New data on the @my_helix SARS-CoV-2 dashboard, which is still focused on B117 variant.

Link: public.tableau.com/profile/helix6…

Thread with specific analysis in California & Florida.
2/ Methods

All numbers are based on positives with Ct<27 for N gene.

Tracking 2 metrics to estimate % of positives that are B117:
- (n SGTF) / (n positives)
- (n B117) / (n SGTF sequenced)

Latest sample collection date:
for SGTF: Jan 22
for sequencing: Jan 15
3/ CA results

Latest 7 day moving average:
- (n SGTF) / (n positives) ~ 0.015
- (n B117) / (n SGTF sequenced) ~ 0.95

estimate: 1.4% of positive cases in CA are B117. Trending up.

@EricTopol SGTF = S Gene Target Failure. This is due to a deletion in t
4/ FL results

Latest 7 day moving average:
- (n SGTF) / (n positives) ~ 0.04
- (n B117) / (n SGTF sequenced) ~ 0.61

estimate: 2.4% of positive cases in FL are B117. Trending up.
5/
Another state where numbers seem to be going up is Georgia. There may be others that we are not seeing with @my_helix testing.

As mentioned before, we are increasing the sequencing of random positive (not SGTF). In this picture, you can see the numbers up to Jan 15.
6/
I am still learning about viruses, so I stay away from interpreting too much these numbers.

Grateful to learn from experts like @K_G_Andersen & his lab. As well as many on Twitter @firefoxx66 @trvrb @ewanbirney
& credit to @my_helix science teams for all of these results.

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Alexandre Bolze

Alexandre Bolze Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @alexbolze

21 Jan
Update. @my_helix launched a dashboard with our results re virus surveillance
So far, you can check trends in by states for:
- % of SGTF by positives
- Ns & % of B117

Link:
Tableau public.tableau.com/profile/helix6…

Helix web helix.com/pages/helix-co…

🧵 with results for CA, FL, MA...
2/
Methods:
ALL numbers are based on positives with Ct<27.

In real life, we return positive results for Ct≥27, but we only sequence (with @illumina) samples with more virus (Ct<27) to optimize seq success.

Still Ns analyzed are large. A couple thousands positives per day
3/
So far, our effort was focused on B117, which is established to be more contagious.

B117 causes SGTF (S gene target failure) in PCR test. But it is not the only variant to do so.

So 2 metrics are useful to track

- (n SGTF / n positives)
- (n B117 / n SGTF sequenced)
Read 10 tweets
1 Jan
Update 🧵 on @my_helix study on the B.1.1.7 variant in the US.

Summary:
- we sequenced 31 samples with S-gene drop out in US
- 4 were B.1.1.7
- 3 from CA, 1 from FL
- Pursuing seq effort with @illumina , & work with @CDCgov

Link: blog.helix.com/sars-cov-2-uk-…
2/

Context: a new strain of SARS-CoV-2, B.1.1.7, was identified in the UK, and has been shown to be more transmissible.

-> need to track & monitor the variant in the US

See this thread for our initial work re B.1.1.7
3/
Reminder:
- H69del/V70del variant present in B.1.1.7 likely leads to S gene drop out in RT-PCR assay.
- H69del/V70del is NOT unique to B.1.1.7. Frequent in other clusters (see pic. all of the green is NOT B1.1.7)

Need to sequence to know if S gene drop outs are B.1.1.7. https://nextstrain.org/groups/neherlab/ncov/S.H69-?c=gt-S_50
Read 13 tweets
24 Dec 20
A thread on S gene drop out patterns in SARS-CoV-2 tests done at @my_helix .

Summary:
- we observe S gene drop out since mid October in US. Up to 0.5% last week.
- more sequencing of the virus is needed in the US.

blog.helix.com/sars-cov2_uk-v…
2/
A new variant of SARS-CoV-2 named B.1.1.7 has been reported in the UK beginning of December, and is likely more transmissible.

Follow these experts: @firefoxx66 @jcbarret @richardneher to know the latest about the variant.

Also @CDCgov summary: cdc.gov/coronavirus/20…
3/
One key point is that the B.1.1.7 variant has not been identified in the US so far.

But the US is doing very little sequencing of the virus compared to the UK for example. So really, we need more information.
Read 14 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!