Backgrounds:

The COVID-19 pandemic led to the implementation of non-pharmacological interventions to decrease respiratory viruses’ transmission. The aim of this study is to describe the impact of these interventions in activity of other common paediatric respiratory viruses during this period.

Methods

Retrospective analysis of the respiratory viruses detected by PCR in nasopharyngeal samples (FilmArray respiratory panel), from children with acute respiratory infections as part of routine care, in an emergency service (ES) of a paediatric tertiary hospital, from January 2015 to June 2021.

Results:

Over the years, we observed an increasing number of samples submitted to PCR and increasing proportion of positive tests until 2020-21 when both have dramatically decreased after the onset of the pandemic.

During the first 15 months of the pandemic, there was a marked reduction in all the other respiratory viruses, with: no detection of Influenza Virus (IV; subtypes H1N1, H3, and IB); detection of one case of Human Metapneumovirus (HMPV) in September 2020; historic low circulation for Respiratory Syncytial Virus (RSV) until late May/early June 2021 when a big epidemic started. For Rhino/Enteroviruses (RV/EV) and Adenovirus (AdV), despite decreased activity, there was a maintained detection, that increased after April 2021 (Figure1).

FIGURE1. Number of specimens tested and number of detected influenza viruses (IF), respiratory syncytial virus (RSV), human coronaviruses (HCoV), parainfluenza viruses (PI), human metapneumovirus (HMP), respiratory adenoviruses (AdV), rhinoviruses/enteroviruses (RV/EV), 2015-2021.

Conclusions/Learning Points:

In conclusion, in the first year of COVID-19 pandemic we observed changes in other respiratory viruses’ detection, although with differences between them, most notably a dramatic decrease for IV, RSV, parainfluenza and HMPV, remaining some detection of RV/EV and AdV. After May-June 2021, we started observing a resurgence except for IV and HMPV that remained undetectable.