New with Steve Drews and Sheila O’Brien from @CANBloodServ and the amazing @AshTuite

Infection fatality ratio for covid-19 in Ontario. Tldr: it’s around 1% after excluding longterm care deaths, same estimate as in many other countries.

medrxiv.org/content/10.110…
Here is the major take home:
We digitized the figure from @GidMK @BillHanage et al’s brilliant work (medrxiv.org/content/10.110…) and overlaid Ontario age specific IFR. Our axis labels have been chopped off.
Ontario is black squares. In older individuals IFR is the same as in estimates from countries. We have higher estimates in younger groups...may reflect the patchy nature of covid in Ontario.
Blood donors from lower risk areas, deaths in higher risk areas not reflected in donor sera? Maybe.

That’s why purposive, random provincial or national serosurvey would have been nice. Oh well...did our best with the data we have, and it looks like other countries.
Also: this is from the spring wave and looks like we did capture around 1 in 5 infections in Ontario...pretty good, around the same as Connecticut.

jamanetwork.com/journals/jamai…

Again, may be an overestimate due to donors being different than the pop as a whole

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More from @DFisman

5 Nov
Ontario's @NDP table a bill that would ensure independence of the CMOH and transparency of public health responses during public health crises.

It's a no-brainer that would help all of us, so I assume it'll have an uphill battle. 😃.

ontariondp.ca/news/honouring…
Encore: merci a @nickelbelt pour ayant fait ca.
To the friends who have pointed out that we have previously had CMOH's recommend unwise courses of action (e.g., de facto criminalization of HIV infection):

yes, there needs to be a mechanism to remove underperforming CMOH's even in a crisis.
Read 4 tweets
30 Oct
👇🏼
Schools are also an upstream enabler if the rest of our economy in a way that bars, gyms and restaurants are not.
Look, I’ve been saying for months now that schools are the one mass gathering it’s hard to cancel.

We don’t want to close them. That’s why reducing class sizes is so critically important.
Looking at data, our hospitalizations and icu’s are surprisingly flat in Ontario. I get that this sucks for people in affected businesses, but the closures are targeted, and many of the outbreak hotspots aren’t close-able.
Read 12 tweets
26 Oct
Asked by a friend to comment on the reasonableness of the IHME forecasts for Canada (30+k deaths by Feb). (covid19.healthdata.org/canada?view=to…). The IHME model is impressive...
And again, based on the 2nd (winter) wave of the pandemic ahead of us, and given that we currently stand around 10k deaths, the projection of 30k deaths by February seems reasonable. Note my earlier tweet about 2:1 ratio of 2nd to 1st wave in 1918/1919.
What's impressive to me in IHME is the forecast that we would/could save 10,000 Canadian lives in the months ahead with a national mask mandate. This, again, seems reasonable, based on best available data.
Read 8 tweets
25 Oct
Global R(t) has been remarkably stable since the first wave. Here it is plotted against global doubling time. Will try to unpack this further when I get a chance but it’s a good news/bad news story: many infections ahead, but this isn’t open-ended.
“Moving average” = 7 day moving average for doubling time.
Just to unpack this a bit, there's a direct relationship between R and doubling time, inasmuch as R(t) is a function of growth rate, as is doubling time. Doubling time may just be a bit more intuitive.
Read 12 tweets
24 Oct
This is amazing. We're headed into the second wave of a once in a century pandemic. Ont and Qc have been backstopped by the feds. Now here come the Cons with a motion to initiate a massive AUDIT of the public health response? Now? October 2020?
ourcommons.ca/DocumentViewer…
Like, THIS is when you're going to tie up PHAC, Procurement, Health Canada, not to mention the companies the govt is working with to procure vaccines and tests, with what looks to be the audit from hell?

Really?
Because PHAC, Health Canada, and every other federal office/bureau/department isn't already hanging on by their fingernails trying to build systems, structures and responses to protect Canadians?

Now? Really?
Read 10 tweets
13 Oct
This (as with the Quebec karaoke superspreader event) is extremely difficult to explain without invoking aerosol. High viral load in resp mucus of the index case (asymptomatic) created a superspreader event.

It would be extremely interesting if the index case was the instructor: prolonged shouting/exhorting during a spin class would make sense in terms of aerosol generation...is that info out there?
Events like this are literally showing us the gateway out of this situation. It is distressing to see that institutional public health across Canada is still reluctant to acknowledge the importance of aerosol: costing time, money, lives now.
Read 4 tweets

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