Masking for COVID-19 Is Associated with Decreased Emergency Department Utilization for Non-COVID Viral Illnesses and Respiratory Conditions in Maryland.

Masking, which is known to decrease the transmission of respiratory viruses, was not widely practiced in the United States until the coronavirus disease 2019 (COVID-19) pandemic. This provides a natural experiment to determine whether the percentage of community masking was associated with decreases in emergency department (ED) visits due to non-COVID viral illnesses (NCVIs) and related respiratory conditions. In this observational study of ED encounters in a 11-hospital system in Maryland during 2019-2020, year-on-year ratios for all complaints were calculated to account for "lockdowns" and the global drop in ED visits due to the pandemic. Encounters for specific complaints were identified using the International Classification of Diseases, version 10. Encounters with a positive COVID test were excluded. Linear regression was used to determine the association of publicly available masking data with ED visits for NCVI and exacerbations of asthma and chronic obstructive pulmonary disease (COPD), after adjusting for patient age, sex, and medical history. There were 285,967 and 252,598 ED visits across the hospital system in 2019 and 2020, respectively. There was a trend toward an association between the year-on-year ratio for all ED visits and the Maryland stay-at-home order (parameter estimate = -0.0804, P = .10). A 10% percent increase in the prevalence of community masking was associated with a 17.0%, 8.8%, and 9.4% decrease in ED visits for NCVI and exacerbations of asthma exacerbations and chronic obstructive pulmonary disease, respectively (P < .001 for all). Increasing the prevalence of masking is associated with a decrease in ED visits for viral illnesses and exacerbations of asthma and COPD. These findings may be valuable for future public health responses, particularly in future pandemics with respiratory transmission or in severe influenza seasons.

Dezman ZDW ，Stryckman B ，Zachrison KS ，Conrad RM ，Marcozzi D ，Pimentel L ，Samuels-Kalow M ，Cairns CB ... -  《-》

Changes in Seasonal Respiratory Illnesses in the United States During the Coronavirus Disease 2019 (COVID-19) Pandemic.

Respiratory tract infections are common, often seasonal, and caused by multiple pathogens. We assessed whether seasonal respiratory illness patterns changed during the COVID-19 pandemic. We categorized emergency department (ED) visits reported to the National Syndromic Surveillance Program according to chief complaints and diagnosis codes, excluding visits with diagnosed SARS-CoV-2 infections. For each week during 1 March 2020 through 26 December 2020 ("pandemic period"), we compared the proportion of ED visits in each respiratory category with the proportion of visits in that category during the corresponding weeks of 2017-2019 ("pre-pandemic period"). We analyzed positivity of respiratory viral tests from 2 independent clinical laboratories. During March 2020, cough, shortness of breath, and influenza-like illness accounted for twice as many ED visits compared with the pre-pandemic period. During the last 4 months of 2020, all respiratory conditions, except shortness of breath, accounted for a smaller proportion of ED visits than during the pre-pandemic period. Percent positivity for influenza virus, respiratory syncytial virus, human parainfluenza virus, adenoviruses, and human metapneumovirus was lower in 2020 than 2019. Although test volume decreased, percent positivity was higher for rhinovirus/enterovirus during the final weeks of 2020 compared with 2019, with ED visits similar to the pre-pandemic period. Broad reductions in respiratory test positivity and respiratory ED visits (excluding COVID-19) occurred during 2020. Interventions for mitigating spread of SARS-CoV-2 likely also reduced transmission of other pathogens. Timely surveillance is needed to understand community health threats, particularly when current trends deviate from seasonal norms.

Rodgers L ，Sheppard M ，Smith A ，Dietz S ，Jayanthi P ，Yuan Y ，Bull L ，Wotiz S ，Schwarze T ，Azondekon R ，Hartnett K ，Adjemian J ，Kirking HL ，Kite-Powell A ... -  《-》

Examining the effect of the COVID-19 pandemic on community virus prevalence and healthcare utilisation reveals that peaks in asthma, COPD and respiratory tract infection occur with the re-emergence of rhino/enterovirus.

Airway disease exacerbations are cyclical related to respiratory virus prevalence. The COVID-19 pandemic has been associated with reduced exacerbations possibly related to public health measures and their impact on non-COVID-19 respiratory viruses. We aimed to investigate the prevalence of non-COVID-19 respiratory viruses during the pandemic compared with prior in Ontario, Canada and healthcare utilisation related to asthma, chronic obstructive pulmonary disease (COPD) and respiratory tract infection. This is a population-based retrospective analysis of respiratory virus tests, emergency department (ED) visits and hospitalisations between 2015 and 2021 in Ontario. Weekly virus testing data were used to estimate viral prevalence for all non-COVID-19 respiratory viruses. We plotted the %positivity and observed and expected counts of each virus to visualise the impact of the pandemic. We used Poisson and binomial logistic regression models to estimate the change in %positivity, count of positive viral cases and count of healthcare utilisation during the pandemic. The prevalence of all non-COVID-19 respiratory viruses decreased dramatically during the pandemic compared with prior. Comparing periods, the incidence rate ratio (IRR) for positive cases corresponded to a >90% reduction for non-COVID-19 respiratory viruses except adenovirus and rhino/enterovirus. Asthma-related ED visits and hospital admissions fell by 57% (IRR 0.43 (95% CI 0.37 to 0.48)) and 61% (IRR 0.39 (95% CI 0.33 to 0.46)). COPD-related ED visits and admissions fell by 63% (IRR 0.37 (95% CI 0.30 to 0.45)) and 45% (IRR 0.55 (95% CI 0.48 to 0.62)). Respiratory tract infection ED visits and admissions fell by 85% (IRR 0.15 (95% CI 0.10 to 0.22)), and 85% (IRR 0.15 (95% CI 0.09 to 0.24)). Rather than the usual peaks in disease condition, during the pandemic, healthcare utilisation peaked in October when rhino/enterovirus peaked. The prevalence of nearly all non-COVID-19 respiratory viruses decreased during the pandemic and was associated with marked reductions in ED visits and hospitalisations. The re-emergence of rhino/enterovirus was associated with increased healthcare utilisation.

Ho T ，Shahzad A ，Jones A ，Raghavan N ，Loeb M ，Johnston N ... -  《-》

Population Decline in COPD Admissions During the COVID-19 Pandemic Associated with Lower Burden of Community Respiratory Viral Infections.

The Coronavirus disease 2019 (COVID-19) pandemic has led to widespread implementation of public health measures, such as stay-at-home orders, social distancing, and masking mandates. In addition to decreasing spread of severe acute respiratory syndrome coronavirus 2, these measures also impact the transmission of seasonal viral pathogens, which are common triggers of chronic obstructive pulmonary disease (COPD) exacerbations. Whether reduced viral prevalence mediates reduction in COPD exacerbation rates is unknown. We performed retrospective analysis of data from a large, multicenter health care system to assess admission trends associated with community viral prevalence and with initiation of COVID-19 pandemic control measures. We applied difference-in-differences analysis to compare season-matched weekly frequency of hospital admissions for COPD prior to and after implementation of public health measures for COVID-19. Community viral prevalence was estimated using regional Centers for Disease Control and Prevention test positivity data and correlated to COPD admissions. Data involving 4422 COPD admissions demonstrated a season-matched 53% decline in COPD admissions during the COVID-19 pandemic, which correlated to community viral burden (r = 0.73; 95% confidence interval, 0.67-0.78) and represented a 36% greater decline over admission frequencies observed in other medical conditions less affected by respiratory viral infections (incidence rate ratio 0.64; 95% confidence interval, 0.57-0.71, P < .001). The post-COVID-19 decline in COPD admissions was most pronounced in patients with fewer comorbidities and without recurrent admissions. The implementation of public health measures during the COVID-19 pandemic was associated with decreased COPD admissions. These changes are plausibly explained by reduced prevalence of seasonal respiratory viruses.

So JY ，O'Hara NN ，Kenaa B ，Williams JG ，deBorja CL ，Slejko JF ，Zafari Z ，Sokolow M ，Zimand P ，Deming M ，Marx J ，Pollak AN ，Reed RM ... -  《-》

Prevalence and contribution of respiratory viruses in the community to rates of emergency department visits and hospitalizations with respiratory tract infections, chronic obstructive pulmonary disease and asthma.

Satia I ，Cusack R ，Greene JM ，O'Byrne PM ，Killian KJ ，Johnston N ... -  《-》