Detection of enterovirus 68 as one of the commonest types of enterovirus found in patients with acute respiratory tract infection in China

Human enterovirus 68 (HEV-68) is an enterovirus associated with respiratory illness. In China, no information about HEV-68 is available for children yet. This study aimed to investigate the presence of HEV-68 in mainland China between 2009 and 2012 and to explore the migration events of HEV-68 across the world. Among 1565 samples tested from children, 41 (2.6%) were positive for HEV and 223 (14.3%) for human rhinovirus (HRV). Seven (17.1%) of 41 HEVs were HEV-68. Two HEV-68- and five HRV-positive samples were detected in 585 adult samples. HEV-68 is the predominant type of enterovirus in children with acute respiratory tract infection (ARTI), followed by HEV-71 and coxsackievirus A6. Three HEV-68-infected children presented with severe pneumonia and one presented with a severe asthma attack. The viruses were attributed to two novel distinct sublineages of HEV-68 based on phylogenetic analysis of partial VP1 gene sequences. Migration events analysis showed that the USA and the Netherlands were possible geographical sources of HEV-68, from where three strains migrated to China. In conclusion, HEV-68 may play a predominant role among the enteroviruses associated with ARTI in children. Additional surveillance is needed to clarify the reason why HEV-68 causes such a wide spectrum of disease, from asymptomatic to severe respiratory disease and even death.