High prevalence of coxsackievirus A2 in children with herpangina in Thailand in 2015

Coxsackievirus (CV) is a member of the genus Enterovirus and the family Picornaviridae. CV infection can cause herpangina, a disease characterized by multiple ulcers on the tonsils and soft palate affecting mostly young children. CV strains are categorized by serotypes. Unfortunately, serotypes responsible for infections in patients are often undetermined. This knowledge gap partly contributes to the ineffective prevention and control of CV-associated herpangina in Southeast Asia. To characterize the viral etiology of children presented with herpangina, 295 throat swabs were tested for human enterovirus infection. Using RT-PCR specific for the viral 5′UTR/VP2 and the VP1 regions, two most frequent CV types found in these samples were CV-A2 (33.33%, 40/120) and CV-A4 (15.8%, 19/120). Phylogenetic analysis of the VP1 gene demonstrated that the CV-A2 strains in this study not only were closely related to those previously identified in Asia and Europe, but the majority clustered into a distinct group. Thus, infection predominantly by CV-A2 and CV-A4 caused herpangina in 2015 in Thailand.