In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

Re:In 4 US state prisons, 3,300 inmates test positive, 96% w... by djsumdog on Sunday April 26, 2020 @12:47AM (#22984520)

Is this test sensitive to just SARS-CoV-2? What is the possibility that other corona viruses (like the ones that cause many of our colds) could create a false positive? I haven't heard anything from a reliable source on that.

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Re:In 4 US state prisons, 3,300 inmates test positive, 96% w... by tim333 on Sunday April 26, 2020 @02:49AM (#22985111)

PCR is pretty selective for SARS-CoV-2

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Re:In 4 US state prisons, 3,300 inmates test positive, 96% w... by gridlockd on Sunday April 26, 2020 @05:51AM (#22985926)

I'm trying to figure out what tests they used. PCR is very specific but only works reliably in the early stages and generally has a high false negative rate.

Antibody tests only work after several days of infection, but some of them are not very specific to SARS-CoV2 and therefore have a high false positive rate.

So you really need use both tests, but you can't just OR the results together, because then a faulty antibody test will massively skew the results upward.

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Re:In 4 US state prisons, 3,300 inmates test positive, 96% w... by KaiserPro on Sunday April 26, 2020 @08:19AM (#22986610)

> but only works reliably in the early stages

No, it only works if there is enough virus to be detected. If you are infected, you will have a high enough count to be detected. Each type of PCR test is highly selective. The point of them is that they can differentiate between many types of virus, depending on how its setup.

> Antibody tests only work after several days of infection

Yes. Depending on the type of test, and how its done. it can be up to a month before these tests are accurate.

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Re:In 4 US state prisons, 3,300 inmates test positive, 96% w... by gridlockd on Sunday April 26, 2020 @09:15AM (#22986911)

In principle yes, but The PCR test is usually a throat swab, where detectable amounts often disappear after a few days, even in severely symptomatic cases.

This is the reason why China started to accept clinical diagnosis like chest scans, causing a sudden big spike in cases.

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Re:In 4 US state prisons, 3,300 inmates test positive, 96% w... by yaur on Sunday April 26, 2020 @10:44AM (#22987492)

Is there a source that says they were using PCR testing? The article seems pretty light on technical details.

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