Variations in the Bacterial Ecosystemsof Mosquito Populations — Haikou and Sanya Cities, Hainan Province, China, 2019

Xun Kang^1,2,&;Yanhong Wang^3,&; Rui Zheng¹; Mamy Jayne Nelly Rajaofera¹;Lin Liu¹; Siping Li¹; Xiaomei Sun^3,4; Le Kang^3,4;Nan Zhang^1,5,#; Zhen Zou^4,# ; Qianfeng Xia^1,#

1.NHC Key Laboratory of Tropical Disease Control, School of Tropical Medicine,Hainan Medical University, Haikou City, Hainan Province, China;

2.State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology, Chinese Academy of Sciences, Beijing, China;

3.CAS Center for Excellence in Biotic Interactions, University of Chinese Academyof Sciences, Beijing, China;

4.Hainan Tropical Disease Research Center (Hainan Sub-Center, Chinese Center forTropical Disease Research), Haikou City, Hainan Province, China;

5.School of Biomedical Engineering, Sun Yat-sen University, Shenzhen City,Guangdong Province, China.

^& Joint first authors.

^# Corresponding authors: Qianfeng Xia, xiaqianfeng@hainmc.edc.cn; Zhen Zou,zouzhen@ioz.ac.cn; Nan Zhang, hy0211075@hainmc.edu.cn.

This study explores the midgut microbiotaof mosquitoes in Haikou and Sanya cities, regions critical for understandingvector-borne disease dynamics in Hainan Province, China. It provides baselinedata on microbial composition and examines their potential role in influencingmosquito biology and vector competence, while highlighting the need for furtherresearch into their association with vector-borne viral infections. Adult mosquitoes were collected using light traps andhuman bait methods. Species identification was conducted through morphologicalexamination and DNA barcoding using the cytochrome c oxidase subunit 1 gene(cox1). The V3–V4 hypervariable regions of the microbial 16S ribosomal RNA(rRNA) gene were sequenced using high-throughput methods to investigate themidgut microbiota. Statistical analyses, including Alpha and Beta diversityassessments of the sequencing results, were performed using SPSS 21.0 and Rversion 3.11.The predominant mosquito species identified were Aedes albopictus, Armigeressubalbatus, and Culex pipiens.Microbiota analysis of 281 midguts revealed that Proteobacteria dominated (85.28%), with significant fractions beingAlphaproteobacteria (52.14%), Gammaproteobacteria (29.90%), and Betaproteobacteria (3.22%). Othernotable phyla included Firmicutes(6.24%), Actinobacteria (3.81%), andlesser quantities of Thermi, Cyanobacteria, and Bacteroidetes. Significant geographic variation in bacterialcommunities was observed between Haikou and Sanya (P<0.05), withunique taxa like Thermi and Cyanobacteria identified only in Haikou andChlamydiae found solely in Sanya. Theanalysis revealed 204 overlapping species, with 473 unique to Haikou and 64 toSanya. While the direct relationship between these microbialvariations and vector-borne disease dynamics requires further investigation,these findings underscore the importance of mosquito microbiota research aspart of broader strategies to mitigate vector-borne disease risks.

海口与三亚蚊虫群体细菌群落的变化—海口和三亚市，海南省，中国，2019年

康迅^1,2,&；王燕红^3,&；郑蕊¹；Mamy Jayne Nelly Rajaofera¹；刘琳¹；李泗平¹；孙晓梅^3,4；康乐^3,4；张楠^1,5,#；邹振^4,# ；夏乾峰^1,#

1. 国家卫生健康委员会热带病防治重点实验室，热带医学院，海南医科大学，海口市，海南省，中国；

2. 害虫与啮齿动物综合管理国家重点实验室，动物研究所，中国科学院，北京，中国；

3. 中国科学院生物相互作用卓越中心，中国科学院大学，北京，中国；

4. 海南热带病研究中心（中国热带病研究中心海南分中心），海口市，海南省，中国；

5. 生物医学工程学院，中山大学，深圳市，广东省，中国。

^& 共同第一作者。

^# 通信作者：夏乾峰，xiaqianfeng@hainmc.edc.cn；邹振，zouzhen@ioz.ac.cn；张楠，hy0211075@hainmc.edu.cn。

本研究旨在探索海南省海口市与三亚市蚊子中肠的微生物群落组成，分析其在蚊媒疾病传播动态中的潜在作用，为进一步揭示蚊子微生物群与病毒感染之间的关系提供基础数据。采用灯诱法和人诱法收集成蚊，通过形态学特征与线粒体细胞色素氧化酶亚基1（cox1）基因条形码技术进行蚊类鉴定。利用高通量测序技术对蚊子中肠中16S rRNA基因的V3–V4可变区进行扩增和分析，采用SPSS 21.0与R 3.11软件进行Alpha与Beta多样性统计分析。鉴定出主要蚊种为白纹伊蚊（Aedes albopictus）、骚扰阿蚊（Armigeres subalbatus）和淡色库蚊（Culex pipiens）。对281份中肠样本的微生物菌群分析显示，变形菌门（Proteobacteria）为主要优势菌门，占比达85.28%，其中包括α-变形菌(Alphaproteobacteria)占52.14%、γ-变形菌(Gammaproteobacteria)占29.90%、β-变形菌(Betaproteobacteria)占3.22%。此外还检测到厚壁菌门(Firmicutes)占6.24%、放线菌门(Actinobacteria)占3.81%、以及少量的热丝菌门（Thermi）、蓝藻门（Cyanobacteria）与拟杆菌门（Bacteroidetes）。海口和三亚之间存在显著的地理差异（P＜0.05），海口特有的分类单元包括Thermi和Cyanobacteria，而三亚则发现了衣原体门（Chlamydiae）。研究共识别出204种重叠物种，其中海口特有473种，三亚特有64种。虽然微生物群落变异与蚊媒疾病传播之间的直接关系仍需进一步研究，但结果强调了深入探索蚊子微生物组在防控蚊媒传播疾病中的重要意义。

For more information:https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.086

Dengue FeverScreening Awareness and Capacity in Healthcare Facilities — Guangzhou City,Guangdong Province, China, 2024

Haipeng Luo^1,2,&; Lei Luo^2,&; Wenhui Liu^2,&;Pengzhe Qin^2,#; Zhoubin Zhang^1,2,#

1. School of Public Health, Sun Yat-senUniversity, Guangzhou City, Guangdong Province, China;

2. Department of Communicable DiseaseControl and Prevention, Guangzhou Center for Disease Control and Prevention,Guangzhou City, Guangdong Province, China.

^& Joint first authors.

^# Corresponding author:Pengzhe Qin, gzcdc_qinpz@gz.gov.cn; ZhoubinZhang, gzcdc_zhangzb@gz.gov.cn.

Dengue feverrepresents a significant public health challenge in tropical and subtropicalregions worldwide, including China. This study aims to enhance early denguedetection and diagnosis by evaluating healthcare facilities' diagnosticcapacity and clinicians' awareness. In June 2024, surveys were conducted in 11secondary and higher-level hospitals and 11 community health centers. Data fromfacilities evaluations and clinician questionnaires were analyzed usingchi-square tests and logistic regression. Secondary and higher-level hospitalsdemonstrated more robust dengue-related institution-building but exhibiteddeficiencies in suspected case screening and public awareness efforts.Additionally, polymerase chain reaction (PCR) testing capacity was limited toone higher-level hospital, and nonstructural protein 1 (NS1) testing costs werehigh in secondary and higher-level hospitals, with varying reimbursement ratesdue to different insurance types and institutional levels. Significant disparitiesin diagnostic awareness were found across hospital levels, department, age, and professional title(P<0.05).Theregression analysis shows that education can significantly enhance diagnosticawareness (OR=13.780, 95% CI: 2.937, 64.650). These findingsunderscore the need for dynamically adjust dengue testing strategies atdifferent epidemic stages and improve NS1 testing cost reimbursement. Also,there should be more efforts in enhancing PCR testing in healthcare facilitiesand promoting health education.

医疗机构的登革热筛查意识和能力— 广州市，广东省，中国，2024年

罗海鹏^1,2,&；罗雷^2,&；刘文辉^2,&；秦鹏哲^2,#；张周斌^1,2,#

1. 公共卫生学院，中山大学，广州市，广东省，中国；

2. 传染病预防控制科，广州市疾病预防控制中心，广州市，广东省，中国。

^& 共同第一作者。

^# 通信作者:秦鹏哲，gzcdc_qinpz@gz.gov.cn；张周斌，gzcdc_zhangzb@gz.gov.cn。

登革热是全球热带和亚热带地区包括中国在内面临的重大公共卫生挑战。本研究旨在通过评估医疗机构诊断能力及临床医生认知现状以提高登革热早期发现与诊断能力。本研究于2024年6月，对广州市11家二级及以上医院以及11家社区卫生服务中心开展机构评估和临床医生问卷调查，并采用卡方检验和二元Logistic回归进行数据分析。研究发现在22家机构中，二级及以上医院在登革热相关制度建设方面优于基层机构，但仍存在疑似病例筛查不足、健康宣教主动性有待提升等问题。此外，调查发现，22家医疗机构中仅1家开展PCR检测能力。同时，二级及以上医院的NS1检测费用相对较高，而不同医保类型和医疗机构级别报销比例不一致。临床医生诊断意识在不同医院级别、科室、年龄、职称间存在显著差异（P<0.05）。回归分析显示，教育可以显著提高诊断意识（OR=13.780，95% CI：2.937, 64.650）。本研究结果突显了在疫情流行期的不同阶段，动态调整登革热查策略并改善NS1检测费用报销机制的必要性。此外还应加强医疗机构PCR检测以及宣传教育工作的建设。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.087

Pathogenic Bacteria Detection inParasitic Fleas — Jiangxi Province, China, 2023

Lijuan He^1,&;Zhiyun Liu^2,&; Like Duan¹; Lin Zhang¹;Xuexia Hou¹; Jingwen Li¹; Qin Hao^1,#

1. National KeyLaboratory of Intelligent Tracking and Forecasting for Infectious Diseases,National Institute for Communicable Disease Control and Prevention, ChineseCenter for Disease Control and Prevention, Beijing, China;

2. Inspection Department of Ji’an CentralPeople’s Hospital, Ji’an City, Jiangxi Province, China.

^& Joint first authors.

^# Corresponding author: QinHao, haoqin@icdc.cn.

Fleasare vectors for the transmission of various pathogens. In order to understandthe pathogens carried by parasitic fleas in domestic dogs and to evaluate thepathogenic risk to humans. In July 2023, 121 fleas were collected from 6 dogsof different farmers' household by body surface examination in Suichuan County,Ji' an City, Jiangxi Province. The flea species were determined bymorphological identification and CoII gene detection. Then whole genomicDNA was extracted from 121 fleas and six pathogens including Borreliaburgdorferi, Borrelia miyamotoi, Anaplasma phagocytophilum, Coxiellaburnetii, spotted fever group Rickettsia and Ehrlichiachaffiensis were detected via Nested-PCR.The positive products weresequenced, and the carrier status of each pathogen was analyzed. A total of 121fleas were identified, with 118 Pulex irritans and 3 Ctenocephalidesfelis. The PCR results showed that Borrelia burgdorferi (5%, 6/118),Borrelia miyamotoi (0.8%,1/118), Borrelia hermsii (9%,11/118), Anaplasmaphagocytophilum (0.8%, 1/118), spotted fever group Rickettsia (0.8%,1/118) and Coxiella burnetii (0.8%, 1/118) were detected in 118 Pulexirritans, and the positive samples also showed mixed infection of Borreliaburgdorferi and Anaplasma phagocytophilum (0.8%, 1/118). This studysuggests that Pulex irritans can carry multiple pathogens, and theirsignificance for public health needs further exploration.

寄生蚤病原菌检测—江西省，中国，2023年

贺丽娟^1,&；刘志云^2,&；段立科¹；张琳¹；侯学霞¹；李静雯¹；郝琴^1,#

1、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；

2、吉安中心人民医院检验科，吉安市，江西省，中国。

^&共同第一作者。

^# 通信作者：郝琴，haoqin@icdc.cn。

跳蚤是多种病原体的传播媒介。为了解家犬寄生跳蚤携带的病原体并评估其对人类的致病风险，2023年7月，在江西省吉安市遂川县，通过体表检查从6户农户的狗身上采集了121只跳蚤。通过形态学鉴定和CoII基因检测确定了跳蚤种类，随后提取了121只跳蚤的DNA，并使用巢式PCR检测了六种病原体，包括伯氏疏螺旋体、米氏疏螺旋体、嗜吞噬细胞无形体、贝纳柯克斯体、斑点热群立克次体和查菲埃立克体。对阳性产物进行测序，并分析了每种病原体的携带情况。共鉴定出121只跳蚤，其中118只为人蚤，3只为猫栉首蚤。PCR结果显示，在118只人蚤中检测到伯氏疏螺旋体（5%，6/118）、米氏疏螺旋体（0.8%，1/118）、赫姆斯疏螺旋体（9%，11/118）、嗜吞噬细胞无形体（0.8%，1/118）、斑点热群立克次体（0.8%，1/118）和贝纳柯克斯体（0.8%，1/118），且有一例阳性样本同时感染了伯氏疏螺旋体和嗜吞噬细胞无形体（0.8%，1/118）。研究表明，人蚤可携带多种病原体，其对公共卫生的意义需进一步探讨。

For more information:https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.088

First Human Case of DiphyllobothriosisDue to Dibothriocephalus Dendriticus Infection — China, November 2023

Jiahui Sun¹; Jiatian Guo¹; Yan Zhou¹;Shaohong Chen¹; Yan Lu^1,#

1. National Key Laboratory of IntelligentTracking and Forecasting for Infectious Diseases, National Institute ofParasitic Diseases, Chinese Center for Disease Control and Prevention, ChineseCenter for Tropical Diseases Research, NHC Key Laboratory of Parasite andVector Biology, WHO Collaborating Centre for Tropical Diseases, National Centerfor International Research on Tropical Diseases, Ministry of Science andTechnology, Shanghai, China.

^# Corresponding author:Yan Lu,luyan@nipd.chinacdc.cn.

Human diphyllobothriosisis a global fish-borne zoonosis affecting approximately 20 million people. Thisstudy reports the first human case of Dibothriocephalusdendriticus (D. dendriticus) inChina and explores its epidemiological and phylogenetic implications. Morphologicalfeatures of eggs and proglottids were examined. The mitochondrial cox1 gene was sequenced for speciesidentification. Phylogenetic analysis and epidemiological data were analyzed totrace the infection source. The expelled tapewormmeasured 50 cm in length and 0.7 cm in width. The gravid proglottid was longerthan wide, with a centrally positioned uterus. Eggs measured63.29±1.17×48.31±0.94 μm (n=15) and had an operculum. The cox1 gene (PQ169609) showed 99.87% homology with D. dendriticus (AM412738.2).Morphological and molecular analyses confirmed the parasite as D. dendriticus. Consumption of rawsalmon in Hong Kong Special Administrative Region (May 2023) and raw trout inBeijing Municipality (August 2022) were identified as potential infectionsources. Phylogenetic analysis linked the strain to one from UK fish(KY552870), suggesting a common origin. This study reports the first humancase of D. dendriticus in China. Ithighlights the emerging threat of D.dendriticus amid globalization and rising fish consumption. Strengtheningfood safety measures is essential to reducing infection risk.

首例由Dibothriocephalus dendriticus引起的人裂头绦虫病病例分析 — 中国，2023年11月

孙家辉¹；郭嘉天¹；周魇¹；陈韶红¹；卢艳^1,#

1. 传染病溯源预警与智能决策全国重点实验室；中国疾病预防控制中心寄生虫病预防控制所（国家热带病研究中心）；国家卫生健康委员会寄生虫病原与媒介生物学重点实验室；世界卫生组织热带病合作中心；科技部国家级热带病国际研究中心，上海，中国。

^# 通讯作者:卢艳，luyan@nipd.chinacdc.cn。

裂头绦虫病是全球流行的鱼源性人兽共患病，感染人数约有2,000万。本研究报道了一例人裂头绦虫病病例，分析了裂头绦虫虫卵、节片的形态学和基因序列的特征及病人的流行病史，并进行了鉴别诊断。观察虫卵、节片形态学特征，扩增裂头绦虫cox1目的基因，通过序列分析和系统发育分析进行虫种鉴定。对病例的流行病学情况进行调查，推断其感染来源。患者排出虫体长度为50cm×0.7cm。孕节长大于宽，子宫位于中心位置。虫卵近椭圆形，有卵盖，大小为63.29 ± 1.17 × 48.31 ± 0.94 μm (n=15)，为裂头属绦虫卵。cox1序列已上传至美国国家生物技术信息中心（NCBI）数据库，登录号为：PQ169609。该序列与枝形裂头绦虫序列（GenBank：AM412738.2）同源性为99.87%，确定虫体为枝形裂头绦虫。流行病学史分析，共有两个可能的感染源。一是2022年8月在北京食用的养殖生鳟鱼；二是2023年5月在香港生食的三文鱼。系统发育分析结果显示本虫体序列与来自英国鲑鱼的虫体序列（KY552870）同源性较高，提示当前病例的感染源自于相同地点的受污染鱼类。本研究报道了中国首例由枝形裂头绦虫感染引起的裂头绦虫病病例。随着全球化进程的加快以及对鱼类产品需求的不断增长，应重视裂头绦虫病在国内流行的潜在风险。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.089

A Clostridium perfringens RelatedFoodborne Diarrhea Outbreak in an Elderly Care Center — Beijing Municipality,China, May 2024

DongranZhang^1,&;Xinhui Guo^2,&;Yunqi Zhang³; Haibo Liu¹; Yuhang Gao¹; WencuiZhang¹; Wenfeng Shi¹; Yao Zhao¹; Lijie Zhang²; Aijun Li^1,#

1.Fangshan Center for Disease Control and Prevention, Beijing, China;

2.Chinese Field Epidemiology Training Program, Chinese Center for Disease Controland Prevention, Beijing, China;

3.Fangshan District Shidu Community Healthcare Center, Beijing, China.

^& Joint first authors.

^# Correspondingauthors: Aijun Li, bjfscdc@163.com.

On May 21, 2024, an elderlycare center in Beijing reported dozens of acute diarrhea cases. The local CDCimmediately initiated an epidemiological investigation to identify the outbreak'setiology and implement control measures. Suspected caseswere defined asdiarrhea≥3 times or vomiting within 24h in the center during May 19–23, 2024. Cases were searched byreviewing the center’s medical records. Food exposure at breakfast and lunch onMay 20 was compared among 24 cases and 70 controls. We interviewed chefs aboutfood preparation practices. Samples were obtained and tested. Investigation identified 77 elderlyand 21 staff cases, aged 22–99 years and all had diarrhea. The epidemiccurve suggested a point-source outbreak. The breakfast and lunch on May 20 weresuspected, and 88% of cases ate Chinese-hamburgers compared with 51% ofcontrols (OR=6.6, 95% CI: 1.7, 37.1). Pork in Chinese-hamburgerswas portioned, blanched for 20 minutes, simmered in spiced broth for 40minutes, and left to cool naturally. Twenty-three patient-samples and a Chinesehamburger sample were positive for C. perfringens. Theoutbreakwas likely caused byChinese-hamburgerscontaminated by C.perfringens. We recommend training of foodhandlers on proper cooling procedures when preparing Chinese hamburgers.

某养老院一起产气荚膜梭菌所致腹泻暴发事件调查—北京直辖市，中国，2024年5月

张冬然^1,&；郭新慧^2,&；张云奇³；刘海波¹；高宇航¹；张文萃¹；史文凤¹；赵耀¹；张丽杰²；李爱军^1,#

1. 房山区疾病预防控制中心，北京，中国；

2. 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；

3. 北京市房山区十渡镇社区卫生服务中心，北京，中国。

^& 共同第一作者。

^# 通信作者：李爱军，bjfscdc@163.com。

2024年5月21日，北京一家养老中心报告了数十例急性腹泻病例。当地疾控中心立即启动了流行病学调查，以确定疫情发生原因并实施控制措施。疑似病例定义为2024年5月19日至23日期间，该养老中心内出现24小时内腹泻≥3次或呕吐者。通过查阅养老中心医疗记录搜索病例。比较了24例病例和70名对照者5月20日早餐和午餐的食物暴露情况。访谈厨师了解食物制备过程。采集样本进行检测。调查共发现77名老年和21名工作人员病例，年龄范围22-99岁，全部出现腹泻症状。流行曲线提示为点源暴发。5月20日的早餐或午餐可能为风险因素，病例和对照分别有88%和51%食用肉夹馍（OR=6.6，95% CI：1.7,37.1）。肉夹馍中猪肉的制作过程为鲜肉分割，焯水20分钟，炖煮40分钟，然后自然冷却。23份患者样本和1份肉夹馍样本检测出产气荚膜梭菌阳性。本次疫情很可能是由污染了产气荚膜梭菌的肉夹馍引起的。我们建议对食品从业人员进行培训，确保在制备肉夹馍时采取适当的冷却程序。

For more information:https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.090

An Alarming Public Health Problem: Ticksand Tick-Borne Pathogens in Urban Recreational Parks

Bo Yi^1,2; Mingqiu Fan¹;Jian Chen¹; Junyi Yao¹; Xin Chen^1,# ; HongxiaLiu^1,#

1. Shanghai Municipal Center for DiseaseControl and Prevention, Shanghai, China;

2. School of Public Health, FudanUniversity Shanghai Medical College, Shanghai, China.

^# Correspondingauthors: Xin Chen, chenxin@scdc.sh.cn; Hongxia Liu,liuhongxia@scdc.sh.cn.

Ticks function as critical vectors for awide range of pathogens that pose significant risks to both human and animalhealth. In recent years, the number and diversity of tick-borne pathogens haveincreased at an unprecedented rate, elevating tick-borne diseases (TBDs) to amajor public health concern on a global scale. TBDs present a dual challenge,not only affecting human populations but also causing substantial economiclosses in livestock industries across the world. The geographic distribution ofmany TBDs is shifting, with emerging, re-emerging, and resurging casesinfluenced by environmental factors such as deforestation and climate change.In China, rapid urbanization and concurrent improvements in urban ecologicalconditions have contributed to the expansion of tick habitats and increasedhuman exposure to tick populations. Recent research warns that ticks and theirassociated pathogens present significant risks in urban environments,particularly in locations such as parks, playgrounds, and zoos. Despite thesethreats, public awareness of tick-borne diseases remains critically low. Thisreview consolidates current knowledge on tick species and tick-borne pathogensfound in urban parks and proposes strategic control measures to informeffective tick management policies both in China and globally.

令人担忧的公共卫生问题：城市公园中的蜱及其传播病原体

伊波^1,2；范明秋¹；陈健¹；姚隽一¹；陈昕^1,#；刘洪霞^1,#

1. 上海市疾病预防控制中心, 上海，中国；

2. 公共卫生学院，复旦大学上海医学院, 上海，中国。

^# 通信作者：陈昕，chenxin@scdc.sh.cn；刘洪霞，liuhongxia@scdc.sh.cn。

蜱是重要的媒介生物，能传播多种影响人类或动物健康的病原体。近年来，由于发现蜱传病原体的范围不断扩大，蜱传疾病（TBDs）在全球范围内逐渐成为新的公共卫生威胁。蜱传疾病不仅影响人类健康，还对全球畜牧业造成巨大损失。在森林砍伐和气候变化等因素的驱动下，许多 TBDs 呈现新发及再现的趋势。随着中国城市化进程的加快，城市生态环境不断改善，这不仅增加了城市蜱的生存环境，还增加了人群与蜱的接触机会。最近，多项研究表明，蜱及其传播病原体在城市地区如公园、游乐场、动物园等造成了相当大的威胁。但公众对蜱的防护意识较低。本文概述了城市公园中发现的蜱种类及其携带的病原体，并提出了公园蜱控制策略，旨在为中国及其他地区有效管理及控制蜱提供决策依据。

For more information:https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2025.091