Multiple genotypes of Echovirus 11 circulated in mainland China between 1994 and 2017.

Echovirus 11 (E-11) is one of the most frequently isolated enteroviruses causing meningitis and other diseases such as hand, foot, and mouth disease (HFMD) and acute flaccid paralysis (AFP). Fifty-nine newly determined E-11 VP1 sequences from the China AFP and HFMD surveillance network and 500 E-11 VP1 sequences obtained from the GenBank database, which were associated with 12 categories of diseases, were screened for phylogenetic analysis. Based on the standard method of genotype classification, E-11 strains circulated worldwide were reclassified into six genotypes as A, B, C, D, E, and F, in which genotype F is newly divided, and genotypes A and C are further divided into A1-5 and C1-4 by this research, whereas genotype D was still divided into D1-5 as in a previous study of Oberste et al. Sub-genotype A1 was the predominant sub-genotype in mainland China between 2008-2017, whereas sub-genotype D5 was the predominant sub-genotype circulated outside China from 1998-2014. However, genotype and sub-genotype spectra showed statistical significance among AFP and HFMD cases (χ2 = 60.86, P < 0.001), suggesting that different genotypes might have a tendency to cause different diseases. Strengthening the surveillance of E-11 might provide further information about pathogenic evolution or specific nucleotide mutation associated with different clinical diseases.