1. A year ago the first person with asymptomatic covid was documented. My colleague @danieloran culled the data from 61 studies, 1.8 million people to determine how often this occurs. Just published @AnnalsofIM
https://www.acpjournals.org/doi/10.7326/M20-6976

2. First a definition:
"The asymptomatic fraction of infection is the proportion of infected persons who never develop, perceive, and report symptoms"
In contrast to "presymptomatic" individuals who ultimately develop symptoms.
Both groups can transmit infections.

3. Here are the 14 longitudinal studies where symptom status was assessed over time

4. And all the PCR and serology studies that categorized people as having or not having symptoms

5. Based on the totality of the data, we conclude that asymptomatic covid occurs in at least one-third of infections.
Some will argue that there is admixture with presymptomatic cases, but review of all the data supports this estimate as being a conservative one.

6. Our oped @statnews today reviews the controversy, that asymptomatic infection occurs very frequently w/ polio and influenza (and many other viruses), the denialism, and the critical need for rapid home testing to identify the covid carriers https://www.statnews.com/2021/01/23/asymptomatic-infection-blunder-covid-19-spin-out-of-control/

7. A short video we made to summarize the findings and implications

8. When Dr @camilla_rothe reported an asymptomatic transmission a year ago, the @NEJM report was refuted and disparaged. She was later named a TIME 100 Person of the Year
https://time.com/collection/100-most-influential-people-2020/5888186/camilla-rothe/

9. The front page @nytimes in late June

10. My favorite cartoon on asymptomatic carriers :-), by @speedbumpcomic