Ct values aren’t perfect - but nor is listening to a heart or taking an X-ray. Nevertheless, these tests have their place when considered in context - as does the Ct value of the PCR
To discard is to throw out some of the most informative data we have about one’s infection
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It can help determine whether a person is early or late in their course of infection. It can tell us about he direction of an epidemic. It holds immense value. We should consider its regular use as a crucial tool in this fight against COVID. Not toss it for its imperfections.
If curious why your lab may not be reporting - for clinical use these assays generally are not being approved to report out the Ct. they should be... with caveats noted. But MDs should be able to use.
For public health, this should be a no brainer-contact tracing, surveillance.
A method to know if a low viral load represents a new infection on the way up or an old infection that has passed is to repeat test a positive 24h later. If load goes up, then def isolate. I’d load remains very low and no known symptoms/exposure, then very likely late infection
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Here we go again with this asinine cautious approach to testing for H5N1
CDC is NOT recommending that people with no symptoms - but who have had contact w infected animals - be tested at all… and certainly are not recommending a swab w any frequency.
Though we should have learned it in 2020, Here’s why this doesnt make sense:
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Firstly, tests are our eyes for viruses. It’s literally how we see where viruses are
If we wait until people are getting sick, we may have missed a major opportunity to find viruses jumping into humans before they learn to become so efficient in us that they cause disease
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So waiting until we actually have highly pathogenic strains harming humans - when we have a pretty discreet population at the moment to survey - is short sighted
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A particularly deadly consequence of measles is its erasure of previously acquired immune memory - setting kids and adults up for infections that they shouldn’t be at risk from!
We found for example that measles can eliminate as much as 80% of someone’s previously acquired immunity to other pathogens! science.org/doi/full/10.11…
An expired test will Not aberrantly turn positive just because it's old
Expiry makes lines not show up. Does make them become dark.
So, if using an expired test:
Do Trust a Positive.
Do Not Trust a Negative.
*And note that many tests have had extended expiry dates...
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Here is a thread about the extensions to the expiration dates.
Not all tests are extended but many of them have and that means that the dates on the box may be different from the actual expiration date. I write about it here and how to find out