COVID-19 outbreaks in nursing homes: A strong link with the coronavirus spread in the surrounding population, France, March to July 2020

PLoS One. 2022 Jan 7;17(1):e0261756. doi: 10.1371/journal.pone.0261756. eCollection 2022.

Abstract

Background: Worldwide, COVID-19 outbreaks in nursing homes have often been sudden and massive. The study investigated the role SARS-CoV-2 virus spread in nearby population plays in introducing the disease in nursing homes.

Material and methods: This was carried out through modelling the occurrences of first cases in each of 943 nursing homes of Auvergne-Rhône-Alpes French Region over the first epidemic wave (March-July, 2020). The cumulative probabilities of COVID-19 outbreak in the nursing homes and those of hospitalization for the disease in the population were modelled in each of the twelve Départements of the Region over period March-July 2020. This allowed estimating the duration of the active outbreak period, the dates and heights of the peaks of outbreak probabilities in nursing homes, and the dates and heights of the peaks of hospitalization probabilities in the population. Spearman coefficient estimated the correlation between the two peak series.

Results: The cumulative proportion of nursing homes with COVID-19 outbreaks was 52% (490/943; range: 22-70% acc. Département). The active outbreak period in the nursing homes lasted 11 to 21 days (acc. Département) and ended before lockdown end. Spearman correlation between outbreak probability peaks in nursing homes and hospitalization probability peaks in the population (surrogate of the incidence peaks) was estimated at 0.71 (95% CI: [0.66; 0.78]).

Conclusion: The modelling highlighted a strong correlation between the outbreak in nursing homes and the external pressure of the disease. It indicated that avoiding disease outbreaks in nursing homes requires a tight control of virus spread in the surrounding populations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19 / epidemiology*
  • COVID-19 / transmission*
  • Communicable Disease Control / methods
  • Disease Outbreaks / prevention & control
  • Disease Outbreaks / statistics & numerical data
  • Epidemiological Models
  • France / epidemiology
  • Humans
  • Nursing Homes / trends*
  • Pandemics
  • SARS-CoV-2 / pathogenicity

Grants and funding

The study was funded by the Agence Nationale de la Recherche (Flash COVID-19 program, ANR-20-COVI-000) and the Fondation de France (Engagement 105969). The funders had no role in the study design; data collection and analysis; the preparation of the manuscript; or the decision to publish it.