Members of Kingston Frontenac Lennox & Addington (KFL&A) Public Health Board reviewed COVID-19 predictions for the area at their October monthly meeting.
Megan Carter, a PhD and research associate at Queen’s University, presented the modelling on Wednesday, Oct. 28, 2020. Working with Dr. Troy Day, a professor in the Department of Mathematics and Statistics, Carter has previously developed prediction models for various COVID-19 scenarios in the region, including the fall return of post-secondary students and Thanksgiving.
“For each scenario, 20 simulations are run with the mean trajectory plotted in black,” Carter explained.
These latest projections cover a 20-day period between Tuesday, Oct. 20, 2020 and Monday, Nov. 9, 2020. The models assume that ten cases were circulating in the community on the start date, though KFL&A Public Health were only aware of and tracking five at that time. Carter noted that not all cases in her prediction modelling will necessarily seek testing or care.
The modelling also assumes that individuals remain infectious in the community, on average, for ten days. Carter produced three scenarios, each with a different time frame for the doubling of the number of cases.
In the KFL&A region, she described the typical timeline for the number of COVID-19 cases to double as 14 days.
“The doubling time is… based on local data up until Oct 15 – a measure of how fast the virus is spreading,” she said.
If the disease continued to progress at this rate, Carter determined the region could add 26 cases of COVID-19 by the end of the modelling period. If the doubling time decreases to 12 days – meaning infection spreads slightly faster — the median projection for cases would be 29. If the doubling time jumped to seven days, the same level of spread occurring at the end of April in Ontario, Carter said the median number of new cases would be 69.
“All scenarios have large uncertainty as they start with a small number of cases,” she noted. Taking into account the range of possibilities projected across all three scenarios, the total number of additional cases in her models could range anywhere from five to 130.
Looking at Public Health prediction modelling on the provincial and national scale, Carter said that “in all scenarios, we see the pandemic lasting into 2022.”
“Infectious disease modelling is complex,” she noted, “but can provide insight to decision-makers. It models what might happen.” Carter said she intends to continuously update her projections for the KFL&A area, at two to three week intervals.