On: U.S. Navy test shows 60 percent of carrier crew have coronavirus antibodies

[avsteele]

This probably under counts the true number of infection significantly.

If the sensitivity/specificity of the test was similar to the paper below, true prevalence for the ship probably approaches 100%.

https://www.biorxiv.org/content/10.1101/2020.05.13.092619v2

[JumpCrisscross → avsteele]

> This probably under counts the true number of infection significantly

Probably not. Ships are unusually concentrated social environments.

[guscost → JumpCrisscross]

Yes, higher dose/severity probably means more likelihood of detectable antibodies:

https://www.biorxiv.org/content/10.1101/2020.05.21.108308v1

> These data show that systemic IgA and IgG production against SARS-CoV-2 develops mainly in severe COVID-19, with very high IgA levels seen in patients with severe ARDS, whereas mild disease may be associated with transient serum titers of SARS-CoV-2-specific antibodies but stimulate mucosal SARS-CoV-2-specific IgA secretion. The findings suggest four grades of antibody responses dependent on COVID-19 severity.

But this does not eliminate the possibility raised by the GP, that some people could be clearing even a severe infection with antibodies that are not specific to SARS-CoV-2, and would never get a positive result on a highly-specific test.

[algorithmsRcool → JumpCrisscross]

I don't understand, wouldn't a concentrated social environment suggest very high infection rates, which aligns with the GP?

[guscost → algorithmsRcool]

It's not just infection rates, it's also dose/severity. See my linked paper.