Spatiotemporal dynamics and genotypic shift of Coxsackievirus A16 in Fujian, China, from 2010 to 2025

Figures

• 

  Figure 1. Pathogen Spectrum Composition of HFMD in Fujian Province from 2010 to 2025. Percentage stacked bars represent the quarterly percentage of EV-A71, CVA16, and other EVs among confirmed HFMD cases. The overlaid curve shows the number of CVA16-associated HFMD cases during the period.

• 

  Figure 2. HFMD epidemiological regions and distribution in Fujian Province from 2010 to 2025. The base map is based on the standard map (No. GS(2024)0650) provided by the National Platform for Common Geospatial Information Services (https://www.tianditu.gov.cn/). The original boundary of the map has not been modified. The pie charts show the pathogen composition in each city. A color gradient from light blue to dark blue indicates the number of CVA16-associated HFMD cases.

• 

  Figure 3. The Age Distribution of HFMD in Fujian Province from 2010 to 2025. (A) Age distribution of HFMD patients by pathogen. Stacked bar chart showing the percentage distribution of age groups among patients infected with different enteroviruses (EV-A71, CVA16, and other EVs) in Fujian Province. (B) Temporal trends in the proportion of age group among CVA16-associated HFMD cases.

• 

  Figure 4. The Temporal distribution of three clusters(B1a–c) of CVA16 in Fujian Province from 2010 to 2025. The overlaid curve indicates the proportion of laboratory-confirmed CVA16 cases during the period.

• 

  Figure 5. The Maximum likelihood phylogenetic tree based on the VP1 region (891 bp). A total of 385 sequences were analyzed, comprising 352 sequences obtained in this study and 33 reference sequences retrieved from NCBI. The phylogenetic tree was constructed using MEGA12 under the maximum likelihood (ML) method, with bootstrap analysis performed using 1,000 replicates. Reference sequences representing all known CVA16 genotypes and subgenotypes were included. Fujian strains and reference sequences were color-coded as indicated in the legend.

• 

  Figure 6. Epidemiological and population dynamics of CVA16 in Fujian Province. (A) Time-scaled maximum clade credibility(MCC) tree based on VP1 region (891 bp) using BEAST v1.10.4. (B) Bayesian Skygrid plot showing the effective population size over time. The solid lines represent the median estimates, and the shaded areas indicate the 95% highest posterior density (HPD) intervals.

• 

  Figure 7. Phylogenetic trees based on the complete genome and different genomic regions of CVA16 strains from Fujian Province. Each tree was constructed using 93 sequences, including 62 sequences obtained in this study and 31 reference sequences retrieved from NCBI. The full-length sequences in the dataset ranged from 7,313 to 7,457 bp. Phylogenetic reconstruction was performed using MEGA12 under the maximum likelihood (ML) method, with bootstrap support assessed via 1,000 replicates. Genomic region boundaries were defined based on the CVA16 strain G-10 (GenBank accession: U05876). (A) In the complete genome tree, the Fujian strains were color-coded according to their respective clades. In the trees for specific genomic regions (B–F), the Fujian strains were distinguished by different symbols as indicated in the figure legend. (B) P1 region; (C) P2 region; (D) P3 region; (E) 5' untranslated region (5'UTR); (F) 3' untranslated region (3'UTR).