一起急性上呼吸道病毒感染暴发流行的病原学分析

Viral etiology of an acute respiratory tract infection

目的探讨2006年2月下旬汕头市某小学暴发的一起急性上呼吸道病毒感染的病原学。方法采集患者急性期咽拭子标本进行腺病毒、B型流感病毒和呼吸道合胞病毒的核酸检测,对PCR结果进行序列测定和分析;咽拭子标本用Hep-2细胞进行病毒分离;用患者双份血清进行腺病毒中和实验和B型流感病毒的血凝抑制试验。结果35份患者的咽拭子标本中用PCR扩增同时检测到了12份腺病毒(阳性率为34.3%)和15份B型流感病毒(阳性率为42.9%),呼吸道合胞病毒核酸检测阴性。序列分析表明腺病毒与江苏省2005年分离的毒株以及广东省2005年分离的3型腺病毒毒株的相似性高达98%,而B型流感病毒与孟斐斯分离到的B型流感病毒同源性高达99%。咽拭子标本用Hep-2细胞未分离到腺病毒和B型流感病毒。病人双份血清的腺病毒中和试验显示抗体没有4倍增长,但腺病毒阳性者晚期血清抗体几何平均值为12.1,腺病毒阴性者即为1.4。而B型流感病毒双份血清血凝抑制试验表明恢复期抗体比较急性期抗体有4倍或以上增长。结论该次急性上呼吸道感染是由B型流感病毒引起的,但可能先前感染过腺病毒。

Objective To explore the viral etiology of an acute upper respiratory tract infection outbreak in the primary school of Shantou city. Methods Nasopharyngeal swab samples from patients in acute clinical period during an upper respiratory tract infection outbreak occurred at a primary school of Shantou city in February, 2006, were eolleetod to detect nucleic acid of adenovirus, influenza B virus and respiratory syneytial virus （RSV） respectively. Polymerase chain reaction （PCR） products were sequenced. Viruses isolated from nasopharyngeal swabs were cultured in Hep-2 and MDCK ceils. Neutralization assay and hemoagglutination inhibition test were conducted to detect antibodies of adenovirus and influenza B virus from paired serum specimens. Results Adenovirus nucleic acid in 12 swabs （34. 3% ） and influenza B virus nucleic acid in 15 swabs （42.9%） were detected from total 35 patient nasopharyngeal swab samples whereas no RSV nucleic acid was found. Sequence analysis indicated that adenovirus had 98% similarity with 2005 isolated viral strain in Jiangsu and type 3 strain in Guangdong and influenza B virus had 99% homology with Memphis strain. There haven＇t observed 4-fold or more adenovirus antibody rise by neutralization assay and geometrical mean value of antibody from convalescent positive patient was 12.1 whereas negative patient was 1. 4. The influenza B virus antibody was observed 4-fold or more rise by using hemoagglutination inhibition assay between convalescent and acute serum samples. Conclusion The outbreak was caused by influenza B virus and had possible adenovirus infection before.