Commentary on the adoption of a test-based versus syndromic-based approach to outbreak declaration and management in hospital and institutional settings

TL;DR

This commentary compares test-based and syndromic-based approaches for managing respiratory infection outbreaks in hospitals, highlighting changes in epidemiological trends during the pandemic.

Contribution

The paper provides a comparative analysis of outbreak management strategies and their implications during the pandemic.

Findings

Epidemiological trends in ARI outbreaks changed significantly during the 2022–2023 season compared to pre-pandemic years.

Test-based approaches introduced complexities in outbreak declaration due to discordant or negative test results.

The commentary discusses benefits and challenges of shifting from syndromic to test-based outbreak management.

Abstract

At present, Ontario, like most other jurisdictions in Canada, uses a syndromic-based surveillance definition for acute respiratory infection (ARI) outbreaks in institutions and public hospitals. Confirmed outbreaks are defined as either two or more ARIs in 48 hours with any common epidemiological link and at least one that is laboratory-confirmed; or three cases of ARIs occurring within 48 hours with any common epidemiological link, and not necessarily with lab confirmation. However, with the adoption of broader test-based approaches for sick patients/residents throughout the pandemic, new challenges have surfaced regarding the declaration and management of ARI outbreaks with a variety of scenarios in respiratory testing results. Decisions, including the determination of epidemiological linkage when there are discordant/negative test results, have become more complicated with the addition of virus-specific test results for every sick individual. The ARI outbreak case definition and management guidance was updated in 2018. The purpose of this commentary is to highlight epidemiological trends in ARI outbreaks in Ontario over the 2022–2023 season compared to the 2018–2019 and 2019–2020 pre-pandemic seasons. This is followed by a discussion around some of the benefits and challenges of implementing a test-based versus syndromic-based approach to ARI outbreaks.