A Study on Enterovirus Genotypes in Busan, Korea from 2017 to 2022

Human enteroviruses (HEV) are pathogens that cause a wide variety of clinical illness such as a hand-foot-mouth disease, herpangina, skin rash, encephalitis, aseptic meningitis and even death in young children. This study was aimed to investigate the prevalence of HEV infection in young children in Busan, Korea and analyze the various genotypes of enterovirus. We collected the stool, throat swab and cerebrospinal fluid samples from admitted pediatrics from 2017 to 2022. HEV detection and genotype identification were performed by real-time RT-PCR and RT-PCR and phylogenetic trees were constructed by neighbor-joining method compared with reference strains. A total of 1,412 samples were collected and 128 cases (9.1%) were detected. Based on partial VP1 sequencing, a total 93 enterovirus isolates were resolved into 4 genotypes and 18 serotypes; Human enterovirus A, B, D (HEV-A, B, D) and Rhinovirus. HEV-A is 30 isolates included 7 serotypes, HEV-B is 63 isolates included 10 serotypes, HEV-D is 1 isolates included 1 serotypes and Rhinovirus is 5 isolated included 3 serotypes. Prevalent serotype was coxsakievirus A10 in 2017, coxsakievirus B5 in 2018, Echovirus 30 in 2019. The temporal distribution of HEV epidemics in Busan showed a remarkable seasonal pattern, from June to September. The genotypes of circulating enteroviruses were diverse from year to year and most of the sequences circulated in Busan showed homology with reference sequences in neighboring countries such as China. Monitoring and genotyping of these enteroviruses will play a role in preventing the development of serious diseases caused by enteroviruses and genotype analysis can be used as a basic data for epidemiological studies.