How are you testing for covid right now?

[Cowboyardee]

Hi all. I'm wondering how covid testing is being performed in your area currently.

Where I am (hospital, ICU, mid atlantic state), I'm seeing tests being ordered from either the state health dept or quest diagnostics. Cases are being tested on the basis of severe (critical) illness with symptoms consistent with covid19. 1st order exposures are also being tested I think (like, spouse of someone covid +). I think that likely exposures with likely symptoms are being tested too. I'm not sure beyond that.

We are doing a single nasal pharyngeal swabs sent for PCR in most cases, I believe.

There is some reason to worry about the possibility of false negatives with nasal pharyngeal PCR swabs - best data I can find is that the sensitivity of the test is only 75% (emcrit's covid19 page discusses this and cites the study they used to estimate this figure), though I would welcome better or updated data if anyone can offer any.

So I'm wondering if other states are routinely sending 2 swabs to double check or have some other procedure.

As is, it appears there could be could be one covid + patient whose test was erroneously negative for every 3 patients who actually test positive, which potentially has some very concerning consequences.

However, I'd love to hear that my thinking is wrong on this matter or be directed to better information. What are you seeing?

[Ullikummi]

We are doing our own PCR tests in the hospital lab, run once a day. Our ID doctors are not taking PUIs off isolation when they turn up negative unless they have another definitive reason for their symptoms, because one in four negatives are really a positive. However, they do not retest unless it would change treatment. So these ‘probably positive’ negative patients are never counted in official stats. This policy only came into effect when we started running our own swabs, like last Monday, so makes me wonder about all those we did take off isolation when we were testing out of house. Pretty scary.