Commentary to "A Case of Recombinant Coxsackievirus A2 Infection with Neurological Complications in Taiwan"

Enteroviruses (EVs) are the predominant pathogens of most childhood illnesses. There are more than one hundred serotypes of EVs belonging to the genus Enterovirus, family Picornaviridae 1 . These viruses were originally classified as polioviruses, coxsackievirus A (CV-As), coxsackievirus B, and echoviruses based on differences in cell tropism, infectivity, antigenicity, and pathogenicity 2 . More recently, these viruses have been re-classified into four species (EV-A, EV-B, EV-C, and EV-D) based on their molecular and biological properties 3,4 . The positive-stranded RNA genome of EVs has approximately 7,500 base pairs, and includes three genomic regions (P1, P2, and P3). The P1 region encodes four structural capsid proteins (VP1 to VP4), while the P2 and P3 regions encode seven nonstructural proteins (2A to 2C, and 3A to 3D). The VP1 capsid protein contains a number of neutralization antigenic sites which are used in virus serotyping 5 . Enterovirus EV-A71 has been reported to cause serious complications of the central nervous system, including encephalitis, meningitis, and poliomyelitis, and there have been several large outbreaks of EV-A71 worldwide in recent decades 6-8 . However, there are limited data on co-circulating non-EV-A71 EV-A strains, which are known to cause outbreaks 9,10 .