1) As Quebec posted its biggest daily increase of #COVID19 cases in a month on Sunday, new evidence is emerging of how younger adult Quebecers, especially those in Montreal, are driving the latest spread of the #coronavirus. In this thread, I'll explain why this is so worrisome.

2) On April 15, before the peak of the first wave of the #pandemic, 17.5% of all #COVID cases were concentrated among Quebecers up to the age of 29. By Sunday, that percentage climbed to 21.4%. On the island of Montreal, this trend is even more pronounced.

3) The demographic in the city that’s behind most of the new #COVID cases is the 20-to-29 age group. From June 12 to July 2, this group comprised 24.7% of all new cases. By Thursday, that rate jumped to 28.19%. What’s of concern is many of these individuals don’t have symptoms.

4) Were it not for public health authorities on July 11 appealing to all Montrealers who’ve been to a bar since July 1 to get tested, we would never have known this age group (and to a lesser extent, those 30-to-39) have been spreading so much of the #coronavirus across the city.

5) If a second wave hits, as experts fear might happen this fall, it’s likely younger adult Montrealers — many of them asymptomatic — who would act inadvertently as the Trojan horse behind that wave. Authorities must consider this as they set to reopen schools in September.

6) Quebec’s top health officer, @ArrudaHoracio, has blamed large house parties for the uptick in #COVID cases. Outbreaks have flared in bars, too, yet the government has been reluctant to close them as a precaution amid the rise in young adult transmission of the #coronavirus.

7) On Sunday, Montreal reported 49 new #COVID cases, a big drop from the previous day but still much higher than two weeks ago. Please see the rising orange line in the chart below. None of the new cases came from the city’s long-term care centres and seniors’ residences.

8) Once again, the Plateau Mont-Royal, where many university students share apartments, reported the most cases in the city (11), followed by the Sud-Ouest (8). Please see the chart below by the Institut national de santé publique du Québec. These stats reinforce the youth angle.

9) The Montéregie posted more cases than Montreal, 52, likely the lingering fallout from the two large youth parties held three weeks earlier on the South Shore. The Laurentians posted 10 new cases, some of them probably arising from a DEK hockey tournament on July 11 in Mirabel.

10) The Saguenay—Lac-Saint-Jean region declared a dozen #COVID cases Sunday. Le Quotidien attributed those cases to temporary farm workers from Mexico and Guatemala. And the Lanaudière region was responsible for 26 cases. Thus, the #coronavirus is now spreading all over Quebec.

11) A video has gone viral of police pepper-spraying a Tim Hortons' customer for refusing to don a mask on the first day they became compulsory in public indoor spaces in Quebec. Given the rising youth transmission and open bars, we can't afford not to wear masks. End of thread.