The Molecular Diagnosis of Parechovirus Infection: Has the Time Come?

Abstract

properties and disease manifestations with enteroviruses, differences were recognized from the beginning. When molecular methods were developed for the diagnosis of enterovirus infection in the 1990s, it became clear that echovirus types 22 and 23 were not detected using pan-enterovirus polymerase chain reaction (PCR) primers [3]. Thus, in 1999, HPeVs were designated as a separate genus of the Picornaviridae family [4]. Since then, the number of HPeV types has increased from 2 to 14, and many more are likely awaiting discovery (http://www .picornastudygroup.com/types/parechovirus/ hpev.htm). HPeVs are difficult to culture, and Vero cells, the optimal cell line, are not commonly used in clinical laboratories in the United States. Thus, HPeV infections have long been underdiagnosed. Ironically, as more sensitive methods have been developed to detect HPeV in research studies, diagnosis in clinical laboratories in the United States has decreased because of the change from conventional cell cultures to enterovirus molecular amplification tests. In short, diagnosis of HPeV infection has gone from bad to worse. Few clinical laboratories and perhaps only 1 commercial laboratory in the United States offer Parechovirus PCR. Typing of HPeV-positive isolates is confined to research laboratories. Therefore, it is not surprising that HPeV3 and HPeV6 infections have not previously been reported in the United States.