Montreal health authorities say the tests are useful to increase screening in areas with higher positivity rates. Overall, the positivity rate in Montreal is around 8.8 per cent. While cases have been gradually decreasing in the city, certain neighborhoods, including Montreal-East and Montreal-North, remain hotspots for the virus. According to Infectious disease specialist Matthew Oughton, who spoke with CTV News on Jan. 19, a positivity rate above 5 per cent is considered to represent a “loss of control.” “All is to say, certainly we’re not capturing all the cases,” he said. “We have to increase the screening in [more affected] neighbourhoods,” said Montreal Public Health Director Dr. Mylene Drouin.