Asymptomatic carriers seem to be rare, though not completely nonexistent.
I think one should expect asymptomatic people to be less infectious than pre-symptomatic people, so it may not be important from a “changing current responses” perspective to understand the prevalence of asymptomatic-ness. That being said, here is a paper that analyzes the Diamond Princess data and claims the asymptomatic rate to be >15%.
https://eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.10.2000180
I haven’t understood their methodology well enough to have a strong opinion about its validity. I think they’re using time series data along with some priors about the shape of the distribution of the random variable “number of days between testing positive and showing symptoms, given that the patient will at some point show symptoms” to conclude that a decent fraction of the Diamond Princess people won’t show symptoms.
The claim is made in paragraph 5 of the discussion section.
I think one should expect asymptomatic people to be less infectious than pre-symptomatic people, so it may not be important from a “changing current responses” perspective to understand the prevalence of asymptomatic-ness. That being said, here is a paper that analyzes the Diamond Princess data and claims the asymptomatic rate to be >15%. https://eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.10.2000180
I haven’t understood their methodology well enough to have a strong opinion about its validity. I think they’re using time series data along with some priors about the shape of the distribution of the random variable “number of days between testing positive and showing symptoms, given that the patient will at some point show symptoms” to conclude that a decent fraction of the Diamond Princess people won’t show symptoms.
The claim is made in paragraph 5 of the discussion section.