Decreased human respiratory syncytial virus activity during the COVID-19 pandemic in Japan: an ecological time-series analysis

Abstract

Background Non-pharmaceutical interventions (NPIs), such as sanitary measures and travel restrictions, aimed at controlling the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may affect the transmission dynamics of human respiratory syncytial virus (HRSV). We aimed to quantify the contribution of the sales of hand hygiene products and the number of international and domestic airline passenger arrivals on HRSV epidemic in Japan. Methods The monthly number of HRSV cases per sentinel site (HRSV activity) in 2020 was compared with the average of the corresponding period in the previous 6 years (from January 2014 to December 2020) using a monthly paired t-test. A generalized linear gamma regression model was used to regress the time-series of the monthly HRSV activity against NPI indicators, including sale of hand hygiene products and the number of domestic and international airline passengers, while controlling for meteorological conditions (monthly average temperature and relative humidity) and seasonal variations between years (2014–2020). Results The average number of monthly HRSV case notifications in 2020 decreased by approximately 85% (p < 0.001) compared to those in the preceding 6 years (2014–2019). For every average ¥1 billion (approximately £680,000/$9,000,000) spent on hand hygiene products during the current month and 1 month before there was a 0.29% (p = 0.003) decrease in HRSV infections. An increase of average 1000 domestic and international airline passenger arrivals during the previous 1–2 months was associated with a 3.8 × 10− 4% (p < 0.001) and 1.2 × 10− 3% (p < 0.001) increase in the monthly number of HRSV infections, respectively. Conclusions This study suggests that there is an association between the decrease in the monthly number of HRSV cases and improved hygiene and sanitary measures and travel restrictions for COVID-19 in Japan, indicating that these public health interventions can contribute to the suppression of HRSV activity. These findings may help in public health policy and decision making.

Epidemiological Consequences of Viral Interference: A Mathematical Modeling Study of Two Interacting Viruses

“…Perhaps the biggest factor not considered in the model is mitigation strategies for reducing spread of SARS-CoV-2, such as wearing of masks and social distancing. These NPIs not only change the time course of the SARS-CoV-2 epidemic, but also help stem the spread of other respiratory viruses (Ngonghala et al, 2020 ) and are largely thought to be responsible for the lack of typical seasonal respiratory viruses in 2020 (Oh et al, 2021 ; Redlberger-Fritz et al, 2021 ; Wagatsuma et al, 2021 ).…”

“…There was a fear that the combined effect of SARS-CoV-2 and illness due to these other respiratory viruses could lead to an excessive burden on the healthcare system (Kissler et al, 2020 ; Xu and Li, 2020 ), but in many parts of the world, the usual seasonal respiratory virus epidemics did not materialize (Casalegno et al, 2021 ; Eisen et al, 2021 ; Le Hingrat et al, 2021 ; Liu et al, 2021 ; Tempia et al, 2021 ; Williams et al, 2021 ). It's not clear if the suppression of other respiratory viruses is due to an interaction between SARS-CoV-2 and these other viruses or due to non-pharmaceutical interventions imposed to control the spread of SARS-CoV-2 (Oh et al, 2021 ; Redlberger-Fritz et al, 2021 ; Wagatsuma et al, 2021 ).…”

Editorial: A Decline in Influenza During the COVID-19 Pandemic and the Emergence of Potential Epidemic and Pandemic Influenza Viruses

“…Where there have been successful vaccination programs for COVID-19, social restrictions and travel restrictions have eased, and children and young adults are returning to schools and universities at a time when the influenza season usually commences [ 9 ]. Reduced exposure to more commonly circulating respiratory viruses reduces the levels of population immunity [ 9 , 11 , 12 ]. As an example, studies from the US, Europe, and Japan have shown that the social restrictions during the COVID-19 pandemic in mid-2020 reduced the levels of respiratory syncytial virus (RSV) infections in children [ 8 , 9 ].…”

“…As an example, studies from the US, Europe, and Japan have shown that the social restrictions during the COVID-19 pandemic in mid-2020 reduced the levels of respiratory syncytial virus (RSV) infections in children [ 8 , 9 ]. However, RSV infection rates in children rose, and infection duration was prolonged when children returned to school in September 2020 [ 12 ].…”

Respiratory syncytial virus pneumonia in an adult cord blood transplant recipient during the SARS‐CoV‐2 outbreak

“…An extensive search for other pathogens identified respiratory syncytial virus (RSV) by PCR of a nasopharyngeal swab, confirming the diagnosis of RSV pneumonia, which rarely affects late phase stem cell transplant recipients [ 1 ]. Epidemic patterns of infectious viruses other than SARS‐CoV‐2 altered substantially in these 2 years, presumably due to the changes in social activities associated with SARS‐CoV‐2 pandemics [ 2 , 3 ]. For instance, RSV infection was highly suppressed in 2020 but had a resurgent outbreak in early summer 2021 [ 4 , 5 ].…”