Comparison of a rapid diagnostic test and microimmunofluorescence assay for detecting antibody to Orientia tsutsugamushi in scrub typhus patients in China

Objective:To evaluate the detection of IgM and IgG antibodies to Orientia tsutsugamushi(O. tsutsugamushi) by rapid diagnostic test(RDT) and microimmunofluorescence assay(ml FA). Methods:RDT using a mixture of recombinant 56-kDa proteins of O.tsutsugamushi and mIFA assay were performed on 20 patients from Fujian and 13 patients from Yunnan Province,and 82 sera samples from healthy farmers in Anhui Province and Beijing City in 2009.Comparison of the RDT and mIFA assay was performed by using X test and the P level of 【0.05 was considered to be significance.Results:Among these 82 normal sera samples,the specificity of RDT was 100%for both IgM and IgG tests.In 33 samples from patients with scrub typhus,5 cases were positively detected earlier by RDT than by mIFA in IgM test,and 2 cases were positive in IgG test.Sensitivities of RDT were 93.9%and 90.9%for IgM and IgG,respectively.The sensitivity of combination lest of IgM and IgG was 100%.Geometric mean titer diluted sera from confirmed cases by IFA and RDT assay were 1:37 vs.1:113(P【0.001) in IgM test and 1:99 vs.1:279 (P【0.05) in IgG test.Conclusions:RDT is more sensitivite than mIFA in the early diagnosis of scrub typhus and it is particularly applicable in rural areas.

Prediction of T cell and B cell epitopes of the 22-, 47-, 56-, and 58-kDa proteins of Orientia tsutsugamushi

Objective:To predict B cell and T cell epitopes of 22-kDa,47-kDa,56-kDa and 58-kDa proteins.Methods:The sequences of 22-kDa,47-kDa,56-kDa and 58-kDa proteins which were derived from Orientia tsutsugamushi were analyzed by SOPMA,DNAstar,Bcepred,ABCpred,NetMHC,NetMHCⅡand IEDB.The 58-kDa tertiary structure model was built by MODELLER9.17.Results:The 22-kDa B-cell epitopes were located at positions 194-200,20-26 and 143-154,whereas the T-cell epitopes were located at positions 154-174,95-107,17-25 and 57-65.The 47-kD a protein B-cell epitopes were at positions 413-434,150-161 and 283-322,whereas the T-cell epitopes were located at positions 129-147,259-267,412-420 and 80-88.The 56-kDa protein B-cell epitopes were at positions 167-173,410-419 and 101-108,whereas the T-cell epitopes were located at positions 88-104,429-439,232-240 and 194-202.The 58-kDa protein B-cell epitopes were at positions 312-317,540-548 and 35-55,whereas the T-cell epitopes were located at positions 415-434,66-84 and 214-230.Conclusions:We identified candidate epitopes of 22-kDa,47-kDa,56-kDa and 58-kDa proteins from Orientia tsutsugamushi.In the case of 58-kDa,the dominant antigen is displayed on tertiary structure by homology modeling.Our findings will help target additional recombinant antigens with strong specificity,high sensitivity,and stable expression and will aid in their isolation and purification.

Comparison of the Efficacy and Safety between Doxycycline and Moxifloxacin in the Treatment of Tsutsugamushi Disease

Objective:To explore the efficacy and safety of doxycycline and moxifloxacin in the treatment of tsutsugamushi disease.Methods:There was a total of 80 cases of tsutsugamushi disease that were treated in Jiangsu Sihong Fenjinting Hospital from January 2017 to August 2020.The patients were divided into group A and group B,with 40 cases in each group.The patients in group A were treated with moxifloxacin whereas those in group B were treated with doxycycline.The efficacy and safety of the clinical treatment between the two groups were compared.Results:The effective rate was 72.5% in group A and 95.0% in group B.Compared with group A,group B was better(p<0.05).The time taken for the resolution of clinical symptoms,the detection indexes of liver function,and the incidence of adverse reactions were also compared between the two groups,in which group B was significantly better than group A(p<0.05).Conclusion:In the clinical treatment of tsutsugamushi disease,doxycycline has better therapeutic effect and higher safety compared to moxifloxacin.It can significantly improve the patienfs liver function,reduce the probability of adverse reactions,and accelerate the patienfs physical recovery.

Clinical Features of Severe Tsutsugamushi Disease Complicated with Hemophagocytic Lymphohistiocytosis

The article discusses a case of severe tsutsugamushi disease complicated with hemophagocytic syndrome in Guangdong Maternal and Child Health Hospital and concludes that blood purification technology has significant therapeutic effect among children with severe HLH complicated with multiple organ dysfunction.

恙虫病临床诊疗专家共识

恙虫病是由恙虫病东方体感染引起的一种自然疫源性疾病,流行于东亚和东南亚地区,主要表现为发热、焦痂或溃疡、淋巴结肿大及皮疹。恙虫病早期症状不典型,容易误诊和漏诊。中国微生物学会人兽共患病病原学专业委员会和中国医药生物技术协会生物诊断技术分会相关专家,根据领域相关研究进展和诊疗经验,并参考国内外相关文献与指南,结合我国临床实践与咨询论证,形成本共识。

恙虫病东方体混合重组抗原应用于胶体金免疫层析试纸条的制备及效价检测

胶体金免疫层析试纸条具有携带方便、操作简单且敏感性、特异性高等特点,近年来开始广泛应用于疾病的诊断。为了实现对恙虫病的快速检测,笔者利用双抗原夹心法,以胶体金标记恙虫病东方体56 kDa混合重组蛋白,56 kDa混合重组蛋白和兔抗恙虫病东方体多克隆抗体分别喷在检测线及质控线上,制备了用于检测恙虫病东方体抗体的胶体金免疫层析试纸条。本研究制备的胶体金试纸条检测限为61 ng/mL,和疟疾、伤寒、血吸虫、出血热以及斑点热等阳性血清无交叉反应,特异性达90%(54/60),检测的敏感性为91.96%(103/112),在4℃下可稳定保存6个月。本试纸条能够应用于人体血清中恙虫病东方体总抗体的检测。

多西环素联合阿奇霉素治疗恙虫病合并肺部感染的效果与安全性评价

目的:探讨多西环素联合阿奇霉素治疗恙虫病合并肺部感染的效果与安全性。方法:选择2019年7月—2022年7月莆田市第一医院收治的150例恙虫病合并肺部感染患者作为观察对象。根据治疗方法差异性分为两组,各75例。对照组使用多西环素,观察组在对照组基础上联合阿奇霉素治疗。比较两组的治疗效果和安全性。结果:观察组治疗总有效率高于对照组,差异有统计学意义(P<0.05)。观察组肺部湿啰音消失时间、肝功能恢复时间、焦痂脱落时间、住院时间均短于对照组,差异有统计学意义(P<0.05)。观察组不良反应总发生率高于对照组,差异有统计学意义(P<0.05)。结论:多西环素联合阿奇霉素治疗恙虫病合并肺部感染,能有效提高患者整体治疗效果,加快症状消失进度,但是联合用药有较高不良反应,治疗安全性低于单一用药。

银翘散合小柴胡汤加减联合米诺环素治疗恙虫病临床观察

目的:观察银翘散合小柴胡汤加减联合米诺环素治疗恙虫病的临床疗效。方法:选取符合纳入标准的恙虫病患者124例,随机分为两组各62例。对照组予盐酸米诺环素胶囊口服治疗,治疗组在对照组基础上联合银翘散合小柴胡汤加减治疗。比较两组患者的临床症状消退时间、实验室指标水平变化及治疗期间不良反应发生情况。结果:治疗组在退热时间、头痛消失时间、皮疹消退时间、焦痂脱落时间等方面均显著短于对照组(P﹤0.05)。治疗组患者的血清谷丙转氨酶、谷草转氨酶值明显低于对照组,差异具有统计学意义(P﹤0.05)。结论:银翘散合小柴胡汤加减联合米诺环素治疗恙虫病疗效较好,能够缩短临床症状消退时间。

成都市4种鼠传病原体的带毒率调查

目的 了解四川省成都市鼠类携带4种常见病原体的情况,为鼠传疾病的防控提供科学依据。方法 2021年9月至2022年8月采用夹夜法在成都市居民区、重点行业和农贸市场等生境捕获鼠类。采用实时荧光定量PCR法检测汉坦病毒、新型布尼亚病毒、钩端螺旋体和恙虫病东方体4种病原体。结果 全市7个区县共捕获鼠类207只,总捕获率为1%。其中褐家鼠150只,占72.46%;黄胸鼠57只,占27.54%。4种病原体检出率分别为汉坦病毒3.86%,钩端螺旋体1.45%,新型布尼亚病毒0.48%,恙虫病东方体尚未检测出。结论 需对重点行业开展灭鼠工作,防止鼠传疾病的发生与流行。

江苏省恙虫病高发地区农民血清学调查及感染危险因素分析

目的了解江苏省恙虫病高发地区农民感染情况及相关危险因素,为恙虫病防控提供流行病学依据。方法在江苏省南部和北部6个高发县/区随机抽取2537名农民为调查对象,应用免疫层析法(胶体金)检测血清样本中恙虫病东方体IgG和IgM抗体,阳性样本采用间接免疫荧光法检测相应的IgM和IgG抗体滴度。结果2537名调查对象IgM抗体均为阴性,IgG抗体血清阳性率为1.58%(男性0.86%,女性2.26%)。多因素分析显示,女性(OR=3.562,P=0.008)、年龄>60岁(参照15~30岁:OR=7.981,P=0.003)、放牧(OR=16.981,P<0.001)、割草(OR=16.152,P<0.001)、养羊(OR=11.212,P=0.005)、钓鱼(OR=5.850,P=0.005)、干农活的时间≥3 h/d(OR=4.263,P=0.002)是恙虫病东方体感染的危险因素。结论江苏省恙虫病高发地区农民室外劳作有较高的暴露风险,应加强个人防护。

A review of the epidemic and clinical study on scrub typhus in China(2010-2020)

Scrub typhus is an acute febrile vector-borne zoonotic disease caused by the obligate intracellular growth bacterium Orientia tsutsugamushi(Ot).Mites are the primary vectors and rodents play a pivotal role in the transmission of scrub typhus.Due to the climate warming,increased human activity and other factors,cases of scrub typhus have been increased sharply during the past decade in China,especially in the northern China.To understand the incidence trend,epidemic pattern,clinical sign,diagnosis and therapy of this diseases as well as genotype evolution of Orientia tsutsugamushi,we summarized and analyzed the current knowledge of scrub typhus in China from 2010 to 2020.The data indicated that the dominate genotypes of scrub typhus in China were Karp,Kato and Gilliam.Although the disease was distributed national wide,Yunnan,Guangzhou and Fujian showed the highest incidence rate.The main vector of scrub typhus in southwest,middle east and southeast of China appeared a geographic preference respectively.Seasonal timing,age and occupation were the key factors that relate to the peak incidence of scrub typhus.Notably,farmer was the occupation with the highest risk of Ot infection.Further study on the epidemic characteristics,risk factors,diagnosis and treatments of scrub typhus will be of benefit to a comprehensive guideline for prevention and control of this ancient disease.

中国恙虫病流行及临床研究进展(2010-2020)

恙虫病是由恙虫病东方体(Orientia tsutsugamushi,Ot)感染引起的急性发热性疾病。主要通过恙螨幼虫叮咬传播,啮齿类动物在恙虫病传播过程中发挥重要作用。随着气候变化和人类活动范围的扩大等原因,我国恙虫病感染病例数和流行区域呈明显增加和北扩趋势。本文基于文献总结分析了2010~2020年我国各地区恙虫病发病情况、流行病学特征、临床研究等进展。结果表明Kato、Karp、Gilliam型为我国恙虫病东方体主要流行基因型;恙虫病在我国各地区均有分布,其中云南、广州、福建等地是高发区;传播媒介种类呈明显地理差异;本病发病高峰期与季节温度、人群年龄、职业等相关。对我国恙虫病流行趋势变化、人群感染风险、环境影响等因素的研究,将为优化媒介防控措施、完善临床诊治方案、提高突发疫情的应急处置能力及精准防控策略的制定提供科学的指导。

基于文字音韵的弧蜮病解读

《金匮要略》中“狐惑”两字从传统考据之音韵、训诂探源当为“弧蜮”。《说文解字注》指出“狐”并非指狐疑之意,当为“弧”之错讹,为“蜮”的外形特征,指身体呈弧形;“惑”非为疑惑之意,当读“蜮”,即江淮水滨之虫。马王堆出土文献《疗射工毒方》对“蜮”的记载突出其具有“射”的功能,符合“蜮”身体呈弧形的外形特征。“狐惑”表现出的“状如伤寒”“蚀于喉”“蚀于阴”“面目乍赤乍黑乍白”等症状与恙虫致病之“偶有畏寒,伴有剧烈头痛全身疼痛乏力,食欲不振;腋下、会阴、肛门出现无痛的庁;丘疹眼结膜的充血”等表现十分吻合。针对此“弧蜮”症状与恙虫致病,通过地下出土与现存传世文献“二重证据”相互佐证,运用训诂学方法,推理出“狐”为“弧”之错讹,“惑”与“蜮”同源,明晰“狐惑”之源流。

71例恙虫病合并肺炎临床观察

目的对恙虫病合并肺炎患者进行临床观察,为本病早期诊断及治疗提供依据和参考。方法选取我院内科2020年1月至2021年6月收治的71例恙虫病合并肺炎患者为研究对象,回顾性调研患者临床资料,归纳总结患者的临床特征、实验室指标特征、肺影像学特征及预后情况。结果71例患者入院时均有发热症状,以入院体温≥39℃者占比较多,为84.51%。66例患者入院时皮肤有特征性焦痂或溃疡,主要见于会阴、腋窝、肛周、外生殖器、腹股沟等部位,另有肺干湿性啰音68例,以轻咳和咳少量白色黏液痰为主的咳嗽咳痰患者68例,是恙虫病合并肺炎的主要症状体征。嗜酸性粒细胞减少、红细胞沉降率升高、C反应蛋白升高与丙氨酸转氨酶升高是恙虫病合并肺炎患者主要实验室指标特征,占比均在70%以上,另有部分白细胞计数异常、血小板计数降低、血尿素氮升高病例,占比在30%左右。胸部CT平扫主要影像学表现为纵隔淋巴结肿大(35.21%),腋窝淋巴结肿大(39.44%),胸腔积液(28.17%),磨玻璃影(14.08%)。经强力霉素积极抗感染辅以对症处理及支持治疗,患者体温恢复正常,呼吸道症状消失,治愈率为100%。结论恙虫病合并肺炎的临床表现多样,以发热、焦痂或溃疡、肺干湿性啰音、咳嗽咳痰为主,实验室检查可见明显炎性反应,胸部CT检查多表现为肺纹理增粗、肺部阴影、淋巴结肿大、胸腔积液等,强力霉素是有效可行的治疗药物,早期诊断、及时治疗对改善患者预后具有积极作用。

河南省首次实验室证实恙虫病暴发疫情

目的调查以发热、头痛、淋巴结肿大、皮疹为主要症状的不明原因疾病病因。方法对可疑病人进行流行病学调查,用血清学、巢式PCR方法检测病人血清抗体滴度、血清型及立克次体特异性基因片段。结果对发生在农村的32例病人中的20例病人进行血清外裴OXk凝集反应,阳性率达100%,其中11份的第2次病人血清OXk反应呈4倍升高;间接免疫荧光法检测IgM和IgG抗体,20份均为阳性,最高达到1∶2560;恙虫病血清学分型Gilliam 4例,Karp6例,Kato 8例。巢式PCR检测病人血凝块,结果3份扩增出Ot特异性DNA片段。结论首次证实河南省出现恙虫病暴发疫情。

近年来我国恙虫病流行病学研究进展

恙虫病主要流行于我国南方,主要动物宿主是啮齿动物,媒介为恙螨。我国恙虫病按季节可分为两型:①夏季型,流行于南方;主要宿主动物为黄毛鼠、黄胸鼠;主要媒介为地里纤恙螨;流行于6-8月;恙虫病东方体型别为Gil1iam型。②秋冬型,流行于江苏、山东省;主要动物宿主为黑线姬鼠、褐家鼠、大仓鼠;主要媒介为小盾纤恙螨;流行于10-12月;恙虫病东方体型别为Kawasaki型。采取以环境整治、灭螨、灭鼠、做好个人防护和宣传教育为主的综合性预防措施证实恙虫病是可防可控的。

我国恙虫病媒介恙螨的依据与鉴定

恙螨是恙虫病唯一的传播媒介。通常确定为恙虫病的媒介恙螨应具有4项标准:①流行病学证据;②有恙虫病东方体(Ot)的自然感染;③能经叮刺传播Ot;④能经卵传递Ot。我国已报告6种媒介恙螨,在分类上均归于纤恙螨属(Genus Leptotrombidium),即:地里纤恙螨、微红纤恙螨、吉首纤恙螨、高湖纤恙螨、海岛纤恙螨和小盾纤恙螨。此外,尚有10种可疑的媒介恙螨。本文介绍这些媒介恙螨的依据与鉴定。

安徽三界地区啮齿动物感染恙虫病东方体调查

目的调查安徽三界地区啮齿动物自然感染恙虫病东方体分离株,并确定其基因型别。方法流行季节在野外用鼠笼捕鼠并鉴定鼠种、携螨率;巢式PCR对鼠脏器进行恙虫病东方体56 kD基因片段检测;将鼠脏器接种小白鼠进行病原体分离,PCR扩增分离株Ot 56 kD基因片段,并将目的片段进行测序,基因序列同源性及进化分析。结果捕获啮齿动物数及其携螨率,黑线姬鼠60%(15/25);褐家鼠45.5%(5/11);东方田鼠和鼩鼱各2只,均阴性。40只野鼠脏器有3只恙虫病东方体PCR扩增阳性,阳性率为7.5%;从黑线姬鼠标本中分离到1株恙虫病东方体Sanjie,56 kD基因片段测定该株与台湾TT0711a和NT0511b分离株同源性最高(98%),系统发生树分析也显示与Kawasaki型共处于同一分支。结论安徽三界地区存在鼠类恙虫病东方体自然感染,黑线姬鼠为其主要宿主,当地恙虫病东方体属Kawasaki基因型。

我国秋冬型恙虫病流行病学研究概况

1986年前,我国恙虫病仅知流行于浙江以南地区,主要属夏季型,以黄毛鼠、黄胸鼠、北社鼠为主要宿主动物,以地里纤恙螨为主要媒介。1986年在江苏、山东发生恙虫病流行,属秋冬型。此后,在天津、山西、河北、河南、安徽、北京发行流行,吉林、辽宁、黑龙江有病例报告。以黑线姬鼠、北社鼠、褐家鼠、大仓鼠、朝鲜姬鼠为主要宿主动物;以小盾纤恙螨为主要媒介,可疑的媒介有姬鼠纤恙螨、东方纤恙螨等。

45年恙螨与媒介恙螨传播恙虫病的基础研究

报告作者等 45年来恙螨以及媒介恙螨传播恙虫病基础研究结果 ,主要包括 :①恙螨调查研究 :种类的发现 ,恙虫病东方体的分离和检测 ,媒介恙螨孳生地及其恙虫病流行 ;②恙螨生活史和实验生态研究 :恙螨培育成功与生活史的实验 ,恙螨实验生态和恙虫病流行的预测预报 ;③恙螨传病机制及其控制恙虫病流行研究 :恙虫病东方体阳性恙螨模型的建立及其东方体在恙螨体内的动态 ,恙螨体内东方体垂直传递和传病潜力 ,以及防灭恙螨与控制恙虫病的流行。