The coronavirus SARS-CoV-2 can survive for as long as 28 days on some surfaces such as phone screens and banknotes, according to research announced by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia.
The research suggests that the virus is a lot more persistent than previously imagined, and could indicate an important vector for the spread of the disease.
Until now, the three most important ways for people to protect themselves and others from the virus that causes Covid-19 have been hand hygiene, mask wearing and social distancing. But the emphasis has been more on masks and distancing, perhaps because of the three, hand hygiene is assumed to already be a habit.
The Australian research confirms that droplets produced by coughing and sneezing are still the main way the virus spreads from one person to another, but it does place a new emphasis on the possibility of being infected indirectly – if one person deposits viral material on a surface, and then another comes along later and picks it up, going on to infect themselves, effectively, by touching their face, eyes and nose.
The research by the Australian Centre for Disease Preparedness (ACDP) in Geelong in Victoria state showed that the virus survived for longer on smooth surfaces like glass, stainless steel and plastic, rather than fabrics like cotton. In addition, lower temperatures are more hospitable to the virus.
“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 ACDP.
“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.”
Previous research from the US showed the virus surviving for 72 hours on plastic and stainless steel, but only 24 hours on cardboard. A more recent study from China reported that it remained “stable on plastic, stainless steel, glass, ceramics, wood, latex gloves, and surgical mask, and remained viable for seven days on these seven surfaces.”
This latest research extends that period to up to 28 days.
“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 hand-washing and cleaning surfaces,” Dr Eagles said.