Sentinel sites and specimens

Sentinel sites

Countries that conduct primary care or hospital-based sentinel surveillance for ILI, ARI, SARI, or pneumonia should continue to collect respiratory specimens using existing case definitions, through sentinel or syndromic networks. It is recommended to use the WHO’s case definition for ILI and SARI for COVID-19 surveillance. Samples collected from sentinel sites should be clearly labelled as such and, if possible, the case definition applied should be included in the labelling (ILI, SARI, etc.)

Case definition

ILI case definition

Acute respiratory infection with:

measured fever of ≥38 ⁰C
and cough;
with onset within the last 10 days.

SARI case definition

Acute respiratory infection with:

history of fever or measured fever of ≥38 ⁰C
and cough;
with onset within the last 10 days;
and requires hospitalization.

Specimens for laboratory diagnosis

Specimens for ILI cases: 

Nasal swab, nasopharyngeal swab, nasopharyngeal aspirate, nasal wash;
Oropharyngeal swabs;
Combined nasal and throat swabs may have a higher yield of virus detection in ILI cases than do oropharyngeal specimens.

Specimens for SARI cases: 

As for ILI cases and/or from lower respiratory tract;
Or, if patients are intubated, endotracheal aspirates or bronchoalveolar lavages may have a higher yield than upper respiratory specimens.

Sentinel sites and specimens

Sentinel sites

Case definition

Specimens for laboratory diagnosis​

Specimens for laboratory diagnosis