一起腺病毒引起的大面积轻型急性呼吸道感染症爆发的流行病学研究

The epidemiological study of acute respiratory infection syndrome broken out by adenovirus type 3 in Dongtai of Jiangsu province

目的了解2004年在江苏东台市大面积轻型急性呼吸道感染症爆发流行的病原学及流行病学特点.方法制订本病的临床诊断标准,采用统一的流行病学个案调查表对病例进行调查,描述流行特征;采用病例对照研究的方法分析流行因素;先在流行区咽拭子标本中分离病原体,并对阳性分离株进行免疫荧光、聚合酶链反应(PCR)、电镜检测,对患者的双份血清进行中和试验.结果东台市发生轻型急性呼吸道感染症871例,疫情波及到10个乡镇,对照研究显示发病危险因素与发热病例的接触、家庭内共用毛巾及与鸡密切接触有关,标本经2个实验室人喉癌传代细胞(Hep-2)分离培养,51%～65%的标本出现了明显的细胞病变效应(细胞呈葡萄串状、折光变强),电镜下可见细胞胞核内大量呈晶格状排列的典型腺病毒颗粒,直接免疫荧光试验、PCR检测及双份血清中和试验均证实为腺病毒感染.用全基因测序的方法进行病毒检测,确定为腺病毒3型.结论2004年发生在江苏省东台市轻型急性呼吸道感染爆发疫情的病原体为腺病毒,传播途径主要以飞沫传播及密切接触为主.

Objective To explore the epidemiological character and pathogenic cause of acute respiratory tract infection syndrome break-out in Dongtai areas of Jiangsu province in 2004. Method Lay down the clinical standard for the cases, take investigation to every ease using the same epidemiological questionnaire, and describe the epidemiological characteristics. Analyze the factors brought out the breakout and / or epidemic throughout the method of case-control. Collect the specimen of pharyngeal swab for the sufferer in epidemic areas to separate and cul- ture etiology agent, test to the positive specimens using immunofluoreacence,PCR, electron microscope technology and neutralize test to the acute phase and convalescence serum of the cases. Result Sttm total,there were 871 cases of acute respiratory tract infection syndrome,and the epidemic affected ten townslups. Two incidence peaks occurred in the last ten days of May and in the middle ten days of June. The most of the cases （94.37 % ） were pupils in the primary and high school or the children in the kindergarten, and some of the cases （ 4.13 % ） were non- students of school. The adults were hardly to infect and be taken ill. The age scope of the cases ranged from 7 months to 18 years. The clinical characteristics were fever accompanied angina and tonsillitis, the course of diseases was about 5 days, and prognosis was all right and no death cases. The study of case-control showed that the risk factors were contact with fever cases,co-use towel within family and nearly contact with chooks. The specimens were separated and cultured throughout Hep-2 ceils in two different laboratory, and obvious cellular pathological changes, where the cells presents the form of grapes cluster and the refraction ability of cells have been enhanced,happened in the 51 ～ 65 percent of the specimens.The large amount typical granule of adenovirus, where array of ceils presents crystal lattice,could be observed in the nucleolus under electron microscope.Those cellular changes all were been testified that ceils had been infected by adenovirus through direct immunofluorescence test,RT-PCR, and neutralize test to the couple of serum. The virus was confirmed as adenovirus type Ⅲ using the method of checking and measuring the virus whole genes sequence. Conclusion The agent of acute respiratory tract infection syndrome broken out in Dongtai areas,Jiangsu province in 2004 was confirmed as adenovirus, and the transmission route mainly were contacts with the aerosol in the air and cases.