四川省绵阳市3例重症恙虫病患者的实验室诊断和临床特征  

Laboratory diagnosis and clinical features analysis of three cases of severe scrub typhus in Mianyang City,Sichuan Province

作　　者：何松余 程森中 朱文鸵 李嘉晋 HE Songyu;CHENG Senzhong;ZHU Wentuo;LI Jiajin(Mianyang People's Hospital,Mianyang,Sichuan 621053,China;The First People's Hospital of Mianyang,Mianyang,Sichuan 621053,China)

机构地区：[1]绵阳市人民医院,四川绵阳621053 [2]绵阳市第一人民医院,四川绵阳621053

出　　处：《中国热带医学》2024年第9期1074-1079,1111,共7页China Tropical Medicine

摘　　要：目的对四川省绵阳市3例重症恙虫病(scrub typhus)患者的致病原进行分析,了解其临床特征,为该地区恙虫病的防治提供依据。方法在2021年6月至2022年8月期间,收集四川省绵阳市3例重症恙虫病患者的血液标本和临床数据。对患者进行流行病学史的调查,对收集的临床数据进行分析;采集患者入院时的急性期全血、血清和2周后的恢复期血清样本,使用间接免疫荧光法检测血清中的抗体滴度;提取全血样本的总DNA,使用巢式PCR的方法扩增立克次氏体目病原菌的标志性基因,运用最大似然法构建系统进化树,确定该恙虫病东方体(Orientia tsutsugamushi)基因型。结果此3例患者一般的症状与其他感染性发热疾病极其相似,其中2例查体可见明显焦痂,3例均引起肺炎;流行病学调查显示均有野生动物接触史或野外劳作史;恙虫病东方体IgG抗体实验显示患者恢复期血清相较于急性期血清抗体均有4倍及以上升高;PCR扩增获得了TSA56基因序列片段,使用BLASTN在NCBI网站上比对结果显示,这些序列与恙虫病东方体TA763基因型和Karp基因型具有相近的亲缘关系。结果表明此3例重症患者确为恙虫病东方体感染。结论对3例临床诊断的重症恙虫病患者进行了实验室确诊,提供了确切的病原学依据,为绵阳市首次报道病原学确诊的恙虫病病例,并分析其临床特征以及基因型,对该地区该类疾病的早期诊断、鉴别诊断、辅助治疗具有指导意义。Objective To confirm three severe scrub typhus patients in Mianyang of Sichuan Province using laboratory diagnosis and analyze their clinical characteristics to provide theoretical evidence for the prevention and treatment of scrub typhus in this area.Methods From June 2021 to August 2022,blood specimens and clinical data were collected from three severe scrub typhus patients in Mianyang of Sichuan Province.The epidemiological history was surveyed and the collected clinical data were analyzed.Acute-phase whole blood,serum samples at admission,and convalescent-phase serum samples two weeks later were collected,and the IgG titers of anti-Orientia tsutsugamushi were detected by indirect immunofluorescence assay(IFA)assays.Total DNA was extracted from anticoagulation whole blood using DNA extraction kit,and semi-nested polymerase chain reaction(PCR)was used to amplify the special gene of O.tsutsugamushi.Phylogenetic trees were constructed using the maximum likelihood(ML)method to determine the genotype of the strains.Results The clinical symptoms of these three patients were extremely similar to other infectious febrile diseases,with two cases showing obvious eschars on physical examination and all three cases causing pneumonia.Epidemiological investigation revealed that all had a history of wild animal exposure or fieldwork.Specific IgG antibodies to O.tsutsugamushi tests showed that convalescent serum antibodies increased by four times or more compared to the acute-phase serum.The TSA56 gene sequence fragment was obtained by PCR amplification,and BLASTn comparison on the NCBI website showed a close phylogenetic relationship with the TA763 genotype and Karp genotype of Orientia tsutsugamushi.The results indicated that these three cases were indeed infections of O.tsutsugamushi.Conclusions Laboratory diagnosis confirmed the clinical diagnosis of severe scrub typhus in three patients,providing specific evidence of etiology.This is the first report of etiology-confirmed cases of scrub typhus in Mianyang City,Sichuan Pr

关 键 词：恙虫病东方体 焦痂 肺炎 病原学诊断 重症恙虫病 绵阳市 

分 类 号：R513.2[医药卫生—内科学]