Clinical course and peculiarities of Parechovirus and Enterovirus central nervous system infections in newborns

Purpose Parechoviruses (HpEV) and Enteroviruses (EV) infections in children mostly have a mild course but are particularly fearsome in newborns in whom they may cause aseptic meningitis, encephalitis, and myocarditis. Our study aimed to describe the clinical presentations and peculiarities of CNS infection by HpEV and EV in neonates. Methods Single-center retrospective study at Istituto Gaslini, Genoa, Italy. Infants aged ≤30 days with a CSF RTq-PCR positive for EV or HpEV from January 1, 2022, to December 1, 2023, were enrolled. Each patient's record included demographic data, blood and CSF tests, brain MRI, therapies, length of stay, ICU admission, complications, and mortality. The two groups were compared to identify any differences and similarities. Results Twenty-five patients (15 EV and 10 HpEV) with a median age of 15 days were included. EV patients had more comorbidities ( p=0.021), more respiratory symptoms ( p=0.012 ), and higher C-reactive protein (CRP) levels on admission ( p=0.027 ), whereas ferritin values were significantly increased in HpEV patients ( p=0.001 ). Eight patients had a pathological brain MRI, equally distributed between the two groups. Three EV patients developed myocarditis and one HpEV necrotizing enterocolitis with HLH-like. No deaths occurred. Conclusions EV and HpEV CNS infections are not easily distinguishable by clinical features. In both cases, brain MRI abnormalities are not uncommon and a severe course of the disease is possible. Hyper-ferritinemia may represent an additional diagnostic clue for HpEV infection and its monitoring is recommended to intercept HLH early and initiate immunomodulatory treatment. Larger studies are needed to confirm our findings.