临床实验室流感病毒检测的相关影响因素分析

目的 在流感流行季节对流感样病例进行流感病毒筛查,分析影响流感病毒阳性检测结果的相关因素,提高流感的阳性检测率.方法 选取发热门诊就诊的流感样病例,采集鼻咽拭子,应用胶体金抗原快速检测法与巢氏PCR法进行流感病毒的检测并对比结果.分析患者就诊时间、临床症状及检测方法、采样部位等因素对阳性率的影响.结果 研究发现年龄>60岁、体温在38.0℃~38.9℃之间、发热2 d就诊的患者,流感病毒阳性检出率高于其他组;鼻拭子及咽拭子流感病毒检出率无统计学差异;不同检测方法,流感病毒胶体金抗原快速检测法阳性检出率为17.6%,核酸PCR阳性检出率为31.0%,差异有统计学意义,流感病毒胶体金抗原快速检测法的敏感性27.6%,特异性86.9%,阳性预测值48.8%,阴性预测值72.8%,与PCR的一致性为68.6%.结论 发病早期就诊的流感样病例,流感病毒阳性检出率偏高;不同标本采样部位流感病毒检出率差别不大.虽然流感病毒胶体金抗原快速检测法操作简单、方便快捷,但其敏感性偏低,且存在一定假阴性结果,而流感病毒核酸检测阳性率较高,但实验要求高,操作过程复杂.

Analysis of the factors influencing influenza virus detection

Objective To screen influenza virus from influenza-like cases in flu seasons, and to analyze factors related to the positiveness of the detection methods, so as to increase the positive detection rate of influenza. Methods Both nasopharynx swabs and oropharynx swabs of infuenza-like patients were collected. The influenza virus were detected by the rapid antigen assay and nested PCR. The results were compared and factors that influence detection rate of influenza virus were analyzed. Results The groups of elder than sixty-years old, temperature between 38.0 and 38.9℃ and two-days of fever have the highest positive rate of influenza virus compared to other group. The positive rate of rapid antigen assay was 17.6%, the positive rate of nested PCR was 31.0%. The rapid antigen assay for influenza had a sensitivity of 27.6% and a specificity of 86.9%. The positive predictive value of the method was 48.8% and the negative predictive value was 72.8%. The consistance of both tests were 68.6%. Conclusions The influenza-like-illlness in two days have the highest influenza virus positive rate. The two different swabs showed no statistically significant difference in detection of influenza virus. The sensitivity of the rapid antigen assay for influenza was low, so there were a certain degree of false negative results.