Objective:To analyze the pangenome, pan drug resistance genes, pan virulence genes, pan replicons, and others of the plasmids carried by hypervirulent Klebsiella pneumoniae (hvKP) in the world and their evolutionary trends over time, and provide evidence for more comprehensive understanding of the evolution of genetic diversity, drug resistance genes, and virulence genes of the plasmids. Methods:From the National Center for Biotechnology Information database, a total 1 738 plasmids were screened from 524 strains with completed genome sequences in 2 136 strains of hvKP carrying plasmids. Through pangenome, pan drug resistance gene, and pan-virulence gene composition and functional analyses, the curves of pangenome size and new gene size against plasmid isolation time were established, revealing the diversity of the plasmid pangenome and its evolutionary patterns.Results:The homologous genes, homologous drug resistance genes, homologous virulence genes, and replicons of the plasmids carried by hvKP comprised of 12 906, 149, 107 and 89 types, respectively. The fitting curves for the number of new genes, new drug resistance genes and new replicons increased with the increase of plasmids in an open state, while the curve for novel virulence genes was in a closed state. A obvious increase in new drug resistance genes was observed during 2018-2019. Among the newly added drug resistance genes during 2021-2023, beside those conferring aminoglycoside resistance, they were mainly new subtypes conferring carbapenem resistance.Conclusions:The pangenome of plasmids carried by hvKP exhibited high diversity, with the plasmid pan genes, pan drug resistance genes, and pan replicon types gradually expanding, while the pan virulence genes remains stable. The increase in novel drug resistance genes in specific years and the emergence of new carbapenem-resistant gene subtypes during 2021-2023 suggested the need for strengthened drug resistance surveillance and prevention efforts, with particular attention to carbapenem resistance.

Objective:To investigate the diversity, temporal dynamics and influencing factors of serotypes of Salmonella among asymptomatic workers in Yulin, Guangxi Zhuang Autonomous Region, from 2013 to 2023, and provide reference for controlling the hidden transmission of Salmonella and for disease prevention among healthy populations. Methods:Anal rectal swabs were collected from asymptomatic workers in Yulin from 2013 to 2023 for the isolation and identification of Salmonella. The diversity of serotypes of Salmonella was evaluated by using Shannon index, while the isolation rates and composition ratio of different serotypes were compared with χ2 test. Spearman correlation analysis was used to evaluate the correlation of natural and social factors with serotype isolation rates for more than eight years, and stepwise multiple linear regression analysis were used to evaluate the impact of social factors on the serotype isolation rates for more than 8 years. Results:A total of 8 073 strains of Salmonella were isolated from 2013 to 2023, with an overall isolation rate of 18.88‰ During the 11-year period, 135 serotypes of Salmonella were identified, and the serotype diversity increased first and then decreased. The serotype with the highest isolation rate was Salmonella Typhimurium (3.04‰), followed by Salmonella Rissen (1.70‰), Salmonella Corvallis (1.41‰), Salmonella Agona (1.36‰), Salmonella Derby (1.22‰), and Salmonella London (1.02‰), accounting for 51.67% of the total Salmonella serotypes isolated. There was no significant trend in isolation rate of Salmonella over the years ( χ2=0.67, P=0.415); however, season significantly influenced the isolation rate, with lower rate being observed in winter and higher rate in summer ( χ2=615.91, P<0.001). The isolation rate of different serotypes of Salmonella was influenced by social and natural factors, showing a positive correlation with temperature, precipitation, and poultry consumption and production levels. Conclusions:The serotypes of Salmonella carried by asymptomatic workers were complex and diverse in Yulin, Guangxi Zhuang Autonomous Region, from 2013 to 2023, and the isolation rates of multi-serotypes increased from 2013 to 2023. Higher isolation rate was observed in summer and the isolation rate was widely influenced by natural factors such as temperature and precipitation, as well as social factors such as economic conditions. It is necessary to pay attention to the Salmonella serotype carriage in healthy population, and strengthen monitoring of both healthy individuals and pathogenic bacteria.

Objective:The objective of this study was to understand the incidence, spatial and temporal distribution characteristics and trends of bacillary dysentery in China from 2005 to 2024 in order to identify the high-risk groups and reveal the potential risk factors and to provide a scientific basis for optimizing the allocation of preventive and control resources, formulating targeted intervention strategies and assessing the effectiveness of the measures.Methods:The nationally reported incidence data of bacillary dysentery was collected from 2005 to 2024 in the Chinese Center for Disease Control and Prevention National Notifiable Diseases Reporting Information System. Descriptive epidemiological methods were used to analyze the population characteristics of bacillary dysentery cases. A Joinpoint regression model was constructed to examine long-term trends in reported incidence rates and spatial dynamic window scanning statistics were applied to detect spatial clusters of bacillary dysentery cases.Results:Between 2005 and 2024, 3 520 247 cases of bacillary dysentery were reported across China, with an average incidence rate of 12.88 per 100 000 people, after which the rate of decline decreased. The incidence rate showed a general downward trend, featuring a significant inflection point in 2016. It exhibited marked seasonality, peaking from May to October (summer-autumn), which weakened over time. From 2005 to 2024, the most likely clusters were in Beijing and Tianjin. Males, infants, the elderly, farmers, and children not in daycare showed many cases.Conclusions:The results revealed that the peak incidence of bacillary dysentery in China from 2005 to 2024 was featured in the summer-autumn months. High-incidence areas were mainly Beijing and Tianjin. The key groups, including males, infants, the elderly, farmers and children not in daycare, were identified. Enhancing surveillance, targeted health education, and preventive measures, especially in these key populations and in regions where the disease shows a high incidence should be strengthened.

Objective:To analyze the epidemiological characteristics and infection sources of cholera in China from 2005 to 2024.Methods:A total of 2 066 cholera cases were included in the study, which were obtained from the China Disease Control and Prevention Information System (CDPCIS) of China CDC. The information on cholera clusters was downloaded from the National Public Health Emergency Event Surveillance System (PHEESS) of China CDC. A total of 128 cholera clusters were included and analyzed in this study. The epidemiological characteristics and infection sources of cholera were analyzed. The Jointpoint model was applied to analyze the incidence trend, and annual percentage change (APC) was also quantified.Results:From 2005 to 2024, a total of 2 066 cholera cases were reported, with an average of 103 cases reported annually. Specifically, the incidence showed a marked downward trend from 2004 to 2015 ( APC=-26.78%, P=0.006). During 2015-2024, the disease remained at low endemic levels, with an average of 18 reported cases annually ( APC=-2.68%, P=0.807). Cholera peak season was from May to October. A total of 24 provinces reported cholera cases, which were mainly distributed in Zhejiang, Fujian, Beijing, Jiangsu, Anhui, Guangdong, and Hainan provinces, accounting for 78.03% of the total cases. Pathogen surveillance indicated an alternating prevalence of Vibrio cholerae serogroups O1 and O139 among laboratory-confirmed cases between 2005 and 2024. There was a disparity in the dominant serogroup of Vibrio cholerae by region. The results from 128 cholera clusters indicated that cholera outbreaks frequently occurred in rural banquets (64.84%), followed by regular restaurants (13.28%). Among these, 63 clusters (49.22%) with identified infection sources indicated that foodborne transmission (95.24%) was the primary mode of cholera transmission, which mainly through seafood and aquatic products, such as soft-shelled turtles, shrimp and shellfish. The characteristics of cholera clusters caused by Vibrio cholerae serogroups O1 and O139 showed statistically significant differences in scale, attack rate, place of residence, setting, and infection source ( P<0.05). Conclusion:Cholera incidence has remained consistently low since 2015 in China, mainly in sporadic cases. Rural gatherings (e.g., wedding banquets) are the main settings for cholera clusters. The main infection sources are predominantly caused by cross-contamination due to improper processing practices of aquatic products, such as soft-shelled turtles.

Objective:To investigate the epidemiological dynamics and spatiotemporal diffusion trend of brucellosis in China from 2010 to 2024.Methods:Data on reported human brucellosis cases in mainland China from January 1, 2010, to December 31, 2024, were collected via the"China Information System for Disease Control and Prevention", including detailed information on the date of onset, gender, age, occupation, and residential address of the cases. The Joinpoint regression and spatial interpolation techniques were used to investigate the spatiotemporal dynamics and population distribution characteristics of human brucellosis in pastoral/semi-pastoral areas and other regions, as well as urban and rural areas, and explore the epidemic trends of the disease.Results:From 2010 to 2024, pastoral/semi-pastoral regions reported 252 094 brucellosis cases, with a mean annual incidence rate of 36.57±7.28 per 100 000. In contrast, other regions cumulatively recorded 519 748 cases during the same period, demonstrating a significantly lower mean annual incidence rate of 2.54±0.74 per 100 000. The incidence rate of human brucellosis in pastoral/semi-pastoral regions exhibited a declining-rebounding-declining trend. Specifically, the incidence rate decreased significantly from 2010 to 2017 (APC=-7.20; P<0.001) and increased notably from 2017 to 2021 (APC=18.00; P=0.015) with a decline again from 2021 to 2024 (APC=-7.53; P=0.027). In other regions, the incidence rate showed a fluctuating upward trend. Specifically, the incidence rate increased significantly from 2010 to 2015 (APC=20.37; P<0.001) and decreased notably from 2015 to 2018 (APC=-21.78; P<0.001), followed by an increase again from 2018 to 2024, a significant upward trend in incidence rate from 2018 to 2021 (APC=26.73; P<0.001) and a non-significant decline from 2021 to 2024 (APC=-0.99; P=0.735), resulting in the maintenance of a relatively high incidence level. Rural areas demonstrated significantly higher brucellosis incidence rates than urban settings (all P<0.001). Brucellosis exhibited a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions between 2010 and 2024. The age structure of patients in pastoral/semi-pastoral areas differed significantly from that in other regions. Specifically, in pastoral/semi-pastoral areas, the incidence rate was higher among the 35-49 age groups, while in other regions, the incidence rate was higher among those aged 55-64. Conclusion:There are notable disparities in the incidence of human brucellosis between pastoral/semi-pastoral areas and other regions in China. Human brucellosis exhibits a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions.

Objective:To analyze the epidemiological characteristics and infection sources of cholera in China from 2005 to 2024.Methods:A total of 2 066 cholera cases were included in the study, which were obtained from the China Disease Control and Prevention Information System (CDPCIS) of China CDC. The information on cholera clusters was downloaded from the National Public Health Emergency Event Surveillance System (PHEESS) of China CDC. A total of 128 cholera clusters were included and analyzed in this study. The epidemiological characteristics and infection sources of cholera were analyzed. The Jointpoint model was applied to analyze the incidence trend, and annual percentage change (APC) was also quantified.Results:From 2005 to 2024, a total of 2 066 cholera cases were reported, with an average of 103 cases reported annually. Specifically, the incidence showed a marked downward trend from 2004 to 2015 ( APC=-26.78%, P=0.006). During 2015-2024, the disease remained at low endemic levels, with an average of 18 reported cases annually ( APC=-2.68%, P=0.807). Cholera peak season was from May to October. A total of 24 provinces reported cholera cases, which were mainly distributed in Zhejiang, Fujian, Beijing, Jiangsu, Anhui, Guangdong, and Hainan provinces, accounting for 78.03% of the total cases. Pathogen surveillance indicated an alternating prevalence of Vibrio cholerae serogroups O1 and O139 among laboratory-confirmed cases between 2005 and 2024. There was a disparity in the dominant serogroup of Vibrio cholerae by region. The results from 128 cholera clusters indicated that cholera outbreaks frequently occurred in rural banquets (64.84%), followed by regular restaurants (13.28%). Among these, 63 clusters (49.22%) with identified infection sources indicated that foodborne transmission (95.24%) was the primary mode of cholera transmission, which mainly through seafood and aquatic products, such as soft-shelled turtles, shrimp and shellfish. The characteristics of cholera clusters caused by Vibrio cholerae serogroups O1 and O139 showed statistically significant differences in scale, attack rate, place of residence, setting, and infection source ( P<0.05). Conclusion:Cholera incidence has remained consistently low since 2015 in China, mainly in sporadic cases. Rural gatherings (e.g., wedding banquets) are the main settings for cholera clusters. The main infection sources are predominantly caused by cross-contamination due to improper processing practices of aquatic products, such as soft-shelled turtles.

Objective:To investigate the epidemiological dynamics and spatiotemporal diffusion trend of brucellosis in China from 2010 to 2024.Methods:Data on reported human brucellosis cases in mainland China from January 1, 2010, to December 31, 2024, were collected via the"China Information System for Disease Control and Prevention", including detailed information on the date of onset, gender, age, occupation, and residential address of the cases. The Joinpoint regression and spatial interpolation techniques were used to investigate the spatiotemporal dynamics and population distribution characteristics of human brucellosis in pastoral/semi-pastoral areas and other regions, as well as urban and rural areas, and explore the epidemic trends of the disease.Results:From 2010 to 2024, pastoral/semi-pastoral regions reported 252 094 brucellosis cases, with a mean annual incidence rate of 36.57±7.28 per 100 000. In contrast, other regions cumulatively recorded 519 748 cases during the same period, demonstrating a significantly lower mean annual incidence rate of 2.54±0.74 per 100 000. The incidence rate of human brucellosis in pastoral/semi-pastoral regions exhibited a declining-rebounding-declining trend. Specifically, the incidence rate decreased significantly from 2010 to 2017 (APC=-7.20; P<0.001) and increased notably from 2017 to 2021 (APC=18.00; P=0.015) with a decline again from 2021 to 2024 (APC=-7.53; P=0.027). In other regions, the incidence rate showed a fluctuating upward trend. Specifically, the incidence rate increased significantly from 2010 to 2015 (APC=20.37; P<0.001) and decreased notably from 2015 to 2018 (APC=-21.78; P<0.001), followed by an increase again from 2018 to 2024, a significant upward trend in incidence rate from 2018 to 2021 (APC=26.73; P<0.001) and a non-significant decline from 2021 to 2024 (APC=-0.99; P=0.735), resulting in the maintenance of a relatively high incidence level. Rural areas demonstrated significantly higher brucellosis incidence rates than urban settings (all P<0.001). Brucellosis exhibited a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions between 2010 and 2024. The age structure of patients in pastoral/semi-pastoral areas differed significantly from that in other regions. Specifically, in pastoral/semi-pastoral areas, the incidence rate was higher among the 35-49 age groups, while in other regions, the incidence rate was higher among those aged 55-64. Conclusion:There are notable disparities in the incidence of human brucellosis between pastoral/semi-pastoral areas and other regions in China. Human brucellosis exhibits a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions.

Objective:To analyze the pangenome, pan drug resistance genes, pan virulence genes, pan replicons, and others of the plasmids carried by hypervirulent Klebsiella pneumoniae (hvKP) in the world and their evolutionary trends over time, and provide evidence for more comprehensive understanding of the evolution of genetic diversity, drug resistance genes, and virulence genes of the plasmids. Methods:From the National Center for Biotechnology Information database, a total 1 738 plasmids were screened from 524 strains with completed genome sequences in 2 136 strains of hvKP carrying plasmids. Through pangenome, pan drug resistance gene, and pan-virulence gene composition and functional analyses, the curves of pangenome size and new gene size against plasmid isolation time were established, revealing the diversity of the plasmid pangenome and its evolutionary patterns.Results:The homologous genes, homologous drug resistance genes, homologous virulence genes, and replicons of the plasmids carried by hvKP comprised of 12 906, 149, 107 and 89 types, respectively. The fitting curves for the number of new genes, new drug resistance genes and new replicons increased with the increase of plasmids in an open state, while the curve for novel virulence genes was in a closed state. A obvious increase in new drug resistance genes was observed during 2018-2019. Among the newly added drug resistance genes during 2021-2023, beside those conferring aminoglycoside resistance, they were mainly new subtypes conferring carbapenem resistance.Conclusions:The pangenome of plasmids carried by hvKP exhibited high diversity, with the plasmid pan genes, pan drug resistance genes, and pan replicon types gradually expanding, while the pan virulence genes remains stable. The increase in novel drug resistance genes in specific years and the emergence of new carbapenem-resistant gene subtypes during 2021-2023 suggested the need for strengthened drug resistance surveillance and prevention efforts, with particular attention to carbapenem resistance.

Objective:To investigate the diversity, temporal dynamics and influencing factors of serotypes of Salmonella among asymptomatic workers in Yulin, Guangxi Zhuang Autonomous Region, from 2013 to 2023, and provide reference for controlling the hidden transmission of Salmonella and for disease prevention among healthy populations. Methods:Anal rectal swabs were collected from asymptomatic workers in Yulin from 2013 to 2023 for the isolation and identification of Salmonella. The diversity of serotypes of Salmonella was evaluated by using Shannon index, while the isolation rates and composition ratio of different serotypes were compared with χ2 test. Spearman correlation analysis was used to evaluate the correlation of natural and social factors with serotype isolation rates for more than eight years, and stepwise multiple linear regression analysis were used to evaluate the impact of social factors on the serotype isolation rates for more than 8 years. Results:A total of 8 073 strains of Salmonella were isolated from 2013 to 2023, with an overall isolation rate of 18.88‰ During the 11-year period, 135 serotypes of Salmonella were identified, and the serotype diversity increased first and then decreased. The serotype with the highest isolation rate was Salmonella Typhimurium (3.04‰), followed by Salmonella Rissen (1.70‰), Salmonella Corvallis (1.41‰), Salmonella Agona (1.36‰), Salmonella Derby (1.22‰), and Salmonella London (1.02‰), accounting for 51.67% of the total Salmonella serotypes isolated. There was no significant trend in isolation rate of Salmonella over the years ( χ2=0.67, P=0.415); however, season significantly influenced the isolation rate, with lower rate being observed in winter and higher rate in summer ( χ2=615.91, P<0.001). The isolation rate of different serotypes of Salmonella was influenced by social and natural factors, showing a positive correlation with temperature, precipitation, and poultry consumption and production levels. Conclusions:The serotypes of Salmonella carried by asymptomatic workers were complex and diverse in Yulin, Guangxi Zhuang Autonomous Region, from 2013 to 2023, and the isolation rates of multi-serotypes increased from 2013 to 2023. Higher isolation rate was observed in summer and the isolation rate was widely influenced by natural factors such as temperature and precipitation, as well as social factors such as economic conditions. It is necessary to pay attention to the Salmonella serotype carriage in healthy population, and strengthen monitoring of both healthy individuals and pathogenic bacteria.

Objective:The objective of this study was to understand the incidence, spatial and temporal distribution characteristics and trends of bacillary dysentery in China from 2005 to 2024 in order to identify the high-risk groups and reveal the potential risk factors and to provide a scientific basis for optimizing the allocation of preventive and control resources, formulating targeted intervention strategies and assessing the effectiveness of the measures.Methods:The nationally reported incidence data of bacillary dysentery was collected from 2005 to 2024 in the Chinese Center for Disease Control and Prevention National Notifiable Diseases Reporting Information System. Descriptive epidemiological methods were used to analyze the population characteristics of bacillary dysentery cases. A Joinpoint regression model was constructed to examine long-term trends in reported incidence rates and spatial dynamic window scanning statistics were applied to detect spatial clusters of bacillary dysentery cases.Results:Between 2005 and 2024, 3 520 247 cases of bacillary dysentery were reported across China, with an average incidence rate of 12.88 per 100 000 people, after which the rate of decline decreased. The incidence rate showed a general downward trend, featuring a significant inflection point in 2016. It exhibited marked seasonality, peaking from May to October (summer-autumn), which weakened over time. From 2005 to 2024, the most likely clusters were in Beijing and Tianjin. Males, infants, the elderly, farmers, and children not in daycare showed many cases.Conclusions:The results revealed that the peak incidence of bacillary dysentery in China from 2005 to 2024 was featured in the summer-autumn months. High-incidence areas were mainly Beijing and Tianjin. The key groups, including males, infants, the elderly, farmers and children not in daycare, were identified. Enhancing surveillance, targeted health education, and preventive measures, especially in these key populations and in regions where the disease shows a high incidence should be strengthened.