2种恙虫病东方体核酸检测方法的比较

Comparison of two methods for the detection of orientia tsutsugamushi nucleic acid

目的探讨巢式PCR法与实时荧光PCR法在恙虫病诊断中的作用。方法采集2010年-2014年北京市404例恙虫病疑似患者的全血样本,分别以巢式PCR法与实时荧光PCR法检测恙虫病东方体的gro EL基因与47 k D蛋白基因,以血清特异性Ig M检测结果为诊断恙虫病的金标准,研究2种PCR方法的灵敏度。结果以急性期血清Ig M阳性或恢复期血清Ig M转阳作为确诊标准,374例患者确诊为恙虫病。其中巢式PCR法检测gro EL基因阳性者323例,灵敏度为86.36%;实时荧光PCR法检测47 k D蛋白基因阳性者328例,灵敏度为87.70%。而单份急性期血清Ig M抗体检测的灵敏度为87.17%。结论实时荧光PCR法的检测时间短,适合用于快速诊断,但对于检测阴性的样本应考虑进行血清Ig M或多个基因的分子生物学检测以明确诊断。

Objective To investigate the value of the nest- PCR and real- time PCR in the detection of orientia tsutsugamushi. Methods Blood samples were collected from 404 suspected scrub typhus cases from Beijing area during 2010- 2014.gro EL gene and 47 k D protein gene of orientia tsutsugamushi were detected by nest- PCR and real- time PCR respectively. The serum specific Ig M test results were used as golden standard for the diagnosis of scrub typhus,so as to investigate the sensitivity of these two PCR methods. Results Scrub typhus Ig M positive in acute sera or changing to positive in covalent sera were considered as the golden standard for the confirmed diagnosis,374 cases were confirmed as the scrub typhus. In these 374 cases,323 were with gro EL gene positive by nest- PCR,and the sensitivity was 86. 36%,while,328 were with 47 k D protein gene positive by real- time PCR,and the sensitivity was 87. 70%. And the sensitivity of Ig M test in acute sera was 87. 17%. Conclusion Real- time PCR was suitable for the rapid diagnosis of scrub typhus,but Ig M test or multiple gene molecular assay should be considered to be carried out for verifying the diagnosis of samples with negative results.