0 Members and 2 Guests are viewing this topic.
Quote from: sonofdaxjones on January 21, 2021, 02:41:12 PMCongrats #blueanon nation.You're going to start seeing a reduction in positive cases, because almost right on cue the WHO has issued guidance on Ct. Soon to come to the U.S. if not already here. Instead of Ct values of 37-40 in PCR testing, we'll see Ct values of 30 . . . tops. Thus reducing the amplification of already low viral loads that in the vast majority of cases are both asymptomatic and non-infectious. Cases are most certainly going to drop simply by this measure alone. How appropriately timed . . . should have bet on it.There's only one state that requires Ct value reporting, Florida. As someone who designs and does qPCR assays all the time - anything that comes up after cycle 30-32 is pretty much trash (spurious products, primer dimers, etc.). Reducing your cycles by 10 will save you ~15 mins per run and allow you to process more samples a day. Good, common sense molecular biology - especially for any diagnostics lab.
Congrats #blueanon nation.You're going to start seeing a reduction in positive cases, because almost right on cue the WHO has issued guidance on Ct. Soon to come to the U.S. if not already here. Instead of Ct values of 37-40 in PCR testing, we'll see Ct values of 30 . . . tops. Thus reducing the amplification of already low viral loads that in the vast majority of cases are both asymptomatic and non-infectious. Cases are most certainly going to drop simply by this measure alone. How appropriately timed . . . should have bet on it.There's only one state that requires Ct value reporting, Florida.
Subject: FW: COVID - KDHE Ct valueI reached out to both BioFire and Cepheid (GeneXpert) about cycle counts. BioFire does not utilize a Ct. value (cycle value) to determine positive or negative specimens, it is qualitative and is based on melt curve analysis. Below is the response from Cepheid. Since this test is an EUA, I do not want to go off-label and adjust how we report our results. A validation study will be very involved and quite honestly, costly. I also don't think the CLIA inspectors will want us to deviate from manufacturer's guidelines on the EUA.I went back through our last 19 positive specimens from the GeneXpert and 11 of the 19 fell between a Ct. value of 35 and 45. However, we are testing asymptomatic patients on this analyzer, so Ct. values should be higher because they aren't symptomatic which typically means the patient will have a lower viral load.Thoughts? From: CEP Medical Science - Infectious Diseases <[email protected]>Sent: Thursday, January 28, 2021 12:16 PM*** NOTICE: This message originated from outside ----- *** Dear --,The 4plex test will report a positive SARSCOV2 target out to 45 cycles. We designed this test with more cycles than usual to give extra high sensitivity. To control the COVID-19 pandemic it’s important to accurately identify cases and not have false negative results in persons under suspicion.Our test with the above cutoff has been fully validated through rigorous analytical and clinical studies to provide high sensitivity without compromising specificity. If you elect to report results with SARSCOV2 Ct values above 35 as “negative”, this is an off-label modification and must be validated by your laboratory, according to relevant laboratory quality regulations. While RT-PCR results with weak positive (late Ct values) may not always correlate with presence of infectious virus, they do indicate the presence of SARS-CoV-2 RNA, and taken together with relevant clinical and epidemiological information can confirm a COVID-19 case. Persons with asymptomatic or mild COVID-19 may have positive Rt-PCR results with late Ct values. Also, persons in the pre-symptomatic phase, or late infection (> 1 week after symptom onset) may have late RT-PCR cycle thresholds. Also, poorly collected specimens may have low target load and produce late Ct values. But to call these results “negative” would only reduce the sensitivity of the test, and lead to missed diagnoses.So to conclude, Cepheid strongly discourages an off-label modification to the test to change positive results with Ct values >35 to negative. This would not increase the specificity of the test, but rather, it would decrease the sensitivity. Any off-label test modifications would have to be validated by the laboratory performing the test.Best,Mike LoeffelholzREDACTED, Ph.D., D(ABMM)Senior Director, Medical AffairsCepheid––––––––––––––––––––––––––––––––––––––––––––––––––––––WWW.CEPHEID.COM
Which makes the J&J results disappointing, because you can stick those back in the Roper and they're good for 3 months.
https://twitter.com/kakape/status/1355143391236005889
Quote from: steve dave on January 29, 2021, 07:21:56 AMhttps://twitter.com/kakape/status/1355143391236005889These details got me jazzed for J&J much more than the overall effectiveness %.
Picking up from the vaccine waste/distribution talk yesterday in the “do you know anyone with covid” thread...A big hospital tweeted this at 11pm local last night:https://twitter.com/Swedish/status/1355048024062500870Success!? Haven’t read yet what the demos of arms they eventually installed the chips in was.https://twitter.com/johnhopperstad/status/1355150661923475458
https://www.king5.com/amp/article/news/health/coronavirus/vaccine/health-workers-stuck-in-snow-give-other-drivers-vaccine/507-6b674eab-f7a0-4fce-b52d-0f96762fcb82
Quote from: Trim on January 29, 2021, 09:21:13 AMhttps://www.king5.com/amp/article/news/health/coronavirus/vaccine/health-workers-stuck-in-snow-give-other-drivers-vaccine/507-6b674eab-f7a0-4fce-b52d-0f96762fcb82This is the can do attitude that will help us kick this thing's ass.
I always assumed it would be like, priority group 1a, priority group 1b, and then gen pop. I sincerely hope they don%u2019t keep trying to stagger this thing. I think you get severely diminishing returns after prioritizing the groups they have.
https://twitter.com/KING5Seattle/status/1355182688441937923
again, I think this discussion is an overreaction based on anecdotes. Supply is still the issue, not an inability to find people to jab.
Quote from: michigancat on January 29, 2021, 11:52:12 AMagain, I think this discussion is an overreaction based on anecdotes. Supply is still the issue, not an inability to find people to jab.There was definitely never an inability to find people to jab. There was a very shitty way of getting the priority people lined up to be jabbed at the right time, and once that had 'chips on the verge of expiration, a decision to not jab them in found people. It's not an overreaction to be pissed about 2300+ of those decisions.
