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Sentinel Household Surveillance Network (SHSN)

The Sentinel Household Surveillance Network monitors respiratory illnesses, how they spread in our communities, and aims to better understand immunity to these illnesses.

Update: The Sentinel Household Surveillance Network (SHSN) public health investigation closes on March 31, 2024. Thank you to participants for contributing to this public health investigation. Remaining tests must be sent by March 25, 2024.


This information is important for public health when developing interventions to prevent or reduce the spread of respiratory viruses, monitor the population's level of immunity, and evaluate vaccination programs.

About SHSN

Approximately 3,000 people are expected to participate across British Columbia. This investigation involves three online surveys and three self-administered dried blood spot tests, collected over six months (baseline, three months and six months). It will monitor for exposure to and immunity to:

  • SARS-CoV-2, the virus that causes COVID-19
  • Influenza A and B 
  • Respiratory Syncytial Virus (RSV)

The surveys ask questions about your background, general health, behaviours, respiratory symptoms and exposure, and vaccination status. The dry blood spot test is self-administered finger prick and placing the blood on a special filter paper, which is sent to a laboratory to test for antibodies against COVID-19, influenza and RSV. Collecting information on antibody levels combined with survey responses will help us further understand respiratory illness and monitor and evaluate levels of immunity within communities. 

Dr. Jat Sandhu,
On Behalf of the Public Health Leadership Committee
BC Centre for Disease Control 

Questions and inquiries

For all questions, please contact us at:

Sentinel Household Surveillance Network Team
 BC Centre for Disease Control and Prevention 
655 W 12th Ave, Vancouver, BC V5Z 4R4
Phone: 604-707-2400 (Ext 272448)
Email: SHSN@bccdc.ca


SHSN frequently asked questions

The SHSN investigation aims to understand important information about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, Influenza A and B and Respiratory Syncytial Virus (RSV), how these viruses spread within our communities, and if British Columbians have developed immunity against these viruses.

The SHSN randomly selected participants from a sample of BC residents who provided permission to be contacted for future research when participating in the BC COVID-19 SPEAK Surveys. 

No, your participation is voluntary. 

A participant may choose to withdraw at any time. Participants may also choose not to answer specific survey questions.
Participants receive an email invitation to be part of this investigation. Participants need to complete a short screening survey. If you meet the criteria to participate you will be enrolled in the investigation.

The investigation involves three online surveys, and three self-administered dried blood spot (DBS) (finger prick) tests collected over six months (baseline, three months and six months). 

All three surveys are completed online and the DBS tests are self-administered at home. Participants will receive a package in the mail that includes a DBS kit with instructions, and once completed participants are asked to return the DBS sample to British Columbia Center for Disease Control (BCCDC) using an enclosed prepaid package. The BCCDC laboratory will analyze the sample to determine the presence of COVID-19 antibodies. Influenza and RSV antibodies may also be analyzed, although antibodies against Influenza and RSV still require validation and interpretation. 
The data will be used by public health and policymakers to: 
  • Monitor community respiratory illness exposure to COVID-19, influenza and RSV, 
  • Identify respiratory illness transmission risk and protective factors; and
  • Assess community-level immunity and evaluate waning immunity.
Safeguards are in place to ensure your privacy. Data collected in this investigation follows strict privacy practices under the BC Freedom of Information and Protection of Privacy Act. The Act governs how your information is collected, who sees it and how the information is used.

We take the privacy and confidentiality of British Columbians seriously and have taken every precaution to ensure that the survey is safe, secure, and asks only what is needed to plan for British Columbia’s future. Furthermore, the collection of personal identifiers is entirely voluntary and is at the discretion of survey participants.

Published data will never include personal or identifiable data and therefore can never identify you or your household. Only aggregated (grouped) data will be published.

Survey frequently asked questions

There is a screening survey, baseline survey and two follow-up surveys, and each takes approximately 5 to 10 minutes to complete.  
The surveys ask questions about the following:
  • Respiratory symptoms and exposure
  • Chronic conditions and symptoms
  • Health status
  • Behavioural factors
  • Daily activities and routine
  • Vaccination information
  • Demographic and living arrangements
Please contact the SHSN team by phone number is 604-707-2400 (Ext 272448) or email SHSN@bccdc.ca. This mailbox and email are checked daily and you can expect a call back in one business day, except for weekends and holidays, when we are closed.

Dried blood spot test frequently asked questions

It takes approximately 10 minutes to do the dried blood spot (DBS) sample. The blood spots must dry for at least 3 hours before being packaged for shipping and sent back to British Columbia Center for Disease Control (BCCDC) for processing.

We ask that participants mail the dried blood spot (DBS) sample back to BCCDC within 24 hours from the time of collection. The sample can be stored at room temperature for 24 hours

You will receive a dry blood spot test kit and instructions by mail. In some circumstances  Canada post may leave a note on your door instructing you to pick up the kit from the nearest post office. 

The dried blood spot (DBS) sample is important because it allows us to estimate how many people have antibodies against COVID-19. By using each participant’s DBS samples combined with their survey responses, we will also have a better understanding of how many British Columbians have antibodies against COVID-19 due to infection, vaccination, or both.

DBS analysis for antibodies against Influenza and Respiratory Syncytial Virus (RSV) is still a relatively new concept and requires testing and interpretation. Therefore, this investigation will help us better understand how we can use the DBS to test antibodies against influenza and RSV. 
When exposed to a new virus, your immune system creates proteins called antibodies to help protect you from infection. COVID-19 is still a new disease, little is known about how long the antibodies last, or if they protect against future infection.

Antibody tests are not used to diagnose a current infection as they don’t detect the virus itself. Therefore, regardless of your test result, you need to continue to follow public health guidelines to reduce the risk of respiratory infection and transmission.
A positive result means that antibodies were detected in your blood sample and a negative result means antibodies were not detected in your blood. 

In rare instances, false positive results may be caused by the cross-reactivity of the test with other viruses. 

The positive result does not infer immunity or protection from reinfection. A negative test result may mean your body has made antibodies, but the antibodies in your sample are too low for them to be detected. 

Antibody tests are not used to diagnose a current infection as they don’t detect the virus itself. Therefore, regardless of your test result, you need to continue to follow public health guidelines to reduce the risk of respiratory infection and transmission.


You will receive your antibody test results by mail as soon as they are available. Timing will depend on the volume of tests that laboratories need to process. The antibody result you will receive will reflect the antibody levels at the time your sample was taken. 

Dried blood spot analysis for antibodies against influenza and RSV, still requires validation and interpretation, so they may not be part of the initial  personal report.

Your results will not represent a medical diagnosis, so we suggest contacting your doctor or other healthcare professional if you have any health concerns.

Yes. Those who have COVID-19 antibodies should still be vaccinated. At this time, we do not know how long someone might be protected from getting sick again after recovering from an infection of COVID-19 or after receiving a COVID-19 vaccine.

 
Once you have antibodies to a particular disease, they provide some protection from that disease. Even if you get sick, antibodies can protect you from getting severely ill because your body has some experience in fighting that disease. However, over time antibodies decrease or wane. After a long enough period, antibodies can fall below a level of detection. Because COVID-19 is a new disease, little is known about how long the antibodies last, or if they protect against future infection. 


Dried blood spot samples are stored in the laboratory at BCCDC  for 12 months from the end of the investigation.
Participating in this investigation does not replace your regular medical care from your primary healthcare provider. Contact your primary healthcare provider if you are concerned about your health or someone you care for. You can also go to an Urgent and Primary Care Centre (UPCC) or call HealthLinkBC at 811 to speak to a nurse.

Go to an emergency department or call 911 if you:
  •  find it hard to breathe
  •  have chest pain
  •  can't drink anything
  •  feel very sick
  •  feel confused
If you have mild symptoms,  stay home until you feel well enough to return to your regular activities. Most people can safely manage their symptoms at home by resting, drinking lots of water and fluids, using  a humidifier or hot shower to ease a cough or sore throat and for fever taking medicine like acetaminophen (Tylenol) or ibuprofen (Advil).

For further information on managing your symptoms, please see COVID-19  or influenza

If symptoms worsen or don’t improve, call 811 or visit a health care provider or urgent care clinic.
Please contact the SHSN team by phone number is 604-707-2400 (Ext 272448) or email SHSN@bccdc.ca.

This mailbox  and email are checked daily and you can expect a call back in one business day, except for weekends and holidays, when we are closed.






SOURCE: Sentinel Household Surveillance Network (SHSN) ( )
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