Clinical Characteristics of Enterovirus A71 Neurologic Disease During an Outbreak in Children in Colorado, 2018

Background: In May 2018, Children's Hospital Colorado (CHCO) noted an outbreak of enterovirus (EV) A71-associated neurologic disease. Methods: A case of EV-associated neurologic disease was defined as any child presenting to CHCO with meningitis, encephalitis, acute flaccid myelitis (AFM), and/or seizures between March 1 and November 30, 2018 with an EV detected from a biologic specimen. EV-A71 cases were compared to other EV cases during the same period. EV-A71-associated AFM cases were also compared to EV-D68-associated AFM cases from 2013-2018. Findings: Of seventy-four children with EV-associated neurologic disease, forty-three (58%) were EV-A71-associated. Median age of EV-A71 cases was 22.7 months (IQR: 4-31.9 months); 34 (79%) were male. Neurologic involvement in EV-A71 cases included meningitis (93%), encephalitis (72%), and AFM (23%). All EV-A71 cases had fever; eighteen (42%) had hand, foot, or mouth (HFM) lesions. Neurologic findings distinguishing EV-A71-associated cases from other EV-associated cases (n=31) included myoclonus (60% vs. 16%, p