The virus that causes COVID-19 can survive much longer than previously thought, remaining infectious on surfaces such as banknotes, glass, phone screens and stainless steel for 28 days, according to a new study.
In comparison, the flu virus has been shown to survive on surfaces for 17 days.
Researchers from the Australian science agency CSIRO conducted experiments on the SARS-COV-2 virus at 68 degrees – room temperature – and in the dark to remove the effect of ultraviolet light, as studies have shown that sunlight can kill the bugs, Reuters reported.
“So in the real world, the results would probably be shorter than we were able to show,”
“It really reinforces the importance of washing hands and sanitizing where possible, and certainly cleaning surfaces that may be in contact with the virus,” Riddell said of the research.
In the study, the virus was dried in artificial mucus on a variety of surfaces at concentrations similar to coronavirus patient samples and then recovered to the insect within a month.
Experiments conducted at 68, 86, and 104 degrees Fahrenheit showed that the virus survived longer in lower temperatures, longer on smooth surfaces, and longer on paper than plastic.
The study also found that the virus stopped being infectious within 24 hours at 104 degrees on some surfaces.
The researchers said that since proteins and fats in body fluids can also significantly increase the survival times of the virus, the study could help explain the apparent persistence of the virus in cold environments.
Some experts have expressed doubts about the real threat posed by surface transmission as the coronavirus is mainly transmitted when people cough, sneeze or speak.
However, there is also evidence that it can be spread by airborne particles.
Previous laboratory tests have found that the virus can survive for two to three days on banknotes and glass and up to six days on plastic and stainless steel, although results may vary.
Professor Ron Eccles, former director of Cardiff University’s Common Cold Center, criticized the Australian study and said the suggestion that the virus could survive for 28 days is causing “unnecessary fear in the public.”
“Viruses spread to surfaces from mucus from coughing and sneezing and dirty fingers and this study did not use fresh human mucus as a vehicle to spread the virus,” he told the BBC.
“Fresh mucus is a hostile environment for viruses as it contains many white blood cells that produce enzymes to destroy viruses and may also contain antibodies and other chemicals to neutralize viruses,” Eccles said.
“In my opinion, infectious viruses only persist in mucus on surfaces for hours rather than days,” he added.