Coronavirus is in the air – too much emphasis on surfaces

A year after the start of the pandemic, the evidence is now clear. The SARS-CoV-2 coronavirus is transmitted primarily through the air – by people who speak and breathe in large droplets and small particles called aerosols. Catching the virus from surfaces – although plausible – appears to be rare (E. Goldman Lancet Infect. Say. 20, 892–893; 2020).

Despite this, some public health agencies still point out that surfaces are a threat and need to be disinfected frequently. The result is a confusing public message when clear advice is needed on how to prioritize efforts to prevent the spread of the virus.

In its most recent public guidelines, updated last October, the World Health Organization (WHO) advised: “Avoid touching surfaces, especially in public places, because someone with COVID-19 would have could touch them before. Regularly clean the surfaces with standard disinfectants. A WHO representative said Nature in January, there is limited evidence of transmission of the coronavirus through contaminated surfaces known as fomites. But they added that fomites are still considered a possible mode of transmission, citing evidence that SARS-CoV-2 RNA has been identified “in the vicinity of people infected with SARS-CoV-2.” And although the United States Centers for Disease Control and Prevention (CDC) says on its website that surface transmission “is not considered a common way of spreading COVID-19″, it also states that ” frequent disinfection of surfaces and objects touched by several people is important ”.

This lack of clarity on the risks of fomites – compared to the much greater risk posed by airborne transmission – has serious implications. People and organizations continue to prioritize costly disinfection efforts, when they could devote more resources to stressing the importance of masks and researching measures to improve ventilation. The latter will be more complex but could make a bigger difference.

The New York City Metropolitan Transit Authority alone estimates its annual COVID-related cleanup costs will be close to $ 380 million by 2023. Late last year, the authority asked the government US federal government advice on whether to focus solely on aerosols. He was told to focus on fomites as well and has so far devoted more resources to cleaning surfaces than to combating aerosols.

Now that it is agreed that the virus is transmitted through the air, both in large and small droplets, efforts to prevent the spread should focus on improving ventilation or installing air purifiers. air rigorously tested. People should also be reminded to wear masks and to maintain a safe distance. At the same time, agencies such as the WHO and CDC need to update their guidance based on current knowledge. Research on the virus and COVID-19 is advancing rapidly, so public health agencies have a responsibility to present clear, up-to-date information that provides what people need to protect themselves and others.