Thread by @michaelmina_lab

At what point did the science of rapid tests get lost??

FREQUENCY • ACCESSIBILITY • SPEED are most important aspects of a test for public health

Talking about tests not detecting in the 1st 24 hours of contagiousness assumes people are testing in those hours. Most don’t.

1/

Most of the time that someone is contagious is not spent in the first 24 hrs of being contagious. Obviously.

Frequent rapid testing for public health has always been about the sensitivity and EFFECTIVENESS of the testing REGIMEN.

2/

If a test fails to turn pos on d 1 but someone wasn’t using the test that day, then it doesn’t matter

It’s MORE likely ppl use a test sometime in days 2,3,4,5,6 or 7 than day 1. Public health testing also must consider the days it DOES detect - not just the days it doesn’t.

3/

This is the difference between public health testing. It has never had to be 100% sensitive nor 100% used. It can identify positives at scale if rolled out systematically + strategically

Every person detected on rapid test = potentially 10s -100s downstream cases averted.

4/

Somewhere along the way people though that any test is bulletproof.

It’s not. They’ve always been 90% or so sensitive for higher viral load people (>95% if very high viral load) and now w Omicron they may be more like 80% if they are missing day 1.

BUT…

5/

There is a bit of a silver lining here in that symptoms are starting earlier than before. Often starting the day after exposure. SO, our bodies are offering us an early warning that sign even w/out a test. Use it! Assume positive. Take the test on day 2 or 3 to confirm.

6/