SARS-COV-2 Transmission and Incubation Stability and Viability
SARS-CoV-2, also known as “severe acute respiratory syndrome Coronavirus 2“, studies compared to other Coronavirus surfacace stability and viability.
Scientists have shown that the virus responsible for the Covid-19 epidemic has a level of outdoor viability comparable to that of the Coronavirus that causes SARS, nearly three hours. However, the study generated criticism.
When the Covid-19 epidemic reaches Europe, the SARS-CoV-2 Coronavirus played hide and seek with the spread from surfaces/contact and numbers. On which surfaces does it last the longest? It is the subject of a study published in The New England Journal of Medicine and conducted by a team at the American National Virology Laboratory at the National Institutes of Health in Hamilton, Montana.
SARS-COV-2 Stability and Viability
Several months after the start of the epidemic, the exact transmission mechanisms of SARS-CoV-2 remain unknown. What scientists are sure of is that the pathogen is transmitted from person to person through droplets or aerosols (droplets less than 5 microns in diameter) expelled by coughing, sneezing, or postillions. These virus-laden bubbles can be inhaled by healthy people nearby, so keeping a distance is imperative.
Only the virus vanishes. But once protected in these drops, it will last much longer. How long exactly? This is what Neeltje van Doremalen and his team wanted to know. They prepared a viral solution for this, which they sprayed on various materials, as well as in a room designed for the study of aerosols, a nebulizer.
Then they waited minutes, hours, even days, and rubbed the media with a cotton swab to collect some viruses and use it to try to infect cells in culture. The lifespan of SARS-CoV-2 in the tested supports was thus determined when the cells were no longer infected with the cotton swab.
Twenty-four hours in cardboard
As a result, the SARS-CoV-2 adapts very well to plastic and stainless steel surfaces – the pathogen survived on them for up to three days. Worryingly, these two types of materials are ubiquitous, especially in hospitals, the authors say, recalling that as of February 11, more than 3,000 Coronavirus infections had occurred in hospital, according to a study published that same month in the Journal of the American Medical Association (JAMA).
In copper, which is found especially in Swiss coins, the virus survives for a shorter time, just four hours. In cardboard like the one used for packages and bundles, the Coronavirus lasted twenty-four hours. What about the drops in the ambient air? More than three hours, virologists measured. Therefore, these results are more conservative than those published by another team this month in the Journal of Hospital Infection and that reported a persistence of up to nine hours in glass, metal, or plastic.
The researchers at Hamilton’s laboratory also compared the stability of SARS-CoV-2 with that of the SARS Coronavirus (responsible for the 2002-2003 epidemic), genetically similar to 80%. The two pathogens survive almost as long on different surfaces, aside from cardboard, where the Covid-19 Coronavirus is more resistant, which the authors attribute to the measurement artifacts. However, the SARS Coronavirus is transmitted less easily than its cousin today.