Among healthy children in the Xizang Autonomous Region from 1996 to 2024, CVA4 genotype C was the dominant strain (84.85%), demonstrating sustained transmission and multiple localized outbreaks.
Observational (n=2,091)
Yes
CVA4 genotype C has established sustained transmission among healthy children in high-altitude regions of China, highlighting the need for targeted enterovirus surveillance to prevent large-scale outbreaks.
Introduction Coxsackievirus A4 (CVA4) causes several diseases, including hand, foot, and mouth disease (HFMD) and herpangina. This study analyzed CVA4 isolates collected between 1996 and 2024 from the Xizang Autonomous Region to elucidate the phylogenetic characteristics and epidemiological patterns of this virus in high-altitude regions. Methods VP1 coding region sequences of CVA4 were obtained through virus isolation and Sanger sequencing. MEGA software was used to construct a maximum likelihood phylogenetic tree based on the VP1 region. The BEAST toolkit was used to generate a maximum clade credibility tree and perform phylogeographic analysis. Results From 2018 onwards, the prevalence of CVA4 among healthy carriers increased significantly, accounting for 62.12% of all detections. Genotyping revealed that most isolates belonged to genotype C, while the remainder were classified as D2. As the dominant genotype, genotype C has spread outward from Xigaze and Lhasa since 2011, leading to multiple asymptomatic infections in Shannan (2020), Xigaze and Lhasa (2023), and Ngari Prefecture (2024). Conclusions Transmission of CVA4 genotype C among healthy children in high-altitude areas suggests strong environmental adaptability, highlighting the need to strengthen enterovirus surveillance and control, including targeted monitoring of CVA4, in these regions.
Kaitao et al. (Thu,) conducted a observational in Healthy children (asymptomatic Coxsackievirus A4 carriers) (n=2,091). Among healthy children in the Xizang Autonomous Region from 1996 to 2024, CVA4 genotype C was the dominant strain (84.85%), demonstrating sustained transmission and multiple localized outbreaks.