This 👇🏼 #Singapore seeing new large #COVID19 clusters, including #B1617 Changi Airport, Tan Tock Seng hospital. Shows a) #VOC import risk, b) better cluster tracking with low case numbers, c) now is not the time to relax measures 🇨🇭 (1/n) straitstimes.com/singapore/heal… Excellent thread from @trvrb on growth of nee #VOCs with added analyses from @TWenseleers

https://twitter.com/trvrb/status/1392132865995857920?s=21

People are talking about *forward* and *backward* #ContactTracing #COVID19

What do they mean?

I made a case study for the @GOARN @WHO contact tracing group

A fictional contact tracer’s tale

My slides are here:
ispmbern.github.io/covid-19/Forwa…

Short thread (1/7) Most #ContactTracing seeks contacts from 2 days before the infected person developed symptoms

#SARSCoV2 can be transmitted before symptoms emerge.
That is looking *forwards*

Who might the index case have infected?

Contacts in quarantine soon enough won’t infect others

2/7

@nataliexdean @EpiEllie Ooh, yes. You should judge risk of bias in #LivingSystematicReviews as you would a standard one. @jhjelliott says, „We propose living systematic review as a contribution to evidence synthesis that combines currency with rigour“ journals.plos.org/plosmedicine/a… 1/n @nataliexdean @EpiEllie @jhjelliott Julian Elliott really started the movement with a project in @cochranecollab community.cochrane.org/review-product… and followed up with a series in J Clin Epidemiol (pt1 here sciencedirect.com/science/articl…) 2/n

This paper is (mostly) being interpreted as showing that #SARSCoV2 viral load is higher in children than adults. But is it? jpeds.com/article/S0022-… @EricTopol @DoctorYasmin @angie_rasmussen @skepteis @apsmunro @mugecevik My pedantic post-publication peer review thread (1/n)

https://twitter.com/EricTopol/status/1296453662022291457

The headline result on Tweets is that VL is higher in children than adults. But the same p-value seems to appear with different comparisons in different parts of the manuscript. Have a look. NB: I am not a fan of p-values or sub-group comparisons (2/n)

The #COVID19 data problem in Switzerland. As ⁦@sbonhoeffer⁩ says, we need to analyse #ContactTracing data to look at where coronavirus is, but they still aren’t available... 1/n

derbund.ch/clubs-oder-fam… The point is to have info to break transmission chains. Showing that families account for a large proportion of #COVID19 is one thing. But it doesn’t show the source of infection. Where did the family member get infected? #ContactTracing should joint the dots... 2/n

This piece on #SARSCoV2 viral load in children and adults has been highly influential.
Can you extrapolate from “Data on viral load” that “we have to caution against an unlimited re-opening of schools and kindergartens in the present situation”
I have serious concerns. 1/7 There are two issues: science and politics
On the science
1. There is no methods section about how study population was selected and who they represent
– yes, I know it is a bunch of samples tested in a virology lab - with no denominators about how many samples tested by age 2/7