Table 1 Influenza surveillance sub-systems and comparative outcomes

1. Non-medically attended community surveillance

1.1. ARI/ILI cases and/or incidence rates

1.2. Proportion of ARI/ILI cases attending a physician^a

2. Virological surveillance

2.1. ARI/ILI specimens for virus typing & subtyping

2.2. ARI/ILI specimens for virus genome sequencing

2.3. ARI/ILI specimens for antiviral drug resistance

3. Community surveillance

3.1. Notified biologically/laboratory-confirmed cases

4. Outbreak surveillance

4.1. ARI/ILI outbreaks in closed settings

4.2. Biologically/laboratory-confirmed outbreaks in closed settings

5. Primary care surveillance

5.1. ARI/ILI GP visits and/or incidence rates

5.2. Biologically/laboratory-confirmed GP visits and/or incidence rates

5.3. Influenza-associated excess GP visits

5.4. Influenza-associated excess work-loss cases

6. Hospital surveillance

6.1. ILI or biologically/laboratory-confirmed Emergency Department visits

6.2. SARI/ILI hospital admissions

6.3. Biologically/laboratory-confirmed hospital admissions

6.4. Influenza-associated excess hospital admissions

6.5. Biologically/laboratory-confirmed influenza ICU admissions

7. Mortality surveillance

7.1 Diagnosed or biologically/laboratory-confirmed influenza deaths

7.2. Influenza-associated excess deaths