The various definitions of an outbreak

As Kingston residents continue to receive reports of new COVID-19 cases in the area, some have shared with us their confusion regarding the seemingly inconsistent ways in which cases are being handled in different contexts.

Noting, for example, that a single case of COVID-19 warranted a declaration of an outbreak at a long-term care facility in region while at least five recent COVID-19 cases linked to party in the University District did not similarly warrant a declaration of COVID-19, several residents have inquired about the differences.

Most of the definitions of an outbreak are governed by the Province of Ontario and/or the legislation pertaining to specific settings. Below are the various definitions of a COVID-19 outbbreak under the varying contexts:

Hospital

The definition of a COVID-19 outbreak in a hospital is set by the province of Ontario. It is defined as at least two cases within a 14-day period where both could reasonably have been acquired in the hospital. The decision to declare an outbreak is made jointly by the hospital’s Infection Prevention and Control (IPAC) team and KFL&A Public Health.

Long-Term Care Home

A single laboratory confirmed case of COVID-19 in a resident or staff of a Long-Term Care Home (LTCH) is considered a confirmed COVID-19 outbreak.

Workplace

The criteria for whether an outbreak exists in a workplace is two or more laboratory-confirmed COVID-19 cases with an epidemiological link in the workplace (e.g., same work area, same shift) within a 14-day period where both cases could have reasonably acquired their infection in the workplace.

Elementary or High school

An outbreak in an elementary or high school is defined as two or more lab-confirmed COVID-19 cases in students and/or staff (or other visitors) in a school with an epidemiological link, within a 14-day period, where at least one case could have reasonably acquired their infection* in the school (including transportation and before/after school care).

Post-secondary school

Ontario does not currently have a set definition for an outbreak in a post-secondary school setting such as a university or college. Dr Kieran Moore, Medical Officer of Health at KFL&A Public Health has indicated that an outbreak would be a sudden increase in cases, but has not provided a set number.