Antiviral Use Among Children Hospitalized With Laboratory-Confirmed Influenza Illness: A Prospective, Multicenter Surveillance Study.

Background: Guidelines state that all hospitalized children with suspected or confirmed influenza receive prompt treatment with influenza-specific antivirals. We sought to determine the frequency of, and factors associated with, antiviral receipt among hospitalized children.

Methods: We conducted active surveillance of children presenting with fever or respiratory symptoms from 1 December 2016 to 31 March 2020 at 7 pediatric medical centers in the New Vaccine Surveillance Network.

Respiratory Syncytial Virus Disease Burden and Nirsevimab Effectiveness in Young Children From 2023-2024.

Importance: During the 2023-2024 respiratory syncytial virus (RSV) season in the United States, 2 new RSV prevention products were recommended to protect infants in their first RSV season: nirsevimab and Pfizer's maternal RSV vaccine. Postlicensure studies are needed to assess prevention product impact and effectiveness.

Objective: To compare the epidemiology and disease burden of medically attended RSV-associated acute respiratory illness (ARI) among children younger than 5 years during the 2023-2024 RSV season with 3 prepandemic RSV seasons (2017-2020), estimate nirsevimab effectiveness against medically attended RSV-associated ARI, and compare nirsevimab binding site mutations among circulating RSV in infants with and without nirsevimab receipt.

Underutilization of Influenza Antiviral Treatment Among Children and Adolescents at Higher Risk for Influenza-Associated Complications - United States, 2023-2024.

Annually, tens of thousands of U.S. children and adolescents are hospitalized with seasonal influenza virus infection.

On-time childhood vaccination before and during the COVID-19 pandemic in seven communities: Findings from the New Vaccine Surveillance Network.

Background: The COVID-19 pandemic raised unprecedented challenges to vaccinating children. This multi-center study aimed to compare on-time vaccination of children before and during the COVID-19 pandemic and identify key factors associated with on-time vaccination.

Methods: This study was conducted among children aged 0-6 years enrolled in the New Vaccine Surveillance Network at seven geographically diverse U.

Pediatric Clinical Influenza Disease by Type and Subtype 2015-2020: A Multicenter, Prospective Study.

Background: Previous investigations into clinical signs and symptoms associated with influenza types and subtypes have not definitively established differences in the clinical presentation or severity of influenza disease.

Methods: The study population included children 0 through 17 years old enrolled at 8 New Vaccine Surveillance Network sites between 2015 and 2020 who tested positive for influenza virus by molecular testing. Demographic and clinical data were collected for study participants via parent/guardian interview and medical chart review.

Prevalence of SARS-CoV-2 in Children Identified by Preprocedural Testing at 5 US Children's Hospital Systems.

Background: The burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic children was initially presumed to be high, which influenced hospital, school and childcare policies. Before vaccines were widely available, some hospitals implemented universal preprocedural SARS-CoV-2 polymerase chain reaction testing on asymptomatic patients. Understanding SARS-CoV-2 prevalence in asymptomatic children is needed to illuminate the diversity of viral characteristics and inform policies implemented during future pandemics.

Influenza C virus in U.S. children with acute respiratory infection 2016-2019.

Influenza C virus (ICV) is an orthomyxovirus related to influenza A and B, yet due to few commercial assays, epidemiologic studies may underestimate incidence of ICV infection and disease. We describe the epidemiology and characteristics of ICV within the New Vaccine Surveillance Network (NVSN), a Centers for Disease Control and Prevention (CDC)-led network that conducts population-based surveillance for pediatric acute respiratory illness (ARI). Nasal or/combined throat swabs were collected from emergency department (ED) or inpatient ARI cases, or healthy controls, between 12/05/2016-10/31/2019 and tested by molecular assays for ICV and other respiratory viruses.

Varicella-Zoster Virus Pretransplant Vaccination and Posttransplant Infections Among Pediatric Solid Organ Recipients in the Two-Dose Varicella Era: A Single-Center, Multi-Organ Retrospective Study.

Background: Varicella-zoster virus (VZV) pretransplant immunization rates, exposures, and posttransplant disease are poorly characterized among pediatric solid organ transplant (SOT) recipients in the two-dose varicella vaccine era.

Methods: A retrospective analysis of the electronic health records among children <18 years old who received SOT from January 1, 2011 through December 31, 2021, was performed at a single center to assess for missed pretransplant varicella vaccination opportunities, characterize VZV exposures, and describe posttransplant disease.

Results: Among 525 children, 444 were ≥6 months old (m.

Respiratory Syncytial Virus-Associated Hospitalizations in Children <5 Years: 2016-2022.

Background: The coronavirus disease 2019 pandemic disrupted respiratory syncytial virus (RSV) seasonality resulting in early, atypical RSV seasons in 2021 and 2022, with an intense 2022 peak overwhelming many pediatric healthcare facilities.

Methods: We conducted prospective surveillance for acute respiratory illness during 2016-2022 at 7 pediatric hospitals. We interviewed parents, reviewed medical records, and tested respiratory specimens for RSV and other respiratory viruses.

A Bayesian System to Detect and Track Outbreaks of Influenza-Like Illnesses Including Novel Diseases: Algorithm Development and Validation.

Background:  The early identification of outbreaks of both known and novel influenza-like illnesses (ILIs) is an important public health problem.

Objective:  This study aimed to describe the design and testing of a tool that detects and tracks outbreaks of both known and novel ILIs, such as the SARS-CoV-2 worldwide pandemic, accurately and early.

Methods:  This paper describes the ILI Tracker algorithm that first models the daily occurrence of a set of known ILIs in hospital emergency departments in a monitored region using findings extracted from patient care reports using natural language processing.

Accuracy of Influenza ICD-10 Diagnosis Codes in Identifying Influenza Illness in Children.

Importance: Studies of influenza in children commonly rely on coded diagnoses, yet the ability of International Classification of Diseases, Ninth Revision codes to identify influenza in the emergency department (ED) and hospital is highly variable. The accuracy of newer International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes to identify influenza in children is unknown.

Objective: To determine the accuracy of ICD-10 influenza discharge diagnosis codes in the pediatric ED and inpatient settings.

Approach for defining human adenovirus infection and disease for central review adjudication in clinical studies.

Background: Pediatric allogeneic hematopoietic cell transplant (allo-HCT) recipients are at risk for morbidity and mortality from human adenovirus (HAdV). HAdV can be detected in an asymptomatic state, referred to as infection or with signs or symptoms of illness, referred to as disease. Standardized case definitions are needed to distinguish infection from disease and allow for consistent reporting in both observational cohort studies and therapeutic clinical trials.

Presentation, management, and outcomes of norovirus in adult and pediatric solid organ and hematopoietic stem cell transplant recipients: A multicenter, retrospective study.

Background: Norovirus (NoV) can cause chronic relapsing and remitting diarrhea in immunocompromised patients.  Few multicenter studies have described the clinical course, outcomes, and complications of chronic NoV in transplant recipients.

Methods: A multicenter retrospective study of adult and pediatric SOT and HSCT recipients diagnosed with NoV between November 1, 2017, and February 28, 2021.

Interim Estimates of 2023-24 Seasonal Influenza Vaccine Effectiveness - United States.

In the United States, annual influenza vaccination is recommended for all persons aged ≥6 months. Using data from four vaccine effectiveness (VE) networks during the 2023-24 influenza season, interim influenza VE was estimated among patients aged ≥6 months with acute respiratory illness-associated medical encounters using a test-negative case-control study design. Among children and adolescents aged 6 months-17 years, VE against influenza-associated outpatient visits ranged from 59% to 67% and against influenza-associated hospitalization ranged from 52% to 61%.

Pre-Transplantation Strategies for Infectious Disease Mitigation and Prevention.

Pediatric Infectious Disease (ID) clinicians play a critical role in helping prevent and mitigate infectious risks in children peri- and post-transplantation. Prevention starts during the pre-transplant evaluation and persists throughout the solid organ transplant and hematopoietic cell transplant continuum. The pre-transplant evaluation is an opportunity to screen for latent infections, plan preventative strategies, optimize immunizations, and discuss risk mitigation practices.

Respiratory Syncytial Virus-Associated Hospitalizations Among Children <5 Years Old: 2016 to 2020.

Background: Respiratory syncytial virus (RSV) is the leading cause of hospitalization in US infants. Accurate estimates of severe RSV disease inform policy decisions for RSV prevention.

Methods: We conducted prospective surveillance for children <5 years old with acute respiratory illness from 2016 to 2020 at 7 pediatric hospitals.

Maternal Vaccine Effectiveness Against Influenza-Associated Hospitalizations and Emergency Department Visits in Infants.

Importance: Influenza virus infection during pregnancy is associated with severe maternal disease and may be associated with adverse birth outcomes. Inactivated influenza vaccine during pregnancy is safe and effective and can protect young infants, but recent evidence, particularly after the 2009 novel influenza A (H1N1) pandemic, is limited.

Objective: To evaluate the effectiveness of influenza vaccination during pregnancy against laboratory-confirmed influenza-associated hospitalizations and emergency department (ED) visits in infants younger than 6 months.

SARS-CoV-2 Epidemiology and COVID-19 mRNA Vaccine Effectiveness Among Infants and Children Aged 6 Months-4 Years - New Vaccine Surveillance Network, United States, July 2022-September 2023.

SARS-CoV-2 infection in young children is often mild or asymptomatic; however, some children are at risk for severe disease. Data describing the protective effectiveness of COVID-19 mRNA vaccines against COVID-19-associated emergency department (ED) visits and hospitalization in this population are limited. Data from the New Vaccine Surveillance Network, a prospective population-based surveillance system, were used to estimate vaccine effectiveness using a test-negative, case-control design and describe the epidemiology of SARS-CoV-2 in infants and children aged 6 months-4 years during July 1, 2022-September 30, 2023.

Approach to vaccinating the pediatric solid organ transplant candidate and recipient.

Solid organ transplantation (SOT) candidates and recipients are at increased risk for morbidity and mortality from vaccine-preventable infections. Children are at particular risk given that they may not have completed their primary immunization series at time of transplant or have acquired natural immunity to pathogens from community exposures. Multiple society guidelines exist for vaccination of SOT candidate and recipients, although challenges remain given limited safety and efficacy data available for pediatric SOT recipients, particularly for live-vaccines.

Infants Admitted to US Intensive Care Units for RSV Infection During the 2022 Seasonal Peak.

Importance: Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections (LRTIs) and infant hospitalization worldwide.

Objective: To evaluate the characteristics and outcomes of RSV-related critical illness in US infants during peak 2022 RSV transmission.

Design, Setting, And Participants: This cross-sectional study used a public health prospective surveillance registry in 39 pediatric hospitals across 27 US states.