Congregate settings (such as prisons, long-term care homes) allow for the rapid spread of COVID-19. As part of her CITF-funded study in three provincial prisons in Quebec, Dr. Nadine Kronfli from the Research Institute of the McGill University Health Centre found that of the 1,100 incarcerated men sampled, 22% were seropositive for a previous SARS-CoV-2 infection. These findings were recently released in a Lancet preprint, therefore not yet peer reviewed.

Key findings:

  • Among the 1,100 study participants, 246 (22%) individuals tested positive for antibodies against the SARS-CoV-2 nucleocapsid protein (i.e., .
  • Factors associated with being seropositive included the amount of time spent in prison, employment during incarceration, meal consumption in shared spaces, and incarceration in a facility following a previous outbreak.

The prisons surveyed for this study account for 45% of Quebec’s provincial prison population. In addition to providing SARS-CoV-2 antibody tests (via traditional blood draws using needles), participants completed questionnaires on sociodemographic and clinical characteristics as well as details about their prison terms.

Dr. Kronfli and her co-authors emphasize the importance of measures to reduce prison populations during pandemics in order to lessen crowding and the risk of disease transmission. Additionally, the authors stress the importance of incorporating multiple preventative interventions such as occupational safety measures, conversion of prison cells into single occupancy, and the promotion of vaccination within correctional facilities.

Kronfi N, Dussault C, Maheu-Giroux M, Halavrezos A, Chalifoux S, and Sherman J, Park, H, Del Balso L, Cheng MP, Poulin S, Cox J. Seroprevalence and Risk Factors for SARS-CoV-2 Among Incarcerated Adult Men in Quebec, Canada (2021): A Cross-Sectional Study. Pre-print The Lancet, November 9 2021 Doi: