Laboratory-Confirmed Influenza Hospitalizations During Pregnancy or the Early Postpartum Period — Suzhou City, Jiangsu Province, China, 2018–2023

Jinghui Sun^1,2; Yuanyuan Zhang²; Suizan Zhou³; Ying Song³; Suping Zhang²; Jie Zhu⁴; Zhiyuan Zhu⁴; Rui Wang⁵; Hong Chen⁶; Liling Chen^1,2#; Haibing Yang²; Jun Zhang⁷; Eduardo Azziz-Baumgartner³; W. William Schluter³

1 School of Public Health, Nanjing Medical University, Nanjing,Jiangsu Province, China;

2 Suzhou Center for Disease Control and Prevention, Suzhou City, Jiangsu Province, China;

3 Influenza Division, National Center for Immunization and Respiratory Diseases, CDC, US;

4 Suzhou Health and Family Planning Statistics InformationCenter, Suzhou City, Jiangsu Province, China;

5 School of PublicHealth, Xuzhou Medical University, Xuzhou City, Jiangsu Province,China;

6 Chinese Center for Disease Control and Prevention, Beijing,China;

7 Suzhou No.5 People’s Hospital, Suzhou City, JiangsuProvince, China.

^# Corresponding author: Liling Chen, liling_chen@163.com.

Pregnancy is associated with increased risk for severe illness and complications associated with influenza infection. Insufficient knowledge about the risk for influenza among pregnant women and their health care providers in China is an important barrier to increasing influenza vaccination coverage and treating influenza and its complications among pregnant women. Improved influenza incidence estimates might promote wider vaccine acceptance and higher vaccination coverage. In Suzhou, active population-based surveillance during October 2018–September 2023 estimated that the annual rate of hospitalization for acute respiratory or febrile illness (ARFI) among women who were pregnant or <2 weeks postpartum was 11.1 per 1,000 live births; the annual rate of laboratory-confirmed influenza-associated ARFI (influenza ARFI) hospitalization in this group was 2.1 per 1,000 live births. A majority of hospitalized pregnant or early postpartum patients with ARFI (82.6%; 2,588 of 3,133) or influenza ARFI (85.5%; 423 of 495) were admitted to obstetrics wards rather than respiratory medicine wards. Only one (0.03%) pregnant or postpartum ARFI patient had received influenza vaccination, and 31.3% of pregnant or postpartum women hospitalized for influenza ARFI received antiviral treatment; the lowest percentage of hospitalized women with influenza ARFI who received antiviral treatment was among women admitted to obstetrics and gynecology wards (29.6% and 23.1%, respectively), compared with 54.1% of those admitted to a respiratory medicine ward. These findings highlight the risk for influenza and its associated complications among pregnant and postpartum women, the low rates of influenza vaccination among pregnant women, and of antiviral treatment of women with ARFI admitted to obstetrics and gynecology wards. Increasing awareness of the prevalence of influenza ARFI among pregnant women, the use of empiric antiviral treatment for ARFI, and the infection control in obstetrics wards during influenza seasons might help reduce influenza-associated morbidity among pregnant and postpartum women.

孕妇或产后早期妇女实验室确诊流感住院情况 — 江苏省苏州市，中国，2018–2023年

孙静慧^1,2；张媛媛²；周穗赞³；宋英³; 张素萍²; 朱杰⁴; 朱志远⁴; 王睿⁵; 陈虹⁶; 陈立凌^1,2#; 杨海兵²; 张钧⁷; Eduardo Azziz-Baumgartner³; W. William Schluter³

1南京医科大学，公共卫生学院；

2苏州市疾病预防控制中心；

3 流感科，国家免疫和呼吸疾病中心，美国疾病预防控制中心，美国；

4苏州卫生信息中心；

5徐州医科大学, 公共卫生学院；

6中国疾病预防控制中心；

7苏州第五人民医院。

^# 通信作者：陈立凌，liling_chen@163.com。

怀孕会增加流感感染相关的重症和并发症的发生风险。国内孕妇及其医疗保健提供者对流感风险了解不足是提高孕妇流感疫苗接种率和治疗流感及其并发症的重要障碍之一。更准确的流感风险估计可能会提高流感疫苗接受度和疫苗接种率。苏州2018 年 10 月至 2023 年 9 月期间基于全人群的主动监测结果估计，怀孕或产后2 周内的妇女（孕产妇）急性呼吸系统疾病或发热性疾病 （ARFI） 住院率为每年11.1例/ 1,000 名活产婴儿；实验室确诊的流感相关 ARFI （流感 ARFI） 住院率为每年2.1 例/ 1,000 名活产婴儿。大部分住院孕产妇ARFI患者（82.6%）或流感ARFI患者（85.5%）收治于产科病房。监测人群中只有 1 名 （0.03%） 孕产妇ARFI 患者接受了流感疫苗接种，31.3% 因流感 ARFI 住院的孕产妇在住院前或住院期间接受过特效的抗病毒治疗；接受抗病毒治疗比例最低的是收治于产科和妇科病房的孕产妇流感 ARFI患者（分别为 29.6% 和 23.1%），而呼吸内科病房收治的孕产妇流感 ARFI患者接受抗病毒治疗的比例为 54.1%。本研究量化了孕产妇流感相关风险，突显了孕产妇人群流感疫苗接种率低、流感患者尤其是收治于妇产科病房患者抗病毒治疗率也较低的问题。提高孕妇流感疫苗接种率，以及提高医疗机构尤其是产科医生对孕产妇流感风险的认识，对 孕产妇ARFI 患者进行经验性抗病毒治疗，加强产科病房流感感染控制，可能有助于降低流感对孕产妇的健康影响。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.231

Social Network Analysis of a Norovirus Outbreak at a Primary School — Zhuhai City, Guangdong Province, China, 2023

Xiling Yin¹, Songjian Xiao¹, Xuebao Zhang¹, Feng Ruan^1# 

1 Department of Health Emergency Management, Center for Disease Control and Prevention of Zhuhai City, Zhuhai City, Guangdong Province, China.

^# Corresponding author: Feng Ruan, jkzxrf@zhuhai.gov.cn.

To analyze the social network spread patterns of a norovirus outbreak in a school and identify key nodes (cases) to provide a theoretical basis for targeted control strategies. A 63 × 63 transmission relationship matrix between each node was established. Based on the lifecycle of the epidemic, from the initial outbreak through its spread and eventual decline, UCINET (6.528) was used to perform network analysis and calculate characteristic parameters. NetLogo (6.1.1) was used to model and simulate the effects of intervention measures during different epidemic periods. The network density of the norovirus outbreak gradually changed from dense (0.871) to loose (0.099) during the lifecycle of the epidemic. The indicators point to 12 key nodes that were identified during the spread and recession periods. By controlling 10 key nodes (eliminating the factors of mixed class hosting at school) during the spread periods, the step length of the curve (819) was significantly reduced. When the 2 key nodes (controlling the spread of vomiting) were eliminated during the recession period, the curve showed that the step length (680) was further reduced. Infected students exhibit priority connection characteristics in different developmental periods in the network topology. Identifying and deliberately targeting key nodes could destroy network connectivity and help reduce the spread of the outbreak.

基于一起学校诺如病毒感染暴发疫情的社会网络分析 — 广东省珠海市，中国，2023年

尹锡玲¹；萧松建¹；张雪宝¹；阮峰^1#

1广东省珠海市疾病预防控制中心，珠海市，广东省，中国。

^# 通信作者：阮峰，jkzxrf@zhuhai.gov.cn。

分析学校诺如病毒感染暴发疫情的社会网络传播模式，识别关键节点（病例），为采取有针对性的控制策略提供理论依据。建立了63×63病例的传输关系矩阵，以暴发、扩散及下降三个疫情发展阶段为基础，采用UCINET（6.528）分析社会网络拓扑结构，并计算特征参数。采用NetLogo（6.1.1）对不同疫情发展阶段干预措施的效果进行建模和模拟。诺如病毒暴发疫情的不同发展阶段显示其社会网络密度逐渐从密集（0.871）转变为松散（0.099）。社会网络参数指标识别出在扩散和下降阶段共有12个关键节点。通过控制疫情扩散期间的10个关键节点（消除学校混班托管的因素），曲线的步长（819）显著减少。在疫情下降期间控制2个关键节点（减少呕吐物引起的感染扩散），曲线显示步长（680）进一步减少。诺如病毒感染病例在网络拓扑结构的不同发展阶段表现出优先连接特征。识别并对关键节点采取针对性控制措施可以破坏网络连接，有助于减少疫情的传播范围。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.232.

Emergence of a New Sublineage of Candida auris Causing Nosocomial Transmissions — Beijing Municipality, China, March-September 2023

Zhenjia Liu^1*; Xinfei Chen^2*; Rongchen Dai^3*; Yu Bai¹; Feiyi Liu^2,3; Yiying Zhao^2,3; Xuesong Shang^2,3; Chunxia Yang¹; Xin Fan^1,2#

1. Department of Infectious Diseases and Clinical Microbiology, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China;

2. Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China;

3. Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.

* Joint first authors.

^# Corresponding author: Xin Fan, fanxin12356@163.com.

Candida auris is an emerging multidrug-resistant fungal pathogen classified as a global public health threat with notable mortality and nosocomial transmission capacity. In China, the first C. auris case was reported from Beijing in 2018. However, large cases of nosocomial transmission have rarely been identified in this municipality. During March–September 2023, C. auris was isolated from 17 patients admitted to CY Hospital in Beijing. All strains were resistant to fluconazole and amphotericin B. In addition, three isolates were resistant to echinocandins. Whole-genome sequencing (WGS) analysis revealed that all strains found in this hospital belonged to C. auris Clade I. These strains were genetically closely related to the C. auris strains reported in two other hospitals in Beijing since 2021, forming a new sublineage different from the Clade I strains causing previous outbreaks in the Eastern Provincial-level administrative divisions (PLADs) and Hong Kong Special Administrative Region. The dissemination of C. auris has become an increasing threat to healthcare facilities in China. The WGS analysis indicates the spread of a unique sublineage of C. auris Clade I isolates in Beijing. Further, enhanced surveillance and hospital infection control of C. auris are warranted to resolve the public health challenge.

耳念珠菌新的亚支系引起医疗机构内传播 — 中国北京直辖市，2004–2022年

刘振嘉^1&; 陈新飞^2&; 戴榕辰^3&; 白羽¹; 刘菲怡³; 赵逸滢²; 尚雪松²; 杨春霞¹; 范欣^1#

1. 感染和临床微生物科，首都医科大学附属北京朝阳医院-北京市呼吸疾病研究所，北京，中国；

2. 疑难重症及罕见病全国重点实验室，中国医学科学院北京协和医院检验科，北京，中国；

3. 中国医学科学院北京协和医学院研究生院，北京，中国。

^* 共同第一作者

^# 通信作者：范欣, fanxin12356@163.com。

耳念珠菌（Candida auris）是一种新发的多药耐药真菌病原体，具有高致死率和院内传播能力，已被列为全球重大公共卫生威胁。我国2018年首次在北京发现了耳念珠菌病例。然而迄今为止，该市罕有大规模耳念珠菌院内传播的报告。在2023年3月至9月期间，北京朝阳医院在住院患者中发现了17例耳念珠菌阳性病例。所有耳念珠菌分离株均对氟康唑和两性霉素B耐药。此外，有3株分离株对棘白菌素类药物耐药。全基因组测序分析显示，该机构的所有菌株均属于耳念珠菌 Clade I分支。所有菌株均与自2021年以来在北京其他医疗机构中分离的耳念珠菌在系统发生学上密切相关，并形成了与既往在中国东部及香港地区引起流行传播的Clade I耳念珠菌不同的亚支系。耳念珠菌传播已成为我国医疗机构面临的严重威胁。全基因组分析表明，北京地区出现了一个独特的耳念珠菌Clade I亚支系的传播。相关机构亟需加强对耳念珠菌的监测和医院感染控制，以应对这一公共卫生挑战。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.233.

Application of an Integrated Risk Matrix and the Borda Count Method on Lassa Fever in Assessing the Importation Risk of EID — 9 African Countries, 1996–2023

Weijing Shang¹; Yu Wu¹; Jue Liu1; Wannian Liang²; Min Liu^1#

1 School of Public Health, Peking University, Beijing, China;

2 Vanke School of Public Health, Tsinghua University, Beijing, China.

# Corresponding author: Min Liu, liumin@bjmu.edu.cn.

Common methods for assessing and responding to outbreaks of emerging infectious diseases (EIDs) are usually applied in isolation and have limitations. This study aimed to integrate the risk matrix and Borda count methods to assess the importation risk of EIDs to China, using Lassa fever (LF) as an example. This study used a mixed-methods approach combining multi-source data with an integrated risk matrix and Borda count method. Data were obtained from the World Health Organization, the Concise Statistics of International Students dataset, the United Nations World Tourism Organization, and the Statistical Yearbook. Importation risk was assessed across two dimensions: possibility and severity. Total importation risk was then categorized into 4 levels (low, moderate, high, and extremely high), corresponding to green, yellow, orange, and red zones, respectively, in the risk matrix assessment index. The Borda count method was used to rank the risks. The importation risk for 9 countries that experienced LF outbreaks from 1996 to 2023 was scored and ranked by importation possibility and severity to derive overall importation risks. This study determined that Nigeria posed the highest LF importation risk to China, ranking first among West African countries with the highest Borda points. Countries with moderate importation risk included Sierra Leone, Burkina Faso, and Ghana. An integrated risk matrix and Borda count method presented in this study may serve as a significant supplement to other risk assessment methods and enrich the current toolbox of public health countermeasures and inform future risk management of the importation of EIDs.

应用风险矩阵和Borda序值法分析拉沙热以评估新发传染病的输入风险 — 9个非洲国家，1996–2023年

商伟静¹；吴俣¹；刘珏¹；梁万年²；刘民^1#

1 北京大学公共卫生学院，北京，中国；

2 清华大学万科公共卫生与健康学院，北京，中国。

^# 通信作者：刘民，liumin@bjmu.edu.cn。

新突发传染病（emerging infectious diseases, EIDs）风险评估的常用方法通常单独使用且存在一定的局限性。本研究旨在联合应用风险矩阵和Borda序值法评估EIDs对中国的输入风险，具体以拉沙热（LF）为例。 本研究采用多源数据，联合风险矩阵和Borda序值法对EIDs输入中国的风险进行评估。研究使用的数据主要来自世界卫生组织、《简明留学生统计》数据集、联合国世界旅游组织和《统计年鉴》。输入风险从可能性和严重性两个维度进行评估；总的输入风险划分为4个等级：低、中、高和极高，分别对应风险矩阵评估指数中的绿色、黄色、橙色和红色区域。采用Borda序值法对风险大小排序。对1996-2023年9个国家的LF疫情输入中国的可能性和严重性风险进行了评估和排序，最终得出了总的输入风险。本研究显示，尼日利亚LF疫情输入中国的风险最高，Borda数值最高，排在西非国家中第1位。输入风险为中等的国家为塞拉利昂、布基纳法索和加纳。本研究提出的风险矩阵和Borda序值法的联合使用可作为当前EIDs风险评估方法的重要补充，丰富现有的公共卫生对策，并为今后EIDs的输入风险管理提供参考。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.234

Retrospective Analysis of the Epidemiological Evolution of Brucellosis in Animals — China, 1951–1989 and 1996–2021

Zhiguo Liu¹, Miao Wang², Yingqi Wang³, Min yuan¹, Zhenjun Li^1,4#

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

2 Ulanqab Center for Disease Control and Prevention, Jining City, Inner Mongolia Autonomous Region, China.

3 Tongliao Center for Disease Control and Prevention, Horqin City, Inner Mongolia Autonomous Region, China.

4 Chinese Center for Disease Control and Prevention, Beijing, China.

^# Corresponding author: Zhenjun Li, lizhenjun@icdc.cn.

Brucellosis poses a significant threat to public health in China. This study utilized a range of epidemiological indices, including seroprevalence and the number of reported cases, to illustrate the epidemic profile of the disease. Although the seroprevalence of brucellosis in animals (including sheep, goats, cattle, and swine) steadily decreased from a severe epidemic level in the 1950s to a low endemic level by 1989, the disease reemerged in 2000. Subsequently, there has been a persistent increase in the frequency of outbreaks and the number of reported cases from 2006 to 2021, with over 98% of reported cases occurring in sheep and cattle. During this period, the culling rate declined, while infection rates increased, nearly reversing their respective trajectories. The decrease in the culling rate of positive animals coincided with an increase in infection rates, indicating that infection among these animals was persistent and circulating. In the southern regions of China, 6.34% (34,070 of 537,797) of cases were reported between 2006 and 2021, whereas in the northern regions, 93.67% (503,727 of 537,797) of cases occurred during the same timeframe. Each time cases increased in the south, they lagged 2 to 5 years behind those in the north, suggesting that stringent control measures for sheep and cattle in the north should be prioritized. These findings provide critical insights into developing control strategies to mitigate the spread of the disease.

动物布鲁氏菌病流行病学演化特征回顾性分析 — 中国，1951–1989和1996–2021年

刘志国¹，王妙²，王瑛琦³，袁敏¹，李振军^1,4

1传染病预警溯源与智能决策全国重点实验室，中国疾病预防控制中心传染病预防控制所，北京，中国；

2 乌兰察布市疾病预防控制中心，集宁市，内蒙古自治区，中国

3 通辽市疾病预防控制中心，科尔沁市，内蒙古自治区，中国

4 中国疾病预防控制中心，北京，中国。

^# 通信作者：李振军，lizhenjun@icdc.cn。

布鲁氏菌病（布病）已对中国公众健康构成重大威胁。本研究采用系列流行病学指标包括血清流行率和报告病例数等阐述该疾病的流行演化特征。尽管动物（包括绵羊、山羊、牛和猪）布病的血清流行率从20世纪50年代的严重流行水平稳步下降到1989年的低流行水平，但该疾病于2000年再次复燃。随后，从2006年到2021年疫情暴发频率和报告病例数持续增加，98%以上的报告病例来自绵羊和牛。在此期间，动物扑杀率下降，相反感染率则上升，两者几乎呈现相反的演化趋势。阳性动物扑杀率的下降与感染率的上升相吻合，表明动物间布病感染持续存在和循环传播。2006年至2021年间, 6.34%（34,070/537,797）的病例报告在南方地区,93.67%（503,727/537,797）的病例发生在北方地区。南方地区每次病例增加总落后于北方地区2-5年，表明迫切需要对北方的绵羊和牛采取严格的监测、防控措施。本研究为制定和实施有针对性的防控策略以遏制布病传播提供了科学的依据和见解。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.235