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The coronavirus that causes Covid-19 can survive on items like banknotes and phones for up to 28 days in cool, dark conditions, according to a study by Australia’s national scientific agency.
Researchers from the CSIRO Center for Disease Preparedness tested the longevity of SARS-CoV-2 in the dark at three temperatures, showing that survival rates declined as conditions became warmer, the agency said Monday.
The scientists found that at 20 degrees Celsius (68 degrees Fahrenheit), SARS-CoV-2 was “extremely robust” on smooth surfaces, such as cell phone screens, and survived for 28 days on glass, steel and plastic banknotes.
At 30 degrees Celsius (86 degrees Fahrenheit), the survival rate dropped to seven days and dropped to just 24 hours at 40 degrees Celsius (104 degrees Fahrenheit).
The virus survived for shorter periods on porous surfaces like cotton, up to 14 days at the lowest temperatures and less than 16 hours at the highest, the researchers said.
This was “significantly longer” than previous studies that found the disease could survive up to four days on non-porous surfaces, according to the peer-reviewed article published in the Virology Journal.
Trevor Drew, director of the Australian Center for Disease Preparedness, said the study involved drying samples of the virus on different materials before testing them, using an “extremely sensitive” method that found traces of live viruses capable of infecting cell cultures.
“This does not mean that this amount of virus is capable of infecting someone,” he told the public broadcaster ABC.
He added that if a person was “careless with these materials and touched them and then licked their hands or touched their eyes or nose, it is very possible that they will become infected more than two weeks after they were contaminated.”
Drew said there were several caveats, including that the study was conducted with fixed levels of virus that likely represented the peak of a typical infection, and there was an absence of exposure to ultraviolet light, which can rapidly degrade the virus.
Humidity was stable at 50 percent, according to the study, as increases in humidity have also been found to be detrimental to the virus.
According to the CSIRO, the virus appears to be spread primarily through the air, but more research is needed to provide more information on the transmission of the virus through surfaces.
“While the precise role of surface transmission, the degree of surface contact, and the amount of virus required for infection have yet to be determined, establishing how long this virus remains viable on surfaces is critical to developing risk mitigation strategies. in high contact areas “. CSIRO’s Debbie Eagles said.
The main message remains that “infectious people are much, much more infectious than surfaces,” Drew told ABC.
“However, it can help explain why even when we get rid of infectious people, we occasionally get these outbreaks again, sometimes even in a country that considers itself free,” he said.
hr / arb / blood
