Clinical Spectrum and Epidemiology of Human Parechovirus Infections in Infants: A Retrospective Study in the Western Part of Sweden.

Background: Human parechovirus (HPeV) infections can cause sepsis and meningoencephalitis in infants. To improve our knowledge of the consequences of HPeV infections in young children, the incidence, clinical spectrum, and short-term outcome among infants infected with HPeV were investigated retrospectively. Methods: The presence of HPeV RNA was investigated by polymerase chain reaction in cerebrospinal fluid from 327 children aged 0 to 12 months sampled between 2014 and 2017. Eighty-one were infected with HPeV and included in the study. These infants were divided into 3 groups based on clinical assessment: HPeV was the presumed cause of disease (n = 35); HPeV could have contributed to or been considered the cause of disease (n = 24); and HPeV was not considered the cause of disease (n = 22). Results: Infection with HPeV type 3 was common in all groups (n = 54), and most children were younger than 3 months (n = 63). The children in the first group (HPeV as presumed cause) had meningoencephalitis (n = 20), viral sepsis (n = 9), or non-severe viral infection (n = 6). The youngest were more prone to develop meningoencephalitis, while the slightly older children had symptoms of viral sepsis or nonsevere viral infection ( Conclusions: HPeV infections were identified in 25% of children with suspected central nervous system infection. The clinical presentation of those infected with HPeV varied with age. HPeV infections may be associated with sudden infant death syndrome, although this is not well studied. The results suggest that HPeV infections may be underdiagnosed in young infants.