Encephalitis Related to Human Parechovirus Type 3

Abstract

Human parechoviruses belong to the Picornaviridae family and are classified into 17 genotypes. Recently, it has been reported that human parechovirus genotype 3 is an important cause of severe infections, including sepsis-like illness and encephalitis, especially in newborns and infants younger than 3 months. There are also reports that human parechovirus genotype 3 infections with central nervous system symptoms lead to high rates of neurological sequelae and death. Here, we report a case of a previously healthy 1-month-old girl who developed encephalitis related to human parechovirus genotype 3 and had a favorable outcome. The patient presented septicemic symptoms, including fever, tachycardia, tachypnea with retractions and seizures without an elevated inflammatory response. She lacked cerebrospinal fluid pleocytosis but had hypercytokinemia. Brain magnetic resonance imaging and electroencephalography showed abnormal findings. Together, these findings strongly suggested acute encephalopathy. She underwent emergency intubation for respiratory failure and mechanical ventilation was started. Intravenous phenobarbital injection was performed to prevent convulsion. She was treated using intravenous immunoglobulin with methylprednisolone pulse therapy. As of 2 years after discharge, her growth development is equivalent to her age and she has had no clinical epileptic seizures. In this case, human parechovirus genotype 3 was detected from pharyngeal swabs, stool, cerebrospinal fluid and blood by polymerase chain reaction assay. The patient was diagnosed definitively with encephalitis related to human parechovirus genotype 3. The symptoms that we observed should be considered for the differential diagnosis of human parechovirus infection. When a patient is suspected of having encephalitis related to human parechovirus, treatment including intravenous immunoglobulin and corticosteroid must be started as soon as possible to prevent neurodevelopmental sequelae. Int J Clin Pediatr. 2019;8(2):37-40 doi: https://doi.org/10.14740/ijcp333