Coronavirus survives on phones and banknotes for weeks

The researchers found that it survived longer at lower temperatures and on non-porous or smooth surfaces such as glass, stainless steel and vinyl, compared to porous complex surfaces such as cotton. It was also found to survive longer on paper banknotes than plastic banknotes.

“Establishing how long the virus really remains viable on surfaces enables us to more accurately predict and mitigate its spread and do a better job of protecting our people,” said Dr Larry Marshall, chief executive, CSIRO.

The research involved drying the virus in an artificial mucus on different surfaces, at concentrations similar to those reported in samples from infected patients and then re-isolating the virus over a month.

Further experiments were carried out at 30° and 40° Celsius, with survival times decreasing as the temperature increased.

The study was also carried out in the dark, to remove the effect of UV light which can rapidly inactivate the virus, something of which train stations and airports have taken note.

The new findings may also help to explain the apparent persistence and spread of the coronavirus in cool environments with high lipid or protein contamination, such as meat-processing facilities.

“While the precise role of surface transmission, the degree of surface contact and the amount of virus required for infection is yet to be determined, establishing how long this virus remains viable on surfaces is critical for developing risk-mitigation strategies in high-contact areas,” said Dr Debbie Eagles, deputy director at the Australian Centre for Disease Preparedness (ACDP).

“Our results show that SARS-CoV-2 can remain infectious on surfaces for long periods of time, reinforcing the need for good practices such as regular handwashing and cleaning surfaces.

“At 20° Celsius, which is about room temperature, we found that the virus was extremely robust, surviving for 28 days on smooth surfaces such as glass found on mobile phone screens and plastic banknotes.

“For context, similar experiments for Influenza A have found that it survived on surfaces for 17 days, which highlights just how resilient SARS-CoV-2 is.”