[Severe human parechovirus-3 sepsis in a 6-week-old infant].

Febrile infants under 3 months of age are often treated with broad-spectrum intravenous antibiotics while awaiting culture results, to prevent mother-to-child bacterial infections. Human parechoviruses (HPeV) have recently been described as etiologic agents of meningitis and severe sepsis in neonates and young infants. They are rarely investigated and are therefore probably underestimated. They cause acute clinical symptoms that can incorrectly suggest a bacterial infection. In the present case, a 6-week-old infant infected with HPeV developed severe sepsis, complicated by hepatic cytolysis, meningitis, acute renal failure, and mild hemophagocytic lymphohistiocytosis. HPeV type 3 was found by routine specific RT-PCR in cerebrospinal fluid, stools, and plasma. The outcome was spontaneously favorable after 4 days. Early diagnosis of the HPeV infection by routine specific RT-PCR reduces unnecessary antibiotic use and extended hospitalization in febrile young infants.