Picornaviruses, including Enterovirus species A to D (EV) and Parechovirus species A (PeV-A), are the leading reported causes of pediatric central nervous system infections in the United States. We investigated the molecular epidemiology of EV and PeV-A over 10 years in cerebrospinal fluid (CSF) collected from children seen at Children’s Mercy-Kansas City (CMKC) from 2007 through 2016.

Parechovirus A (PeV-A) infections have been detected with increasing frequency in US infants under 6 months of age, leading to a Centers for Disease Control and Prevention (CDC) health advisory in July 2022. Clinicians are advised to consider PeV-A laboratory testing of blood and cerebrospinal fluid when infants present with unexplained fever, sepsis-like illness, or neurological issues. Clinical laboratories are encouraged to offer in-house molecular testing for PeV-A to avoid diagnostic delays, unnecessary use of antibiotics, and prolonged hospitalization of infants presenting with sepsis-like illness. While data are evolving on potential neurodevelopmental sequelae after PeV-A infant central nervous system infections, most infected infants return to baseline health for age. This review examines the PeV-A literature with a focus on PeV-A3, including aspects of epidemiology, clinical presentations/management, laboratory diagnostics, genotyping, and post-infectious sequelae related to PeV-A infections in infants.

Background/Objectives: Respiratory viruses circulate year‐round and can spread indoors via inhalation of airborne particles. Effective ventilation and filtration may reduce transmission, particularly in school settings where children and staff spend significant time. This study examines the impact of indoor air quality (IAQ) and ventilation in schools on respiratory virus detection. Methods: During February 27 to March 30, 2023, we assessed the relationship between IAQ and respiratory viruses in two Kansas City, Missouri, elementary schools by collecting bioaerosol samples, student and staff nasal swabs, and monitoring IAQ across 10 rooms (six classrooms, two common spaces, and two nurses’ offices). We calculated air changes per hour (ACH) and analyzed viral detections in nasal swabs and bioaerosol samples by high (≥ 1000 ppm) or low (< 1000 ppm) CO ₂ concentration in classrooms. Results: We collected 173 nasal swabs from 100 participants and 30 bioaerosol samples from 10 rooms. Participants were mostly female (68%) and white (60%). Viruses were detected in 90% of bioaerosol and 35% of nasal samples. Four classrooms and both common spaces had the same virus detected in bioaerosol and nasal swab samples. None of the spaces met the CDC recommended ACH of 5, and only one exceeded ANSI/ASHRAE 62.1‐2022 standards for outdoor air supply. During school hours, 83% of classrooms had high average CO ₂ concentrations. Classrooms with high CO ₂ levels had higher viral detection. Conclusions: Viral presence was found in bioaerosol and nasal samples with some overlap in concurrently collected samples. Findings suggest a possible connection between high CO ₂ levels and virus detection. Improving IAQ and ventilation may reduce respiratory infection risks in schools. However, this study highlights the need to further assess the impact of various environmental modifications on respiratory virus transmission in schools, including determining optimal strategies such as ventilation, filtration, or germicidal ultraviolet energy.

The COVID-19 pandemic highlighted the need for better data to understand how ventilation may impact respiratory virus transmission. We evaluated if there was an association between respiratory viruses detected in school room air samples and nasal swabs from students/ staff in the same room. We performed air and respiratory sampling to detect respiratory viruses at 3 time points between Feb 27 - Mar 28, 2023 in 2 elementary schools. Three classrooms, a multipurpose room, and school nurse’s office in each school had 1 air sample/ room collected using Thermo Scientific AerosolSense™ sampler during 8 school hours. Concomitant respiratory viral testing, using self-collected nasal swabs, was performed in students/ staff enrolled in a respiratory virus surveillance school testing program. Air and respiratory specimens were tested for adenovirus (AdV); coronaviruses (CoV) 229E, HKU1, NL63, OC43; human metapneumovirus (hMPV), influenza A and B (Flu), parainfluenza virus 1-4 (PIV), respiratory syncytial virus (RSV), rhinovirus/ enterovirus (RV/EV), and SARS-CoV-2 using the Hologic® Panther Fusion® Respiratory Assay. Detected respiratory viruses in room air and respiratory samples were compared to determine likelihood of capturing current human respiratory viral infections in room air and additional viruses circulating from unsampled students/ staff in the same room. RV and AdV in human respiratory samples were typed by partial genomic sequencing to understand if viruses were similar. Concomitant respiratory virus detection from student and staff nasal swabs and air samplers (N=student/staff tested per room) Concomitant respiratory virus surveillance in air samples and students/ staff can be performed to better understand the role of ventilation and respiratory virus transmission. Additional studies, including sequencing data and symptom assessment, are needed. Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, FAAM, Abbott: Honoraria|Altona Diagnostics: Grant/Research Support|Baebies Inc: Advisor/Consultant|BioMerieux: Advisor/Consultant|BioMerieux: Grant/Research Support|Bio-Rad: Grant/Research Support|Cepheid: Grant/Research Support|GSK: Advisor/Consultant|Hologic: Grant/Research Support|Lab Simply: Advisor/Consultant|Luminex: Grant/Research Support

We report the complete genome sequences of four parechovirus-A3 (PeV-A3) isolates from Children’s Mercy Kansas City (CMKC), United States of America (USA): PeV-A3-MO-12-CMKC/CSF/MO/USA/2012 (isolated in 2012 from cerebrospinal fluid), PeV-A3-8C-CMKC/CSF/MO/USA/2022/ (isolated in 2022 from cerebrospinal fluid), PeV-A3-9C-CMKC/CSF/MO/USA/2022 (isolated in 2022 from cerebrospinal fluid), and PeV-A3-11B-CMKC/Blood/MO/USA/2022 (isolated in 2022 from blood). Sequence analysis revealed multiple mutations throughout the genome of the PeV-A3 isolates in comparison to the prototypic PeV-A3 A308/99 reference sequence (AB084913). Several unique amino acid changes were observed in the PeV-A3 isolates from 2022 that were absent in the PeV-A3 isolate from 2012. Phylogenetic analysis comparison determined that the sequenced PeV-A3 isolates from 2022 cluster together as a separate clade.

Between January 2023 and March 2023, self-collected nasal swabs in UTM from children and staff with ARI symptoms were collected as part of an ongoing school-based surveillance study in a large Missouri school district. Samples were tested on the QIAstat-Dx Respiratory SARS-CoV-2 Panel and the fully automated Hologic Panther Fusion system, which can detect a total of 21 respiratory viruses. Percent Agreement analysis was performed to compare the performance of each platform. Of 200 samples collected, QIAstat detected viruses in 111 samples (55.5%) and Hologic in 115 samples (57.5%). Both assays showed high overall agreement (90%), with a PPA (Positive percentage agreement) of 89%, an NPA (Negative percentage agreement) of 94%. Parainfluenza (PIV) showed 100% PPA and NPA followed by adenovirus (Adv) (PPA: 100%; NPA: 97.9%) and rhinovirus (RV) (PPA: 92% and NPA: 94%). Human metapneumovirus (hMPV) had the lowest PPA (47%) but a high NPA (99%) (Table 1). The median CT values for QIAstat and Hologic were 28.8 (IQR 23.65 - 32.5) and 29.3 (IQR 24.2 – 34.5), respectively. QIAstat missed 19 detections, including hMPV (9, 53%), coronavirus NL63 (4, 16%), and RV (4, 8%), with a corresponding median Ct of 39.1 (IQR 34.5 – 41.2) on Hologic. Hologic missed 12 detections, with RV being the most common target (9, 17%), and a corresponding median Ct of 32.9 (IQR: 30.3-35.5) on QIAstat. QIAstat and Hologic exhibit comparable performance (overall agreement 90%) for detecting viral respiratory pathogens from self-collected nasal swabs. Viral detections missed by QIAstat assay had low viral loads, while targets missed by Hologic assay had moderate viral load; additional investigation is needed. Our findings suggest that both STA platforms are suitable for diagnosing respiratory viral infections in self-collected nasal swabs in school-setting. Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, FAAM, Abbott: Honoraria|Altona Diagnostics: Grant/Research Support|Baebies Inc: Advisor/Consultant|BioMerieux: Advisor/Consultant|BioMerieux: Grant/Research Support|Bio-Rad: Grant/Research Support|Cepheid: Grant/Research Support|GSK: Advisor/Consultant|Hologic: Grant/Research Support|Lab Simply: Advisor/Consultant|Luminex: Grant/Research Support