Differentiating Impacts of Non-Pharmaceutical Interventions on
Non-Coronavirus-Disease-2019 Respiratory Viral Infections:
Hospital-Based Retrospective Observational Study in Taiwan
Background Physical distancing and facemask use are worldwide recognized
as effective non-pharmaceutical interventions (NPIs) against the
coronavirus disease 2019 (COVID-19). Since January 2020, Taiwan has
introduced both NPIs but their effectiveness on non-COVID-19 respiratory
viruses (NCRVs) remain underexplored. Methods This retrospective
observational study examined electronic records at a tertiary hospital
in northern Taiwan from pre-COVID (January–December 2019) to post-COVID
period (January–May 2020). Patients with respiratory syndromes were
tested for both enveloped (e.g. influenza virus and seasonal
coronavirus) and non-enveloped RVs (e.g. enterovirus and rhinovirus)
using multiplex reverse-transcription polymerase chain reaction assays.
Monthly positivity rates of NCRVs among adult and pediatric patients
were analyzed with comparison between pre- and post-COVID periods.
Results A total of 9693 patients underwent 12127 multiplex RT-PCR tests.
The average positivity rate of NCRVs reduced by 11.2% (25.6% to
14.4%) after nationwide PHIs. Despite the COVID-19 pandemic, the most
commonly identified enveloped and non-enveloped viruses were influenza
virus and enterovirus/rhinovirus, respectively. Observed reduction in
NCRV incidence was predominantly contributed by enveloped NCRVs
including influenza viruses. We did not observe epidemiological impacts
of NPIs on non-enveloped viruses but an increasing trend in
enterovirus/rhinovirus test positivity rate among pediatric patients.
Our data were validated using Taiwan’s national notification database.
Conclusions Our frontline investigation suggests that the current NPIs
in Taiwan might not effectively control the transmission of
non-enveloped respiratory viruses, despite their protective effects
against influenza and seasonal coronavirus. Hydrogen peroxide or
chloride-based disinfectants should be integrated into national
preventative strategies against respiratory viral infections in the