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

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.