RSV Season 2022: Most US Infants in ICU Were Full-Term, Previously Healthy

In a study of 600 infants who were in the intensive care unit (ICU) for respiratory syncytial virus (RSV), most infants were full-term and previously healthy during the fall of 2022; however, infants that were less than 3 months and born prematurely were more at risk of intubation, according to results of a study published in JAMA Network Open.¹

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“Most of the infants in our study receiving ICU-level care were young, healthy, and born at term,” said Natasha Halasa, MD, MPH, Craig Weaver Professor of Pediatrics in the Division of Pediatric Infectious Diseases at Monroe Carell Jr. Children’s Hospital at Vanderbilt University, said in a press release. “Although mortality was rare, our findings emphasize the significant illness caused by RSV in young infants.”²

Investigators aimed to evaluate the characteristics and outcomes of critical RSV for infants in the United States during the peak 2022 transmission season. They used a cross-sectional study, which included data from public health prospective surveillance registries of 39 pediatric hospitals in 27 states between October 17 and December 16 2022. Infants included were admitted to the ICU for 24 or more hours with a laboratory-confirmed RSV infections, according to the study authors.¹

Information on demographics, clinical characteristics, signs and symptoms, laboratory values, severity, and clinical outcomes were included in the study. Clinical outcomes included receipt of noninvasive respiratory support, invasive mechanical ventilation, or death, according to the study authors. The investigators assessed the associations between intubation status, demographic factors, gestational age, and underlying conditions.¹

The first 15 to 20 infants at each site were included in the sample, with a median age of 2.6 months, 60.2% being male, 28.9% born prematurely, and 81.2% having no underlying medical conditions. The median length of hospitalization was 5 days. According to the study investigators, the primary reason for ICU admission was lower respiratory tract infections (LRTI) at 99% and apnea or bradycardia at 12.8%, and approximately 23.8% received invasive mechanical ventilation.¹

Non-intubated infants mostly received high-flow nasal cannula at 40.5%, bilevel positive airway pressure at 25%, and continuous positive airway pressure at 8.7%, according to the study authors. Furthermore, infants that were younger than 3 months, those who were born less than 37 weeks’ gestation, and those publicly insured has a high risk of intubation.¹

The study authors noted that 4 infants received extracorporeal membrane oxygenation, and 2 died. Furthermore, of the 17 infants born less than 29 weeks’ gestation, 15 had no documentation of receiving palivizumab.¹

“Our data support the need for RSV preventative interventions targeting all infants to reduce the burden of severe RSV illness, including nirsevimab, the long-acting RSV-neutralizing monoclonal antibody. The drug was recently approved by the [FDA], and a maternal vaccine for RSV prevention is under consideration,” Halasa said in the statement. “These products may protect both high-risk and healthy infants from medically attended RSV-associated LRTI.”²

Halasa added that the study findings may be helpful for future RSV prophylaxis and maternal RSV vaccines as well as other studies and recommendations.²

References

1. Halasa N, Zambrano LD, Amarin JZ, Steward LS, et al. Infants Admitted to US Intensive Care Units for RSV Infection During the 2022 Seasonal Peak. JAMA Netw Open. 2023;6(8):e2328950. doi:10.1001/jamanetworkopen.2023.28950
2. Study finds most infants receiving ICU-level care for RSV had no underlying medical condition. News release. EurekAlert. August 15, 2023. Accessed November 17, 2023. https://www.eurekalert.org/news-releases/998363