Introduction Recently two new serotypes of human parechovirus (HPeV; a picornavirus) have been identified as the cause of sepsis and meningitis in neonates and young infants.

Objective To establish the incidence, symptoms and clinical course of HPeV infections among young infants in the Juliana Childrens Hospital (The Hague, The Netherlands) in 2006.

Methods Retrospective study among infants younger than 3 months in whom blood cultures were obtained because of fever of initially unknown origin and/or sepsis-like symptoms. Symptoms, laboratory data, clinical course and treatment of infants with a HPeV infection were established.

Results Blood cultures were obtained in 324 infants. Bacterial infections were found in 133 infants (41%), viral infections in 71 (22%). In 122 infants (38%) no infection was identified. In 70 of these, however, no viral diagnostic studies were performed. In 18 infants (5.6%) HPeV was identified (positive PCR) in cerebrospinal fluid or blood. Most of these infections occurred in late summer. All infants with HPeV infections were admitted (mean duration 4.7 days). Symptoms, laboratory data and therapeutic measures are presented in the table.

Conclusion Among young infants with fever of unknown origin and/or sepsis-like symptoms HPeV was identified in 5.6%. As viral studies were not performed in 70 infants (21.6%) the incidence of HPeV infections among these infants might be higher.