We have heard Health Minister Vaughan Gething say several times how well our Trace, Track, Protect system is performing.

And if we look at the raw numbers it is hard to argue with that.

But there are very real questions to be asked as to whether TTP is effective.

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First things first, TTP was a real success in the summer.

Outbreaks in Merthyr, Wrexham and Anglesey were nipped in the bud and never spread into more wider community transmission. It also gave experts real time data on how the virus was moving & what the riskiest settings were.

But now things are totally different because there are just so many cases.

For the entire month of July, tracers had to contact 451 combined positive cases and their contacts.

On December 28 alone they had to contact 8,266.

This is where we need to start looking beneath the headline figures Vaughan Gething always quotes.

(Stay with me on this)

Let's take the last week of December (Dec 27 - Jan 2) as an example:

A whopping 13,910 positive cases were eligible for follow-up and of them, 12,827 (92%) were reached and asked to provide details of their recent contacts

Of the 31,205 close contacts that were eligible for follow-up, 25,760 (83%) were successfully contacted & advised accordingly, or had their case otherwise resolved.

It's a drop from the summer but with the enormous caseload they now have, this is to be expected.

Not bad right?

So there is clearly no huge issues around actually contacting people. But what about how long it is taking to make that contact?

If we look at the same week it shows:

Of the positive cases, 13,910 cases in that period, 69% of them were reached within 24 hours of referral. A total of 87% were reached in 48.

In terms of the 31,205 close contacts, 66% were reached within 24 hours of being identified by a positive case with 75% in 48 hours.

However, these figures for tracing contacts plummet if, instead of measuring the length of time from when the postive case identified them, we measure it from the time the positive case first appeared on the system.

If we measure the time taken to find contacts from when the positive case was first identified, only 32% of close contacts were reached in 24 hours with that rising to 52% in 48 hours.

If we take that week as an example we can say the following things:

- About half of people who have contact with a positive case don't hear from tracers within two days of TTP being aware of a case.

-Only 10,000 of the 32,000 close contacts that week were alerted by TTP within 24 hours of the positive case being referred to TTP.

- Just under a third of positive cases don't hear from contact tracers within 24 hours.

So what does this actually mean?

To understand what this all means it is worth creating a timeline for how people are tracked in Wales to understand why it is so hard to control the virus.

To do this, let's imagine a person called Dave and assume they follow the guidance.

Imagine Dave got symptoms on January 1 and immediately isolates.
He books a test and has one the next day (there is usually space within 24 hours but back in the autumn there were real issues getting quick tests).

By the time that result comes back positive (which is usually within 72 hours but was often far longer in the autumn) he then awaits a call from contact tracers.

As we know, he has an 87% chance of getting that call within 48 hours but it may be longer.

The contact tracers will then ask for his close contacts for the 2 days before he started showing symptoms.

We know these contacts have a 50/50 chance of being contacted within 2 days of testing positive.

So how long could it take for a contact of Dave to be told to isolate?

Well let's add it up:

- Two days since they met.

- One day to get a test.

- Three days for a result.

- Two days for tracers to speak to the positive test and contact you (though about 50/50 to be longer than that).

All told you are looking at 8 days from that point of contact before the contact tracers can get to you.

By that point you're nearly at the end of the 10 day isolation period you would have to do anyway. And this is if you are lucky with getting a test, having it come back etc.

The first thing to stress is that this is not a criticism of the workers within the TTP system.

They are up against an absolute avalanche of work with limited resources. They can only react as fast as the testing allows.

And even then they are totally reliant on people actually picking up the phone and providing reliable and timely contact details.

Though staff are working as hard as they can, there are inherent limitations in what TTP can possibly do, given the time scales they are working to.

The WHO defines a successful tracing system as one where that can trace and quarantine 80% of close contacts within 3 days.

Saying "90% of contacts reached" means very little from a virus containment point of view if it is nine days after they have met.

Full story: https://www.walesonline.co.uk/news/politics/huge-problem-track-trace-protect-19615382