Zerr, Danielle M.

Abstract Importance Respiratory syncytial virus (RSV) hospitalization rates are highest among children <2 years of age. RSV immunization with infant monoclonal antibody or maternal vaccine is recommended to protect all U.S. infants in their first RSV season. For certain high-risk children aged 8−19 months entering their second RSV season, the monoclonal antibody nirsevimab is recommended. Little is known regarding preexisting health conditions as risk factors for RSV-associated respiratory failure in children during their second season. Objectives To describe children admitted to the pediatric intensive care unit (PICU) for RSV during their second RSV season by preexisting health conditions, and to compare demographic and clinical characteristics across groups. Design, Setting, and Participants Surveillance registry of children 8-<24 months old admitted to the PICU in 30 pediatric hospitals in the 2023-2024/2024-2025 RSV seasons. All children had an RSV-positive respiratory sample and received respiratory support with high flow nasal cannula, noninvasive ventilation, or invasive mechanical ventilation (IMV). Exposure Preexisting health conditions potentially increasing risk of severe RSV disease. Main Outcomes and Measures Patients were classified into four mutually exclusive groups by preexisting health conditions: 1) U.S. nirsevimab eligible criteria, 2) other identified RSV risk conditions (with some evidence of increased risk for severe RSV), 3) other preexisting conditions, and 4) no preexisting conditions. Patient demographic characteristics and level of respiratory support received were compared. Results Among 574 children: 47 (8.2%) had U.S. nirsevimab eligibility criteria, 76 (13.2%) had other RSV risk conditions, 96 (16.7%) had other preexisting conditions, and 355 (61.8%) had none. A higher proportion of children with nirsevimab eligibility factors (40.4%) than those with other identified RSV risk conditions (17.1%) required IMV, which was higher than other (10.4%) or no (5.9%) preexisting health conditions (p trend <0.001). Conclusions and Relevance Approximately 20% of children admitted to the PICU with severe RSV were in the defined groups that met U.S. nirsevimab-eligibility criteria or that had an identified RSV risk condition associated with known risk for severe RSV. A considerable proportion of both groups of children required IMV for respiratory support. These findings may help inform future deliberations regarding U.S. second season nirsevimab-eligibility recommendations. Key Points Question What preexisting health conditions are present in children aged 8–<24 months admitted to the pediatric intensive care unit for severe RSV disease in their second RSV season and how do clinical outcomes differ? Findings Among 574 children, 8% were eligible for nirsevimab in the U.S. and 13% had other preexisting conditions with known risk for severe RSV. Children with preexisting conditions, particularly those eligible for nirsevimab, were more likely to require invasive mechanical ventilation than those without. Meaning These findings may inform future deliberations regarding which children in their second RSV season might benefit from RSV preventive products.

Abstract Infectious diseases (ID) research is vital for global public health, typically led by physician-scientists. This Perspective addresses challenges in the ID workforce and suggests solutions. Physician-scientists have made key discoveries that have significantly impacted human health. The importance of ID research in understanding diseases, leading to treatments and vaccines, is emphasized, along with the need to address persistent and new infections, antimicrobial resistance, and threats like HIV and influenza. The paper analyzes the physician-scientist workforce's struggles, including funding, training, and research-practice integration gaps. We suggest increased funding, better training, and mentorship, more collaborative and interdisciplinary research, and improved recognition systems. The article stresses the urgency of supporting physician-scientists in ID, advocating for proactive prevention and preparedness, and calls for immediate action to enhance ID research and care.

ImportanceRespiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections (LRTIs) and infant hospitalization worldwide.ObjectiveTo evaluate the characteristics and outcomes of RSV-related critical illness in US infants during peak 2022 RSV transmission.Design, Setting, and ParticipantsThis cross-sectional study used a public health prospective surveillance registry in 39 pediatric hospitals across 27 US states. Participants were infants admitted for 24 or more hours between October 17 and December 16, 2022, to a unit providing intensive care due to laboratory-confirmed RSV infection.ExposureRespiratory syncytial virus.Main Outcomes and MeasuresData were captured on demographics, clinical characteristics, signs and symptoms, laboratory values, severity measures, and clinical outcomes, including receipt of noninvasive respiratory support, invasive mechanical ventilation, vasopressors or extracorporeal membrane oxygenation, and death. Mixed-effects multivariable log-binomial regression models were used to assess associations between intubation status and demographic factors, gestational age, and underlying conditions, including hospital as a random effect to account for between-site heterogeneity.ResultsThe first 15 to 20 consecutive eligible infants from each site were included for a target sample size of 600. Among the 600 infants, the median (IQR) age was 2.6 (1.4-6.0) months; 361 (60.2%) were male, 169 (28.9%) were born prematurely, and 487 (81.2%) had no underlying medical conditions. Primary reasons for admission included LRTI (594 infants [99.0%]) and apnea or bradycardia (77 infants [12.8%]). Overall, 143 infants (23.8%) received invasive mechanical ventilation (median [IQR], 6.0 [4.0-10.0] days). The highest level of respiratory support for nonintubated infants was high-flow nasal cannula (243 infants [40.5%]), followed by bilevel positive airway pressure (150 infants [25.0%]) and continuous positive airway pressure (52 infants [8.7%]). Infants younger than 3 months, those born prematurely (gestational age &amp;lt;37 weeks), or those publicly insured were at higher risk for intubation. Four infants (0.7%) received extracorporeal membrane oxygenation, and 2 died. The median (IQR) length of hospitalization for survivors was 5 (4-10) days.Conclusions and RelevanceIn this cross-sectional study, most US infants who required intensive care for RSV LRTIs were young, healthy, and born at term. These findings highlight the need for RSV preventive interventions targeting all infants to reduce the burden of severe RSV illness.