Fig 1.
Epidemiology of Paratyphoid Fever in Taiwan.
The data includes 223 confirmed cases of paratyphoid fever reported in Taiwan between 2001 and 2024. Case numbers reflect both imported and domestically acquired infections, as detailed in the Methods section.
Fig 2.
Phylogenetic tree of 88 Salmonella enterica serovar Paratyphi A isolates recovered in Taiwan between 2007 and 2024.
The tree was inferred from core-genome single-nucleotide polymorphism (cgSNP) profiles using the maximum likelihood method. Isolates from domestically acquired cases are highlighted in red. The cluster containing 50 paratype 2.4 isolates from Taiwan and Indonesia is outlined in red and corresponds to HierCC cluster HC20_15313. Additional metadata for the 88 isolates are provided in S2 Table.
Fig 3.
Spatiotemporal distribution of Salmonella enterica serovar Paratyphi A cases in Taiwan.
Each case is mapped to the corresponding township or district of residence; however, for visual clarity, only city and county boundaries are displayed. Paratype 2.4 isolates from 2007 to 2019 are shown in shades of red, while those from 2022 to 2024, associated with the recent outbreak, are shown in shades of blue. Other paratypes are indicated by white star-shaped symbols. The background dot-density layer represents population distribution, with one dot corresponding to 5,000 persons. This figure was created using QGIS version 3.44x (https://qgis.org/). The basemap shapefile and demographic data were obtained from the Ministry of the Interior’s Statistical Map Service Platform (https://segis.moi.gov.tw/STATCloud/QueryInterface?DV=1) and are licensed under the Open Government Data License, version 1.0 (https://data.gov.tw/license).
Fig 4.
Sankey diagram showing the distribution of Salmonella enterica serovar Paratyphi A paratypes by country of origin.
The diagram visualizes 1,074 isolates, with each flow representing the connection between a specific paratype and the reported country of origin. The width of each flow is proportional to the number of isolates, and each color corresponds to a distinct paratype.
Fig 5.
Phylogenetic tree of Salmonella enterica serovar Paratyphi A isolates.
The tree was inferred from core genome single-nucleotide polymorphism (cgSNP) profiles using Gubbins v3.3.1 with maximum likelihood estimation, applying the General Time Reversible (GTR) substitution model and the Discrete Gamma correction. A total of 1,074 isolates from Taiwan and endemic countries were included. Colors indicate paratypes, countries of origin, and sequence types (STs), as shown in the accompanying legend. Arrows in the innermost ring denote isolates recovered in Taiwan from imported cases—that is, infections acquired abroad but diagnosed and cultured domestically. Others_a includes gyrA mutations D87Y, D87N, D87G, and the S83F-D87G double mutation; Others_b comprises ST1938, ST1939, and ST2216. Additional metadata are provided in S3 Table.