Thread by @globalhlthtwit

My lengthy thread on test, trace and isolate in light of Sir Patrick Vallance’s comments and the Public Accounts Committee Report committees.parliament.uk/committee/127/… (1)

Yesterday, when asked about his assessment of TTI by Greg Clark, Sir Patrick Vallance said ” Test and trace is working very well at the moment” (March 9 Science Select Committee, 11.32am) (2) parliamentlive.tv/Event/Index/36…

Sir Patrick agreed that “The isolate bit is very important (at all levels of cases)..TTI is more important as case numbers fall”. He also identified the importance of backward contact tracing i.e finding which contacts caused the case infection in order to identify clusters.(3)

Is TTI WORKING? Greg Clark MP chair of the Select Committee then asked: 'Unlocking depends upon the vaccine and reducing transmission, but how important is TTI to rate of unlocking? (4)

"The Test, trace isolate programme (Baroness Harding evidence to committee) assesses the impact of TTI on R value is up to 0.8. Have you assessed their assessment? Sir Patrick: No. "I dont know which of the modelling groups may have been linked in with JBC assessment.” (5)

PUBLIC ACCOUNTS COMMITTEE VIEW? Did they share Sir Patricks sanguine view of test, trace and isolate? No. Their report states "The Department of Health & Social Care (DHSC) justified the scale of investment, in part, on the basis that an effective test and trace system...(6)

"...would help avoid a second national lockdown - but since its creation we have had two more lockdowns...The “unimaginable” cost of Test & Trace has failed to deliver the central promise of averting a second - and third - lockdown. (7)

The Chair of PAC said “British taxpayers cannot be treated by Government like an ATM machine...(The TTI programme) must now “wean itself off its persistent reliance on consultants” (8)

"In early Feb 2021 NHST&T said it was still employing around 2,500 consultants, at an estimated average daily rate of around £1,100, with the highest daily rate paid of £6,624. It is concerning that the DHSC is still paying such amounts... (9)

– which it considers “very competitive rates - to so many consultants." (From Boston Consulting Group, Deloittes, PWC and others) (10)

TESTING "The percentage of total laboratory testing capacity used in Nov/Dec 2020 remained under 65%, and even with the spare capacity, NHST&T has never met the target to turn around all tests in face-to-face settings in 24 hours." (11)

TRACING "NHST&T had also contacted over 2.5 million people testing positive for COVID-19 in England and advised more than 4.5 million of their associated contacts to self-isolate.” That's a ratio of 2 contacts to 1 case, most of them in the same household. (12)

A Nature review nature.com/articles/d4158… reported "The number of contacts identified for each COVID-19 case varies wildly, from an average of 17 per case in Taiwan, to 2 in the United Kingdom” Boots on the ground+ local second and third order testing was secret of success (13)..

.. in countries like Vietnam, Taiwan, together with use of local apps to monitor compliance with isolation. "Wealthy nations struggled to hire enough contact-tracers, marshal them efficiently or make sure that people do self-isolate when infected or that they quarantine.” (14)

Another China study showed "The spread of COVID-19 was effectively controlled in Wanzhou by breaking the transmission chain through social distancing, extensive contact tracing, mass testing and strict quarantine of close contacts.” nature.com/articles/s4159… (15)

An recent pre-print review which modelled data in China concluded : stringent lockdown with broad (self- and contact tracing) quarantine interventions reduced the pool of susceptible individuals, effective contact rate and secondary transmissions. medrxiv.org/content/10.110… (16)

"For example, if the estimated time for 50% of initial susceptible population of China to be self-quarantined (∼2 weeks from Jan. 21) had been delayed by just one week, then the total number of cases would be approximately 10 times larger” (17)

MASS TESTING PAC Report "In reality full compliance with self-isolation rules can be low. NHST&T plans to increase the proportion of cases identified through the mass testing of people without symptoms. (18)

"However, the interim report on the Liverpool mass testing pilot did not find clear evidence that the pilot reduced positive COVID-19 cases or hospital admissions." (19)

EFFECTIVENESS of TTI? "NHST&T publishes a lot of performance data but these do not demonstrate how effective test and trace is at reducing transmission of COVID-19. For NHST&T to be effective in breaking chains of COVID-19 transmission, it must identify.. " (20)

"..as many people as possible who are infected with or exposed to the virus, as quickly as possible, within 48-72 hours of the original case developing symptoms, i.e. from ‘cough to contact’." (21)

ISOLATION? "effectiveness relies on people self-isolating .. “independent verified analysis” suggested that its activities in October 2020 contributed to a reduction in the “R number” provided that people with the virus start self-isolating once they develop symptoms..(22)

"... i.e. before even engaging with the test and trace system. They assume that people self-isolate as required..in particular between developing symptoms and receiving their test results. In reality full compliance with self-isolation rules can be low.” (23)

"NHST&T weekly performance data.. do not provide an overview of the speed of the process from beginning to end (“cough to contact”) and thus do not allow readers to understand the overall effectiveness of the programme." (24)

SUMMARY. In contrast to Sir Patricks view, PAC believes testing is not rapid enough, nor sustainable, tracing is not local + numbers way too low, claimed effectiveness is simply wrong + self-isolation way too low. Financial support for poor people is not effective.

After a year, we have not produced an isolation system that works. And we have committed eye-watering sums (£37,000 billion) to a failed system. Surely senior people should now consider their positions.