Thread by @kearnsneuro

1. @itv's @Peston has been holding feet to flames about the UK's lack of #TestingForCovid19 and shares this per capita league table. UK comes last, amongst 20 countries. But he's getting flak themed: "what's the point in testing "mild" cases"?

2. Speaking as a doctor in the @NHS, and with public health training, I can't see any way to exit lockdown without a BIG increase in public health infrastructure. I think community testing is a key part of that. #TestTestTest

3. However, this seems to be a genuine question people are asking. Why #test? E.g. a few times when I've been driving to or from work @NHSGGC, @Nigel_Farage has been arguing he doesn't see the point. Many @LBC callers share his view; they can't see benefit in testing mild cases.

4. There must be an ongoing failure to communicate the very powerful arguments for why it is important to #TestAndTrace all possible cases and isolate +ves.

These are reasonable Q.s and it's a failing that the arguments for scaling up testing aren't winning out in the UK.

5. I'll highlight what I think are three good reasons why wide testing for #COVIDー19 is important (as a necessary part of a broader strategy).

(Stick with me for the third, it's a case study of #BOJO @BorisJohnson)

6. First, mild cases need their transmission chains broken just as much as severe ones. Because SARS-2-CoV can cause very mild disease or no symptoms at all in some people, but the next transmission can kill someone. It's like russian roulette.

7. Second, we cannot break transmission chains effectively enough simply by isolating people and their households once they become symptomatic.

This is because a lot of transmission occurs from pre-symptomatic people. 44% in this study:

nature.com/articles/s4159…

8. So by the time someone gets a symptom we can expect them to have infected 44% of the people they were going to.

Since R0~3 (at least), if everyone perfectly isolated at the exact moment they became symptomatic, R would still be >1 So exponential, which is why we locked down.

9. The majority of the rest of transmission is also expected in the next 48 hours.

So the 48 hours before and after the first mild sniffle, or low fever, or dry cough is critical.

Pretty much everyone with any symptoms has mild symptoms this early. So test early = test mild.

10. If we test early (mild) then we're in the race: it is possible to track contacts down before they spread it.

Find cases; isolate and test them; turn around the tests ASAP; and then race to contact trace the people that test +ve; isolate and test their contacts; repeat.

11. We need to treat it as a race, accumulating marginal gains (per @SirBrailsford), to get slicker at every part of the process.

The better we get, the less extreme distancing needed.

To end lockdown, you have to get good enough at racing virus to win in an open race.

12. The whole point of lockdown (which is definitely working in UK) is to get cases low enough to give us a chance to contain transmission: to start racing chains of infection.

We need to build capacity (compete in more races) and sharpen processes (get faster). #exitstrategy

13. Third reason, and this is the point I feel most strongly about, and where I shall use Boris as an example, we are calling quite significant symptoms "mild" and we are managing these in the community (good in principle).

But without testing don't know we're managing COVID.

14. Testing early (when mild) and monitoring people who test positive closely for persistent symptoms can prevent tragic deaths. E.g. of frontline HCWs, who still struggle to get tested, like Julie Omar.

When people get seriously sick from COVID they do so fast. We know that.

15. Julie Omar was a trauma and orthopaedics nurse at Redditch's Alexandra Hospital, Worcestershire. According to the telegraph she "died at home while self-isolating with symptoms."

That is nothing short of an outrage. This struck me as appalling.

telegraph.co.uk/news/0/nhs-wor…

16. In preparing the #NHS for #COVID, we listened to our Italian colleagues who were hit early.

They stressed lessons comparing Lombardy and Veneto.

Lombardy = epic private hospitals;
Veneto = epic community public health.

Veneto coped (much) better + mortality was lower.

17. The Italian message was:

Treat this in your communities where you can. Don't let your hospitals get overwhelmed. 👌👌

The WHO had a similar message:

"engage very deeply with communities". Mike Ryan

So we aimed to encourage people with COVID to stay home if they can.

16. In Scotland, Covid Assessment Centres were set up to ensure that mild cases stayed in the community and didn't swamp hospitals.

They are designed to protect surgeries and hospitals and to redirect "mild" cases home. And I bet the GPs and nurses who staff them are brilliant.

17. But not even GPs, experts managing uncertainty, can see people with potentially serious (but "mild"-for-COVID) symptoms (fever, breathlessness, cough, etc.) and know with confidence the cause without tests.

People go home untested. Diagnosis:
??-COVID-19.
?Something else.

18. We are not engaging with communities if we're not even testing them. Actually we're failing them.

Graph below from @d_spiegel from ONS excess mortality data speaks for itself.

Similarly FT this morning 41,000 deaths total in UK:
ft.com/content/67e6a4…

19. Unwell people are being sent home across this country without tests and being told things like: it might get worse, before it gets better.

But sometimes it just gets worse, sometimes it gets worse quickly, and sometimes it just isn't even COVID.

20. We know this is happening because we're seeing it in the eerie absence of the life-threatening menaces that we normally treat as hospital doctors.

Just about every hospital specialist is quietly stressing about this same issue...

21. Haematologists are concerned about less acute blood cancers showing up. These often present with mild-for-covid symptoms: fever & fatigue.

Neurologists patients w/ treatable conditions, where breathless can = relapse, have died at home. ?Cause.

Cardiologists are noticing less heart failure (mild-for-covid breathlessness).

Same story; every specialty.

22. Now, contrast this with the case of @BorisJohnson

Tested at home on 1st day of symptoms, quick result, so no diagnostic uncertainty. Regularly checked on for a week, persistent fever, so his name was pencilled on a bed in hospital, just in case.

That's community engagement.

23. Notice it was only possible because he had access to a quick test. His contacts were alerted early and able to isolate themselves in the pre-symptomatic period before any of them were likely to develop symptoms themselves and infect their own contacts.

24. On a Sunday evening, the #PrimeMinister, whose gov once pretended that the NHS didn't work weekends, was rushed in to receive escalating levels of care. He "owes his life" to the integrated care he received at, but also before, hospital.

25. When we ask the government to scale up to #TestAndTrace mild cases, we ask for an exit strategy, and we ask for the same care and community engagement that @BorisJohnson enjoyed for everyone else.

Thanks due to some people who have had the clear vision to be pushing this message loudly and clearly:
@piersmorgan @devisridhar @globalhlthtwit @AllysonPollock @richardhorton1 @timcolbourn @AdamJKucharski @BBCHughPym @Peston

@threadreaderapp unroll, thanks