Dr. Christoph Schwinghammer
I'm a surgeon, endoscopist, sportsman, photographer, webdesigner and blogger

COVID-19: Aerosol and Surface Stability of SARS-CoV-2

Viruses didn’t become ubiquitous by being wimps: From the rhinoviruses that cause the common cold to the new coronavirus that has spread across the world, they are able to survive on surfaces far away from the living cells that they need in order to reproduce. How long they can lurk before a living organism comes along to infect depends on the kind of surface and the properties of the virus: The Covid-19 virus, according to a new study, sticks around on plastic surfaces for up to three days, but for a shorter period on metals.

The survival of the coronavirus on surfaces is similar to that of the SARS virus, to which it’s related. On plastic, after eight hours only 10% of what researchers deposited was still there, according to a study published on Tuesday in the New England Journal of Medicine. But the virus didn’t become undetectable until after 72 hours. On stainless steel, the numbers began plummeting after just four hours, becoming undetectable by about 48 hours. On copper and cardboard, virus was undetectable by eight hours and 48 hours, respectively.

The fewer the virus particles on a surface, the lower the chances that someone touching it will become infected. “You have to get a certain level of virus exposure to be infected,” said Ross McKinney, chief scientific officer of the American Association of Medical Colleges. And infection cannot happen through the skin: to “self inoculate,” one must transfer virus from, say, the fingers to the nose or eyes, where it can enter the body via mucus membranes.

Source: statnews.com/

As shown in Panel A, the titer of aerosolized viable virus is expressed in 50% tissue-culture infectious dose (TCID50) per liter of air. Viruses were applied to copper, cardboard, stainless steel, and plastic maintained at 21 to 23°C and 40% relative humidity over 7 days. The titer of viable virus is expressed as TCID50 per milliliter of collection medium. All samples were quantified by end-point titration on Vero E6 cells. Plots show the means and standard errors ( bars) across three replicates. As shown in Panel B, regression plots indicate the predicted decay of virus titer over time; the titer is plotted on a logarithmic scale. Points show measured titers and are slightly jittered (i.e., they show small rapid variations in the amplitude or timing of a waveform arising from fluctuations) along the time axis to avoid overplotting. Lines are random draws from the joint posterior distribution of the exponential decay rate (negative of the slope) and intercept (initial virus titer) to show the range of possible decay patterns for each experimental condition. There were 150 lines per panel, including 50 lines from each plotted replicate. As shown in Panel C, violin plots indicate posterior distribution for the half-life of viable virus based on the estimated exponential decay rates of the virus titer. The dots indicate the posterior median estimates, and the black lines indicate a 95% credible interval. Experimental conditions are ordered according to the posterior median half-life of SARS-CoV-2. The dashed lines indicate the limit of detection, which was 3.33×100.5 TCID50 per liter of air for aerosols, 100.5 TCID50 per milliliter of medium for plastic, steel, and cardboard, and 101.5 TCID50 per milliliter of medium for copper.
Christoph Schwinghammer

Christoph Schwinghammer

I'm a general surgeon and endoscopist, currently occupied at the Kepler University Hospital in Linz, Austria. Further I'm a sport enthusiast, amateur photographer and freelance web designer.

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