tarrant

Welcome to TARRANT Viral Watch

Influenza surveillance remains a priority at the local, provincial, national and international levels, with new value brought to surveillance systems after the 2009 H1N1 Swine Influenza pandemic, and the 2019-2022 Covid-19 pandemic.

Our goal is to detect influenza-like illness (ILI) clinically as it occurs in the community and to measure influenza Covid-19 and other respiratory viruses in the lab. Data is collected by volunteer sentinels (physicians and nurse practitioners), and is compiled by TARRANT Viral Watch prior to being forwarded to Alberta Health and Alberta Health Services, the Public Health Agency of Canada, and ultimately the World Health Organization. This contributes to our provincial, national and international picture of influenza activity, and helps us to detect epidemics and pandemics.

In addition, through data collected with each viral swab about each patient’s immunization status, and symptoms, we contribute to the 4-province Sentinel Practitioner Surveillance Network (SPSN) that uses a test-negative Case-control design to measure vaccine effectiveness against each subtype of influenza and Covid-19. By conducting mid-season analyses early each new year, we contribute to the information used by WHO to decide the contents of the next season’s immunization. 

Our program name honours Dr. Michael Tarrant, whose years of dedication before his death in June 2003 ensured that Alberta has one of the best community sentinel practice programs in the world.

Due to the dedication of our sentinels, Alberta remains a major contributor to national and international influenza surveillance and vaccine effectiveness research, thus giving Alberta a stronger presence in national pandemic planning and surveillance initiatives.

History of TARRANT

  • 1975 - Recording of Influenza-like Illness began in Alberta. Sentinels were part of the National Research System (NaReS) and reported individually to the national network.
     
  • 1979 - The provincial Viral Watch program was formed. Its purpose was to perform syndromic surveillance in Alberta; using doctor-reported signs and symptoms of influenza in the community as an early warning system for influenza outbreaks.
     
  • 1983 - The program evolved to include the collection of specimens from patients with ILI for virologic confirmation in the laboratory. This unique feature of Viral Watch allowed the program to go beyond monitoring influenza symptoms to actual verification of disease presence.
     
  • 2003 - Following the death of Dr. Michael Tarrant, the driving force behind Viral Watch, the program was renamed TARRANT (The Alberta Recording and ReseArch NeTwork) in his honour. 
     
  • 2006 – TARRANT began a long-term collaboration with the British Columbia Centre for Disease Control using sentinel surveillance data to evaluate influenza vaccine effectiveness.
     
  • 2009 - The program is now known as TARRANT Viral Watch, paying homage not only to the past contributions of Dr. Tarrant but also looking towards the future evolution of the network. Although our primary focus is influenza, other respiratory viruses are also monitored.
     
  • 2010 – TARRANT Viral Watch expanded the data collected to monitor viruses beyond influenza. These include Enterovirus 68 that causes ILI and other symptoms similar to influenza. Continued surveillance of these viruses allows for a greater understanding of the circulating viruses within Alberta.
     
  • 2015 - Evaluation of influenza vaccine effectiveness continues. Data collected now suggests that repeat vaccinations can cause negative interference, reducing vaccine effectiveness and diminishing the protection provided by the current season vaccine. Further research is needed to explore and understand the effects of consecutive vaccinations.  
     
  • 2019- onset of pandemic COVID-19. Due to pandemic restriction, many practitioners closed down their offices.  Tarrant expanded its operation to sample from pandemic community assessment centres, to ensure we could measure what is occurring in the community. Covid-19 was dominant, and most other respiratory viruses ceased transmitting during the lockdown precaution period. Tarrant measured the successive waves of Covid-19 types. Immunization details are added to the data collection, to enable vaccine Covid-19 effectiveness to be measured. 
     
  • 2021 Pandemic precautions were ceased and offices opened up again. Tarrant measures a spike of other viruses: first adenoviruses in the summer, then other respiratory viruses returned to a more standard pattern. 
     

Definitions

Sentinel

A volunteer primary care physician or nurse practitioner that participates in a surveillance network. TARRANT Viral Watch sentinels actively monitor ILI and LRTI in their patients to provide early information about what respiratory viruses are circulating in an area.  

Syndromic Surveillance

The systematic and ongoing collection, analysis and interpretation of data related to a specific disease. TARRANT Viral Watch conducts active surveillance for influenza-like illness and lower respiratory tract infection.

Influenza-like Illness (ILI)

Respiratory illness with acute onset, with fever, and cough, and with one or more of- sore throat, arthralgia, myalgia or prostration- which may be due to influenza virus. (Presentation may vary in pediatric and elderly populations.)

ICD-9 code 487

Lower Respiratory Tract Infection (LRTI)

Any acute infection with significant involvement of the respiratory tract below the larynx, as identified by history, physical signs and/or radiological findings.

ICD-9 codes 466, 486

Patients exhibiting ILI with lower tract involvement, code as LRTI as LRTI takes precedence over ILI