Spectrum of Parvovirus B19 infection and its pathogenesis

人类细小病毒B19（B19）被认为只有一种免疫血清型。我们遇到了一个病人谁似乎有再感染后3年的主要感染。分析其初次感染和继发感染时血清中B19 DNA的基因型，并与同期流行的感染性红斑患者进行比较。检测长巢式PCR扩增的DNA产物。用限制性内切酶酶切图谱分析基因组类型。从感染性红斑患者中获得的菌株在3年内发生了变化。当分析和比较我们的患者的血清样本时，原发性和继发性感染的基因组类型没有差异，该患者似乎有再感染。潜伏性B19感染可能在原发性感染后持续存在。B19 IgM和DNA的二次检测被认为是由于潜伏感染后的再激活，B19可以通过输血和血浆衍生产品传播。我们于1992年1月至5月在我院进行了大规模的血液制品B19筛查。在3，342份由浓缩红细胞冷冻保存的血浆样品中，22份样品经酶免疫法检测为细小病毒B19（B19）IgM阳性。在这22份样本中，11份（0.33%）经聚合酶链反应检测B19 IgG和B19 DNA均呈阳性，表明存在B19污染。其发生率明显高于敏感的受体介导血凝试验（0.012%）。研究结果表明，该方法具有足够的灵敏度和特异性来检测人血浆中的B19，其使用可能有助于预防免疫功能低下患者或孕妇等易感人群中输血介导的病毒感染。

Human parvovirus B19 (B19) is believed to have only one immunoserotype. We encountered a patient who appeared to have reinfection 3 years after the primary infection. The genome type of B19 DNA obtained from his serum in the primary infection and during the secondary infection was analyzed and compared with those from patients with erythema infectiosum which was prevalent during the same time period. DNA products amplified by long nested PCR were examined. Genome types were analyzed by restrictive endonuclease cleavage pattern. The strain obtained from erythema infectiosum patients changed during the 3 years. There was no difference in genome type between the primary and the secondary infection when serum samples from our patient who seemed to have a reinfection were analyzed and compared. Latent B19 infection may persist after a primary infection. The secondary detection of B19 IgM and DNA was assumed to be due to reactivation after a latent infection.B19 can be transmitted through blood transfusion and plasma-derived products. We attempted a large-scale screening of B19 in blood products transfused in our hospital from January to May in 1992. Among 3,342 plasma samples kept frozen from packed red blood cells, 22 samples were positive for parvovirus B19 (B19) IgM by enzyme immunoassay. Of these 22 samples, 11 (0.33%) were positive for both B19 IgG and B19 DNA by polymerase chain reaction indicating contamination with B19. The incidence was obviously higher than in those (0.012%) tested by the receptor-mediated haemagglutination assay considered as a sensitive method. The findings suggest that the method reported has enough sensitivity and specificity to detect B19 in human plasma and its use might help prevent transfusion mediated viral infection in those susceptible such as immunocompromised patients or pregnant women.