The study claims that SARS-CoV-2 can remain infectious on surfaces for long periods of time, reinforcing the need for good practices such as regular hand washing and cleaning surfaces
Multiple researchers across the world are still trying to develop robust knowledge about the Covid-19 virus. A new research now suggests that the Covid-19 virus could survive on common surfaces such as glass and even banknotes for as long as 28 days in certain conditions.
According to a laboratory study by Australia's national science agency, the virus that causes Covid-19 can remain on surfaces such as stainless steel and glass, similar to the ones found on smartphones, for a considerable amount of time.
The new research has been published in the Virology Journal. It claims that SARS-CoV-2 can remain infectious on surfaces for long periods of time, reinforcing the need for good practices such as regular hand washing and cleaning surfaces.
The Australian Centre for Disease Preparedness (ACDP) undertook this research and found that SARS-CoV-2 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.
Another set of researchers at Australia's national science agency, CSIRO also found that the novel coronavirus survived 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 CSIRO Chief Executive Larry Marshall.
"At 20 degrees 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," Debbie Eagles, Deputy Director of ACDP added.
According to the researchers, a similar test has been conducted on Influenza A virus and it managed to survive on smooth surfaces for up to 17 days. The Covid-19 virus lasted an extra 11 days, indicating its high resilience compared to previously known Influenza virus A.
The researchers first dried the virus in an artificial mucus on different surfaces, at concentrations similar to those reported in samples from infected patients and then re-isolated the virus for over a month. Further experiments were carried out at 30 and 40 degrees Celsius, with survival times decreasing as the temperature increased.
This new study was carried out in the dark in order to avoid factoring in the effect of UV light on the virus. Direct sunlight is known to rapidly inactivate the Covid-19 virus.
"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," Eagles said.
According to Professor Trevor Drew, Director of ACDP, many viruses remain viable on surfaces outside their host.
"How long they can survive and remain infectious depends on the type of virus, quantity, the surface, environmental conditions and how it's deposited -- for example touch vs droplets emitted by coughing," Drew said.
"Proteins and fats in body fluids can also significantly increase virus survival times," he said.
The study may also help to explain the apparent persistence and spread of SARS-CoV-2 in cool environments with high lipid or protein contamination, such as meat processing facilities and how we might better address that risk, the researchers said