Figure 2.

Weekly number of samples testing positive for RSV (A) captured by the SARI pilot surveillance and (B) reported by the NRC^a, Belgium, week 41 2018–week 2 2019 (n = 508)

NRC: national reference centre for respiratory pathogens; RSV: respiratory syncytial virus; SARI: severe acute respiratory infection.

^a The distribution is based on the total number of RSV-positive tests reported to the NRC by the hospital laboratories in Belgium (including outpatients and inpatients, without any case definition; typing was not performed).

^b The arrow indicates the start of the seasonal official SARI surveillance, which, in 2019, began in week 2. Compared to the pilot surveillance, the official SARI surveillance involves three additional hospitals.

For the SARI surveillance (panel A), the weekly number of samples tested are represented by diamonds. The number of RSV-positive samples in the histograms are stacked, with different colours representing samples positive for RSV-A, RSV-B, or both RSV-A and RSV-B.