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

Abstract

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.

Keywords: clinical diagnosis; encephalitis; infants; meningitis; parechovirus; sepsis-like illness.

Fig 1

Management aid for considering PeV-A RT-PCR testing. *, some experts would not perform lumbar puncture or test for EV, HSV, or PeV if urinalysis during screening for sepsis suggests possible urinary tract infection, i.e., pyuria, positive nitrite, or leukocyte esterase; $, institutions/laboratories that focus in-house PeV-A testing to selected months, e.g., June through October, or to outbreak years, e.g., biennially matching local circulation patterns, usually have a defined mechanism allowing PeV-A testing requests outside of predefined testing timeframes; #, testing blood when CSF is either PeV-A test negative or not available can increase diagnostic yield by as much as 20%; &, also consider testing during PeV-A season and during outbreak years when an infant displays a classic PeV-A presentation, e.g., fever > 38.6°C, irritability, mottling, and lymphopenia (20).