The molecular diagnosis of parechovirus infection: has the time come?

Human parechoviruses (HPeVs) as a distinct entity are largely unknown to clinicians and often forgotten by diagnostic virologists. In this issue of Clinical Infectious Diseases, Sedmak et al [1] report the association of HPeV with sudden unexplained infant deaths. Over a period of 17 years, the Milwaukee County Medical Examiner’s Office and the City of Milwaukee Health Department Laboratory investigated the role of viruses in deaths of children aged !2 years. Although enteroviruses and adenoviruses were the most commonly identified viruses, HPeV type 1 (HPeV1) was isolated from 18 decedents, HPeV type 3 (HPeV3) from 3, and HPeV type 6 (HPeV6) from 1. These are the first confirmed cases of HPeV3 and HPeV6 infection in the United States, as well as the first fatal cases associated with HPeV3. In 1956, what we now call HPeV1 and HPeV type 2 were first isolated by Wigand and Sabin [2] from the stool samples of 2 children with diarrhea in Ohio, and the isolates were designated echovirus types 22 and 23, within the enterovirus genus of the Picornaviridae. Although HPeVs share many