RSV Infections More Frequent, Severe in Older Adults

Older adults were more likely to have respiratory syncytial virus (RSV) infection that was more severe compared with influenza A/B, according to a study published in Journal of Clinical Virology. The researchers concluded that RSV will continue to be a problem in older adults.

RSV is the leading cause of hospitalization in children in the winter months, with research also suggesting that severe RSV infections can also occur in adults. Treatment for RSV can only be symptomatic and supportive in the absence of a proper vaccine. The effect of RSV on morbidity and mortality in older adults is lacking given the expected wave of RSV after the pandemic, and so this study aimed to examine patient characteristics, clinical presentation, risk factors, and outcomes in adults with RSV infection compared with influenza A/B and COVID-19.

The data for this study were retrospectively collected for 2017 to 2020 from a maximum care hospital. Any adult that had a positive polymerase chain reaction (PCR) test for RSV, influenza A/B, and COVID-19 and influenza-like symptoms in the time range were included. Data on vaccination status for influenza were not available. Clinical symptoms of a respiratory infection were also recorded from patient records.

Nasal, nasopharyngeal, or orophanryngeal swabs were taken for testing. Duration of hospital stay was calculated in all patients and rate of complications, rate of intensive care stay, frequency of mechanical ventilation, rate of bacterial superinfections, and hospital mortality were all of interest in this study.

There were 1537 patients with respiratory symptoms who were included in this study; 318 had a positive PCR test for RSV, 591 for influenza A, 289 for influenza B, and 342 for COVID-19. Patients who had RSV and influenza A/B had data collected from January to April in all 4 years whereas data on patietns who had COVID-19 were collected throughout 2020.

Peaks for RSV were found between calendar weeks 7 and 9; for influeza A, between weeks 6 and 9; for influenza B, between weeks 8 and 9; and for COVID-19, between weeks 15 and 49 for Influenza B, and CW 15 and 49. The detection rate for RSV or influenza A/B decreased from 32.12% in 2017 to 15.31% in 2020, while RSV positivity rates were more frequent than influenza B in 3 of the 4 seasons, ranging from 2.9% to 9.1%.

In the oldest patient group to have patients with RSV infections, the average age was 75.1 years, significantly older than the 70.8 years seen among patients with COVID-19 at hospitalization. Coughing was the most prevalent symptom among patients with RSV, but it was the last prevalent in patients with COVID-19, and headaches were most often found in patients with influenza B and were rare in patients with RSV. Patients with influenza B and COVID-19 were fatigued most often.

Risk factors were found in most of the patients included, with most having at least 1 of 5. Chronic obstructive pulmonary disease was more prevalent in patients with RSV vs influenza B and COVID-19, and kidney diseases were more common in patients with RSV compared with patients with influenza A and COVID-19.

Duration of hospital stay was longer in patients with RSV compared with patients with influenza A or influenza B; however, patients with COVID-19 stayed in the hospital longer. Patients with RSV had a higher risk of developing pneumonia, acquiring bacterial superinfection, going on mechanical ventilation, and having a fatal outcome compared with influenza A/B, but had a lower risk of all those outcomes compared with patients with COVID-19. Patients with RSV also had the second highest risk of being transferred to the intensive care unit, behind patients with COVID-19.

The retrospective design of the study was one of its weaknesses, the authors noted. Other potential limitaitons on finding generalizability were that the indication for testing was made by a treating physician, who relied on obvious symptoms and therefore could have test bias, and comparing RSV and influenza A/B to the original strain of COVID-19 is more historical in nature than generalizable to the present.

The researchers concluded that RSV is a leading cause of respiratory disease in older adults. With vaccinations for influenza and COVID-19, RSV will continue its severe and fatal infections in this group, making awareness of the effect of RSV on older adults more important than ever, they emphasized.

Reference

Ambrosch A, Luber D, Klawonn F, Kabesch M. Focusing on severe infections with the respiratory syncytial virus (RSV) in adults: risk factors, symptomatology and clinical course compared to influenza A/B and the original SARS-CoV-2 strain. J Clin Virol. Published online February 14, 2023. doi:10.1016/j.jcv.2023.105399