows from her time working in the laboratory that viruses are often refrigerated or frozen to preserve them. And like Adalji, she is not surprised by the report’s findings.
“They are trying to connect all the dots,” Hoyen said of the researchers who produced the report. ” . . . . . but at this point I don’t think we have enough information to worry about this.”
Mark Cameron, associate professor in the Department of Population and Quarantine Health Sciences at Case Western Reserve School of Medicine, dismisses the report for the same reason.
“A virus can survive indefinitely under these laboratory conditions, and therefore the study has absolutely no bearing on real-world transmission risks,” wrote in an email. “With millions of cases mounting, there has been no evidence that COVID-19 can be transmitted on our food and no evidence of cases being caused by consumer handling or consumption of food.”