Not All Is Quiet in the CSF: Human Parechovirus Causing Neonatal Meningoencephalitis

Introduction: Human Parechovirus (HPeV) is a common virus but may cause meningoencephalitis with important characteristic features in neonates. Evidence is emerging to support early treatment with IVIg for patients with severe HPeV infections. We present a newborn with seizures resulting from HPeV meningoencephalitis successfully treated with IVIg.


Description: A term 10-day-old female presented with irritability and seizures requiring sepsis/meningitis evaluation and treatment. She had a normal white cell count with lymphocytic predominance and normal inflammatory markers. CSF analysis showed no pleocytosis, with normal protein, red cell count, and glucose. No organisms were identified on gram stain or cultures.
She had an elevated NT pro-BNP and troponin, though normal function on echo, concerning for subclinical myocarditis. Head ultrasound was normal. MRI brain revealed diffuse symmetric diffusion restriction throughout the supratentorial deep and subcortical white matter, characteristic of HPeV meningoencephalitis. CSF polymerase chain reaction (PCR) was positive for HPeV. She was treated with IVIg with prompt recovery.


Discussion: In the case of our 10-day-old presenting with focal seizures and shock, the diagnosis was made early in her clinical course by way of her positive meningoencephalitis PCR panel. HPeV infection should be a key consideration in neonates presenting with encephalopathy, seizures, or sepsis-like illness, particularly in the first months of life. Physicians should maintain a high index of suspicion for HPeV meningoencephalitis, especially in cases with normal CSF studies, no CSF pleocytosis. Our case highlights the utility of early PCR evaluation of the CSF in symptomatic neonates, which might otherwise be delayed, in order to facilitate early treatment. While supportive care remains central, early treatment with IVIg and consideration of high dose steroids may provide significant benefit. Additionally, close seizure monitoring and early cardiac evaluation is crucial. Ultimately, long-term neurodevelopmental follow-up is essential to identify and address subtle deficits that may not be evident during infancy.