Canada and the International Health Regulations: Assessment and Reporting

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• Public health emergency of international concern
• How to identify a potential public health emergency of international concern
• The IHR assessment and reporting process in Canada

Public health emergency of international concern

The International Health Regulations (IHR) define a public health emergency of international concern as:

• "an extraordinary event which is determined, as provided in these Regulations:
  • to constitute a public health risk to other States through the international spread of disease and
  • to potentially require a coordinated international response"

This definition:

• implies a situation that is serious, sudden, unusual or unexpected
• carries implications for public health beyond the affected country's border
• implies that immediate international action may be needed

The requirement to report an event that may constitute a public health emergency of international concern covers events that pose a public health risk regardless of the source. These include infectious diseases, contaminated food, natural disasters, chemical agents and radiological-nuclear events.

The 2024 amendments to the IHR introduced a pandemic emergency.  This is defined as a public health emergency of international concern that is caused by a communicable disease and:

• has, or is at high risk of having, wide geographical spread to and within multiple States;
• is exceeding, or is at high risk of exceeding, the capacity of health systems to respond in those States; and
• is causing, or is at high risk of causing, substantial social and/or economic disruption, including disruption to international traffic and trade; and
• requires rapid, equitable and enhanced coordinated international action, with whole-of government and whole-of-society approaches

A pandemic emergency is now the highest level of alert that the WHO can declare.

How to identify a potential public health emergency of international concern

Events that may constitute a public health emergency of international concern are assessed using the IHR Annex 2 decision instrument. Events that meet the necessary criteria must be notified to WHO within 24 hours (IHR Article 6). However, certain diseases must automatically be reported to WHO. These include all cases of:

• smallpox
• poliomyelitis due to polioviruses
• human influenza caused by a new subtype
• severe acute respiratory syndrome (SARS)

Events involving the following diseases always require assessment against the IHR Annex 2 decision instrument. This is because of their ability to cause serious public health impact and to spread rapidly around the world:

• cholera
• pneumonic plague
• yellow fever
• viral haemorrhagic fevers (Ebola, Lassa, Marburg)
• West Nile fever
• other diseases of special national or regional concern, such as dengue fever, Rift Valley fever and meningococcal disease

The Annex 2 decision instrument must also be used for any event of potential international public health concern, and those of unknown causes or sources, in particular clusters of cases of severe, acute respiratory disease of unknown or novel cause, and those involving other events or diseases than those that have been listed.

Note: If an event does not meet the criteria for notification under Article 6 of the IHR, other reporting requirements may still apply.

The IHR assessment and reporting process in Canada

In Canada, technical experts from relevant federal and provincial/territorial governments collaborate on the IHR assessment and reporting process.

A country (State Party) must assess all reports of urgent events occurring within its territory within 48 hours using the IHR Annex 2 decision instrument.

Following this assessment process, the country (State Party) then has 24 hours to notify WHO of events that meet the reporting criteria in the IHR Annex 2 Decision Instrument.

A country is to communicate timely, accurate and sufficiently detailed public health information on the notified event to WHO. Where possible, this information should include:

• case definitions
• laboratory results
• source and type of risk
• number of cases and deaths
• conditions affecting the spread of the disease
• health measures taken

A country is also to report any difficulties and support needed in responding to the event.

If the event does not meet the criteria for notification under IHR Article 6, other reporting requirements may still apply.

WHO's technical teams assess all reported events, as well as other public health risks. These teams provide technical guidance to all countries. They will also offer assistance when requested.

The responsibility for determining if an event is a public health emergency of international concern lies with WHO's Director-General. This person is advised by a committee of experts (IHR Emergency Committee), who follow the criteria and procedures set out in the Regulations.