Diagnosis, management, and outcomes of parechovirus infections in infants: an overview.

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.

Multi-center clinical evaluation of the Panther Fusion SARS-CoV-2/Flu A/B/RSV assay in nasopharyngeal swab specimens from symptomatic individuals.

The symptomology is overlapping for respiratory infections due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), influenza A/B viruses, and respiratory syncytial virus (RSV). Accurate detection is essential for proper medical management decisions. This study evaluated the clinical performance of the Panther Fusion SARS-CoV-2/Flu A/B/RSV assay in nasopharyngeal swab (NPS) specimens from individuals of all ages with signs and symptoms of respiratory infection consistent with COVID-19, influenza, or RSV. Retrospective known-positive and prospectively obtained residual NPS specimens were collected during two respiratory seasons in the USA. Clinical performance was established by comparing Panther Fusion SARS-CoV-2/Flu assay results to a three-molecular assay composite comparator interpretation for SARS-CoV-2 and to the FDA-cleared Panther Fusion Flu A/B/RSV assay results for all non-SARS-CoV-2 targets. A total of 1,900 prospective and 95 retrospective NPS specimens were included in the analyses. The overall prevalence in prospectively obtained specimens was 20.7% for SARS-CoV-2, 6.7% for influenza A, and 0.7% for RSV; all influenza B-positive specimens were retrospective specimens. The positive percent agreement of the Panther Fusion assay was 96.9% (378/390) for SARS-CoV-2, 98.0% (121/123) for influenza A virus, 95.2% (20/21) for influenza B virus, and 96.6% (57/59) for RSV. The negative percent agreement was ≥98.5% for all target viruses. Specimens with discordant Panther Fusion SARS/Flu/RSV assay results all had cycle threshold values of ≥32.4 (by comparator or by Panther Fusion SARS/Flu/RSV assay). Only five co-infections were detected in the study specimens. The Panther Fusion SARS-CoV-2/Flu/RSV assay provides highly sensitive and specific detection of SARS-CoV-2, influenza A virus, influenza B virus, and RSV in NPS specimens.

A Comparison of Pathogen Detection and Risk Factors among Symptomatic Children with Gastroenteritis Compared with Asymptomatic Children in the Post-rotavirus Vaccine Era.

OBJECTIVE: To describe demographics, pathogen distribution/seasonality, and risk factors in children seeking care for acute gastroenteritis (AGE) at a midwestern US emergency department during 5 postrotavirus vaccine years (2011-2016), and further, to compare the same data with matched healthy controls (HC). STUDY DESIGN: AGE and HC participants <11 years old enrolled in the New Vaccine Surveillance Network study between December 2011 to June 2016 were included. AGE was defined as ≥3 diarrhea episodes or ≥1 vomiting episode. Each HC's age was similar to an AGE participant's age. Pathogens were analyzed for seasonality effects. Participant risk factors for AGE illness and pathogen detections were compared between HC and a matched subset of AGE cases. RESULTS: One or more organisms was detected in 1159 of 2503 children (46.3%) with AGE compared with 99 of 537 HC (17.3%). Norovirus was detected most frequently among AGE (n = 568 [22.7%]) and second-most frequently in HC (n = 39 [6.8%]). Rotavirus was the second most frequently detected pathogen among AGE (n = 196 [7.8%]). Children with AGE were significantly more likely to have reported a sick contact compared with HC, both outside the home (15.6% vs 1.4%; P < .001) and inside the home (18.6% vs 2.1%; P < .001). Daycare attendance was higher among children with AGE (41.4%) compared with HC (29.5%; P < .001). The Clostridium difficile detection rate was slightly higher among HC (7.0%) than AGE (5.3%). CONCLUSIONS: Norovirus was the most prevalent pathogen among children with AGE. Norovirus was detected in some HC, suggesting potential asymptomatic shedding among HC. The proportion of AGE participants with a sick contact was approximately 10 times greater than that of HC.

Prevalence and clinical presentation of EV-D68 infections in Kansas City children during the 2022 season.

Seasonal EV-D68 infections can strain medical care resources due to increased pediatric hospitalizations for respiratory illness. In this study, we examine Kansas City's 2022 EV-D68 season. Rhinovirus/enterovirus (RV/EV) positive respiratory specimens from standard of care testing were salvaged and tested by EV-D68 specific PCR. Of the 1412 respiratory specimens tested from July 1 to September 15, 2022, 346 (23%) were positive for RV/EV and EV-D68 was detected in 134/319 (42%) salvaged RV/EV positive specimens. The median age of children with EV-D68 infections was 35.2 months (IQR 16.1, 67.3), which was older than children with non-EV-D68 RV/EV infections (16 months, IQR 5, 47.8), but younger than children infected during the 2014 EV-D68 outbreak. EV-D68 infection was more likely to cause severe disease in children with asthma compared to those without asthma. Real-time EV-D68 monitoring for outbreaks could potentially improve resource utilization by hospitals and help prepare for surges of respiratory disease.

Disruption of seasonal enterovirus and parechovirus detections in the CSF and plasma of children during the COVID-19 pandemic.

BACKGROUND: Enteroviruses (EV) and parechovirus (PeV) are a common cause of CNS infection in children. Both viruses demonstrate consistent seasonal patterns, with detections mainly in the summer-fall months. While research has shown COVID-19 pandemic-related disruption of traditional seasonality of respiratory pathogens, the pandemic's impact on non-respiratory pathogens is less understood. The aim of this study was to quantify the EV/PeV seasonal variations during pre-COVID years compared to variations observed during the COVID pandemic. METHODS: Patients with EV/PeV testing of CSF/plasma between January 2012 through September 2022 were identified. Restricted cubic spline methods were used to model the detections. Poisson models were utilized to model pre-COVID (2012-2019) EV/PeV detections. The expected seasonal trends from these models were then compared to the observed EV/PeV detections during the COVID pandemic (2020-2022). RESULTS: A total of 5199 patients were included. The annual pre-pandemic proportion of EV detections ranged between 7.5%-20.3%. PeV exhibited a biennial pattern with peak proportions between 8.0%-16.3%. EV/PeV detections during the COVID pandemic period, especially during 2020 and 2021, were considerably lower than would have been expected based on pre-pandemic modeling. However, PeV detections from January through September 2022 nearly reached the pre-pandemic modeled expectation, including instances of exceeded expectations. CONCLUSIONS: A significant disruption in expected seasonal EV/PeV detections was observed during the early phases of the COVID-19 pandemic. However, testing that occurred during summer-fall of 2022, when social mitigation initiatives were relaxed, showed a rapid increase in detections. Additional data are needed to further understand which public health initiatives are effective at decreasing EV/PeV transmission.

Comparison of diagnostic performance of five molecular assays for detection of SARS-CoV-2.

We compared the performance of the Abbott Real Time SARS-CoV-2 assay (Abbott assay), Aptima™ SARS-CoV-2 assay (Aptima assay), BGI Real-Time SARS-CoV-2 assay (BGI assay), Lyra® SARS-CoV-2 assay (Lyra assay), and DiaSorin Simplexa™ COVID assay for SARS-CoV-2 detection. Residual nasopharyngeal samples (n = 201) submitted for routine SARS-CoV-2 testing by Simplexa assay during June-July 2020 and January 2021 were salvaged. Aliquots were tested on other assays and compared against the CDC 2019-nCoV Real-Time RT-PCR assay. Viral load in positive samples was determined by droplet digital PCR. Among 201 samples, 99 were positive and 102 were negative by the CDC assay. The Aptima and Abbott assays exhibited the highest positive percent agreement (PPA) at 98.9% while the BGI assay demonstrated the lowest PPA of 89.9% with 10 missed detections. Negative percent agreement for all 5 platforms was comparable, ranging from 96.1% to 100%. The performance of all five assays was comparable.

Diagnostic Yield of Saliva for SARS-CoV-2 Molecular Testing in Children.

Pediatric saliva specimen demonstrated high sensitivity (93%) and specificity (96.2%) compared to paired nasopharyngeal swabs (NPS) by Aptima SARS-CoV-2 Assay (Aptima). Viral loads were comparable in both specimen types. Saliva is a safe, noninvasive, and acceptable alternative specimen for SARS-CoV-2 detection in children.

Emergence of Parechovirus A3 as the Leading Cause of Central Nervous System Infection, Surpassing Any Single Enterovirus Type, in Children in Kansas City, Missouri, USA, from 2007 to 2016.

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. The overall prevalence for EV was 16% (862/5,362) and 7% (271/4,016) for PeV. Among all picornavirus CSF detections, EV was 76%, and PeV-A was 24%. Multiple EV types cocirculated each year, with a total of 31 EV types detected in the 10-year period; the majority belonged to EV-B species (96%). Two PeV-A types were detected; PeV-A3 was the dominant PeV-A type (95%). The top five picornaviruses (PeV-A3, 26%; E30, 11%; E6, 10%; E18, 9%; E9, 7%) in the CSF of infants accounted for two-thirds of all detections, and PeV-A3 was the leading picornavirus detected. Routine testing and reporting of PeV-A in addition to EV, especially in children under 6 months old with acute febrile illnesses, could reduce hospital stays and antibiotic usage.

Positive Impact of Routine Testing for Enterovirus and Parechovirus on Length of Hospitalization and Antimicrobial Use among Inpatients ≤6 Months of Age.

Enterovirus (EV) and parechovirus (PeV) are leading viral causes of central nervous system (CNS) infection among hospitalized neonates and young infants, yet testing for PeV is not routinely performed. The goal of our study was to determine how EV and PeV CSF RT-PCR testing impacted the duration of antibiotic use and the length of hospitalization (LOS) in children ≤6 months old with suspected CNS infection. This retrospective cohort study at Children's Mercy Kansas City evaluated data from patients ≤6 months old for whom routine CSF EV and PeV reverse transcription-PCR (RT-PCR) testing was performed during January 2011 to December 2018. Electronic data were abstracted from the electronic medical record, including demographics, systemic antimicrobial use, imaging data, herpes simplex virus (HSV) testing, and overall hospital charges. Among 1,926 patients, 345 (17.9%) were RT-PCR positive for EV and 172 (8.9%) were positive for PeV. A significantly shorter LOS was observed for patients with EV (51.6 h; P < 0.001) and PeV (66.3 h; P = 0.048) compared to patients that tested negative for both viruses (74.1 h). Discontinuation of empirical antibiotic therapy following test result availability occurred more frequently for PeV patients (57.8%; P = 0.03) and EV patients (65.4%; P < 0.001) than RT-PCR-negative patients (48.5%). Routine EV/PeV RT-PCR testing of cerebrospinal fluid (CSF) samples in children impacted care of hospitalized neonates and young infants. Rapid and prompt diagnosis has the potential to reduce antibiotic usage, length of stay, and patient charges.

Host Immune Response to Enterovirus and Parechovirus Systemic Infections in Children.

BACKGROUND: Enterovirus (EV) and parechovirus type A3 (PeV-A3) cause infections ranging from asymptomatic to life-threatening. Host immune responses in children, particularly innate responses to PeV-A3, remain largely unknown. The aim of this study was to determine aspects of the cytokine/chemokine responses to EV and PeV-A3 in cerebrospinal fluid (CSF) and plasma obtained from children with systemic/central nervous system infection. METHODS: A total of 74 salvaged CSF samples (27 with EV, 23 with PeV-A3, and 24 with neither EV nor PeV-A3) and 35 paired blood samples (10 with EV, 14 with PeV-A3, and 11 with neither) were studied. Concentrations of cytokines and chemokines were measured using a customized 21-plex MILLIPLEX MAP Human Cytokine/Chemokine Magnetic Bead Panel. Additionally, clinical characteristics data for all the patients were collected from electronic medical records to evaluate the potential association between the immune response and presentations. RESULTS: We demonstrate that EV and PeV-A3 infections induce different cytokine/chemokine immune responses in children. EV induces more robust responses in CSF with significantly elevated levels of fractalkine, interferon (IFN)-α2, IFN-γ, interleukin (IL)-1Rα, IL-4, IL-8, and tumor necrosis factor α; PeV-A3 induces less robust or absent responses in CSF but robust responses in plasma, with significantly higher concentrations of IFN-α2, IL-15, IL-1Rα, interferon-γ-inducible protein-10, and monocyte chemoattractant protein-1. CONCLUSIONS: High cytokine/chemokine concentrations in the plasma of PeV-A3 patients compared with EV patients could explain higher/more prolonged fever in PeV-A3 patients, whereas relatively low cytokine/chemokine concentrations in PeV-A3 CSF might explain the absence of CSF pleocytosis.