Thread by @ADMBriggs

Week 22 Test & Trace data summary. 22/10/20 – 28/10/20.

Tests⬇️, cases⬆️

Turnaround times much better, but overall performance unchanged meaning over 24,000 cases and 131,000 contacts still not reached.

Summary in pics, detail in thread

gov.uk/government/pub…

There were 1,482,528 individuals tested this week, which is actually 3% lower than the week before.

However, number of positive tests up by 8% to 137,180 (similar % increase for P1 and P2)

Plus now >10m people in Eng have been tested at least once - that's quite something.

Positivity rates climbing ever higher, and is now 10.9% in pillar 2 (9.9% the week before) and 4.8% in pillar 1 (4.2% the week before).

To make full sense of the picture, need to separate symptomatic vs asymptomatic testing. But shows STILL unlikely to be testing enough.

And the PHE and national data are telling us, these cases are increasingly translating to admissions and deaths.

https://twitter.com/ADMBriggs/status/1324436230730321922?s=20

Some good news - test turnaround times really seem to be improving.

This is so important for controlling transmission.

It's one place where mass testing using rapid kits - as being trialled in Liverpool - can really make a difference.

But for it to have a real impact, it still needs a functioning contact tracing system...

So in the most recent week, a new record of 139,781 cases were transferred to the system. Up 16% on the week before.

And an impressive 83% of these were reached by Test & Trace.

But as case numbers rise, that 17% not reached means 24,000 cases weren't. Nor were their contacts.

The vast majority (112,530) were not managed by PHE health protection teams - i.e. not part of ongoing outbreaks in specific settings.

Note this definition is now different from previous 'complex' cases which would include single cases in high risk settings like care homes.

This will naturally reduce the proportion of cases that are managed by PHE health protection teams - HPTs (3,130 cases this week, a 4% increase on last week compared with the 16% rise in cases not managed by HPTs)

And in terms of those being reached - nearly half (47%) are reached online rather than by phone. More than double the proportion at the beginning of October.

*If* this can produces equally reliable data to phone calls, then this will be really helpful as T&T demand increases.

The proportion willing to provide details of contacts remains high at 83%, and from these 327,203 contacts were identified.

This is a 14% increase on last week, and the increase is entirely from cases not managed by HPTs.

The avg number of contacts per case not managed by HPTs is the same as last week at 2.8.

But avg contacts per case managed by HPTs continues its steep decline and is now just 3.7 per case compared with 31 at the start of Sept.

I've speculated before that this may be a consequence of social distancing, more COVID-secure workplaces, safer practices in schools etc. But it is striking.

The data are v skewed: T&T rpt median number of contacts/case managed by HPTs to be 6 (5 last wk).

May suggest not many outbreaks with 20+contacts, but lots around 6-10. Or if contacts aren't double counted, then outbreaks with lots of cases and the same wider gp of contacts.

Back to the data, for cases not managed by HPTs, the success rate remains stubbornly at just 60%.

This means over 131,000 contacts not reached and not asked to isolate.

However, the time taken for T&T to reach cases and their contacts has seen a dramatic jump to 67% from just 44% the week before.

I really hope this isn't a one off.

+ as we say in our PR today, local authority contact tracing systems take cases that aren't reached within 24hr by the national team, learning about how best to make contact with these harder to reach cases.

This local knowledge will likely be key to improving total number of cases & contacts reached. But gov needs to ensure that local systems have sufficient staff, + financial and technical resources, if they are to play a larger role when working with T&T.
health.org.uk/news-and-comme…

And here's our updated tracker with @cfraserepi
health.org.uk/news-and-comme…

So turnaround times better, but still a whole lot of cases & contacts not reached. Not to mention challenges so many people have with having to isolate.

Therefore support for those isolating & T&T improvement remains so important if we're going to avoid further lockdowns.

Wk 21 T&T @felly500 @trishgreenhalgh @deb_cohen @martinmckee @carolecadwalla @mgtmccartney @ADPHUk @Jeanelleuk @fascinatorfun @profchrisham @petermbenglish @HPIAndyCowper @Davewwest @HSJEditor @KateAlvanley @IndependentSage @nedwards_1 @chrischirp @SamanthaJonesUK

@ewanbirney @TimHarford @devisridhar @FurberA @andrewleedr
@kieran_walshe @DrChadborn