收集婴幼儿急疹及淋巴系统增生性疾病患者外周血单个核细胞进行体外培养，从７例婴幼儿急疹及２例淋巴系统增生性疾病患者中分离出一种病毒，此病毒能在ＰＨＡ激活的人脐血单个核细胞中传代生长，产生典型ＣＰＥ：形成气球样巨细胞。电镜下观察，感染细胞中可见直径１８０ｎｍ左右，有包膜，疱疹样病毒颗粒；血清学试验证明分离株与ＨＳＶ－１，２、ＨＣＭＶ、及ＥＢＶ无抗原交叉，而与ＨＨＶ－６ＧＳ株间存在抗原一致性；多聚酶链反应表明该分离株ＨＨＶ－６特异性ＤＮＡ阳性；综合以上结果，初步认为该分离株为ＨＨＶ－６。同时还用ｐＣＲ法对所收集的标本直接检测ＨＨＶ－６特异性ＤＮＡ。ＰＣＲ法与病毒分离法相比较，前者ＨＨＶ－６检出率为８８．８％（１６／１８）．后者为３８．９％（７／１８）。

eripheral blood samples from patients with exanthem subitum and lymphoproliferative dis-orders were collected.Mononuclear cells were separated from patients blood and were cultured invitro.As a result,virus strains were isolated from the peripheral blood mononuclaear cells of sevenpatients with exanthem subitum and two patients with lymphoproliferative disorders.The isolatescould propagate in the PHA stimulated umbillical cord blood mononucalear cells and the cytopathiceffects characterized by large ballonlike cells were observed after infection Electronmicroscopy ofinfected cells ultrathin section showed the size of enveloped virus particles is 180 nm in diameterand the particles morphologically resemble herpesgroup virus.Serological test further demonstrated that the isolates lacked immunological cross-reactivity with HSV-1 and 2. HCMV and EBV,butwere shown to be antigenically related to HHV-6 GS strain; HHV-6 specific DNAs were detectedin all the isolate by polymerase chain reaction.