Last week’s tentative observation that we might have passed the seasonal low in new COVID infections and can expect rising numbers in coming weeks appears to have been supported by the most recent data. As illustrated in the Ontario graphs included in our weekly composite chart, both the positivity rate for COVID PCR testing and hospital/ICU admissions have again begun to climb following several months of continuing declines.
For the third week in a row, the more independent Canadian COVID-19 Resource Canada COVID hazard index hasn’t been updated with no explanation. Should that continue for another week, it would be time to replace it with another chart. Their last most recent estimate from was one in every 136 Ontarians being infected and hence infectious.
What has been changing surprisingly rapidly is the mix of COVID strains responsible for new infections in both Canada and the USA. There have also been significant revisions to the data published last week by Public Health Canada, when the newly-dominant NB.1.8.1 strain was stated to account for 70% of all new COVID infections. That estimate has been retroactively reduced, with the most recent estimate now being 58%. Even more interesting, the second-place strain in Canada is now yet another new recombinant variant, XFG, which has managed a more than 1000% increase over the past eight weeks.
This week’s composite chart includes the most recent US Centers for Disease control data, which is no longer as wildly divergent from its Canadian equivalents as we have seen in recent weeks. The previously dominant LP.8.1 strain, which is now down to fourth place in Canada, is just barely hanging onto its lead in the US at 38%, with NB.1.8.1 only a single percentage point behind. XFG, in third place, is also growing fairly rapidly, though not as quickly as in Canada.