All cases, including both deaths, were concentrated in a "limited area" in the east end of Montreal, in Rosemont–La Petite-Patrie and Mercier–Hochelaga-Maisonneuve.
Of the 10 cases reported, six were found in men and four were found in women. The average age of people with cases was 71 years old, and 90% of cases were found in people 50 years or older.
Seventy percent of the identified cases were found in immunocompromised patients, and each of the 10 patients was hospitalized due to the illness.
Montreal public health trying to identify the source of new cases
Public health has not yet identified a common source of the cases, but it is not excluding the possibility of "a common environmental source," said Annie Dufour, media relations advisor for the CIUSSS du Centre-Sud-de-l'Île-de-Montréal, in an email.
The Legionella bacteria that cause the disease can be found almost anywhere in the environment — mainly in freshwater, like lakes and rivers, but sometimes in significant quantities of artificial water sources like water cooling towers and water heaters. The bacteria also multiply in warm water, according to information provided by Montreal public health.
Legionellosis is transmitted by fine contaminated microdroplets that can travel long distances in the air — however, the chances of contracting the disease are very low since it isn't transmitted from person to person, Dufour said.
Symptoms of Legionnaires' disease are similar to COVID-19 and include high fever, chills, cough, fatigue, muscle pain and loss of appetite.
Dufour said the DRSP received 45 reports of the disease in 2020, but cases may have been underreported due to COVID-19. As of August 4, the DRSP has received 21 reports of the disease, comparable to 2019 for the same time period.
The pandemic has hit people in ways they may have never imagined before — and some more than others. A recent study conducted by Santé Montréal found that Montrealers' mental health was more affected by COVID-19 in Quebec than the rest of Quebecers.
"In February 2021, about 1 in 3 Montrealers who responded showed symptoms consistent with generalized anxiety disorder (GAD) or probable depression, compared with about 1 in 5 respondents in the rest of Québec," the study stated.
Depuis le début de la pandémie, la santé psychologique des Montréalais est plus affectée que celle des autres Québé… https://t.co/HXFfbD97tT
More specifically, some groups presented a higher proportion of symptoms of generalized anxiety disorder (GAD), namely women, younger people, Anglophone, essential workers, and workers in the health and social services network.
The five main factors associated with GAD that people felt include strong feelings of loneliness, low level of social support, feelings of inconsistency, being a victim of stigmatization, and having experienced significant financial losses.
The overall findings of the study showed that "Montrealers' mental health seems to not be as good as before the pandemic. The situation in Montréal worsened between September and November 2020, then remained stable in February 2021."