This is a summary, written by members of the CITF Secretariat, of:

Galarneau J-M, Labrèche F, Durand-Moreau Q, Ruzycki S, Adisesh A, Burstyn I, Zadunayski T, Cherry N. Excess risk of Covid-19 infection and mental distress in healthcare workers during successive pandemic waves. Analysis of matched cohorts of healthcare workers and community referents in Alberta, Canada. medRxiv.2023Sep12. doi:

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study, published in preprint and not yet peer-reviewed, found that healthcare workers (HCW) in Alberta had a higher incidence of SARS-CoV-2 infection and of mental health issues compared to community members (referents) seen in pre-pandemic physician consultations who were matched on gender, age, and geographic location. Excess infection was most notable early in the pandemic and during the fifth (Omicron) wave. The excess incidence of mental health conditions, including stress/adjustment reaction or depressive disorder, was seen with each wave of the pandemic, increasing to a peak in the fourth wave in Alberta, as evident from administrative health data. This study was led by Dr. Nicola Cherry (University of Alberta).

Key findings:

  • HCWs had a greater risk of SARS-CoV-2 infection compared to community members (referents): a higher percentage of HCWs tested positive for SARS-CoV-2 by PCR or physician medical report than matched community referents.
  • When compared to referents, cases among HCWs identified by PCR tests were predominantly higher in the fifth wave of the pandemic, while those from physician records were much higher in the first wave.
  • HCWs were also at an increased risk of mental health conditions such as anxiety, stress/adjustment reactions, and depressive disorders, compared to community members.
  • Anxiety was the mental health condition most often recorded in physician records.
  • The incidence of mental health conditions including stress/adjustment reaction or depressive disorder increased with each wave of the pandemic, peaking in the fourth wave.

These findings emphasize the ongoing challenges faced by HCWs during the pandemic, not only in terms of occupational infection risk but also mental well-being. Administrative data provided an opportunity to analyze the evolution of these risks over the course of the pandemic.

This study recruited healthcare workers from Alberta, British Columbia, Ontario, and Quebec from early 2020 to summer 2022. Participants in Alberta had consented to match individual records on Covid-19 immunization and SARS-CoV-2 polymerase chain reaction (PCR) testing to the Alberta’s administrative health database (AHDB). HCWs were matched with community members on gender, age, location, and physician consultations between April 2019 and March 2020.