Key Points

• SARS-CoV-2 circulation is not decreasing in S21.

• The incidence rate was rising despite stable testing rates. The positivity rate also increased by 2.1 percentage points. The 30–39 age group recorded the highest incidence rate. For two consecutive weeks, the effective R has been decreasing slightly. Nevertheless, over the 7-day rolling period from May 22 to 28, 2022, it remains significantly above 1 (1.02 – 95% CI [1.00–1.05]).

• The L452R mutation, present in several sublineages of the Omicron variant (BA.4, BA.5, BA.2.11), was detected in 36% of samples screened in S21, compared to 11% the previous week. This increase in the proportion of L452R mutations is a point of concern regarding the establishment of a new Omicron sublineage in the region. Furthermore, a sample of these specimens, sequenced by the CHUM virology laboratory or the CNR, confirmed the presence of the Omicron BA.5 sublineage.

• In terms of hospital admissions, the situation was generally stable in S21. However, an increase in the number of visits to pediatric emergency departments was observed.