152 - Human Parechovirus infections in newborns. Clinical and neurological manifestations, and short-term outcomes of nine cases presenting at a level four Neonatal Intensive Care Unit (NICU)

Human Parechovirus (HPeV) infections can present with apnea, seizures and characteristic brain magnetic resonance imaging (MRI) findings in newborns. Recently, HPeV has been associated with sudden infant death syndrome. The Center for Diseases Control issued a Health Advisory for the increase in incidence of HPeV in the United States in 2022.

Objective:

Describe the clinical course, laboratorial findings, treatment, initial and follow up brain MRI findings of nine infants positive for HPeV PCR in serum or CSF admitted to a level IV NICU in the spring of 2022 in Dallas, TX.

Design/Methods:

Retrospective case series of nine neonates diagnosed with confirmed HPeV infection from March-May/2022. Baseline characteristics, clinical course, laboratory tests, and treatments were reviewed. MRI images were reviewed by a pediatric neuroradiologist. Basic descriptive statistics were used for quantitative data. Frequencies and percentages listed for categorical data.

Results:

Four infants had serum HPeV PCR positive, and five infants were positive in the CSF. Two infants were HPeV positive in blood, and negative in CSF, but presented with seizures and MRI findings. Temperature instability, fussiness, seizures, and apnea or desaturations were the most common symptoms. Hypotension was present in six of the infants (Table 1). One infant born premature presented at 26 days of life and died after intractable seizures and shock. Initial complete blood count was normal for eight infants. Hypoglycemia was noted in two infants. Inflammatory markers were normal or mildly elevated in all infants. All CSF samples showed normal infectious markers. All infants with seizures had abnormal MRI findings with T1/T2 abnormalities, and extensive restrictive diffusion in the white matter. Cerebral edema was present in four infants, and leptomeningeal enhancement in two infants (Table 2). Two of those patients received intravenous immunoglobulin and required treatment with two antiepileptic drugs (AED). The remaining required three or more AED. The infant that died was on a continuous midazolam infusion. Follow up brain MRIs showed improved or resolved restrictive diffusion signals in five infants, and worsened in one infant. Gliosis and encephalomalacia were present in five infants.

Conclusion(s): HPeV can cause severe neonatal infections encephalitis with seizures, respiratory failure, hypotension, white matter changes and extensive restrictive diffusion in brain MRI, and encephalomalacia in later stages. Further studies are needed to delineate risk factors for severe disease and long term outcomes of affected neonate.