While world health authorities and experts advise you to frequently sanitise your hands to prevent the spread of Covid-19, there is no need to give your groceries the same treatment.

Prof Wolfgang Preiser, head of medical virology at Stellenbosch University’s department of pathology, told the Sunday Times that assuming the groceries are clean there is no need to disinfect them.

“Packaging is extremely unlikely to be contaminated with a viable (still infectious) virus unless visibly soiled. In any case, packaging is removed before the preparation and consumption of food. Throw it away or recycle it and wash your hands with soap and water — done.”

A study published in medRxiv found the virus can live on cardboard for up to 24 hours, and up to two to three days on plastic and stainless steel.

“Studies suggest that coronaviruses, including preliminary information on the Covid-19 virus, may persist on surfaces for between a few hours and several days,” the research finds. “This may vary under different conditions: type of surface, temperature and humidity.”

However, Preiser says food products are typically kept under strict hygiene conditions and handled by cautious staff, so the risk of getting Covid-19 through any of this is virtually nil.

Angela Rasmussen, a virologist at the Center for Infection and Immunity at Columbia University's Mailman School of Public Health told US National Public Radio the probability of getting infected from a contaminated surface is low.

Respiratory droplets would have to have landed on the exact spot on the box you are touching in a large enough number to include infectious particles and you would have to touch your face in the time between touching it and washing/sanitising your hands.

Dr Susan Louw, haematopathologist at the National Health Laboratory Service, said the World Health Organisation has indicated there is no evidence that people can catch Covid-19 from food or food packaging.

“Covid-19 is a respiratory illness and the transmission route is through person-to-person contact and through direct contact to respiratory droplets generated when an infected person coughs, sneezes or talks. It’s not a food-borne disease so it can’t grow in food or survive for a very long time on the packaging of food.

“If it is present on the packaging it still hasn’t been proven that that virus can actually cause the disease in the people who handle the packaging — it may just be viral particles, pieces of virus instead of an intact virus.”

She warned that sanitising may cause more harm than good.

“What could be dangerous is if sanitising agents are ingested. That could be more dangerous than actually ingesting some viral particles that are not contagious.”