Prior RSV infections increase COVID-19 severity

Key takeaways:

• Patients with an RSV infection within 3 years of COVID-19 infection had an increased risk for severe illness.
• Risk factors such as diabetes and congestive heart failure added to COVID-19 severity.

RSV infections contribute to the burden and severity of COVID-19, increasing susceptibility and chance for hospitalizations, according to a study published in the European Journal of Allergy and Clinical Immunology.

Even infections that are clinically mild can cause adverse effects due to structural damage in the airways as well as immunological changes, Hwan Jin Lee, of the department of internal medicine, research center for pulmonary disorders, Jeonbuk National University Hospital in Jeonju, Republic of Korea, and colleagues wrote.

This population-based cohort study examined the association between prior RSV infection and COVID-19 severity. Researchers used data from the National Health Insurance Service database and found that 18,535 of 8,644,520 individuals had a record of RSV infection between 2017 and 2019. A noninfected group of an equal size was selected for propensity score matching.

The primary outcomes included: COVID-19 susceptibility, which was defined by a positive SARS-CoV-2 test; hospitalizations, defined as an admission of a COVID-19 infected patient; and severity, which included either an intensive care unit admission, extracorporeal membrane oxygenation treatment, mechanical ventilator use or death.

When analyzed for COVID-19 susceptibility, the RSV infection group showed a significantly higher incidence of COVID-19 than the noninfection group with an adjusted hazard ratio of 1.11 (95% CI, 1.03-1.2). This result was even higher in patients with an underlying condition such as angina (aHR = 1.5; 95% CI, 1.2-1.89).

Among patients with COVID-19 related hospitalizations, 743 of 18,535 in the RSV infection group developed COVID-19. This infection group showed a significantly higher risk for hospitalization than the noninfection group (aHR = 1.23; 95% CI, 1.02-1.48). Patients who contracted RSV within a year of COVID-19 infection also had a more significant adjusted hazard ratio of 1.5 (95% CI, 1.09-2.09) compared with the noninfection control group.

In terms of COVID-19 severity, the infection group had a significantly higher risk for COVID-19 severity than the noninfection group (aHR = 3.13; 95% CI, 1.58-6.19). This effect was more evident in patients aged at least 65 years (aHR = 5.35; 95%, CI 2.33-12.27), patients with diabetes (aHR = 2.92; 95% CI, 1.26-6.77) and patients with congestive heart failure (aHR = 2.91; 95% CI, 1.17-7.23). Patients who contracted RSV in the previous year also had significantly higher COVID-19 severity compared with the noninfection group (aHR = 5.16; 95% CI, 2.21-12.09).

Researchers found that regardless of RSV infection severity, there was a significant increase in COVID-19 severity, suggesting that the RSV infection increases the chance for adverse clinical progression of COVID-19, all of which contribute to the burden of COVID-19.