Question Period Note: OUTBREAK MONITORING

To closely monitor the emergence and spread of COVID-19 in communities across Canada, the Government of Canada is working with provincial, territorial and international partners to detect signals and investigate transmission patterns.

Key Messages
• The Government of Canada uses multiple data sources, including daily case information by province and territory, and any developing outbreaks, to monitor the situation in Canada.

• The Public Health Agency of Canada analyzes data it receives from the provinces and territories to monitor patterns of transmission.

• We continue to use early warning systems to collect and exchange timely information on illness clusters in Canada and internationally.

• The Canadian Network for Public Health Intelligence platform is also facilitating the secure, timely exchange of information between local, regional, provincial, territorial, and federal public health officials related to events of public health concern.

Outbreak monitoring and response is part of the core work of the Public Health Agency of Canada (PHAC). Existing initiatives are based on many years of epidemiological expertise and include both technological solutions as well as communication channels. Initiatives include:
• Public Health Alerts (PHA), administered and distributed by the Canadian Network for Public Health Intelligence (CNPHI), facilitate the secure, timely exchange of information between local/regional, provincial/territorial (PT), and federal public health officials regarding events of public health concern.
• FluWatch is an online health surveillance system that helps track the spread of influenza and influenza-like illnesses across Canada and is an important part of Canada's national influenza surveillance program.
• The Global Public Health Intelligence Network is an early-warning and situational awareness system for potential chemical, biological, radiological and nuclear public health threats worldwide. This includes monitoring of infectious disease outbreaks.
• Outbreak intelligence is gathered via “web scraping” (in-depth scanning) of PT websites/press releases and media coverage, and information is assessed daily by epidemiologists.
• The Canadian COVID-19 Outbreak Surveillance System collects and collates outbreak data provided by contributing PTs to report on aggregated outbreak trends.

These initiatives have been leveraged to effectively monitor and respond to this pandemic. This includes collecting granular and near real-time data, and the use of new and complementary data streams.

Engagement with PTs

PHAC works closely with PTs to monitor and respond to outbreaks. PTs report case level data to PHAC, which are analyzed on a daily basis in order to monitor epidemiological trends for early detection of new patterns of transmission.

PHAC also supports PTs with the management of outbreaks of national concern. PHAC can be called upon by PTs to investigate and to provide additional technical expertise or specialized skills as required. This includes the deployment of personnel (including field epidemiologists and public health officers) to support the investigation of outbreaks.

PHAC provides ongoing national coordination and federal leadership for multijurisdictional COVID-19 outbreaks, or complex single jurisdiction COVID-19 outbreaks. Since early May 2020, PHAC has been involved in the investigation of a number of multijurisdictional or complex outbreaks, including:
• industrial worksite outbreaks
• outbreaks associated with social gatherings
• agricultural sector outbreaks
• outbreaks amongst those in communal living settings and institutions

PHAC is promoting rigorous epidemiologic investigations of COVID-19 outbreaks in Canada in order to respond more effectively to these outbreaks and to increase our understanding of COVID-19 transmission dynamics and risks, and has developed guidance, resources and tools for epidemiologic investigation of COVID-19 outbreaks.

From a national perspective, there is considerable interest in monitoring case clusters and outbreaks related to COVID-19, especially during the winter respiratory illness season. PHAC, in collaboration with PT partners, produced guidance on outbreak investigations in schools to support a systematic approach to outbreak response in this setting.

Defining an “Outbreak”

The purpose of the “outbreak” definition is to trigger management activities (e.g., an investigation of the source, and implementation of measures to control spread). The definition of an outbreak of an infectious disease is contextual – it is typically defined as the occurrence of disease cases in excess of what is usually expected. As COVID-19 is a novel disease, the threshold required to initiate public health management activities is low.

Outbreak definitions for COVID-19 may differ across PTs depending on settings. PTs have varying definitions of outbreaks for different settings, typically with a minimum of at least 2 cases occurring in a setting within a certain period of time. In closed populations or settings with vulnerable individuals (e.g., correctional facilities, long-term care facilities, shelters), there tends to be a lower threshold, where only one confirmed case may be needed to declare an outbreak.

To ensure consistent terminology is applied in national COVID-19 surveillance and monitoring activities, PHAC and PTs developed a definition for a “multijurisdictional COVID-19 outbreak”. A multijurisdictional COVID-19 outbreak is one that:
• occurs in more than one Canadian province or territory
• occurs in Canada and involves another country/countries
• the management of the outbreak involves multiple PT or international public health agencies or authorities

Key Facts
• The Global Public Health Intelligence Network is an early-warning and situational awareness system for potential chemical, biological, radiological and nuclear public health threats worldwide. This includes monitoring of infectious disease outbreaks.
• Outbreak intelligence is gathered via “web scraping” (in-depth scanning) of PT websites/press releases and media coverage, and information is assessed daily by epidemiologists.
• The Canadian COVID-19 Outbreak Surveillance System collects and collates outbreak data provided by contributing PTs to report on aggregated outbreak trends.