Characteristics, epidemiology and clinical importance of human parechoviruses

Human parechoviruses (HPeVs) are single-stranded, positive-sense RNA viruses. Although originally described as echovirus 22 and 23 within human enteroviruses because of their clinical and morphological properties, they have since been shown to be distinct from this and other picornavirus groups in several features of their genome organisation, structure and replication. HPeVs show genetic and antigenic heterogeneity and a number of distinct types are known to circulate widely in human populations throughout the world. HPeV1 causes mostly gastrointestinal and respiratory tract infections. HPeV3 can cause sepsis and meningoencephalitis in neonates and infants younger than 3 months, which could lead to neurological sequelae and death. In young infants, the typical clinical presentation includes fever, severe irritability, and rash, often leading to descriptions of “hot, red, angry babies”. Nowadays, the most sensitive method for detecting HPeV is real-time polymerase chain reaction assays. In the treatment of infections, no specific antiviral therapy has been available so far and the use of monoclonal antibodies is still being evaluated. More research is therefore needed to understand the specific characteristics of this viruses and to develop appropriate treatment strategies