This week's Test & Trace data - for 25th to 31st March (around the last week of school before holidays)

- LFD tests down
- big variations in LFD use across the country
- and increase contacts per case.…
The number of people tested week on week has fallen for the past two weeks, down to 4.8m from a high of 6.2m.
The fall is due to reductions in LFD use - down 23% to 5.5m.
And this is driven by drops in testing in secondary schools - down 33% on the past week.

Partly this will be from an overlap with school hols, but it also may relate to the shift to testing at home rather than the first week being in school.
In terms of what this means for case numbers, some of that's picked up here:
There are significant differences in LFD use by region. T&T publish absolute values, but when looking at rates per 100,000, the biggest difference is between London and the SW.

LFD use in SW was 12,224 tests per 100,000, nearly double that in London at 6,877 per 100,000.
The differences by upper tier local authority are greater, varying over 5-fold from 3,045 LFDs used per 100,000 in Tower Hamlets, to 16,026 per 100,000 in N Somerset.
Some of this will be due to differences in the proportion of people eligible for the various government testing schemes, but it may also reflect differences in knowledge of test availability, willingness to get tested (for a range of reasons), or test access and availability.
Barriers to test uptake relate to barriers to isolation adherence.

And whilst more info for these differences between regions would be helpful, it's likely that the same barriers that have been studied for PCR testing will relate to LFD use.…
Finally, differences in uptake rates may be a result of - and exacerbate - inequalities.

Easy test access, clear & consistent comms (that is language appropriate), & adequate support if testing positive are all v likely to help.

Ideally all co-designed with those most affected.
In terms of contact tracing, 25,767 cases were transferred to T&T and 23,243 (90%) were reached.

Of these, 19,844 (85%) gave details of close contacts.

All similar to the week before.
These 19,844 cases identified 85,573 contacts - or 3.6 contacts per case overall.

Almost all cases and contacts are now handled by T&T and local authority contact tracing teams.
This is because many cases that were previously classed as complex or high risk are now more manageable, - the organisations are better equipped at handling cases, guidance is always improving, T&T/local contact tracing teams have improving processes.
And this also gives more space for PHE Health Protection Teams to concentrate on handling variants of concern.
The avg number of contacts/case has been rising wk on wk from a low of 2.0 since mid Feb.

And while the proportion of people giving details of contacts and the proportion of contacts that are from the same HH hasn't changed since last week, it does point to more social mixing.
As lock down eases further, we should expect the number close contacts identified to rise further still.
The percentage of contacts reached has remained steady at 90%
And the total end-to-end journey time is also relatively static and has been for some time.

There are efforts with local authority contact tracing systems to speed this up (taking all or certain cases from the national team earlier etc) so will be interesting to see if it helps.
Finally, as hinted at earlier in the thread, none of these data tell us anything about people not getting tested or unable to adhere to isolation.

We know this is important, particularly for tackling ongoing inequalities in case rates and areas with enduring transmission.
So while reported T&T performance remains relatively good, it's crucial to still study test uptake and isolation adherence, and to continue to develop and push for policies that can support those most in need.
This includes tackling the many structural factors underlying ongoing high case rates across much of the country.

Here's the link to our freshly updated @HealthFdn T&T performance tracker, with @cfraserepi.

Has some great figures, and looks into some of the testing in more detail.…
And finally for info, barring something of particular interest, I'm going to move to writing these T&T threads, as well as the PHE COVID surveillance threads, every fortnight (or so) rather than weekly.

I do love all these data, but you know, Thursday evenings were once fun.

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More from @ADMBriggs

8 Apr
This week's @PHE_uk COVID surveillance report, 29th March to 4th April (incl. start of the school hols). 🧵

⬇️ case rates, partly from fewer 10-19y/o LFDs with no clear sign yet of schools leading to ⬆️cases in older ages

+ important variation by region…
Further drop in cases in the most recent week following a bit of a flattening off in previous weeks - with some of this due to school holidays and fewer LFD tests.

Worth noting that for March, both REACT and ONS surveys suggest that case rates are generally static.
Big drop in LFD use, which is mainly due to a drop in test use by secondary schools (see T&T data).

The drop off has accelerated with the school holidays, but the move from testing in school to at home may have contributed over the past few weeks.
Read 19 tweets
8 Apr
Latest update from REACT-1.

Looks 11-30 March (schools fully reopened on 8th March).

- Suggests infection rates fell by around 60% between Feb and March to 0.2%
- Big differences by age, region, and deprivation
- R now estimated at approx 1.…
Falls across all regions but highest rates still in NE, NW, and Yorkshire and Humber (round 9 is swabs from 4th-23rd Feb, round 10 is 11th-30th March)

Includes 12% probability R>1 for Y&H between two rounds. <1% in all other regions.

This is consistent with ONS survey data.
Highest infection rates among 5-12y/o (as does ONS), but REACT suggests lower infection rates among school age children than ONS does.
Read 4 tweets
1 Apr
PHE latest COVID surveillance report now out, as is ONS.

Covers 22nd-28th March 🧵

-cases down all ages except 10-19yrs.
-Significant geographical variation.
-Vax still motoring.
Fall in case rates in all age gps (incl 5-9y/o) *except* for 10-19y/o where they've increased by 7% to 110 cases/100,000.

Lowest cases rates are among 70-79y/o at just 11/100,000, and generally there's a step decrease in case rates for ages 60yrs+ compared to those <60yrs.
And among 10-19y/o, case rates seem to be rising mainly among 10-16y/os.
Read 27 tweets
27 Mar
If this is true, it is so disappointingly shortsighted.

I hope that @MattHancock and @Jochurchill4 will reconsider.

A quick walk through the evidence. 🧵
Nearly one in four reception age children and one in three children at year 6 are overweight or obese.

And there are stark inequalities - children in yr 6 are *more than twice* as likely to be obese if living in the most deprived areas compared to the least.
The government is aiming to halve childhood obesity by 2030 and reduce inequalities.

You can't do this with one or two policies here and there. Obesity is complex and multifaceted. To make any kind of dent, you need a multifaceted solution.…
Read 19 tweets
25 Mar
And most recent T&T data, 11/3 to 17/3. 🧵

- More testing
- Fewer cases
- And the numbers of non-household close contacts is rising again.

This week, just a short thread to pull out main points.… Image
Small increase in number of people tested but rise of 1.3m in number of LFDs used, driven by secondary schools. ImageImageImage
And case rates generally still falling, except among school age children

Read 10 tweets
25 Mar
This week's PHE surveillance report is now out, covering 15-21 March. 🧵

- increasing case rates among 5-9y/o and 10-19y/o
- important geographic variation
- hospital data still improving
- vax going strong
- and inequalities persist.…
Number of PCR and LFD tests done similar to the previous week, but positivity (percentage of tests that are positive) for PCR still trending down and is now 2.1%

For LFDs it's 0.19% compared with 0.15% the week before.
Case rates are falling less slowly, but they're still falling across all ages...

*except* 5-9y/o where they're up 59% to 63.5/100,000, and 10-19y/o where they're up 26% to 100.7/100,000.

Case rates lowest in vaccinated cohorts.
Read 23 tweets

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