While a World Health Organization representative initially advised people to use contactless payments when making purchases during the pandemic, the international health agency later clarified its advice, instead urging people to wash their hands after handling money.
It’s advice worth heeding in light of new research from Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
“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 Dr. Larry Marshall.
A study published this October in Virology Journal found SARS-CoV-2, the virus that causes COVID-19, can survive for up to 28 days on common surfaces such as banknotes. Researchers dried virus particles in an artificial mucus on different surfaces (and at concentrations similar to those reported in samples from infected patients) before re-isolating the virus over a month. Experiments were carried out at 20, 30 and 40 degrees Celsius, with survival times decreasing as the temperature increased. The tests were also done in the dark to remove any effect from ultraviolet light, which may inactivate the virus as other research has shown.
CSIRO researchers not only found SARS-CoV-2 survived longer at lower temperatures, but it tended to survive longer on non-porous or smooth surfaces such as glass, stainless steel and vinyl (compared to porous, complex surfaces such as cotton).
“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,” said Dr. Debbie Eagles, deputy director of the Australian Centre for Disease Preparedness (ACDP), where the research was undertaken.
For context, similar experiments for “Type A” influenza viruses – the only influenza viruses known to cause flu pandemics – found it survived on surfaces for 17 days, highlighting “just how resilient SARS-CoV-2 is,” Eagles said.
“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,” she added.
In partnership with the Australian Department of Defence, CSIRO undertook the studies in collaboration with the 5 Nation Research and Development (5RD) Council, which comprises representatives from Canada, the United States, the United Kingdom, New Zealand and Australia. Each country is conducting research on different aspects of virus survivability, and the results are shared as they become available.
To read the full study, “The effect of temperature on persistence of SARS-CoV-2 on common surfaces,” visit bit.ly/3iWXvuG.