Abstract: Background The diagnosis of encephalitis depends on the finding of pathogens in the brain parenchyma or cerebrospinal fluid (CSF). But the success rates of finding pathogens by microscope are low by the traditional specimens handling procedure in which pathogens are detected by direct centrifugation of CSF getting from lumbar puncture. The process of pathogen collection from the CSF such as centrifugation and washing would cause the destruction and loss of pathogens, resulting in a lower rate of pathogen discovery. Therefore, in order to increase the detection rate of pathogenic microorganisms in CSF, these traditional steps need to be improved. Methods CSF samples of 23 patients with suspected viral encephalitis and 10 control patients with fracture were prepared by two methods: traditional specimens handling procedure (TSHP) and improved specimens handling procedure (ISHP). In the ISHP, a final concentration of 2.5% glutaraldehyde was added to CSF in a glass tube, mixed and kept not moving in 4 ℃ for 2 to 4 h or in 37 ℃for 1 h. Then a smear was made from the sediment formed in the tube to check pathogens by microscope. As for the TSHP, pathogens were collected by direct centrifugation of CSF which had not been treated after lumbar puncture, and checked through Gimenze staining. Results There was no statistically significant difference between the two dealing procedures in the control group ( P = 1.000). As for the case group, there were 10 cases showing positive in Pandy test after TSHP, and visible sediments were seen in all the 23 cases after ISHP. There was statistically significant difference between two kinds of CSF treatment for the finding of pathogens (P = 0.000). Seven cases presented pathogen growth in CSF and were diagosed as rickettsial infections by Gimenze staining, immunofluorescence assay (IFA) and polymerase chain reaction (PCR). Conclusion Improved specimens handling procedures of CSF contribute to the seperation of cells, pathogens and proteins.

Key words: Encephalitis, viral, Glutaral, Centrifugation, Precipitation, Cerebrospinal fluid; Cytological techniques

摘要： 研究背景 脑炎的明确诊断有赖于在脑实质或脑脊液中发现病原体，但脑脊液标本制备过程中所经历的离心、洗涤等步骤均可导致病原体结构破坏、丢失，直接影响诊断效度。为了提高阳性检出率，有必要对传统脑脊液标本镜检处理程序中可能导致病原体减少的步骤进行改良。方法 采集23例疑似病毒性脑炎患者和10例对照者的脑脊液标本，分别采用 加入戊二醛溶液使之终浓度达2.5%，混匀、静置4 h 后肉眼观察沉淀物形成再离心收集病原体方法；或不经戊二醛溶液处理即离心收集病原体方法。Gimenze 染色检测脑脊液病原体。结果 对照组患者两种脑脊液处理方法，差异无统计学意义（P = 1.000）。疑似病毒性脑炎组经传统脑脊液标本镜检10例Pandy 球蛋白定性试验阳性，经改良脑脊液标本镜检23例均可见沉淀物形成，差异具有统计学意义（P = 0.000）；其中7 例患者脑脊液培养可见病原体生长，经 Gimenze 染色、免疫荧光染色和聚合酶链反应明确诊断为立克次体感染。结论 改良脑脊液标本镜检处理方法可有效分离细胞、病原体和蛋白质。

关键词: 脑炎, 病毒性, 戊二醛, 离心法, 沉淀, 脑脊髓液, 细胞学技术