Montreal’s public health authority has issued a warning following two highly contagious cases of pulmonary tuberculosis reported since October 2024. Both cases involved significant delays in diagnosis, with one taking nearly six months. The patients, who are no longer contagious, had risk factors associated with marginalized populations and vulnerability. Health officials are investigating potential links to a previous TB outbreak in the region (2003–2016), as the disease can remain latent for years.

Dr. Kevin Schwartzman, McGill respirologist specializing in TB, states:

“We don’t usually need to be as concerned about the people who are already diagnosed as about the people who haven’t yet… Once somebody is diagnosed and put on treatment, they become less contagious quite quickly.” The symptoms, as described by Dr. Schwartzman, are “basically like having a chest infection that won’t go away.”

The Direction régionale de santé publique de Montréal (DRSP) urges health professionals working with marginalized populations to be vigilant for TB symptoms, as contact tracing for these cases is expected to be difficult and incomplete. TB cases in Montreal spiked in 2024, rising to over 200 from an annual average of 121.

TB typically requires prolonged exposure (100–120 hours) for transmission and is more likely to affect people with HIV, poor nutrition, or substance use. The DRSP emphasizes this warning is aimed at professionals, not the general public.

Read more:

Public health authority urges vigilance as two tuberculosis cases confirmed in Hochelaga-Maisonneuve, The Gazette, Leora Schertzer, April 2, 2025.