Unfortunately, our labs were too buried dealing with the preventable 3rd Wave from ignoring the threat from B117, and didn't get time to develop rapid screening for B.1.617.
Hence, on 1 May, AB Health announced cut from 100% sampling for variants, to undisclosed sampling rate.
We were never told the sampling rate for any variant, especially the very resource-intensive B.1.617, much less in aggregate.
I number-crunched an aggregate sampling rate by subtracting cumulative screens on two dates, and dividing by the difference in their cumulative cases.
In June, it became obvious that B.1.617 by Date Reported was much higher than the 0.4% of Variants during the month of May.
It also became clear the sampling rate for B.1.617 was much lower than the 48% aggregate for variants over May. Things became unacceptably opaque.
Before 9 June's results, AB Health updated the Variant Screened total every day.
But then I pointed out that "putting our numbers in context" that B.1.617 was only 5% of cases was misleading, by Reported Date or Case aka Swab Test Date.
Despite AB Health removing the "Specimens Screened" stats I used to help show @CMOH_Alberta B.1.617 minimization was misleading:
• At 1 June, no B.1.617 ID after 17 May. Dove off cliff as if the 2-wk full genome screening was stopped completely 1 May - not sampled at all since.
Most leading indicator Wastewater Sampling looks like Feb/Mar Start of 3rd Wave. Steep Decline ended suddenly at end of May, now rising slowly.
B.1.617 is no longer a HIDDEN leading indicator. Now 11.2% of recorded cases since 1 June.
Variants.
💥B.1.617 continues to explode among variants, but don't miss P1🔥 82% growth since 1 May.
AB Health still not providing number of cases screened for variants, which prevents me from reporting % coverage or % ID. I'm assuming the 2 missing days sampled at April rates.
Variants II
Odd to call B117 part of "Old Covid" since it arrived in January, was minimized in February, then drove the 3rd Wave.
B.1.617 is getting all the attention, but don't forget P1 which has been growing since February. Both are driving the 4th Wave.
With my spreadsheet, I use Reported Date. So I get around 9.2%, not 5%.
But there shouldn't be that much difference from the Retrospective Testing in June. Only ~800 more cases from before June have been screened so far, and in May ~17K were not screened.
So I got the AB Health stats which identify Variants by Swab Test Date.
From 1 May to 5 June*, exponential growth of B.1.617. Misleading of CMOH to "put our numbers in context" as only ~5% in last week, when this⤵️ is the 💥growth.
Nothing remarkable in general downward trend of "Old Covid" - Original Wild Strain and B117.
BIG 🔥 in "New Covid" of B.1.617 and P1 Variants of Concern.
(see rest of thread)
B.1.617 has exploded and appears to be drastically under screened in May.
• ⏫38 in last day, to 74 in just 4 days of June, vs 51 in all of May.
• 🔥from 0.4% of variants thru May, to 9.1% so far in June.
• Pushing P1 down relatively from 8.8% thru May, to 5.1% so far in June.
I have been warning about B.1.617 undercount in Alberta since early May in increasingly stronger terms. Not an epidemiologist, but I can see issues hidden in stats or spin.
I built my Variant Spreadsheet with cumulative stats, to find hidden problems between any points in time.
I think we’re seeing the same thing in Alberta:
• “Old Covid” of B117 📉
• “New Covid” of P1 & B.1.617 📈
• New Covid masked by under 50% screening for variants since 1 May, despite restrictions imposed to contain variant-driven spread.
Keys:
• Most leading indicator Wastewater Sampling bounced up to pre-3rd wave level. Nice work @ucalgaryCHI to publish on 48-hr target. 👍
• @CBCFletch 7-day average of New Cases up. Daily used to pull average down - now lifting it up.
Variant Crunches.
AHS claims it is screening ~90% of cases, but cases ⏬80%.
In real numbers, AHS has been performing as few as 160 tests daily. See @ByMatthewBlack 📉.
Premier Kenney imposed #COVID19AB restrictions without any exit criteria.
4.4m Albertans aren't going to do this again without a clear "Are we there yet?"
Let's meet or beat last summer:
• We did it before
• We have vaccines to help us now
• Summer-Summer comparison is fair
I propose this clear, balanced scorecard.
• Mix of leading & lagging indicators.
• Existing, official data sources.
• Measures of success or trouble we already know
• Simple to update or replicate
I propose targets from 1 July 2020 (Canada Day).
• We were out of lockdown
• We thought we had #COVID19 under control then
• Symbolic date for all 🇨🇦 (like 4th of July 🇺🇸)
• Achievable again, especially with vaccines