Pathogenic spectrum and epidemiological analysis on hand, foot, and mouth disease in Shenyang from 2013 to 2017

Objective To understand the pathogenic spectrun and epidemiological characteristics of hand, foot, and mouth (HFMD) in Shenyang city, 2013-2017. Methods Samples of HFMD were collected in Shenyang during 2013 to 2017. Enterovirus 71 (EV71), coxsackievirus A (Cox A) 16, Cox A6 and Cox A10 were screened by real time quantitative RT-PCR (reverse transcription-PCR). The complete VP1 genes were amplified by traditional RT-PCR for the samples which were positive only for enterovirus genus. The amplicons were sequenced and the genotypes were confirmed by alignment analysis. The phylogenetic analysis was applied for entire VP1 gene of Cox A6. Results From 2013 to 2017, 2 881 samples were collected in Shenyang and the positive rate of enterovirus was 71.71% (2 066/2 881). The differences of positive rates among years were statistically significant (x2=50.62, P<0.01). Fifteen types of enterovirus were detected, including EV71, Cox A6, Cox A16, Cox A10, Cox A4, Cox A2, Cox A12, Cox A5, Cox B2, Cox A8, Cox A9, Cox B3, E9, E16 and poliovirus type-3. The Cox A6 isolates from Shenyang during 2013 to 2017 could be classified into the cluster D3a in the phylogenetic tree. Conclusions All three types of enterovirus, EV71, Cox A6 and Cox A16 were responsible for HFMD in Shenyang city. Cox A6 was the second predominant pathogen in Shenyang area.