Influenza Deaths

A death resulting from a clinically compatible illness in a laboratory-confirmed influenza case, unless there is a clear alternative cause of death identified (e.g. trauma, poisoning, drug overdos, etc.).

A Medical Officer of Health or relevant public health authority may use their discretion when determining if a death was due to influenza, and their judgement will supersede the above criteria.

A death due to influenza may be attributed when influenza is the cause of death or is a contributing factor.

Influenza Outbreaks

Influenza 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. Influenza 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. 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.

Lab Positivity

Influenza 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) Q/RT-PCR tests are the only COVID-19 tests included in this calculation.

Vaccine coverage

Individuals who received one dose was calculated as (# of individuals who received at least one dose) / (population estimate).