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It is unclear whether these patients are shedding viral RNA particles from their prior infection or actual infectious virus from an ongoing infection. The way t
by unsrsly 7y ago
It is unclear whether these patients are shedding viral RNA particles from their prior infection or actual infectious virus from an ongoing infection. The way to tell the difference would be to perform viral cultures instead of the PCR-based test.
- hcknwscommenter 7y agoYour post makes little sense to me. viral RNA particles are virus no? You distinguish between viral RNA particles and "actual infectious virus". What is the difference between the two?
- lbeltrame 7y agoI think the OP means the actual, infective and complete virus (fully assembled) as opposed to the RNA of the virus, which can also be released by degraded/inactivated viruses.
- hcknwscommenter 7y agoBut he says "viral particles" which is a term of art and means an assembled shell (envelope for enveloped viruses like corona). If there is viral RNA in the viral particle, its an assembled shell and thus a virus. Sure some people make viral particles in the lab to package other things, but that's certainly not what OP is referring to.
- unsrsly 7y agoSorry, I could have been clearer and said something like RNA fragments (non-infectious residue of the virus). It's true that in a clinical situation, you need to treat the positive PCR as infectious until proven otherwise. But from a research standpoint, it seems possible that someone who previously had a high viral load in their lungs, and is now recovering, could have detectable Sars-Cov2 RNA fragments for a period of time despite the presence of endogenous RNAse. And they might not be contagious.
- pvaldes 7y ago>viral RNA particles are virus no? Only in the same way as blood is people. Viruses are a DNA/RNA core packaged in proteins plus a borrowed disguise that acts like an envelope and would put the crownb part in coronavirus. Some are naked and lack the envelope, other (i.e coronavirus) not.
- usrusr 7y agoPCR tests will still detect signature bits of RNA even when the virus is physically broken and no danger at all. Virions are not alive like bacteria are, but they are still more than the pure RNA ("data"). To be infective they need the whole, intact package of RNA and a set of tooling molecules that the parent cell created created alongside the RNA copy (or that were taken from regular cell stocks). In year 2000 computer terms, the virus doesn't just need the bytes of the VBS file, it also needs the email header that says "ILOVEYOU".
- hcknwscommenter 7y agoNot really though. Naked RNA is incredibly unstable when just out in the environment or floating around in blood, mucus, etc. Sure, if you dump a pot of naked RNA on the floor, mop it up and analyze it that second your PCR test will pick it up, but you would have to be right quick about it.