New coronavirus “can survive 28 days on surfaces”, Australian study finds
Researchers from the Australian National Science Agency (CSIRO) found that at 20 degrees, SARS-CoV-2 is “extremely resistant” on smooth surfaces, such as telephone screens, glass or even glass. steel.
Knowledge is being refined on the lifespan of the coronavirus causing the Covid-19 pandemic, Sars-CoV-2. A study by the Australian National Science Agency (CSIRO), published Monday, October 12, shows that in a cool and dark environment, the new coronavirus can survive for up to twenty-eight days.
Researchers from the CSIRO’s disease prevention department have found that the warmer the temperatures, the lower the survival rate of Sars-CoV-2. They found that at 20 degrees, SARS-CoV-2 is “extremely resistant” on smooth surfaces, such as phone screens. It can survive 28 days on glass, steel and polymer banknotes. At 30 degrees this survival rate drops to 7 days and at 40 degrees it is only 24 hours.
On porous surfaces such as cotton, the virus survived less time, up to fourteen days at the lowest temperature and less than 16 hours at the highest. Compared to previous studies, which had shown that the coronavirus could survive for up to four days on non-porous surfaces, this time is “significantly longer”, according to Journal of Medical Virology.
Trevor Drew, director of the Australian Center for Disease Prevention, explained that this study involved drying samples of the virus on different materials before testing them with a method “extremely delicate”. It has made it possible to find traces of living virus capable of infecting cell cultures.
However, “it does not mean that this amount of virus could infect someone”, he said on the public channel ABC. However, if a person “careless with these materials would touch them, then lick your hands or touch your eyes or nose, you could be infected more than two weeks after they were contaminated”.
Trevor Drew expressed reservations in particular because this study was carried out with fixed levels of virus, probably corresponding to the peak of an infection, and in the absence of exposure to ultraviolet light which can rapidly alter the virus. Humidity was kept at 50%, according to the study, because a rise in humidity is also bad for the virus.
According to the CSIRO, the virus is mainly spread in the air but further research is needed to better understand its mode of transmission through surfaces.Trevor Drew recalled that the main message is that “contaminated people are much more contagious than surfaces”. “It may nevertheless help to explain why, even when there are no more contagious people, sometimes [l’épidémie] come back even if the country is considered virus-free “, he stressed.