Human enterovirus A71 (EV-A71) isolated from acute flaccid paralysis patients without symptoms of hand foot and mouth disease

Abstract

Background: Human enterovirus A-71 (EV-A71) is one of the causative agents for hand, foot, and mouth disease (HFMD). It is also reported to cause acute flaccid paralysis (AFP) during HFMD outbreaks and very rare to isolate them from non-HFMD cases. Materials and Methods: A total of 2809 stool samples from AFP cases were cultured on RD and L20B cells. Positive on L20B was screened for poliovirus and those only positive on RD were subjected to non-polio EV (NPEV) screening by real-time polymerase chain reaction. Phylogenetic analysis using VP1 and VP4 gene was constructed. Results: A total of 74 EVs were isolated, 61 were NPEV and 13 were poliovirus Sabin like. The NPEVs were identified as coxsackieviruses, echoviruses, and EV-A71. Phylogenetic analysis showed that this EV-A71 belong to subgenogroup B5. Conclusions: The discovery of EV-A71 which caused AFP in patients but not related or associated with HFMD outbreaks showed that this virus could circulate independently. It should be investigated thoroughly as their ability to cause paralysis on the eradication of polio.