Testing which variant?

Message

Bayleaf · #1 Post by **Bayleaf** » Sat Dec 18, 2021 9:25 am

Do people who test positive get told which variant they have? How is it recognised? Just a curiousness going around my head!

niemeyjt · #2 Post by **niemeyjt** » Sat Dec 18, 2021 9:45 am

Variant testing is 1.6% in France (29th November figure) so I think the answer is "NO".

2021-12-18_09-43.png

exile · #3 Post by **exile** » Sat Dec 18, 2021 10:19 am

As J says no. The test itself just says you have it. To establish which variant you have the sample has to be sent off for full genome sequencing and that is impractical for each and every positive sample (UK as well as France), so they rely on sample testing by which they (hope to) establish the growth and spread of each variant. Think of it as being a bit like a poll just before an election.

tagh · #4 Post by **tagh** » Sat Dec 18, 2021 1:00 pm

UK tests for the variant substantially more than France, apparently, hence the discrepancy in the apparent number of cases

Char · #5 Post by **Char** » Sat Dec 18, 2021 1:04 pm

There are lots of graphs on this site, I don't know which varient is which - https://www.gouvernement.fr/info-corona ... _mutations

niemeyjt · #6 Post by **niemeyjt** » Sat Dec 18, 2021 1:06 pm

tagh wrote: ↑Sat Dec 18, 2021 1:00 pm UK tests for the variant substantially more than France, apparently, hence the discrepancy in the apparent number of cases

Correct - as per the graph above - about ten times the number.

That was also the South African argument (and previously the "Kent" argument) - we find because we test, not because we have more than anyone else.

MAD87 · #7 Post by **MAD87** » Sat Dec 18, 2021 2:23 pm

The sequencing tests cost a fortune.

niemeyjt · #8 Post by **niemeyjt** » Sat Dec 18, 2021 2:25 pm

MAD87 wrote: ↑Sat Dec 18, 2021 2:23 pmThe sequencing tests cost a fortune.

Maybe the UK Government gets "mates' rates"?

exile · #9 Post by **exile** » Sat Dec 18, 2021 6:30 pm

tagh wrote: ↑Sat Dec 18, 2021 1:00 pm UK tests for the variant substantially more than France, apparently, hence the discrepancy in the apparent number of cases

I don't know if that is the case tagh.

In the early days of omicron I think the numbers quoted will have been the numbers measured but as omicron takes over I would expect them to do some clever sums - so if Omicron tests are 40% of all those sequenced and 100x tests have been done then 40x tests are omicron. It could even be more sophisticated than that breaking down case levels, positive tests and omicron positives across regions.

exile · #10 Post by **exile** » Sat Dec 18, 2021 6:42 pm

niemeyjt wrote: ↑Sat Dec 18, 2021 1:06 pm
tagh wrote: ↑Sat Dec 18, 2021 1:00 pm UK tests for the variant substantially more than France, apparently, hence the discrepancy in the apparent number of cases
Correct - as per the graph above - about ten times the number.

That was also the South African argument (and previously the "Kent" argument) - we find because we test, not because we have more than anyone else.

At the risk of being controversial, I think it is much more complicated than as you suggest.

Certainly testing more will find more but if it were as simple as that, why do we in France now "enjoy" a significant peak in cases - a peak that would seem to be not yet omicron. The major variant in Europe at the moment is still Delta - so while UK cases rocketed with Delta back in the summer (Euros effects in part?) and then established an uncomfortable plateau through the autumn, European levels remained by and large much lower and only in the last 6 weeks have taken off (a la Euros peak in the UK).

So where that leaves me is that as Omicron takes off here it is going to get a whole lot worse unless recent delta infection provides enhanced protection from omicron. Long term that does not seem to be the case but we can hope that perhaps we can get through winter without omicron overtopping our health service defences.

France in Focus

France in Focus