SARS-CoV-2 Surveillance System in Canada: Longitudinal Trend Analysis

Area of Science:

• Epidemiology
• Public Health Surveillance

Background:

• The COVID-19 pandemic necessitated adaptive public health responses globally.
• Varied regional success in controlling SARS-CoV-2 spread highlighted the need for advanced surveillance metrics.
• Effective governance and sociopolitical factors influenced pandemic containment strategies.

Purpose of the Study:

• To develop advanced COVID-19 surveillance metrics for Canada, including country, province, and territory levels.
• To incorporate pandemic dynamics like speed, acceleration, jerk, and persistence into surveillance.
• To identify regions at risk of explosive growth and those with successful outbreak control.

Main Methods:

• Employed a longitudinal trend analysis study design using 62 days of COVID-19 data from Canadian public health registries.
• Utilized an empirical difference equation to model daily new cases based on prior cases and testing levels.
• Applied a dynamic panel model estimated using the generalized method of moments (Arellano-Bond estimator in R).

Main Results:

• Canada's overall transmission speed decreased from 8.4 to 7.5 daily new cases per 100,000 population between two consecutive weeks in February 2021.
• Ontario and Quebec showed reduced transmission speeds, while Nunavut experienced a significant increase (3.3 to 10.9 daily new cases per 100,000 population).
• Persistence of new cases indicated 7.5 transmissions from 7 days prior during the latter week.

Conclusions:

• Canada demonstrated effective COVID-19 control, particularly during the initial shutdown and subsequent waves.
• Enhanced surveillance is crucial for identifying emerging outbreaks and potential explosive growth.
• Proactive health policy informed by advanced surveillance can improve pandemic management.