一例新型H1N1和季节性H3N2流感混合感染病例的检测和结果分析

Test and analysis of a mixed infection case with new influenza A H1N1 and seasonal influenza H3N2

目的对一例新甲型H1N1和季节性H3N2亚型流感病毒混合感染病例进行检测。方法鼻咽拭子的核酸样本和细胞培养物100倍稀释的核酸样本经实时荧光PCR方法鉴定流感病毒亚型。病毒经MDCK细胞培养后进行红细胞凝集试验(HA)和红细胞凝集抑制试验(HI)。结果鼻咽拭子和细胞培养物实时荧光PCR检测为季节性H3N2阳性(CT值25.837 VS 15.675);新甲型H1N1阳性(CT值20.267 VS 25.169)。季节性H3N2 HI滴度为>1280,新甲型H1N1 HI滴度为80。结论在两种亚型共同流行期间,采用实时荧光PCR方法可检测人季节性H3N2和新甲型H1N1混合感染病例。季节性H3N2在细胞培养液中的病毒核酸量多于新甲型H1N1,而且季节性H3N2呈现较高的HI滴度。对于本次混合感染样本检测中呈现的一些特点有待进一步研究。

Objective To detect one case with mixed infection of new influenza A H1 N1 and seasonal influenza H3N2. Meth- ods The virus nucleic acid from nasopharyngeal swabs and its 100 times dilution of cell culture were tested by real - time PCR to identify the influenza virus subtypes. The virus isolation of cell culture was also tested by haemagglutination test （HA） and haemagglutination inhibition tests（HI）. Results The nasopharyngeal swabs and cell culture specimens were both positive for seasonal influenza H3N2 （ CT value 25. 837 VS 15. 675 ） , and positive for new influenza A HIN1 （ CT value 20. 267 VS 25. 169）. The HI titer was greater than 1280 for seasonal influenza H3N2, while that was 80 for new influenza A H1N1. Con- clusion In the co - circulated period, the mixed infection of new influenza A H1 N1 and seasonal influenza H3N2 viruses could be tested by real - time PCR. The nucleic acid amount of seasonal influenza H3N2 was more than that of new influenza A H1N1 in MDCK cell culture. The HI test showed high titer to seasonal H3N2. The interesting phenomenon in this mixed infection test needs further attention for analysis.