Coronavirus may be most infectious when symptoms are mildest, small study finds

[Judi Lynn]

By Nicoletta Lanese - Staff Writer 4 hours ago

. . .


People infected with the novel coronavirus shed large quantities of the virus early in their illness and likely become less infectious as the disease wears on, according to a small study.

The research, posted Sunday (March 8) to the preprint database medRxiv, is still preliminary, because it has not yet been peer-reviewed and because it included only nine participants. Still, it may hint at why the new virus spreads so easily: Many people may be at their most infectious when exhibiting only mild, cold-like symptoms.

"This is in stark contrast to SARS," a related disease caused by a different coronavirus, the authors noted. In SARS patients, viral shedding peaked about seven to 10 days into the illness, as the infection spread from the upper respiratory tract into deep lung tissue. In seven patients with COVID-19, the disease caused by the new virus, "peak concentrations were reached before Day 5 and were more than 1,000 times higher" than those seen in SARS patients, the authors wrote.

This peak appeared later in two patients whose infections had progressed into their lungs, sparking the first signs of pneumonia. In these severe cases, viral shedding reached maximum levels around Day 10 or 11. In the mild cases, viral shedding dipped steadily after Day 5, and by Day 10, patients likely weren't contagious anymore, the authors noted.

More:
https://www.livescience.com/coronavirus-sheds-early-in-disease.html

[Warpy]

1. Operative words, "small study."

However, I guesstimated some time ago that the worst period for passing it on was the late prodromal stage.

If this is the case, there is no way of stopping it. Handwashing, avoiding crowds, learning on how to suffer the sneers of strangers who think you're wiping your nose on your sleeve when you're just scratching it safely, and staying away from other people if you start to feel at all ill are the tools we have to work with.