By Aashish Mishra
Kathmandu, Oct. 14: The novel coronavirus can survive on smooth surfaces for up to 28 days, a new Australian study suggests.
The study by Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia’s national science agency, shows that, at 20 degrees Celsius, SARS-CoV-2 remains “extremely robust” and infectious on surfaces like paper and polymer banknotes, glass (including those found on mobile phone screens) and stainless steel for 28 days. This is longer than what previous studies have found.
The results of the study were released on Monday and they have been published in Virology Journal.
For context, the Influenza A virus has been found to survive on similar surfaces for 17 days. “This shows how resilient SARS-CoV-2 is,” the study quotes Dr. Debbie Eagles, deputy director of Australian Centre for Disease Preparedness, as saying.
CSIRO scientists looked at the effects of temperature on the survivability of the coronavirus and conducted experiments at 20, 30 and 40 degrees Celsius. They concluded that the virus survives longer at cooler temperatures, smoother surfaces and on paper currency.
However, Dr. Sameer Mani Dixit, general secretary of the Nepal Public Health Foundation, while calling the findings important, said that they needed to be put in perspective before interpreting.
“Experts have been warning that COVID-19 infections may spread from contaminated surfaces. This study once again confirms it,” Dixit said, adding, “But this should not be a cause for panic.
Actual transmission depends on several factors like the viral load, contact with the infected person, ejection of droplets and others.”
The study itself also notes how research has demonstrated that direct sunlight can deactivate the virus. That is why the experiments were carried out in the dark. While talking to the Reuters news agency, the lead researcher Dr. Shane Riddell has also said that the real world survival period of the virus would likely be shorter than the period documented in the laboratory.
Ultimately, these findings reinforce the need for handwashing and sanitisation of commonly touched surfaces, according to Dr. Dixit. “Surfaces that are touched by many people need to be cleaned frequently and we should all take care to wash our hands with soap and water.”
Dixit further highlighted the importance of mask as a safeguard against COVID-19. “When one is wearing a mask, neither do their own droplets escape out nor do they inhale others’droplets.”
The exact infectious dose of the coronavirus is not yet known but expert estimates range from 300 to 1,000 particles.