The decreased prevalence of non-COVID-19 respiratory viruses during the pandemic is associated with a decrease in emergency department (ED) visits and hospitalizations owing to asthma, chronic obstructive pulmonary disease (COPD), and respiratory tract infection (RTI), according to study findings published in Thorax.
Researchers assessed the prevalence of non-COVID-19 respiratory viruses during the pandemic vs before, as well as health care utilization related to asthma, COPD and respiratory tract infections during this same time period. Toward that end, the researchers conducted a population-based, retrospective time series analysis of weekly respiratory virus testing results, ED visits, and hospitalizations from April 26, 2015, to May 1, 2021, in Ontario, Canada.
Data were obtained for influenza A and B, respiratory syncytial virus (RSV), parainfluenza, adenovirus, human metapneumovirus (hMPV), human rhino/enterovirus, and coronavirus for the study period. COVID-19 testing data, including the number of tests and positive tests, and weekly aggregated data for all ED visits and in-patient hospitalizations also were collected.
The data for respiratory virus testing were visualized by plotting the observed and expected weekly proportion of positive tests and weekly number of positive tests for each virus during the study period.
Going forward, non-COVID-19 respiratory virus patterns may be altered and lead to atypical peaks in respiratory-related health care utilization, which could have implications on the timing of vaccine administration, development of novel vaccines, hospital bed planning, and public health policy.
During the pandemic, the prevalence of all non-COVID-19 respiratory viruses decreased compared with the prepandemic periods, based on percent positivity or number of positive tests. The incidence rate ratio (IRR) for influenza was 0.01 (95% CI, 0.00-0.08), and the IRR for RSV was 0.03 (95% CI, 0.00-0.28).
Rhino/enterovirus cases had the least amount of decrease (IRR, 0.52; 95% CI, 0.18-1.54), which was not statistically significant. In addition, rhino/enterovirus appeared to continue its seasonal pattern.
ED visits and hospital admissions associated with asthma, COPD, and respiratory tract infection decreased compared with the prepandemic period. Asthma-related ED visits and hospital admissions were reduced by 57% (IRR, 0.37; 95% CI, 0.33-0.48) and 61% (IRR, 0.39; 95% CI, 0.33-0.46), respectively. COPD-related ED visits declined by 63% (IRR, 0.37; 95% CI, 0.30-0.45), and hospital admissions were reduced by 45% (IRR, 0.55; 95% CI, 0.48-0.62). The greatest reductions occurred for respiratory tract infection, with associated ED visits decreasing by 85% (IRR, 0.15; 95% CI, 0.10-0.22) and hospitalizations by 85% (IRR, 0.15; 95% CI, 0.09-0.24).
During the pandemic, the highest number of hospital visits for all 3 conditions occurred in October, when public health measures were relaxed in Ontario; this was in contrast to the usual peaks in disease condition (asthma exacerbations occurring in September and COPD exacerbations and RTIs occurring in January).
Among several limitations, the investigators were not able to obtain baseline characteristics for individual patients or confirm that patients had asthma or COPD. Also, the participants were from Ontario, Canada, and the findings may not be generalizable to other populations.
“Going forward, non-COVID-19 respiratory virus patterns may be altered and lead to atypical peaks in respiratory-related health care utilization, which could have implications on the timing of vaccine administration, development of novel vaccines, hospital bed planning, and public health policy,” stated the researchers.
Disclosure: Unrestricted funding for this study was provided by AstraZeneca Canada. Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.