Studies show RSV’s severity and impact on long-term health

Often confused for a common cold, respiratory syncytial virus (RSV) can in fact be serious and should be studied more closely. In studies led by Singapore General Hospital (SGH), researchers collaborating under the Program for Research in Epidemic Preparedness And REsponse (PREPARE) found that the illness could be of comparable severity to other more well-known respiratory viral infections (RVIs)—such as influenza and COVID-19.

In three large-cohort studies, the researchers looked at the severity of RSV, risk of cardiac complications, and long-term complications in patients who had RSV infections severe enough to require hospitalization, versus influenza and COVID-19 hospitalizations. Throughout all three studies, it was found that RSV was of comparable severity to influenza and COVID-19.

Dr. Ian Wee, Consultant, Department of Infectious Diseases, SGH and Deputy Lead, Databases Core, PREPARE, and first author for all three papers, said, “With about five to ten percent of those experiencing flu-like symptoms having respiratory syncytial virus, it may not be as common compared to influenza or COVID-19, and more research about the illness is needed. However, this does not make the infection any less serious than other RVIs, especially in Singapore’s tropical climate where year-round transmission of RSV occurs.”

Disease severity

Published in The Lancet Regional Health – Western Pacific, the first study examined close to 13,000 adult hospitalizations for RSV, COVID-19 and influenza, and compared risk of 28-day mortality and intensive-care-unit admission, which are indicators of severity. Among patients hospitalized for RSV, about one in 20 died within 28 days of hospital admission.

Overall, hospitalizations due to RSV were more severe than influenza, with higher death rates and more intensive care admissions. RSV was of comparable severity to COVID-19 hospitalization in individuals previously boosted against COVID-19; the study pre-dated the availability of RSV vaccination in Singapore.

Risk of cardiac complications

The second study, published in JAMA Network Open, compared the risk of acute cardiac complications—defined as any cardiac, cerebrovascular or thrombotic event, such as abnormal or irregular heartbeat, heart failure, stroke, deep venous thrombosis, or pulmonary embolism.

Assessing almost 33,000 adult hospitalizations for RSV, COVID-19 and influenza, slightly more than one in ten RSV hospitalizations had an acute cardiovascular event. These odds were significantly higher than patients hospitalized for COVID-19, as well as for patients with vaccine-breakthrough influenza hospitalizations.

Long-term complications

The third study looked at long-term complications following RSV infection in adults and children. Published in Clinical Microbiology and Infection, it studied about 83,000 adults hospitalized due to RVI.

In adults hospitalized for RSV, an increased risk of long-term cardiovascular and neurological complications was observed up to 300 days post-hospitalization. This study also assessed pediatric RVI hospitalizations among 24,340 patients aged 0 to 17 and found that there was a higher risk of post-acute respiratory complications such as wheeze/bronchitis following RSV hospitalization, versus COVID-19/influenza.

Understanding RVIs and RSV

RVIs are infections caused by viruses that affect the respiratory system, from the nose and throat to the airways and lungs. Beyond RSV, influenza, and COVID-19, other viruses can also cause respiratory infections. Common symptoms of RVIs include cough, sore throat and nasal congestion; while mild and self-resolving in most instances, progression to more severe illness (e.g. pneumonia or respiratory failure) can occur, particularly among at-risk groups.

RSV is a respiratory virus that causes characteristic flu-like symptoms, including runny nose and sore throat. Like other respiratory viruses, it spreads through close contact, exposure to respiratory droplets from coughing or sneezing, or contaminated objects and surfaces.

Most individuals experience only mild symptoms; however, young children, older adults, those who are immunocompromised or have existing respiratory or cardiac conditions are at higher risk of severe RSV.

Dr. Wee added, “One common point across the three studies was that young children and elderly patients face the greatest risk of short-term and long-term complications following respiratory viral infections, especially those with pre-existing medical conditions.

“RSV can have a significant impact on one’s health, and at-risk individuals should remain vigilant and discuss RSV protection with their health care providers. The public should also protect against all RVIs by maintaining good personal hygiene, such as practicing hand hygiene, staying home if feeling unwell, and wearing a mask if needing to leave home when symptomatic.”