[DocSavage87]

For those that didn't follow the link, this article (published 12/21; I don't know when it was submitted) primarily summarizes information from other studies:

• The earlier high estimates of asymptomatic infections has been revised down to 17-20%.
  
• About 49% of those that initially report as asymptomatic eventually do get symptoms.
  
• There is no test to detect if a person is infectious.
  
• Viral load is similar whether or not a person has symptoms (but that doesn't necessarily mean they are equally infectious).
  
• The duration of viral shedding is shorter for those that remain asymptomatic.
  
• Viral culture studies suggest that people with SARS-CoV-2 can become infectious one to two days before the onset of symptoms and continue to be infectious up to seven days thereafter; viable virus is relatively short lived.
  
• Symptomatic and presymptomatic transmission have a greater role in the spread of SARS-CoV-2 than truly asymptomatic transmission.
  
• The transmission rates to contacts within a specific group (secondary attack rate) may be 3-25 times lower for people who are asymptomatic than for those with symptoms.[url=https://www.bmj.com/content/371/bmj.m4851#ref-1][/url]
  
• A city-wide prevalence study of almost 10 million people in Wuhan found no evidence of asymptomatic transmission
  
• People with a symptom of coughing would seem to be more likely to spread the virus to any contact.
  
• People without symptoms are more likely to have more contacts.
  

Between the 20% asymptomatic cases, and the 49% that are initially asymptomatic but later develop symptoms,  a number of 40% that are initially asymptomatic seems about right.

Agree.  I also think there isn't consistent use of terms in reporting between "asymptomatic" and "pre-symptomatic".  Here's an example of a pre-symptomatic case that spread the virus during a gathering despite testing.  Remember that just because you test positive doesn't mean you are free from the virus.  It takes time for test positivity and there's a non-negligible % of false negative results as well.  (We saw a false positive crush any chance we had of winning vs Oregon.)

[tweet]
https://twitter.com/darakass/status/1343...59648?s=20
[/tweet]

[DocSavage87]

For those that didn't follow the link, this article (published 12/21; I don't know when it was submitted) primarily summarizes information from other studies:

• The earlier high estimates of asymptomatic infections has been revised down to 17-20%.
  
• About 49% of those that initially report as asymptomatic eventually do get symptoms.
  
• There is no test to detect if a person is infectious.
  
• Viral load is similar whether or not a person has symptoms (but that doesn't necessarily mean they are equally infectious).
  
• The duration of viral shedding is shorter for those that remain asymptomatic.
  
• Viral culture studies suggest that people with SARS-CoV-2 can become infectious one to two days before the onset of symptoms and continue to be infectious up to seven days thereafter; viable virus is relatively short lived.
  
• Symptomatic and presymptomatic transmission have a greater role in the spread of SARS-CoV-2 than truly asymptomatic transmission.
  
• The transmission rates to contacts within a specific group (secondary attack rate) may be 3-25 times lower for people who are asymptomatic than for those with symptoms.[url=https://www.bmj.com/content/371/bmj.m4851#ref-1][/url]
  
• A city-wide prevalence study of almost 10 million people in Wuhan found no evidence of asymptomatic transmission
  
• People with a symptom of coughing would seem to be more likely to spread the virus to any contact.
  
• People without symptoms are more likely to have more contacts.
  

Between the 20% asymptomatic cases, and the 49% that are initially asymptomatic but later develop symptoms,  a number of 40% that are initially asymptomatic seems about right.

Agree.  I also think there isn't consistent use of terms in reporting between "asymptomatic" and "pre-symptomatic".  Here's an example of a pre-symptomatic case that spread the virus during a gathering despite testing.  Remember that just because you test positive doesn't mean you are free from the virus.  It takes time for test positivity and there's a non-negligible % of false negative results as well.  (We saw a false positive crush any chance we had of winning vs Oregon.)

[tweet]
https://twitter.com/darakass/status/1343...59648?s=20
[/tweet]