COVID-19 Public Health Measures May Have Lowered Cases of Respiratory Syncytial Virus

Incidence rates of positive acute respiratory infection (ARI), which is caused by respiratory syncytial virus (RSV) and called RSV-positive ARI, were higher in the pre-COVID-19 pandemic RSV season than during the COVID-19 pandemic season, with cases at 1126 and 212 respectively, according to investigators who published their results in JAMA Network Open. Additionally, quality of life (QoL) in older adults decreased during the COVID-19 pandemic season vs the pre-COVID-19 pandemic RSV season; the downward trend may be attributed to public health measures.

“RSV-positive ARI is likely to pose a major burden to older adults in a predictable manner as the global population ages unless such RSV epidemiology is interrupted by public health measures, which were undertaken during the worldwide public health crises, such as the COVID-19 pandemic,” wrote study authors.

RSV-positive ARI is estimated to infect 1.15 million people aged 65 years and older in the United States. With an estimated 14.5% hospitalization rate, it is associated with severe morbidity and mortality, and it can threaten QoL among older adults.

Prior studies have examined how RSV-positive ARI impacts short-term morbidity and mortality in hospitalized patients, but few looked at its long-term impact and effects on QoL. This study aims to address the long-term (beyond 28 days) implications of RSV-positive ARI on adults aged 50 years and older.

Investigators enrolled 2325 adults aged 50 years and older from southeast Minnesota in a community-based prospective study. The cohort was 96% non-Hispanic White and 59% female with an average age of 67 years. Follow-up outcomes were measured at 2 and 4 weeks, 6 or 7 months, and 12 or 13 months post-RSV-positive ARI.

Participants were assessed during 2 RSV seasons (October 1 to April 30) between 2019 and 2021. ARI cases were also assessed mid-pandemic during a non-RSV season (May 2021 to September 2021).

Prior to the COVID-19 pandemic, rate of RSV-positive ANI was 2.50% (48.6 per 1000 person-years). Based on the study, there were no identifiable RSV-positive ARI cases during the pandemic. As the pandemic continued, cases rose to an incidence rate of 0.4% (10.2 per 1000 person-years).

Clinical infection symptoms might also last beyond 3 months of overcoming RSV-positive ARI, according to investigators. These findings reflect the results of prior research that calculated long-term outcomes compared to influenza, where “patients with RSV-positive ARI were more likely to have shortness of breath (RSV, 16.1% vs influenza, 9.1%) and cough (RSV, 8.6% vs influenza, 3.5%), compared with those with influenza.”

The results of the current study also support those of other studies that showed RSV-positive ARI remained relatively consistent across geographical regions and over time, thus remaining a burden on QoL without public health interventions.

However, the study includes some limitations. Chiefly, only 1 RSV season was unaffected by the COVID-19 pandemic. Additionally, the study did not assess short-term outcome measures immediately after infection onset. Further, there is the possibility of confounding variables, and lastly, findings may not be generalizable due to a lack of racial or ethnic diversity.

“RSV-positive ARI was associated with significant long-term impacts on health-related QOL beyond the acute infection in adults [aged] over 50 [years]. An effective RSV vaccine might be an important measure to mitigate the impact of RSV-positive ARI, especially in older adults,” study authors wrote.

Reference

Juhn Y, Wi C, Takahashi P, et al. Incidence of Respiratory Syncytial Virus Infection in Older Adults Before and During the COVID-19 Pandemic. JAMA Netw Open. 2023;6(1):e2250634. doi:10.1001/jamanetworkopen.2022.50634