Circulation of respiratory viruses is normally highest in the fall and winter. For the purposes of reporting and comparisons over time and between viruses, the respiratory season typically runs from late August of the current year to late August of the following year. The current season, 2023-2024, starts on August 27, 2023 and ends on August 24, 2024. Additional information on respiratory season, and a full calendar for the current season, can be found on the Data Notes page.
Respiratory virus data included in the interactive data application is up-to-date as November 25, 2023. Among its new features, the dashboard now includes RSV cases and positivity, with plans to collect Severe Outcomes data in the near future.
Testing and data sources vary for different respiratory viruses in Alberta. A subset of respiratory viruses have available data and are included in this dashboard. Those viruses include: Adenovirus, non-COVID-19 Coronavirus, SARS-CoV-2 (COVID-19), Human Metapneumovirus (hMPV), Seasonal Influenza, Parainfluenza, Respiratory Syncytial Virus (RSV) and Rhinovirus/Enterovirus.
COVID-19 and seasonal influenza are notifiable diseases in Alberta. As per the notifiable disease guidelines, these diseases have enhanced surveillance that provides information such as hospital and ICU admissions that is not available for diseases that are not notifiable, including RSV. Please see the Public Health Notifiable Disease Guidelines for more information.
Communicable Disease Reporting System (CDRS), Alberta Health Communicable Disease Outbreak Management (CDOM) Provincial Surveillance Information (PSI), Alberta Health Alberta Health Care Insurance Plan (AHCIP) Quarterly Population Registry, Alberta Health Immunization/Adverse Reactions to Immunization (Imm/ARI), Alberta Health
The Provincial Surveillance Information system (PSI) is a laboratory surveillance system which receives positive results for all Notifiable Diseases and diseases under laboratory surveillance from Alberta Precision Labs (APL). The system also receives negative results for a subset of organisms such as COVID-19. The system contains basic information on characteristics and demographics such as age, zone and gender. The Communicable Disease Reporting System (CDRS) at Alberta Health and the Communicable Disease Outbreak Management (CDOM) system at Alberta Health Services contains information on COVID-19 and influenza cases. Information such as hospitalizations and ICU admissions are received through enhanced case report forms sent by Alberta Health Services (AHS).
Vaccinations and AEFIs are reported to the Provincial Immunization and Adverse Reaction to Immunization (Imm/ARI) repository. In Alberta, all health practitioners are required by law to report Adverse Events Following Immunization (AEFI) to Imm/ARI. The reporting requirements are outlined in the Immunization Regulation, under the Public Health Act. Case definitions are further defined in the AEFI Policy. As of January 1, 2021, all health practitioners are required to report all (both provincially funded and privately purchased) vaccinations electronically to Imm/ARI.
A death resulting from a clinically compatible illness in a laboratory-confirmed influenza case or a laboratory-confirmed COVID-19 case, unless there is a clear alternative cause of death identified (e.g. trauma, poisoning, drug overdose, etc.).
A Medical Officer of Health or relevant public health authority may use their discretion when determining if a death was due to influenza or COVID-19, and their judgement will supersede the above criteria.
A death due to influenza or COVID-19 may be attributed when influenza or COVID-19 is the cause of death or is a contributing factor.
Hospital and ICU Admissions
A hospital or ICU admission in a laboratory-confirmed influenza case or a laboratory-confirmed COVID-19 case is counted when the reason for admission is either directly resulting from the disease, or when the disease is a contributing factor for the admission.
Reason for hospital and ICU admission was not collected for COVID-19 cases prior to 2022-02-01.
Hospital and ICU admission data can have reporting delays. Data for the previous week may be incomplete and should be interpreted with caution as updates may occur in the following weeks as case report forms are submitted by AHS.
Outbreaks that occur in group settings such as hospitals, residential institutions, schools, and child care facilities are reported to Alberta Health. Outbreaks are defined as the occurrence of a communicable disease in a community, region, or setting where the number of cases is more than would be expected for a defined period of time. Outbreaks in hospitals, residential institutions, and other closed communities are defined as two or more cases of influenza-like illness, with at least one laboratory-confirmed case for the disease type. School influenza outbreaks require greater than 10 per cent absenteeism or absenteeism that is 10 per cent higher than baseline levels. Please see the Public Health Disease Management Guidelines: Influenza, Seasonal and Public Health Disease Management Guidelines: Epidemics for more information.
Percent positivity in Alberta is calculated using the Test Over Test method, which is the same method employed by the US Centers for Disease Control and Prevention. The calculation is as follows:
Daily Number of Positive Tests / (Daily Number of Positive Tests + Daily Number of Negative Tests)
Not all respiratory viruses are tested in all circumstances. Respiratory viruses other than COVID-19, RSV and influenza are only tested on a respiratory pathogen panel (RPP) in certain circumstances, including during outbreaks, when someone is admitted to ICU, or in instances where a physician is participating in a sentinel surveillance program.
Individuals who received one dose was calculated as (# of individuals who received at least one dose in the current season) / (population estimate).
*‘Other Providers’ include Alberta Health Services (AHS) non-Public Health, non-AHS (including Long-term care (LTC) sites) and Physicians from AHS, IDSM, and First Nations and Inuit Health Branch (FNIHB). Includes influenza immunization doses administration data from AHS (AHS non-Public Health, non-AHS (including LTC sites) and Physicians), AH (IDSM, WHS and Covenant OHS) and FNIHB for the month of Oct, Nov, Dec, Jan, Feb, Mar 2021/22.
COVID-19 wastewater surveillance data
Alberta’s COVID-19 wastewater surveillance program covers approximately 80% of Albertans. Sampling occurs twice per week at each wastewater treatment plant and testing occurs at the Provincial Lab for Public Health.
Two SARS CoV-2 gene targets, the N1 and N2 genes, are tested for in the wastewater. The quantity of virus present is then normalized to the approximate population of the catchment area of the wastewater treatment plant. This method enables comparisons in the quantity of virus between municipalities, which was not previously possible.
The Fort Saskatchewan wastewater treatment plant includes 13 municipalities in the Edmonton area, and also receives some wastewater from northeast Edmonton.
The content and format of this report are subject to change. Cases are under investigation and numbers may fluctuate as cases are resolved.
Alberta Health follows the reporting schedule established by the Public Health Agency of Canada for influenza reporting, which starts in late August or early September each year, and runs until late August or early September of the next year. Respiratory season usually occurs in the fall and winter each year. As such, classifying seasons in this way allows the data to be combined for the fall and winter for each season. Data is reported by week. Each week runs from Sunday to Saturday. Below is the weekly schedule established by the Public Health Agency of Canada for the current season.
Historical and current respiratory virus season start and end dates