摘要目的 对2006年广州地区登革热患者的血清进行检测,并对分离的病毒株进行E基因序列分析,以了解可能的传播来源.方法 用免疫层析法(ICT)检测患者血清登革病毒IgM和lgG抗体,并用酶联免疫吸附试验(ELISA)检测登革病毒非结构蛋白1(NS1)抗原和IgM抗体;C6/36细胞微量法对发病2 d内患者的血清进行登革病毒的分离培养,并用免疫荧光检测(IFA)及RT-PCR法对病毒分离株进行鉴定;测定分离株DV1-GZ42/06的E基因序列,与国内外参考株、流行株进行同源性比较并构建系统进化树.结果 ICT法检测患者登革病毒IgM和IgG的检出率分别为89.5%(433/484)及38.0%(184/484).ELISA法检测患者血清NSI抗原的检出率为:第1～2天92.7%(38/41)、第3～5天83.3%(70/84)、第6～10天10.9%(5/46);IgM抗体的检出率分别为2.4%(1/41)、51.2%(43/84)及97.8%(45/46).病毒分离培养阳性率为61.0%(25/41),IFA及RT-PCR法汪实为登革1型病毒.分离株Guangzhou/42/06的E基因序列与登革1型病毒标准株Hawaii/45的核苷酸同源件为94.6%;与Thailand/NI09VI04、Vietnam/06和Vietnam/07的同源性高,分别为99.0%、98.6%和98.6%,且处于同一进化分支上,亲缘关系很近,而与广东省2006年前分离株亲缘关系较远.结论 登革病毒NS1抗原检测在登革病毒感染的早期诊断中有重要价值.2006年广州地区出现的登革热疫情由输入性病例引起本地暴发流行的可能性大.

abstractsObjective To detect dengue virus infection by serological method and to determine the sequences of E gene of dengue virus isolated from Guangzhou in 2006.so as to clarify the possible origin of dengue fever.Methods IgM and IgG antibodies to dengue virus were detected by immunochromatographic test(ICT);NSI antigen and IgM antibody were detected by enzyme-linked immunosorbent assay(ELISA).The virus was cultured and isolated from the serum samples within 2 days using C6/36 cell lines and was identified by immuno-fluorescence assay(IFA)and RT-PCR.The E gene of isolated virus DV1-GZ42/06 was sequenced;homological analysis and phylogenetic tree analysis were performed by comparing with the reference strains and epidemic virus strains.Results The positive rates of IgM and IgG of dengue virus in patients were 89.5%(433/484)and 38.0%(184/484)by ICT,respectively.The positive rates of NS1 antigen were 92.7%(38/41)in day 1 to day 2,83.3%(70/84)in day 3 to day 5,and 10.9%(5/46)in day 6 to day 10;and the IgM detection rates were 2.4%(1/41),51.2%(43/84)and 97.8%(45/46)at the same period by ELISA.Twenty-five strains of dengue virus were isolated from 41 serum samples(6 1.O%)and were identified as type 1 dengue virus by IFA and RT-PCR.The sequencing and phylogenetic analysis of the E gene showed that the homology between the isolated Guangzhou/42/06 strain and standard strain Hawaii/45 was 94.6%.and it had a high homology with the Thailand/NI09V104,Vietnam/06.and Vietnam/07 isolates(99.0%,98.6%and 98.6%,respectively)and belonged to the same cladogram,but had low homology with the isolated strain from Guangdong before 2006.Conclusions The detection of NS1 antigen is important in the early diagnosis of dengue fever.The outbreak of dengue fever in Guangzhou in 2006 was possibly caused by the cases from neighboring countries.