When cases of Covid-19 first began emerging in Australia, some people reported disinfecting their groceries before bringing them into their homes, and there were also concerns that the virus could be living on the surfaces of packages in the mail.

An epidemiologist with La Trobe University, Associate Prof Hassan Vally, said just over one year later it has become clear surface transmission is not as significant a factor in Covid-19 spread as once feared.

While surface transmission is not impossible, Vally said its role in spread needs perspective.

Close contact aerosol spread is the driving factor in Covid-19 transmission, primarily when an infected person is in close contact with another person and transmit small liquid particles [droplets and aerosols] containing the virus, especially when they cough and sneeze.

In a piece for the Conversation, Vally said: “This isn’t to say surface transmission isn’t possible and that it doesn’t pose a risk in certain situations, or that we should disregard it completely.

“In my opinion, 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 the cough or sneeze (within 1–2 hours),” Goldman said.

Fuelling the concern about surface spread were seemingly alarming but overblown studies, including one from the Australian government agency CSIRO that found a droplet of fluid containing the virus at concentrations similar to levels observed in infected patients could survive on surfaces such as cash and glass for up to 28 days.