Spatial Transmission Dynamics of Respiratory Syncytial Virus A in China

Respiratory syncytial virus (RSV), a major cause of acute respiratory infections (ARIs) globally, poses a significant threat, especially to vulnerable populations. However, the spatial transmission dynamics of RSV strains, including the influence of environmental and socioeconomic factors, remain inadequately understood. This study applied genetic sequences and phylogenetic methods to quantify evolutionary and spatial dispersal dynamics of RSV subgroup A (RSVA) across China from 2011 to 2019. We assessed viral population trends, mapped interprovincial transmission patterns, and evaluated the influence of meteorological and socioeconomic factors on viral spread. Our results revealed cyclical fluctuations in effective population size every 3-5 years, and a predominant southward spread driven by interprovincial transmission networks. We found that higher winter relative humidity (RH), urbanization rate, and human mobility promoted viral spread, while higher winter temperature and elevated urban population density appeared to inhibit it. These findings provide crucial insights into RSVA dispersal in China, underscoring the importance of regional surveillance networks and targeted interventions to curb cross-regional spread, and offer a valuable framework to inform RSV vaccine rollout strategies and guide resource allocation in high-risk areas.