139例临床诊断流行性腮腺炎突破病例实验室核实诊断结果分析

Laboratory confirmation of 139 clinical diagnosed breakthrough mumps cases

目的对临床诊断流行性腮腺炎(流腮)突破病例进行核实诊断,评估其真实性和诊断方法可靠性。方法分别用酶联免疫吸附试验法(ELISA)和反转录–聚合酶链式反应(RT-PCR)方法检测2015—2017年浙江省宁波市鄞州区临床诊断流腮病例血清特异性IgM抗体和病原学标本病毒核酸,分析不同采样时间标本的阳性率,比较突破病例和无免疫史病例阳性率,比较不同类型标本阳性率等。结果突破病例发病8～32 d血清IgM抗体阳性率(95.00%,19/20)明显高于第1～7天(36.37%,36/99),差异有统计学意义(Fisher精确检验,P<0.001)。突破病例病原学标本病毒核酸阳性率为6.47%(9/139),无免疫史病例阳性率为16.67%(6/36),二者差异无统计学意义(χ2=3.79,P>0.05)。突破病例阳性标本采样时间主要为发病第2～3天。突破病例含漱液阳性率(11.94%,8/67)明显高于咽拭子(1.39%,1/72),差异有统计学意义(Fisher精确检验,P<0.05)。结论从发病后期采样IgM检测结果分析临床诊断流腮突破病例大部分为真实病例。但发病第1～7天两种方法做核实诊断可靠性均不高,建议检测发病7 d之后IgM抗体做核实诊断。

Objective To confirm the clinical diagnosis of breakthrough mumps cases and evaluate the validity of the clinical diagnosis and the sensitivities of laboratory methods.Methods For the clinical diagnosed mumps cases reported in Yinzhou district of Ningbo during 2015–2017,the serum IgM against mumps virus was detected with enzyme-linked immunosorbent assay(ELISA) and viral RNA extracted from strains isolated from throat swabs or oral fluids were detected by using reverse transcription-polymerase chain reaction(RT-PCR),the positive rate of samples collected in different time,the positive rates of breakthrough cases and cases without immunization history,and the positive rates of different type samples were compared.Results The positive rates of IgM were 36.37%(36/99) at 1–7 days after onset and 95.00%(19/20) at 8–32 days after onset,the difference was significant(Fisher’s exact test,P<0.001).For the viral RNA detection,6.47%(9/139) of breakthrough cases were positive,16.67%(6/36) of unvaccinated cases were positive,the difference was not significant(χ^2=3.79,P>0.05).The positive samples(throat swabs and oral fluids) were mainly collected within 2–3 days after onset.Only 1.39%(1/72) of throat swabs of breakthrough cases were positive,but 11.94%(8/67) of oral fluids of breakthrough cases were positive,the difference was significant(Fisher’s exact test,P=0.015).Conclusion According to the results of IgM detection,we confirmed most clinically diagnosed breakthrough mumps cases,but the sensitivities of ELISA in detection of IgM and RT-PCR in detection of viral RNA were not high in acute phase(1–7 days).It is suggested to detect IgM 7 days later after onset for confirmation.