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自2004年4月18日起至6月末,江苏省东台市发生以发热、咽部充血、扁桃体肿大为临床表现的原因不明的疫情暴发,发病人群以中小学生、幼儿为主,地域以许河镇、新街镇以及临近乡镇为主。疫情涉及东台市9个镇,合计报告709例,分布在75个学校,240个班级。暴发的特点为传染性强,短期内出现大量的患者,发病有班级聚集性特点,未发现成人感染。临床表现以发烧(100%)、咽部充血(91.40%)、扁桃体肿大(60.22%)、咽痛(50.00%)为主;X线检查可发现肺纹理增强(90.3%)。用Hep-2细胞从患儿20份咽拭子标本中分离到12株病毒,经PCR扩增腺病毒L3部分基因及其PCR产物的序列测定和分析,证实这12株病毒为腺病毒3型;对28份咽拭子标本直接进行DNA提取和PCR扩增,有17份标本PCR扩增L3部分基因呈阳性,经序列测定和分析,也为腺病毒3型。这29个阳性标本L3基因的1 446个核苷酸的序列与GenBank上所发表的腺病毒3型序列同源性高达99.5%。双份血IgG检测:对江苏省采集10份患儿急性期和恢复期双份血清,以从患儿咽拭子分离到的腺病毒3型作为抗原,进行病毒抗体测定,6份患儿的双份血清腺病毒总IgG滴度呈4倍以上增高。患儿急性期血IgA检测:对暴发疫情34例患儿急性期血清(发病时间为1~3天)进行腺病毒IgA抗体测定,结果有9份标本为阳性,1份标本为可疑阳性,阳性率为26.47%。IgA阳性率低可能与血清采集时间过早有关,机体还未全部产生IgA。另外,还对江苏省送检的从患儿血培养基培养的细菌毒株进行了鉴定,对其16S rRNA基因进行了基因扩增及序列分析,序列测定和分析提示为A组M3型化脓性链球菌。实验研究结果并结合此次疫情的流行病学和患儿的临床表现,证实腺病毒3型是引起此次儿童不明原因轻型呼吸道传染病暴发的病原体,部分病例伴有原发或继发化脓性链球菌感染。
From April 18, 2004 to the end of June, there was an unexplained epidemic outbreak in Dongtai City, Jiangsu Province, where fever, pharyngeal hyperemia and tonsil enlargement were the major clinical manifestations. Most of the patients were primary and secondary students and young children, Township, New Town and the main township. The outbreak involved nine towns in Dongtai, with a total of 709 cases, distributed in 75 schools and 240 classes. Outbreaks characterized by strong contagious, a large number of patients appear in the short term, the incidence of class aggregation features, found no adult infection. The clinical manifestations were fever (100%), pharyngeal hyperemia (91.40%), tonsil enlargement (60.22%) and sore throat (50.00%). X-ray examination showed enhancement of lung texture (90.3%). Twelve viruses were isolated from 20 throat swab specimens of children with Hep-2 cells. Sequencing and analysis of the PCR products of partial L3 gene of adenovirus by PCR showed that the 12 viruses were adenovirus type 3 ; 28 samples of throat swabs were directly extracted DNA and PCR amplification, 17 samples were PCR-amplified L3 part of the gene was positive, after sequencing and analysis, but also for adenovirus type 3. The 1 446 nucleotide sequence of L3 gene of these 29 positive specimens shared 99.5% homology with the published sequence of adenovirus type 3 in GenBank. Duplicate blood IgG test: Twelve sera from acute and convalescent children were collected in Jiangsu Province. Adenovirus type 3 isolated from throat swabs of children was used as antigen for virus antibody assay. Six children Double serum adenovirus total IgG titer increased more than 4 times. Acute blood IgA detection in children: outbreaks of 34 cases of children with acute onset of serum (onset time of 1 to 3 days) for adenovirus IgA antibody determination, the results of 9 specimens were positive, 1 specimen was suspicious positive, positive The rate was 26.47%. Low IgA positive rate may be related to premature serum collection, the body has not yet produced all IgA. In addition, the bacterial strains cultured in blood culture medium of children were also examined in Jiangsu Province. The 16S rRNA gene was amplified and sequenced. The sequencing and analysis of the 16S rRNA genes indicated that the group A was M3-type purulent Streptococcus. The experimental results combined with the epidemiology of the epidemic and the clinical manifestations of children confirmed that adenovirus type 3 is caused by the children of unexplored light respiratory infectious disease outbreaks of pathogens, some cases accompanied by primary or secondary suppurative Streptococcus infection.