Molecular epidemiological study of the G protein of human respiratory syncytial virus detected in patients with acute respiratory infections in Gyeonggi Province, South Korea.

To investigate the molecular characteristics of human respiratory syncytial virus (HRSV) detected in Gyeonggi Province from 2015/16 to 2017/18, 2331 specimens from patients with sporadic acute respiratory illness and 85 specimens from four HRSV outbreaks in the postpartum care center were analyzed by real-time reverse transcription PCR. HRSVs were detected in 97 of the 2416 (4.0%) specimens, and among the positive specimens, 38 (39.2%) were identified as HRSV-A and 59 (60.8%) as HRSV-B. During the study periods, HRSV-B predominated in all seasons, except in 2016/17 during which HRSV-A predominated. Depending on the age groups, HRSV prevalence was the highest in 0- to 2-year-old patients. Comparison of noninfected subjects with HRSV-infected subjects revealed that HRSV infection more frequently resulted in fever, nasal obstruction, and wheezing, although the frequency of sore throat was low; however, comparison of the symptoms between HRSV-A- and HRSV-B-infected patients revealed no significant differences in symptoms. Phylogenetic analysis showed that all HRSV-A patients had an ON1 genotype, and all HRSV-B patients had an BA9 genotype. These results provide a valuable reference regarding the circulating pattern and molecular characterization of HRSV. Continuous monitoring will be essential to detect newly emerging HRSV genotypes.