US Infants Admitted to ICU in 2022 for RSV Mostly Young, Healthy, and Born at Term

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Most US infants admitted to an intensive care unit (ICU) for respiratory syncytial virus (RSV) lower respiratory tract infections (LRTIs) during fall 2022 were young, healthy, and born at term, according to a new study published in JAMA Network Open.¹

Findings from the cross-sectional study underscore the need for preventative interventions in all infants to reduce their risk of severe RSV, the leading cause of LRTIs and infant hospitalizations worldwide, noted study authors.¹

In the US specifically, an estimated 58 000 to 80 000 children aged <5 years are hospitalized annually due to RSV infection, according to the US Centers for Disease Control.

“The COVID-19 pandemic disrupted typical RSV circulation patterns, leading to atypical US epidemics during 2021 and 2022,” wrote researchers led by Natasha Halasa, MD, MPH, division of pediatric infectious diseases, Vanderbilt University Medical Center, Nashville, Tennessee. “Specifically, a surge in RSV-related hospitalizations and ICU admissions among infants and young children occurred in the fall of 2022.”¹

Until recently there has been only 1 US-licensed product to help prevent RSV-associated LRTI. Use of IM palivizumab has been limited to high-risk infants and its high cost has prohibited wider distribution. With the recent US Food and Drug Administration approval of a long-acting monoclonal RSV-neutralizing antibody against RSV for infants and young children, the authors emphasize the importance of identifying infants at risk for severe RSV infection to assess efficacy and to guide recommendations for vaccine usage.¹

Halasa and colleagues conducted the current study to evaluate the characteristics and outcomes of RSV-related critical illness in US infants during the RSV seasonal peak of 2022. They used a public health prospective surveillance registry in 39 pediatric hospitals across 27 states to identify infants who were admitted for ≥24 hours between October 17, 2022, and December 16, 2022, to a unit providing intensive care due to laboratory-confirmed RSV infection.¹

FINDINGS

A total of 600 infants (median age 2.6 months; 60.2% male) were enrolled in the study, of which81.2% had no underlying medical conditions and 28.9% were born prematurely. Approximately one-quarter of the infants were intubated.¹

The primary reasons for admission were LRTI (99%) but infants who were intubated more frequently had apnea or bradycardia (12.8%), according to researchers. Two infants died during hospitalization, but for the remainder of the population, the median hospitalization duration was 5 days.¹ The authors state that even though mortality during the study was rare, “our findings emphasize the significant illness caused by RSV in young infants.”²

Investigators observed that 23.8% of infants underwent invasive mechanical ventilation for a median of 6 days, 70.6% of whom were aged <3 months. Among infants who did not require intubation, researchers found that 40.5% received high-flow nasal cannula followed by bilevel positive airway pressure for 25% of infants and continuous positive airway pressure for 8.7%. Four infants (0.7%) required extracorporeal membrane oxygenation.¹

Infants aged <3 months, those born prematurely, or those publicly insured were at a higher risk for intubation, according to the study results.¹

“These findings support the use of new preventative interventions, including long-lasting monoclonal antibodies in all infants and maternal vaccination” when the latter becomes available, wrote Halasa and colleagues.¹

References:

1. Halasa N, Zambrano LD, Amarin JZ, et al. Infants admitted to US intensive care units for RSV infection during the 2022 seasonal peak.JAMA Netw Open. 2023;6:e2328950.
2. Jessica Pasley. Study finds most infants receiving ICU-level care for RSV had no underlying medical condition. Vanderbilt University Medical Center Reporter. Published August 15, 2023. Accessed August 18, 2023. https://news.vumc.org/2023/08/15/study-finds-most-infants-receiving-icu-level-care-for-rsv-had-no-underlying-medical-condition/