Thread by @jeffgilchrist

COVID-19: Parents set up rapid screening for schools when government didn't

We already know that children have less symptomatic COVID-19 infection than adults, yet schools in Ontario are relying on passive symptom screening to allow children to attend school. 🧵1/

The Delta variant is making this even worse, where 74% of infections with Delta take place during the pre-symptomatic phase ( nature.com/articles/d4158… ). 2/

This is one reason why Delta has replaced the original and Alpha variants because people are infecting others for days before they even know they are sick which makes symptomatic screening even less effective at schools. 3/

What can be done instead? Rapid tests are very accurate when COVID-19 virus levels are high enough that a person is infectious, which is when you want to stop a person from going to school to prevent transmission. Follow @michaelmina_lab for more info on rapid tests. 4/

The Ontario government has been sitting on a huge stockpile of rapid tests they have never deployed. Rapid tests started being given out to small businesses so some enterprising parents decided to set up their own community rapid screening program ( toronto.ctvnews.ca/parents-at-ont… ). 5/

The parents set up a website ( ebcat.org ), created instructions for how to do the tests, picked up the rapid tests and distributed them to parents. They even partnered with a hospital to manage any children that did test positive. 6/

Results are available in 15 minutes. The plan was to test children twice a week, on Mondays and then Wed/Thu to try and actively detect children who had become infected and were infectious but pre-symptomatic or asymptomatic when their viral load was highest. 7/

These parents had now done what the Ontario government should have done in the first place to help make schools safer and ensure they stay open longer and reduce educational disruption to students. 8/

Other parents started setting up their own rapid test programs and then the Ontario government found out what was going on and shut everyone down ( cp24.com/news/ford-gove… ). 9/

The Minister of Health cracked down on boards of trade, ordering them to stop distributing tests to community groups and restrict distribution to small businesses only. 10/

The opposition parties have asked the provincial government to expand and not curtail access to rapid tests in schools. In the meantime, the large stockpiles of rapid tests continue to sit in warehouses. 11/

The Chief Medical Officer of Health in Ontario keeps trying to claim that transmission doesn't occur in schools and that children are getting infected in the community. Unfortunately the data doesn't seem to actually support that position. 12/

Only a few school boards actually have similar or lower COVID-19 case counts that reflect what is going on in their surrounding communities (

https://twitter.com/imgrund/status/1443965209970888705

). 13/

The majority of school boards have significantly higher (sometimes more than 4x higher) case counts than their communities. You can see in the image all of the school boards in the 3 red boxes. 14/

Ottawa for example is at 270% higher cases in schools than in the community, and Sudbury is the worst with 640% higher than the community. 15/

Remember that none of the students < 12 are vaccinated so the virus can infect and transmit much more easily in this population. 16/

In order to reduce transmission we need to ensure that fewer infected students attend school, and since 74% of transmission happens before any of the school screening criteria would identify a child who may be infected, a different approach such as rapid testing is required. 17/

If you want to learn why few child-to-child transmission events in schools are detected with symptomatic based testing, look at this thread which explains the math:

https://twitter.com/jeffgilchrist/status/1445029389243146242

18/