Thread by @WinstonBharatMD

It seems Air Canada has managed to convince the federal government to employ rapid testing as an opt out of quarantine on the basis of preliminary results from a massively flawed study.

Seems like a bad idea. @BillBlair @marcomendicino @celliottability @IrfanDhalla

1/n

First, Australia and New Zealand remain the gold standards for the “Western world” in regards to COVID response. Both had mandatory hotel (not home w/relatives) quarantine at port of arrival, before going anywhere, mandatory testing AND drastically reduced int’l flights. 2/n

Australia diverted ALL international flights out of Victoria when Melbourne’s numbers skyrocketed in 2nd wave and cut total international arrivals by 40% concurrent with other restrictions. This is what happened after. 3/n

The federal government will be increasing international travel to Canada when South Asia, Central/South America, Europe and the USA continue to see alarming numbers of cases. This is sabotaging provincial responses to the pandemic & the exact opposite strategy of Aus & NZ. 4/n

Air Canada publicly lobbied for relaxed quarantine measures seemingly before *sponsoring* a study examining point of arrival testing to reduce subsequent quarantine requirements for international arrivals. It’s favoured outcome is obvious. It publicly declared it beforehand. 5/n

One of the investigators was kind enough to answer questions on the methodology. It’s not great. 6/n

Air Canada recently tweeted this. 1% of 15000 tested is 150 positive tests. Yet over the same period 170 FLIGHTS were identified as carrying COVID positive passengers. 7/n

In other words, over Air Canada’s period for this preliminary analysis, more arriving international flights were identified as carrying COVID positive patients, despite no mandatory testing, than Air Canada picked up positive individual passengers in its study.

8/n

Air Canada’s methodology uses voluntary participation, consent in only English and French, and participants are shown how to do a *self-administered* nasal/oral swab, whatever that is, and are given 2 kits for home use which are couriered to the investigators.

9/n

Voluntary: Eliminates anyone who has a reason not to be tested +ve, ex those who were symptomatic travellers (flights identified so close to arrival as to stretch limits of PHU turnaround shows this is happening) or whose quarantine cohabitants would face issues quarantining 10/n

English and French: the biggie. The majority of positive flights since August have come from places where English is either not the official language or widely spoken. This eliminates the majority of passengers arriving on these flights (only Star Alliance considered). 11/n

This language issue alone makes the Air Canada study literally meaningless for assessing the utility of this process for our international arrivals to Canada. It excludes the linguistically diverse passengers from among the highest risk regions of the world. This = bias. 12/n

Moreover, what are the test characteristics of a “self administered nasal/oral swab”? The SN of a single admin of a standard, uncomfortable, professionally taken NPS isn’t great i.e. only 75% (some reports 85%) with disease test positive on any one swab. 13/n

I’ve had two of these tests and cannot imagine anyone doing a proper one to oneself. It’s very unpleasant. But let’s assume all participants get it in a first go with whatever instructions they get after an 8-18hr flight.

14/n

It is simply ludicrous to say, “I see your airport swab is negative, enjoy Square One mall on the way home and visiting your relative in hospital tomorrow. Don’t forget test #2 in a week”.

A single negative test does not mean someone doesn’t have the virus. 15/n

We know enough about testing early in the course and the multitude of reasons for false negatives to use a single point of arrival test as a “get out of quarantine card”. Especially when contact tracing has collapsed.

16/n

Conveniently the collapse of contact tracing ensures there will be no way of knowing just how bad an idea this is. But we’ve likely had thousands of international flights arrive with positive passengers & this isn’t a hypothetical. 17/n

Bad idea flying in the face of restrictions Canadians face at home & the strategy used by countries that got it right.

Probably better optics than a ✈️ bailout.

#covidontario #COVIDCanada

@PhilTsekouras @deonandan @Travisdhanraj @JPTasker @picardonhealth @CPHO_Canada

18/n