LFD tests are mainly used for testing people without symptoms and PCR tests are used for those with (new) symptoms.
LFD tests now outnumber PCR tests every week. 1/4
Unsurprisingly positivity rates for PCR tests are much higher than for LFD tests. Reassuringly positivity rates are coming down in both cohorts.
BUT if we are relying more on more on LFD tests then we *must* use them carefully! 2/4
Firstly, they should NEVER be used as a "green light" to indicate no infection - only as a "red light" to indicate that you've got Covid and should isolate.
Do a confirmatory PCR for positive LFDs to minimise false positives & ENSURE support for isolation! 3/4
this messaging at the moment is the wrong way round and dangerous as pointed out by @ReicherStephen
PS I do think that used very carefully with proper confirmatory testing & support for isolation, they could be a valuable public health tool in some high traffic settings.
• • •
Missing some Tweet in this thread? You can try to
force a refresh
A reasonably detailed dive into the latest numbers & (some) implications.
TLDR: things going in right direction but don't think unlocking will be easy.
2. Confirmed cases are still falling & we are back at levels last seen in early December. Positivity rates (accounting for changes in numbers of tests) are also falling in all 4 nations (and in all age groups).
ONS infection survey entirely consistent with this picture.
3. Cases and positivity rates also falling across all English regions & LAs. However, E. Mids, Yorks & Humber and N.East falling slowest.
Obviously falls are GOOD, BUT the green diamonds show where we were at the end of Aug last year.
MINI THREAD: One way in which the Kent (B117) variant might help us vs SA variant... Both are more transmissible that older variants & so quickly become dominant.
BUT SA not more transmissible than Kent (we think) - so Kent, already dominant in UK, should stay dominant. 1/2
This is good because all vaccines work well against Kent (B117) & it doesn't seem to be re-infecting people who've already had covid.
But SA can re-infect people & evade (somewhat) AZ vax. Unknown is how that might help SA over time as it has more people it can spread to. 2/2
SHORT THREAD ON SCHOOLS:
When schools go back is a tricky issue. I'm not going to get into it here BUT wanted to highlight a couple of data points from PHE surveillance & ONS infection survey this week. 1/5
Firstly, since early Jan, there have been a number of outbreaks at nurseries (open) & special need schools (30% attendance) (and yes - Covid).
A few at primary schools (20% attendance) and v few at 2nd-ary schools (5% attendance). 2/5
Added to that among young school age kids, case rates going down for primary school ages but UP in pre-school and nursery age children.
The number of people in hospital with Covid is either flat or coming down in all 4 nations - excellent and a sign that infections really are going down (at least in older groups).
BUT they are still higher than April peak everywhere 1/4
In England, hospital admissions are now coming steadily down from 12th Jan peak and are now below the April peak too... good! 2/4
This is true for all regions of England (good!). You can see that they started going down in previous tier 4 regions (London, SE, EoE) about 7-10 days earlier than other regions. 3/4