MicrobeTV
3 HN mentions · mentioned in 3 months, 2020–2021
36:47 · 129K views · Jul 17, 2020
Dr. Anthony Fauci joins the This Week in Virology podcast to discuss SARS-CoV-2 transmission, testing, immunity, vaccines and preparedness.
Cited in debates over PCR cycle thresholds, as a place where Fauci addressed them directly.
3 comments from Hacker News
>That's not a false positive. False positive happens when there are no viral particles in the sample, but the test comes back positive. Those are very rare with rt-PCR and can usually be tracked down to cross-contamination. Cycle count has nothing to with those. You're not arguing with me. You are arguing with Fauci. this video If you could explain to me if you don't mind. Why are you saying Fauci is wrong? Was he lying again? >If there is no SARS-CoV-2 genetic material in the sample, there's nothing for rt-PCR to amplify. I made my entire post literally Fauci and not me at all. I made no comments or assertions.
PCR positive doesn't mean infected. You'll need an high amount in PCR, i.e. low cycle threshold for the probability to be high. Antigen tests will show if there was/is an infection. PCR does not show infection only presence. (WHO has now put out guidance about this. They don't have to it's well known.) If you're European this may be strange to you but I'm the U.S. we don't receive the cycle count when the RNA for the virus is detected. Here's Fauci talking about it a little: this video
Why are cases important? Assuming PCR, can get whatever result you want with the cycle threshold (discussion begins around minute 3:50): this video Want more positive cases? Use a higher threshold. Want to scare the population into compliance? Use a higher threshold. Want to demonstrate that person X or policy Y was effective against stopping spread? Use a lower threshold.