Stramer Susan L, Glynn Simone A, Kleinman Steven H, Strong D Michael, Caglioti Sally, Wright David J, Dodd Roger Y, Busch Michael P
American Red Cross, Gaithersburg, Md, USA.
N Engl J Med. 2004 Aug 19;351(8):760-8. doi: 10.1056/NEJMoa040085.
Testing of blood donors for human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) RNA by means of nucleic acid amplification was introduced in the United States as an investigational screening test in mid-1999 to identify donations made during the window period before seroconversion.
We analyzed all antibody-nonreactive donations that were confirmed to be positive for HIV-1 and HCV RNA on nucleic acid-amplification testing of "minipools" (pools of 16 to 24 donations) by the main blood-collection programs in the United States during the first three years of nucleic acid screening.
Among 37,164,054 units screened, 12 were confirmed to be positive for HIV-1 RNA--or 1 in 3.1 million donations--only 2 of which were detected by HIV-1 p24 antigen testing. For HCV, of 39,721,404 units screened, 170 were confirmed to be positive for HCV RNA, or 1 in 230,000 donations (or 1 in 270,000 on the basis of 139 donations confirmed to be positive for HCV RNA with the use of a more sensitive HCV-antibody test). The respective rates of positive HCV and HIV-1 nucleic acid-amplification tests were 3.3 and 4.1 times as high among first-time donors as among donors who gave blood repeatedly. Follow-up studies of 67 HCV RNA-positive donors demonstrated that seroconversion occurred a median of 35 days after the index donation, followed by a low rate of resolution of viremia; three cases of long-term immunologically silent HCV infection were documented.
Minipool nucleic acid-amplification testing has helped prevent the transmission of approximately 5 HIV-1 infections and 56 HCV infections annually and has reduced the residual risk of transfusion-transmitted HIV-1 and HCV to approximately 1 in 2 million blood units.
1999年年中，美国引入了通过核酸扩增检测献血者1型人类免疫缺陷病毒（HIV-1）和丙型肝炎病毒（HCV）RNA的方法，作为一项研究性筛查试验，以识别血清转化前窗口期内的献血。
我们分析了美国主要采血项目在核酸筛查的前三年中，对“小混合样本”（16至24份献血的混合样本）进行核酸扩增检测时，所有抗体检测呈阴性但被确认为HIV-1和HCV RNA阳性的献血。
在筛查的37164054单位血液中，有12单位被确认为HIV-1 RNA阳性，即每310万份献血中有1份呈阳性，其中只有2份通过HIV-1 p24抗原检测发现。对于HCV，在筛查的39721404单位血液中，有170单位被确认为HCV RNA阳性，即每23万份献血中有1份呈阳性（或根据使用更敏感的HCV抗体检测确认为HCV RNA阳性的139份献血计算，每27万份献血中有1份呈阳性）。初次献血者中HCV和HIV-1核酸扩增检测呈阳性的比例分别是多次献血者的3.3倍和4.1倍。对67名HCV RNA阳性献血者的随访研究表明，血清转化发生在首次献血后的中位数为35天，随后病毒血症清除率较低；记录了3例长期免疫沉默的HCV感染病例。
小混合样本核酸扩增检测每年有助于预防约5例HIV-1感染和56例HCV感染，并将输血传播HIV-1和HCV的残留风险降低至约每200万单位血液中有1例。
