By Stan Deresinski, MD, FACP, FIDSA
Clinical Professor of Medicine, Stanford University
SYNOPSIS: In individuals 75 years of age or older, respiratory syncytial virus infection was associated with more severe illness than was influenza virus infection.
SOURCE: Recto C, Fourati S, Khellaf M, et al. Respiratory syncytial virus vs. influenza virus infection: Mortality and morbidity comparison over 7 epidemic seasons in an elderly population. J Infect Dis 2024; Apr 4:jiae171. doi: 10.1093/infdis/jiae171. [Online ahead of print].
Recton and colleagues retrospectively examined patients 75 years of age or older with either respiratory syncytial virus (RSV) or influenza virus infection seen at the Henri Mondor hospital in Paris between March 31, 2016, and May 5, 2022. A total of 558 patients were included in the study cohort, including 125 with RSV and 433 with influenza, with mean ages of 85.5 years and 84.7 years, respectively. While chronic congestive heart failure was more prevalent in those with RSV (48.8% vs. 36%, P = 0.010), there was no difference in other preexisting comorbidities. Among the minority for whom the information was available, influenza vaccination had been received by 54.3% and 55.9% (P = 0.243) of the RSV and influenza groups, respectively, while immunosuppressive therapies had been received by 12.8% and 9.2% (P = 0.243) of the entire cohort, respectively.
The median interval from symptom onset to emergency department presentation was longer with RSV (three days vs. two days; P = 0.024) patients, who, on initial evaluation, had lower oxygen saturation (92% vs. 94%; P = 0.019), more frequent complaints of dyspnea (64.0% vs. 44.1%, P < 0.001), and more frequent wheezing (32.8% vs. 15.9%, P < 0.001). Infection of the lower respiratory tract (LRTI, defined as at least one of the following: dyspnea, wheezing, oxygen saturation < 90%, pulmonary consolidation) also occurred more frequently in RSV infection (83.2% vs. 61.5%, P < 0.001). Influenza patients, 67.7% of whom received oseltamivir, were less likely to receive antibiotics (35.8% vs. 47.2%, P = 0.021).
RSV-infected patients were more likely to be hospitalized (83.2% vs. 70.0%, P = 0.003), to be admitted to the intensive care unit (7.3% vs. 3.0%, P = 0.034), and to have longer median duration of hospitalization (nine days vs. five days, P = 0.002). There was no significant difference in mortality rates (9.6% vs. 9.7%).
COMMENTARY
This study clearly demonstrates the severity of RSV infection in individuals 75 years of age or older and also demonstrates that its severity in this age group is greater than infections due to influenza virus. Patients with RSV were more likely to have presented with dyspnea, wheezing, lower oxygen saturation, and involvement of the lower respiratory tract, including with consolidative pneumonia. Although not associated with greater mortality, RSV infection was associated with a greater likelihood and longer duration of hospitalization, and of intensive care unit admission.
There is no effective medication for treatment of RSV infection, but there are two vaccines (and at least one more likely to be approved soon). Unfortunately, the Centers for Disease Control and Prevention reported on May 10, 2024, that, among adults 65 years of age and older, while 73.5% had received that year’s influenza vaccine, only 24.4% had received one of the RSV vaccines.1
REFERENCE
- Centers for Disease Control and Prevention. Vaccine trends — adults. Reported May 10, 2024. https://www.cdc.gov/respiratory-viruses/data-research/dashboard/vaccination-trends-adults.html
