Evaluating the prevalence and molecular epidemiology of echovirus 11 isolated from sewage in Shandong Province, China in 2010

Echovirus 11 (E11) is an important human pathogen, but its genetic information in China is in scarce. In this study, 12 sewage samples from Jinan city and 18 from Linyi city were collected in Shandong Province, China in 2010, and E11 was the predominant serotype with 54 isolates from 16 samples. Numbers of E11 isolates reached peaks in August in both Jinan and Linyi city, while another peak occurred in December in Linyi. The complete VP1 genes of all these isolates were sequenced and phylogenetically compared with clinical isolates from Shandong in 1994–2010 (n = 29) and global E11. Shandong isolates segregated into five clusters, four in genogroup A and one in genogroup C. Environmental isolates belonged to two clusters of genogroup A, with high inter-cluster genetic divergence (18.5–20.9%). No local clinical E11 was isolated in the two cities in 2010, revealing the value of environmental surveillance in investigating circulating viruses. These findings underscored the significance of environmental VP1 sequence divergences in comprehending the local enterovirus circulation, and updated the global molecular epidemiology of E11.