A team of Australian researchers have found that the virus causing Covid-19 can survive at room temperature for up to 28 days on surfaces like glass, stainless steel and banknotes — much longer than the flu virus and longer than previous studies have found — highlighting the need for regular cleaning and handwashing.
The study, published in Virology Journal, found that the novel coronavirus could survive longer at lower temperatures and on smoother surfaces like the glass found on cell phone screens and banknotes.
The study measured the survival rates of the novel coronavirus on different surfaces at temperatures of 20, 30, and 40 degrees celsius on different kinds of surfaces.
However, the experiment was conducted in the dark — UV light is known to kill the virus.
The studies show the new coronavirus to be more resilient than flu — under the conditions it survived for 17 days.
While coronavirus is mostly transmitted through droplets when people talk, cough or sneeze, it is possible to be infected by touching contaminated surfaces. It is not, however, believed to be a common route of transmission. While this study emphasises the need to maintain proper levels of hygiene, particularly through diligent handwashing and surface cleaning, it is important to remember that it was conducted under laboratory conditions that may not adequately represent real life. The absence of light is a good example of this, with UV light being known to kill the virus.
Dr Debbie Eagles, one of the authors of the paper, said: “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 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.“
Professor Ron Eccles, who is the former director of the Common Cold Centre at Cardiff University, told the BBC that the suggestion the virus could survive for 28 days causes “unnecessary fear in the public.” He said the study did not use “fresh human mucus as a vehicle to spread the virus,” which would normally help neutralize viruses. “In my opinion infectious viruses will only persist for hours in mucus on surfaces rather than days,” he said.
The effect of temperature on persistence of SARS-CoV-2 on common surfaces (Virology Journal, Open Access)