Seasonal dynamics and genetic diversity of human rhinoviruses in patients with acute respiratory infection in Bangkok in 2024

Human rhinoviruses (HRVs) are significant contributors to respiratory illnesses, particularly acute respiratory infections (ARIs). In this study, we investigated the prevalence and genotypes of HRV circulating in Bangkok in 2024. Nasopharyngeal swabs were collected from 8,097 patients hospitalized with ARIs, resulting in a 14.5% HRV positivity rate (n = 1,320). Among these, children under 12 years accounted for the largest proportion (54.5%), highlighting a substantial disease burden in this age group. Molecular typing was performed on a subset of 360 HRV-positive samples. HRV-A was the most frequently detected type (64.4%), followed by HRV-C (33.1%) and HRV-B (2.5%). Seasonal variation was observed, with HRV-A predominating during the rainy season. Genotyping revealed diverse circulating strains, with HRV-C42, HRV-A73, and HRV-C32 among the most prevalent genotypes, indicating a shift from previously identified strains. Phylogenetic analysis demonstrated that circulating HRV strains in Bangkok share close genetic relationships with isolates from other countries, suggesting ongoing global transmission dynamics. These findings highlight the evolving landscape of HRV infections and underscore the importance of ongoing surveillance and genetic characterization to monitor circulating strains. This information is crucial for informing public-health strategies aimed at controlling respiratory infections, particularly among vulnerable populations such as children and the elderly.