Human Health Issues related to Avian Influenza in Canada

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6 Human Surveillance

Surveillance activities are critical for characterizing and monitoring the impact of the outbreak on human health, guiding public health actions and providing data necessary for national and international reporting of the event.

6.1 General Recommendations

Surveillance activities should include:

1. Development of an outbreak case definition that includes details regarding specific symptoms, incubation period, exposures and locations of concern in addition to laboratory test results that are associated with confirmed cases. The case definitions found in appendices A and B can be modified and used by the affected P/T at the time of the outbreak to address the unique characteristics of the outbreak.

2. Dissemination of the outbreak case definition to all relevant stakeholders including the public health outbreak investigators, occupational health authorities responsible for persons involved in controlling the outbreak (e.g. EC or CFIA employees), the national Pandemic Influenza Committee (i.e., all other P/Ts and surveillance working group members including VPRIS) and other stakeholders who might be involved in case detection (e.g. local physicians or hospitals).

3. Development and dissemination of an outbreak reporting questionnaire to public health outbreak investigators. The form used in the 2004 BC outbreak is provided in Appendix F.

4. Consideration of database and reporting tools that will be used to store and summarize the collected data and assist with case/ information management.

5. Identification of potential human cases and contacts and administration of the outbreak questionnaire to collect epidemiological information and implement the appropriate investigation and public health measures. This will involve communication with a designated person(s) at the affected site/farm(s) and enquiring about any farmers, families, employees, crews, visitors or others who may have had contact with avian influenza infected/contaminated or potentially infected/contaminated birds, people or material at the affected site/farm. Through this process, the number of ill persons (potential cases) and potentially exposed persons (contacts) can be identified and follow-up initiated. Further follow-up and communication will be required for all individuals identified as potential cases and the contacts. This process can also be used to ensure that educational materials, including public health recommendations, have been received and that any questions are addressed.

6. Ongoing surveillance for human illness linked to affected sites/farms (see details in section 8.2 re. surveillance of contacts of an avian source of virus)

7. Ongoing timely reporting on any human cases and control measures put in place, through the normal reporting channels (i.e., local public health to P/T authority to the Public Health Agency of Canada). As this information will dictate the pandemic phase for the country, it will also be shared with the Pandemic Influenza Committee and the World Health Organization.

8. Notification^[12] of any P/Ts that would be receiving ill individuals linked to the outbreak (e.g. workers who have come to assist in clean-up or culling activities and who are now symptomatic and returning to their home P/T) by the affected P/T public health authority^[13].

9. Notification of asymptomatic individuals linked to the outbreak who are leaving the affected P/T that they should be aware of the possibility of symptom development up to 10 days after last exposure. Should symptoms develop, they should be instructed to both see a physician and report their symptoms and link to the outbreak to a local public health authority. They should also be asked to restrict their activities as a precaution until a diagnosis can be made. (Note: These individuals may also be provided with contact information for public health individuals in the affected P/T and asked to contact them in order to facilitate further follow-up).

10. An assessment for evidence of human influenza strains currently circulating in or near the affected area(s).

11. Consideration of any special studies (e.g., serosurveys for evidence of asymptomatic infection) that might require data or laboratory specimen collection during or following the outbreak.

Jurisdictions not involved in the outbreak should ensure that the identification of any individuals with compatible illness within their jurisdiction and with a link to the outbreak, are notified to the P/T public health authorities in the P/T with the outbreak. These individuals should be managed as per the recommendations in this document for management of cases.

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