. 2021 Dec 5;16(3):417–428. doi: 10.1111/irv.12941

TABLE 1.

Influenza surveillance subsystems and comparative outcomes

Surveillance subsystem	Outcome
1. Non‐medically attended community surveillance	1.1. ARI/ILI/COVID‐like cases and/or incidence rates
1. Non‐medically attended community surveillance	1.2. Proportion of ARI/ILI/COVID‐like cases seeking care
2. Virological surveillance	2.1. ARI/ILI/COVID‐like specimens for virus typing & subtyping
	2.2. ARI/ILI/COVID‐like specimens for virus genome sequencing
	2.3. ARI/ILI/COVID‐like specimens for antiviral drug resistance
3. Community surveillance	3.1. Notified biologically/laboratory‐confirmed cases
3. Community surveillance	3.2. Serum samples for population immunity estimates
4. Outbreak surveillance	4.1. ARI/ILI/COVID‐like outbreaks in closed settings
4. Outbreak surveillance	4.2. Biologically/laboratory‐confirmed outbreaks in closed settings
5. Primary care surveillance	5.1. ARI/ILI/COVID‐like GP visits and/or incidence rates
	5.2. Biologically/laboratory‐confirmed GP visits and/or incidence rates
	5.3. Associated excess GP visits
	5.4. Associated excess work loss cases
6. Hospital surveillance	6.1. ILI/COVID‐like or biologically/laboratory‐confirmed Emergency Department visits
	6.2. SARI/ILI/COVID‐like hospital admissions
	6.3. Biologically/laboratory‐confirmed hospital admissions
	6.4. Associated excess hospital admissions
	6.5. Biologically/laboratory‐confirmed ICU admissions
7. Mortality surveillance	7.1. Diagnosed or biologically/laboratory‐confirmed deaths
7. Mortality surveillance	7.2. Associated excess deaths

Note. Adapted from El Guerche‐Séblain et al. ¹³

Abbreviations: GP, general practitioner; ICU, intensive care unit; ILI, influenza‐like illness; (S)ARI, (severe) acute respiratory illness.

^{^a}

Not included in El Guerche‐Séblain et al. ¹³