Can't say I buy that. Why the change in recommendations on everyone including healthy if asymptomatic spread is so rare. Another study says 30% and likely 40-45% of spread is from asymptomatic. Some of these gatherings like the choir in Washington and others no one reported any symptoms yet many in the gathering got infected. Some asymptomatic infections are having damage done to their lungs and don't even realize it.
Section from a Time article a few days ago:
In a
study published June 3 in the Annals of Internal Medicine, researchers at the Scripps Research Translational Institute reviewed data from 16 different groups of COVID-19 patients from around the world to get a better idea of how many cases of coronavirus can likely be traced to people who spread the virus without ever knowing they were infected. Their conclusion: at minimum, 30%, and more likely 40% to 45%.
Topol and his co-author, Daniel Oran, searched for published and unpublished studies that included asymptomatic people and focused on 16 different groups of people screened or tested for COVID-19 around the world. Among others, these included a cohort of more than 13,000 people in Iceland who volunteered to be tested for COVID-19 (the largest group included), as well as residents of Vo, Italy; passengers on the
Diamond Princess cruise ship where an outbreak occurred; visitors to homeless shelters in Boston and Los Angeles; prison inmates; college students; and nursing home residents in King County, WA.
Five of these studies included follow up testing of the participants; they showed that only a small fraction of people who were asymptomatic when they tested positive the first time then went on to develop symptoms. That allowed the researchers to distinguish between people who are pre-symptomatic—those who test positive but eventually go on to develop symptoms—and those who are truly asymptomatic, and test positive for COVID-19 but never develop obvious symptoms. Among the more than 2300 people sampled in the Vo population, none of the 41% who had no symptoms when they tested positive ever developed symptoms over a 14 day period.
That wouldn’t be worrisome if it weren’t for other research beginning to show that levels of virus in people who are asymptomatic are similar to those among people who develop symptoms. That suggests that while they may not be outwardly showing any signs of illness, asymptomatic people are still carrying a potentially dangerous burden of infectious virus that they can spread to others.
Another concern, says Topol, is that the virus may be damaging the bodies of asymptomatic in other, silent ways. Among the 331 passengers on the
Diamond Princess cruise ship who tested positive but did not have symptoms, 76 people had CT scans of their lungs and nearly half showed signs of lung tissue damage typical of coronavirus infection. “People who are getting infection without symptoms are actually doing a lot of damage to their bodies and they don’t know it,” says Topol. Another small
study in South Korea that studied 10 asymptomatic people from a group of 139 COVID-19 patients supports these findings.
https://time.com/5848949/covid-19-asymptomatic-spread/
