Question Testing negative and then later infected

[koinflipper]

With millions of tests being done worldwide, seems it is possible that someone tests negative for antigen and was truly not infected. But then be infected after testing and be asymptomatic. Wouldn't this mean that testing of health care providers would need to be done multiple times as they are potentially exposed daily at work?

Also, what is sensitivity and specificity of antibody testing for those who supposedly recovered and are "immune". I read that some of these antibody tests are not actually testing for presence of Covid-19 antibodies but elevated IgG and other immunoglobulins. Wouldn't these be elevated with other viral infections?

 

[harpat949]

That is correct, I agree.
I commented on several blogs that testing is impractical and of very limited value in determining who is not infected because the person can get infected soon after the test.

 

[Hayseed]

There are problems with testing. It's a one-shot. What we need is a fast acting wearable virus detector, like a dosimeter. They could be hung at gates and in enclosed areas too. And we could network them also, with IOT. Or maybe as simple as a swab that changes color. Hey bud.......have you got an extra swab?

We now, can detect many different molecules. We can improve this. Tricorder tech for cellphones. Sense a spectrum of molecules.

 

[koinflipper]

Heard on news yesterday that India has a quick paper strip test. Just turns different colors for negative and positive. It is for the virus itself.