When cases of Covid-19 began to appear in Australia, some people reported disinfecting their groceries before bringing them into their homes, and there were also concerns that the virus could live on the surfaces of the parcels in the mail. During Victoria’s extensive closure, workers’ teams could be seen walking in city streets disinfecting traffic light buttons, benches and even fences.
An epidemiologist at La Trobe University, associate professor Hassan Vally, said just over a year later it became clear that surface transfer was not as important a factor in the spread of Covid-19 as had ever been feared. is not. Although surface transfer is not impossible, Vally said his role is in perspective on distributed needs.
“I want to be clear that nothing should change in terms of hand washing and personal hygiene,” Vally said. “However, we can be less anxious to wash every surface 20 times a day, and only concentrate on good hand hygiene and social distance and stay home when we are sick, which should be more than enough to stop us from spreading the virus. . “
Aerosol distribution with close contact is the driving force in Covid-19 transfer, mainly when an infected person is in close contact with another person and transfers small liquid particles. [droplets and aerosols] containing the virus, especially if they cough and sneeze. These aerosols then enter the nose, mouth and eyes of people in the area.
In a piece for the conversation, Vally said: ‘This does not mean that the transfer of the surface is not possible and that in certain situations it poses no risk, or that we should disregard it completely. But we must recognize that the threat of surface transfer is relatively small. ‘
Emanuel Goldman, a professor of microbiology at Rutgers University in the USA, wrote in the medical journal The Lancet that studies warned about the transfer of the surface in the laboratory had been carried out, and that they “closely matched the actual scenarios “.
“In my opinion, the chance of transmission through inanimate surfaces is very small, and only in cases where an infected person coughs or sneezes on the surface, and someone else touches the surface shortly after coughing or sneezing (within 1-2 hours ), ”Goldman said.
“I do not agree with the error of the warning, but it can go to extremes that are not justified by the data.” Disinfection of surfaces and the use of gloves can from time to time be reasonable precautions in institutions such as hospitals, he said, but are probably too excessive for less risky environments.
Concerns about the surface distribution were apparently worrying, but too overlapping studies, including one by the Australian Government Agency CSIRO, found that a drop of fluid containing the virus in concentrations similar to levels observed in infected patients surfaces such as cash and glass could survive. up to 28 days.
What many of the news reports about the study did not mention was that it was conducted in the dark to remove the effect of ultraviolet light killing viruses. Humidity and temperatures in the real world fluctuate constantly, differing from carefully controlled temperatures in a laboratory. Email, for example, goes through the entire system through different humidities and temperatures and will also be exposed to light, making the survival of the virus in the mail extremely unlikely.
The science was not wrong, Vally said, but the interpretation and explanation of the results was.
But aren’t too many hygienic measures better to be absolutely safe?
Vally said the problem is the exhaustion of compliance.
“A lot of psychological research has been done that says we only have a certain amount of willpower and a certain amount of details that we can draw attention to,” Vally said. “That’s why Apple founder Steve Jobs wore the same clothes every day, based on the idea that you can make just as many decisions every day and exercise certain willpower.
‘For me, as we learn more about the virus, we need to make sure we are not worried about things we should not be worried about; we do not want to draw our attention to things that are out of proportion to the threat it poses. This way we will have more energy to focus on the things that are important, and that also help us save money and time. ‘
Peter Collignon, an infectious disease doctor and professor at the Australian National University, agreed that all the available evidence says that people are close to each other who talk, cough, sing and breathe which causes virus spread.
“They breathe in and it gets in their nose and eyes, and that’s the biggest risk factor,” he said. This is why eye protection, especially in quarantine hotels and hospitals, should be prioritized as much as masks and social distance, he said.
Collignon cites a large study published in the Journal of the American Medical Association that found that 19% of health care workers became infected despite wearing three-layer surgical masks, gloves, and shoe covers and using alcohol. After the introduction of face shields, no worker was infected.
“I think we underestimated how important the eyes are and overemphasize surfaces,” Collignon said.