> Asymptomatic cases (truly asymptomatic or not yet symptomatic) caused the most infections, which explains the ease with which SARS-CoV-19 is spreading across the world.
The WHO initially made a statement warning of asymptomatic transmission which it later retracted. The media has since reported that somewhere south of 20% of asymptomatic carriers are contagious. The research cited in this study to back up the asymptomatic spreader claim are the following:
A paper about n=4 patients speculating on how one of them seemingly got the virus from asymptomatic family members. This study states "SARS cases are infectious only during their symptomatic period and are noninfectious during the incubation period."
This study of n=1 used contract tracing to find a colleague they were recently in contact with. The colleague tested positive despite being asymptomatic and thus the conclusion is the virus is spread while asymptomatic.
Maria van Kerkhove, infectious disease epidemiologist and the COVID-19 technical lead for the WHO has this to say:
"From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual. It's very rare."
The WHO initially made a statement warning of asymptomatic transmission which it later retracted. The media has since reported that somewhere south of 20% of asymptomatic carriers are contagious. The research cited in this study to back up the asymptomatic spreader claim are the following:
* https://www.eurosurveillance.org/content/10.2807/1560-7917.E...
Research estimating asymptomatic proportion using a statistical model. That's right, a model based on early rough estimates from another model.
* https://academic.oup.com/jid/article/221/11/1757/5739751
A paper about n=4 patients speculating on how one of them seemingly got the virus from asymptomatic family members. This study states "SARS cases are infectious only during their symptomatic period and are noninfectious during the incubation period."
* https://www.nejm.org/doi/10.1056/NEJMc2001468
This study of n=1 used contract tracing to find a colleague they were recently in contact with. The colleague tested positive despite being asymptomatic and thus the conclusion is the virus is spread while asymptomatic.
Maria van Kerkhove, infectious disease epidemiologist and the COVID-19 technical lead for the WHO has this to say:
"From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual. It's very rare."
https://www.cbc.ca/news/health/who-covid-19-asymptomatic-spr...