Viral Load Dynamics of Chikungunya Virus in Human Specimens — Foshan City, Guangdong Province, China, 2025

Shuichun Wan^1,&; Xin Zhang^2,&; Xiao Cong^3,&; Yi Liu¹; Shen Huang²; Mingyi Zhou⁴; Changyun Sun²; Xiaofang Peng²; Huan Zhang²; Yihai Yu^1,#; Baisheng Li^4,#; Jianfeng He^2,#

1 Foshan Shunde 3rd People's Hospital (Foshan Shunde DistrictBeijiao Hospital), Foshan City, Guangdong Province, China;

2 Guangdong Provincial Key Laboratory of Pathogen Detection for Emerging Infectious Disease Response, Guangdong Provincial Center for Disease Control and Prevention,Guangdong Workstation forEmerging Infectious Disease Control and Prevention, Chinese<Academy of Medical Sciences, Guangzhou City, Guangdong Province,China;

3 Organ Transplant Center, the First Affiliated Hospital, SunYat-sen University, Guangzhou City, Guangdong Province, China;

4 School of Public Health, Sun Yat-sen University, Guangzhou City,Guangdong Province, China.

^& Joint first authors.

^# Corresponding author: Yihai Yu, congx3@mail2.sysu.edu.cn; Baisheng Li, sjkzx_wjs@gd.gov.cn; Jianfeng He, sjkzx_hejianfeng@gd.gov.cn.

Chikungunya virus (CHIKV), an arthropod-borne alphavirus transmitted by Aedes aegypti and Aedes albopictus, causes fever, severe joint pain, and rash. By 2025, it has triggered outbreaks in 119 countries, endangering 5.5 million people. Recent epidemics in Foshan, China, have strained healthcare systems, underscoring the need to characterize viral load dynamics across infection phases. This study collected 1,156 clinical samples from four Foshan hospitals in July 2025, spanning 6 days before to 12 days after symptom onset. Specimens included serum (904 valid), saliva (22), urine (4), throat swabs (3), and stool (37). CHIKV RNA was quantified via qRT-PCR; timepoints and specimen types with insufficient samples were excluded. Serum showed the highest positivity (90%), followed by saliva (68%), throat swabs (15%), and urine (11%); stool was negative (0%). Serum also had the highest viral loads, confirming its optimal utility. Viral RNA was detectable as early as 1 day pre-symptom onset (Day －1). Days 0–7 post-onset marked explosive replication and elevated loads, representing the optimal sampling window. From Day 8 onward, loads declined, requiring IgG testing to avoid false negatives. This study show serum is the gold standard for acute CHIKV diagnosis, with superior positivity and viral loads. Pre-symptomatic viral shedding (Day –1) supports enhanced port-of-entry screening to intercept imported cases. Days 0–7 post-onset is the optimal sampling window for acute infection. During clearance (Day 8+), IgG testing complements molecular diagnostics to reduce gaps. These findings inform evidence-based diagnosis, outbreak control, and resource allocation.

基孔肯雅病毒在人体样本中载量的动态分析 — 佛山市，广东市，中国，2025年

万水春^1,&；张欣^2,&；丛潇^3,&；刘轶¹；黄莘²；周明毅⁴；孙长云²；彭晓放²；张欢²；余一海^1,#；李柏生^4,#；何剑峰^2,#

1. 佛山市顺德区第三人民医院（佛山市顺德区北滘医院），佛山市，广东省，中国；

2. 广东省新发传染病应急检测技术研究与应用重点实验室，广东省疾病预防控制中心，广东新发突发传染病防治工作站（中国医学科学院），广州市，广东省，中国；

3. 器官移植中心，附属第一医院，中山大学，广州市，广东省，中国；

4. 公共卫生学院，中山大学，广州市，广东省，中国。

^& 共同第一作者。

^# 通讯作者: 余一海，congx3@mail2.sysu.edu.cn；李柏生，sjkzx_wjs@gd.gov.cn；何剑峰，sjkzx_hejianfeng@gd.gov.cn。

基孔肯雅病毒（CHIKV）是由埃及伊蚊和白纹伊蚊传播的虫媒甲病毒，可引发发热、剧烈关节痛和皮疹等症状。截至2025年，该病毒已在119个国家导致暴发疫情，威胁着550万人的健康。中国佛山近期出现的疫情使当地医疗系统面临压力，凸显出明确各感染阶段病毒载量动态的重要性。2025年7月，从佛山四家医院收集了1156份临床样本，覆盖症状出现前6天至出现后12天的时间段。标本类型包括血清（904份有效样本）、唾液（22份）、尿液（4份）、咽拭子（3份）和粪便（37份）。采用qRT-PCR技术对CHIKV RNA进行定量检测，排除样本量不足的时间点和标本类型。结果发现，血清的阳性检出率最高（90%），其次为唾液（68%）、咽拭子（15%）和尿液（11%），粪便均为阴性。血清的病毒载量也最高。病毒RNA在症状出现前1天（–1天）即可检出。发病后0–7天为病毒复制活跃期，病毒载量较高；8天以后病毒载量下降。该研究表明，血清是基孔肯雅病毒急性期诊断的金标准，具有更高的阳性率和病毒载量。症状出现前1天即可检测到病毒为强化口岸筛查提供依据，可提前拦截输入病例。发病后0–7天为急性期最佳采样期，8天以后需结合IgG抗体检测以避免漏诊。研究结果为疫情防控、资源分配以及减少传播风险提供了科学支持。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.182

Genotypic Characteristics of Mycobacterium Tuberculosis Based on Whole Genome Sequencing — Southern Xinjiang Uygur Autonomous Region, China, 2021–2023

Palidanguli Abudureheman¹; Senlu Wang²; Le Wang²; Gulina Badeerhan²; Kailibinuer Wumaier²; Nianqiang Liu²; Xiaowei Ma¹; Xijiang Wang^{2, #}

1. School of Public Health, Xinjiang Medical University, Urumqi City, Xinjiang Uygur Autonomous Region, China;

2. Xinjiang Uygur Autonomous Region Center for Disease Control and Prevention, Urumqi City, Xinjiang Uygur Autonomous Region, China.

^# Corresponding author: Xijiang Wang, wxj@xjcdc.com.

Southern Xinjiang Uygur Autonomous Region, China, experiences a substantial tuberculosis burden, yet comprehensive genotypic characterization of Mycobacterium tuberculosis strains in this region remains limited. This study collected Mycobacterium tuberculosis strains and corresponding epidemiological data from patients between January 2021 and June 2023. Bacterial isolates underwent whole-genome sequencing using the Illumina next-generation sequencing platform. We constructed phylogenetic trees using iqtree and generated minimum spanning trees based on GraphSNP analysis, applying a clustering threshold of 12 single nucleotide polymorphisms (SNPs) to identify transmission clusters. Lineage 2 emerged as the predominant strain type, accounting for the majority of isolates, followed by Lineages 4 and 3. Notably, Lineage 2 demonstrated significantly elevated clustering rates compared to other lineages. Genetic diversity analysis revealed that Lineage 2 strains exhibited the most limited intra-lineage variation, whereas Lineage 3 displayed the greatest genetic heterogeneity among strains. Our investigation demonstrates substantial genetic polymorphism among Mycobacterium tuberculosis strains circulating in southern Xinjiang. These findings highlight the critical need for enhanced transmission control strategies, with particular emphasis on intensive surveillance and prevention measures targeting Lineage 2 strains.

基于全基因组测序的结核分枝杆菌基因型特征 — 新疆南部，中国，2021–2023年

帕里旦古丽·阿不都热合曼¹；王森路²；王乐²；古丽娜·巴德尔汗²；凯丽比努尔·吾买尔²；刘年强²；马晓薇¹；王希江^2,#

1.公共卫生学院，新疆医科大学，乌鲁木齐市，新疆维吾尔自治区，中国；

2.新疆维吾尔自治区疾病预防控制中心，乌鲁木齐市，新疆维吾尔自治区，中国。

^# 通信作者：王希江, wxj@xjcdc.com。

中国新疆南部地区结核病负担较高，但对该地区结核分枝杆菌基因型的系统研究仍然有限。收集从2021年1月至2023年6月，结核分枝杆菌菌株和相应的患者流行病学数据，使用Illumina二代测序平台对细菌分离株进行全基因组测序，使用iqtree构建系统发育树，并基于GraphSNP生成最小生成树。结果发现，谱系2为主要流行谱系，其次为谱系4和谱系3，且谱系2总体成簇率较高。谱系2的遗传多样性差距最小，而谱系3的遗传差距最大。该研究揭示了新疆南部结核分枝杆菌菌株的遗传多态性。这些发现强调了加强传播控制措施的必要性，特别是对于谱系2需进一步加强防控。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.181

Epidemiological Characteristics of Tuberculosis Among Interprovincial Migrants — China, 2019–2023Da Xu^1,2,&, Xue Li^3,&, Feifei Tian^4,&, Zhezhe Cui⁵, Wei Chen^2,3,#

1. National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China;

2. Chinese Field Epidemiology Training Program, Chinese Centre for Disease Control and Prevention, Beijing, China;

3. National Center for Tuberculosis Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing, China;

4. Daxing Center for Disease Control and Prevention, Beijing, China;

5. Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning City, Guangxi Zhuang Autonomous Region, China.

^& Joint first authors.

^# Corresponding author: Wei Chen, chenwei@chinacdc.cn.

Tuberculosis (TB) represents one of China's most significant infectious diseases, with inter-provincial population migration posing a challenge to controlling its spread. This study examined TB cases among inter-provincial migrants across China from 2019 to 2023. TB surveillance data were extracted from China's Tuberculosis Information Management System and analyzed using R software (version 4.4.0). After information desensitization, the relevant information of TB patients with differing current and permanent address codes were extracted. Between 2019 and 2023, we identified 123,945 TB cases among inter-provincial migrants, representing 4.03% (123,945/3,077,951) of all reported TB cases. The primary destination provincial level administrative divisions (PLADs) for TB patients were Guangdong (48,183 cases, 38.9%), Zhejiang (27,383 cases, 22.1%), Fujian (8,582 cases, 6.9%), Beijing (7,959 cases, 6.4%), and Shanghai (7,403 cases, 5.9%), collectively accounting for 80.3% of all inter-provincial migrant TB cases. The PLADs with the highest outflow of TB migrants were Sichuan (15,155 cases, 12.23%), Hunan (14,707 cases, 11.87%), Guizhou (13,927 cases, 11.24%), Jiangxi (8,892 cases, 7.17%), and Hubei (8,441 cases, 6.81%). Among these migrant cases, 66.2% were male, 93.0% were newly diagnosed, 2.4% exhibited drug resistance. The proportion of individuals aged 45-64, aged ≥65 and re-treated exhibited a significant annual increase (P<0.001). The overall successful treatment rate was 89.5%, while 5.3% experienced adverse treatment outcomes. Throughout the study period, the lowest proportion of TB cases among inter-provincial migrants occurred in February. From 2019 to 2023, the characteristics of TB among inter-PLADs migrants patients have undergone certain changes. The migration of TB primarily flows from economically weaker regions to more developed areas, with the main destination PLADs relatively stable. Effective TB control among inter- PLADs migrants requires targeted screening programs focusing on individuals from major source and destination PLADs. Tailored strategies should be developed based on the migration patterns of different PLADs.

跨省流动结核病患者流行病学特征分析 — 中国，2019–2023年

许达^1,2,&；李雪^3,&；田飞飞^4,&；崔哲哲⁵；陈伟^2,3,#

1.传染病预防控制所，中国疾病预防控制中心，北京，中国； 

2.现场流行病学培训项目，中国疾病预防控制中心，北京，中国； 

3.结核病预防控制中心，中国疾病预防控制中心，北京，中国；

4.北京市大兴区疾病预防控制中心，北京，中国； 

5.广西壮族自治区疾病预防控制中心，南宁市，广西壮族自治区，中国。

^& 共同第一作者。

^# 通讯作者：陈伟，chenwei@chinacdc.cn

结核病是中国重要的传染病之一，而跨省人口流动为其传播控制带来了挑战。本研究分析了2019年至2023年中国跨省流动结核病患者流行病学特征。本研究从中国结核病信息管理系统提取监测数据，采用R软件（4.4.0版）进行分析。经信息脱敏处理后，筛选现住址与户籍地址编码不一致的结核病患者的相关信息。2019–2023年，共发现123,945例跨省流动结核病患者，占全国报告结核病例总数的4.03%（123,945/3,077,951）。病例主要流向地为广东（48,183例，38.9%）、浙江（27,383例，22.1%）、福建（8,582例，6.9%）、北京（7,959例，6.4%）和上海（7,403例，5.9%），合计占比达80.3%。病例主要来源地为四川（15,155例，12.23%）、湖南（14,707例，11.87%）、贵州（13,927例，11.24%）、江西（8,892例，7.17%）和湖北（8,441例，6.81%）。病例中男性占66.2%，新确诊者占93.0%，耐药率为2.4%。45–64岁、≥65岁及复治患者比例逐年显著上升（P<0.001）。总体治疗成功率为89.5%，不良治疗结局占5.3%。研究期间，跨省流动肺结核病例占比最低的月份为每年2月。2019–2023年间，跨省流动肺结核患者特征呈现一定变化趋势。流动呈现从经济欠发达地区向发达地区迁移的特征，主要流入地相对稳定。建议针对主要来源地和流入地人群开展精准筛查，并根据不同省份流动特征制定差异化防控策略。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.180

An Outbreak of Isoniazid-Resistant Tuberculosis in a School Originating from Household Transmission — Guigang City, Guangxi Zhuang Autonomous Region, China, November 2024

Da Xu^1,2,3,&;  Xiaoyan Liang^1,&;  Lingyun Zhou^1,&;  Wei Chen^3,4;  Jing Ye¹;  Juan Li¹;  Weihua Yao⁵; Jinhui Zhu^6,#;  Zhezhe Cui^1,#

1. Institute of Tuberculosis Control and Prevention, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning City, Guangxi Zhuang Autonomous Region, China;

2. National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China;

3. Chinese Field Epidemiology Training Program, Chinese Centre for Disease Control and Prevention, Beijing, China;

4. National Center for Tuberculosis Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing, China;

5. Guigang City Center for Disease Control and Prevention, Guigang City, Guangxi Zhuang Autonomous Region, China;

6. Guangxi Key Laboratory of Major Infectious Disease Prevention and Control and Biosafety Emergency Response, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning City, Guangxi Zhuang Autonomous Region, China.

^& Joint first authors.

^# Corresponding authors: Zhezhe Cui, gxcdctbi@wsjkw.gxzf.gov.cn; Jinhui Zhu, cdc@wsjkw.gxzf.gov.cn.

On November 27, 2024, an active pulmonary tuberculosis case (pathogen positive) was identified in a senior high school in Guigang City, Guangxi Zhuang Autonomous Region, China. A comprehensive field epidemiological investigation was conducted to identify close contacts. Close contacts underwent detailed interviews regarding their exposure history and symptoms, followed by diagnostic testing including the recombinant M. tuberculosis fusion protein test or interferon-γ release assay, along with chest X-ray or CT imaging. Suspected cases were subjected to comprehensive laboratory evaluation, including sputum smear microscopy, sputum culture, and molecular biological testing. Drug susceptibility testing and genomic sequencing analysis were performed on culture-positive strains. Epidemiological associations were systematically assessed. Screening encompassed 957 close contacts (919 from the senior high school and 38 from the index case's junior high school class). Among these contacts, 18 active pulmonary tuberculosis cases (16 epidemiologically linked and 2 sporadic), 12 suspected cases, and 36 latent tuberculosis infections were identified. Four M. tuberculosis strains were successfully isolated from epidemiologically associated cases (including the index case, his junior high school classmate, high school deskmate, and current teacher). Genomic sequencing revealed that all strains exhibited isoniazid resistance and demonstrated high genetic homology (with <6 single nucleotide polymorphisms, SNPs). The index case had exhibited symptoms including cough and expectoration during junior high school; however, no abnormalities were detected during the physical examination upon senior high school enrollment. Additionally, routine daily health screenings conducted during morning and afternoon periods yielded consistently normal results. The investigation revealed that the index case had significant family contact history, with his father, two uncles, grandfather, and grandmother diagnosed with active pulmonary tuberculosis between 2019 and 2025, three of whom had confirmed isoniazid-resistant tuberculosis. This outbreak represented a tuberculosis cluster resulting from household transmission that subsequently spread across different school grades and classes. The delayed identification of the index case, attributable to multiple systemic factors, constituted the primary driver of disease dissemination. These findings underscore the critical importance of screening close contacts, particularly those who are teachers or students within affected families.

一起由家庭传播导致学校耐异烟肼结核病暴发的聚集性疫情调查分析 — 贵港市，广西壮族自治区，中国，2024年11月

许达^1,2,3,&；梁小烟^1,&；周凌云^1,&；陈伟^3,4；叶婧¹；李鹃¹；姚伟华⁵；朱金辉^6,#；崔哲哲^1,#

1.结核病防控所，广西壮族自治区疾病预防控制中心，南宁市，广西壮族自治区，中国；

2.传染病预防控制所，中国疾病预防控制中心，北京，中国；

3.中国现场流行病学培训项目，中国疾病预防控制中心，北京，中国；

4.结核病预防控制中心，中国疾病预防控制中心，北京，中国；

5.贵港市疾病预防控制中心，贵港市，广西壮族自治区，中国；

6.广西重大传染病防控及生物安全应急响应重点实验室，广西壮族自治区疾病预防控制中心，南宁市，广西壮族自治区，中国。

^& 共同第一作者。

^# 通信作者：崔哲哲，gxcdctbi@wsjkw.gxzf.gov.cn; 朱金辉，cdc@wsjkw.gxzf.gov.cn。

2024年11月27日，广西贵港市某高一年级发现一例活动性肺结核患者（病原学阳性）。采用现场流行病学调查的方法，确定密切接触者；对密切接触者进行密切接触史和可疑症状问诊、重组结核杆菌融合蛋白试验或γ-干扰素释放试验、胸部x射线或CT等肺结核相关检查；对疑似患者进行痰涂片、痰培养和分子生物学检测；培养阳性菌株进行药敏及测序分析；判定流行病学关联。筛查密切接触者957人（高中919人和指示病例初中同班38人），共发现活动性肺结核患者18例（其中16例有流行病学关联，2例散发）、疑似肺结核患者12例和潜伏感染者36例。在有流行病学关联的病例中分离获得4株结核分枝杆菌（包含指示病例、其初中同学、高中同桌、现任课教师），测序显示均为单耐异烟肼且高度同源（<6 SNPs (single nucleotide polymorphisms)）。流调发现指示病例在初中时就出现咳嗽、咳痰等症状，但高中入学体检、在校期间晨午检等未发现异常；他有家庭接触史，其父亲、2位叔叔、爷爷、奶奶共5人于2019-2025年间被确诊为活动性肺结核，其中3位为异烟肼耐药肺结核。该疫情是由家庭传播引发的跨学龄、跨班级的肺结核聚集性疫情，多环节导致指示病例发现延迟是引起该起疫情扩散的主要原因，凸显了对家庭密切接触者中学生和教师排查的重要性。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.183

A Foodborne Outbreak Associated with ST59-spa t441-SCCmec IVa Methicillin-resistant Staphylococcus aureus Producing Enterotoxins A and B — Puyang City, Henan Province, China, September 2024

Zhijie Zhao^1,&; Xiaoyue Wei^2,&; Aimei Wang¹; Wanting Wang²; Xiaofei Meng¹; Wentao Liu²; Yanlin Chang¹; Yakun Zhao²; Guangkang Li¹; Jianling Chen²; Yongli Li³; Yuanhai You²; Ling Zhao¹; Jianzhong Zhang²; Xianying Yan¹; Zhigang Cui²; Guofeng Xu¹; Haijian Zhou²; Xiaomei Yan^2,#; Qingjie Zhang^1,#

1. Puyang Key Laboratory for Infectious Disease Prevention and Control, Puyang Center for Disease Control and Prevention, Puyang City, Henan Province, China;

2. National Key Laboratory for Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China;

3. Henan Provincial Center for Disease Control and Prevention, Zhengzhou City, Henan Province, China.

^& Joint first authors.

^# Corresponding authors: Xiaomei Yan, yanxiaomei@icdc.cn; Qingjie Zhang, pycdczqj@163.com.

On September 16, 2024, the Puyang City CDC received a report of a suspected foodborne disease outbreak involving 14 individuals who developed nausea, vomiting, and diarrhea following attendance at a hotel banquet. Upon notification, the District CDC immediately deployed a specialized investigation team to characterize the epidemiological features of the outbreak, identify the causative pathogen, assess potential transmission risks, and implement effective control and prevention measures. We integrated comprehensive on-site epidemiological investigations, clinical symptom analyses, and laboratory diagnostics to isolate and identify pathogenic agents from retained food samples, environmental specimens, and anal swabs collected from affected cases. The recovered isolates underwent enterotoxin-virulence-gene profiling, antimicrobial-susceptibility testing, and phylogenetic analyses. Additionally, we characterized the architecture of the enterotoxin-A-linked pathogenicity island vSaβ. A total of 4 S. aureus strains were successfully isolated from 22 leftover food samples, 2 environmental swabs, and 2 patient anal swabs. Contaminated donkey and goose meat served as the outbreak source. All isolates harbored sea and seb enterotoxin genes, exhibited PEN-OXA-ERY-CLI resistance patterns, and were identified as clonal ST59-spa t441-SCCmec IVa CA-MRSA strains. Phylogenetic analysis positioned the outbreak strains within the Asia-Pacific clade, distinguishing them from the North American ST59 sub-lineage. Comprehensive analysis of the sea-associated virulence island vSaβ identified a novel structural arrangement containing a type A IEC cluster (sea-sak-chp-scn). The detection of foodborne ST59 CA-MRSA clones in this outbreak underscores the prevalence and transmission risks associated with this hypervirulent lineage. These findings emphasize the critical need to strengthen surveillance measures for CA-MRSA among food industry workers.

一起与ST59-spa t441-SCCmec IVa产肠毒素A和B耐甲氧西林金黄色葡萄球菌相关的食物中毒事件 — 濮阳市，河南省，中国，2024年9月

赵志杰^1,&; 魏销玥^2,&; 王爱梅¹; 王婉婷²; 孟晓飞¹; 刘文韬²; 常艳林¹; 赵雅坤²; 李广康¹; 陈建伶²; 李永利³; 尤元海²; 赵令¹; 张建中²; 闫现营¹; 崔志刚²; 徐国锋¹; 周海健²; 闫笑梅^2,#; 张清杰^1,#

1. 传染病预防控制重点实验室，濮阳市疾病预防控制中心，濮阳市，河南省，中国；

2. 传染病溯源预警与智能决策全国重点实验室，传染病预防控制所，中国疾病预防控制中心，北京，中国；

3. 河南省疾病预防控制中心，郑州市，河南省。

^& 共同第一作者。

^# 通信作者：闫笑梅，yanxiaomei@icdc.cn; 张清杰, pycdczqj@163.com。

2024年9月16日，濮阳市疾病预防控制中心接到一起疑似食源性疾病暴发报告，14人在参加酒店宴会后出现恶心、呕吐、腹泻等症状。区疾控中心在接到报告后，立即派出专门小组调查疫情流行病学特征，鉴定病原，评估潜在传播风险，实施有效防控措施。本研究整合现场流行病学调查、临床症状分析及实验室检测等方法，对留样食品、环境样本及病例肛拭子进行病原体分离与鉴定。随后对分离株开展肠毒素毒力基因谱分析、药敏试验、系统发育分析，并对 sea 相关毒力岛 vSaβ 的结构进行解析。从 22 份留样食品、2 份环境样本及 2 份病例肛拭子中分离到 4 株金黄色葡萄球菌；污染源为受污染的驴肉和鹅肉。所有菌株均携带 sea 和 seb 肠毒素基因，表现 青霉素-苯唑西林-红霉素-克林霉素耐药，且为ST59-spa t441-SCCmec IVa CA-MRSA克隆菌株。系统发育分析表明，此次暴发菌株属于亚太谱系，不同于北美 ST59分支。对sea相关毒力岛的深入分析发现了一个包含A型IEC簇的新结构（sea-sak-chp-scn）。本研究在暴发中检出的 ST59 CA-MRSA 食源性克隆凸显该高毒力谱系的流行及传播风险，亟需加强食品从业人员的 CA-MRSA 监测。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.184