Molecular typing and epidemiological profiles of human respiratory syncytial virus infection among children with severe acute respiratory infection in Huzhou, China

Background

Human respiratory syncytial virus (HRSV) is an important pathogen causing severe acute respiratory infection (SARI), particularly in children under 5 years old. We investigated the HRSV infection status and genogroups in pediatric patients with SARI between January 2019 and December 2022 in Huzhou, China.

Methods

Nasopharyngeal swabs (NPSs) were collected from pediatric patients in the First People's Hospital of Huzhou. Real-time quantitative RT-PCR for respiratory syncytial virus (A/B)was performed with an QuantStudio 7 Flex Real-Time PCR System. For genotyping, the primer sets A-F/A-R and B-F/B-R were used to amplify the G protein sequences of HRSV-A and HRSV-B, respectively. Phylogenetic analysis was performed using MEGA software.

Results

In total, 973 NPSs were collected between January 2019 and December 2022, and 63 samples were positive for HRSV nucleic acid, representing a detection rate of 6.47%. Of the positive specimens, 28 were classified as HRSV-A and 35 were classified as HRSV-B. Infection with HRSV was found in all age groups tested, with children < 5 years old accounting for 88.89% of the positive cases. The detection rate was high from November to the following March. Phylogenetic analysis clustered HRSV-A strains into the ON1 genogroup and HRSV-B strains belonged to the BA9 genogroup.

Conclusions

HRSV is an important respiratory pathogen among children in Huzhou, China, with a high incidence in children under 5 years old between winter and spring. HRSV subgroups A and B were co-circulating, and ON1 and BA9 were the two main genogroups identified in this study.