Abstract:
Background : The emergence of the Severe Acute Respiratory
Syndrome Coronavirus 2 (SARS-CoV-2) in early 2020 and subsequent
implementation of public health and social measures (PHSM) disrupted the
epidemiology of respiratory viruses. This work describes the
epidemiology of RSV observed during two winter seasons (weeks 40 to 20)
and inter-seasonal periods (weeks 21 to 39) during the pandemic between
October 2020 and September 2022.
Methods : Using data submitted to The European Surveillance System
(TESSy) by countries or territories in the World health Organization
(WHO) European Region between weeks 40/2020 and 39/2022, we aggregated
country-specific weekly RSV counts of sentinel, non-sentinel and Severe
Acute Respiratory Infection (SARI) surveillance specimens and calculated
percentage positivity. Results for both 2020/21 and 2021/22 seasons and
inter-seasons were compared to pre-pandemic 2016/17 to 2019/20 seasons
and inter-seasons.
Results : Although more specimens were tested than in pre-COVID-19
pandemic seasons, very few RSV detections were reported during the
2020/21 season in all surveillance systems. During the 2021
inter-season, a gradual increase in detections was observed in all
systems. In 2021/22, all systems saw early peaks of RSV infection, and
during the 2022 inter-seasonal period, patterns of detections were
closer to those seen before the COVID-19 pandemic.
Conclusion : RSV surveillance continued throughout the COVID-19
pandemic, with an initial reduction in transmission, followed by very
high and out-of-season RSV circulation (summer 2021) and then an early
start of the 2021/22 season. RSV circulation during the 2022/23 season
had not yet normalised.
Key
words:
Respiratory Syncytial Virus; sentinel; non-sentinel; severity;
surveillance; epidemiology; Europe; COVID-19 pandemic