茂名地区无偿献血者72例HCV感染特征及检测效果评价分析

目的测定茂名地区部分丙型肝炎病毒感染献血者中不同感染状态比率及其分子特征,分析丙型肝炎病毒感染基因型分布流行特征及趋势,评价ELISA法检测血液HCV的效果。方法对本地区献血者中抗-HCV检测呈反应性的血液标本采用定量PCR方法检测血浆中病毒载量,同时采用巢式PCR技术扩增核酸片段,进而将血液标本分为病毒自然清除(RNA-/抗-+)与病毒血症(RNA+/Ab抗-+)2种状态,并分析2种状态在献血者性别方面的差异。HCV RNA阳性标本通过分析5’-NCR序列进行基因分型。比较ELISA与NAT检测方法的符合性。结果72份抗-HCV呈反应性的标本中,病毒自然清除50份(69.4%),病毒血症22份(30.6%)。22份PCR定量阳性标本中基因分型阳性17份,其中基因1型占17.6%(3/17),基因2型占11.8%(2/17),基因3型17.6%(3/17),基因6型47.1%(8/17),无法准确定型5.8%(1/17)。试剂A检测呈反应性标本中核酸确认阳性标本占32.3%;试剂B为54.5%。女性病毒血症的比例(2/19)比男性(20/53)低27.2%(χ2=9.637,P0.05)。结论茂名地区献血者HCV感染病毒自然清除率约为69.4%,HCV基因型中6型为主要基因型,女性献血者更容易清除病毒。现行2遍ELISA检测策略安全有效,但同时存在特异性不高的弊端,实施ELISA加NAT检测的策略,更能保证血液的安全和降低检测假阳性。     

江苏地区无偿献血者HCV基因型的分布

目的探讨江苏地区献血者感染的HCV基因型及亚型。方法收集2013年来自江苏省血液中心ELISA双试剂检测抗-HCV阳性献血者血清标本,使用HCV核酸定量检测试剂盒检测HCV RNA载量;同时使用RNA提取试剂提取HCV RNA,反转录PCR法扩增HCV Core区基因片段,并对扩增产物进行测序,利用进化树分析基因型和亚型。结果 2013年抗-HCV阳性标本139例(0.20%),其中64例抗-HCV阳性血清标本经荧光定量检测,RNA阴性30份,阳性34份。经巢式PCR扩增能够分型的标本24份,包括1a(71.7%)、1b(7.5%)、2a(7.5%)和3b(1.9%)3种基因型和4种亚型。年龄偏大(35岁)以及男性的HCV RNA阳性标本的病毒滴度与抗-HCV水平(S/CO值)都高于RNA阴性标本,并且存在性别差异,但年龄间无差异。结论江苏无偿献血者感染的HCV基因型以1型为主,其中1b为优势基因亚型。病毒血症献血者的HCV抗体水平显著升高,HCV RNA在自然感染进程中的变化有待通过进一步随访进行研究。     

深圳地区抗-HCV阴性/NAT初筛阳性献血者的HCV窗口感染期确认

目的了解深圳地区血液筛查中抗-HCV阴性/NAT初筛阳性献血者的检出情况及其HCV窗口感染期的确认。方法 2008-2014年本中心采用酶免(ELISA)及病毒核酸检测方法(NAT)筛查492 325份无偿献血者样品,获得6例抗-HCV阴性/NAT初筛阳性献血者,使用荧光定量检测方法(QPCR)和巢式PCR(Nested-PCR)确认其HCV RNA是否存在并随访跟踪复查,以确定6例献血者核酸检测结果假阳性或HCV窗口感染期的性质。结果本中心在这7年期间,492 325份献血者的抗-HCV阴性/NAT初筛阳性检出率为1/82 054(6/492 325);6例抗-HCV阴性/NAT初筛阳性献血者,确认1/6例(16.7%)处于HCV窗口感染期,1/6例(16.7%)判定为核酸检测采血管血样污染HCV造成假阳性结果,4/6例(66.7%)判定为核酸仪器检测过程中出现假阳性导致NAT初筛阳性。故本中心目前献血者HCV窗口感染期检出率为1:492 325。结论目前核酸检测存在假阳性情况,需建立额外核酸扩增方法及追踪随访才能确定样品性质,确保病毒感染窗口期结果的准确性。     

国产HCV RNA分型试剂盒检测结果分析

目的分析丙型肝炎病毒(HCV)RNA分型试剂盒检测深圳市抗-HCV阳性献血者结果。方法收集2014-2015年158份深圳市抗-HCV阳性献血者血液样本,应用聚合酶链反应(PCR)-荧光探针法进行HCV RNA定量检测,病毒载量1.0×103 IU/mL的样本经HCV RNA分型试剂盒检测HCV基因型,分析不同基因型所占比例,病毒基因型与载量之间的相关性。结果 158份抗-HCV阳性献血者PCR-荧光探针法检出HCV RNA阳性样本54例,病毒载量1.0×103 IU/mL的45例,全部得到分型结果,HCV 1b型、2型、3型、6型分别占57.78%(26/45)、6.67%(3/45)、8.89%(4/45)、26.67%(12/45)。单因素方差分析结果显示,1b型与2型病毒载量差异有统计学意义(F=2.861,P0.05);不同性别间HCV RNA定量检测结果及抗-HCV S/CO值结果差异有统计学意义(P0.05);不同年龄段各基因型分布比例经Fisher精确检验,差异有统计学意义(P0.05)。结论 HCV 1b型、6型仍为深圳市无偿献血人群感染HCV的主要基因型,而HCV 2型和3型比例有所减少。     

抗-HCV,HCV RNA检测在丙型肝炎中的应用价值探讨

目的探讨抗-HCV,HCV RNA检测在丙型肝炎诊断中的临床价值。方法选择2018年5月-2018年12月检验科收集的143例抗-HCV(S/CO≥1)初筛实验阳性的血清标本,分别采用酶联免疫吸附法(ELISA)及荧光定量聚合酶链反应法(PCR)、日立7600全自动生化分析仪,进行抗-HCV、HCV RNA病毒载量、ALT检测。结果143例抗-HCV初筛阳性患者中,99例HCV RNA阳性(69.23%),且随着S/CO比值的增高HCV RNA检出的阳性率增加,差异有统计学意义(P<0.01);99例HCV RNA阳性患者中93例抗-HCV的S/CO>10,但随着S/CO的增大,HCV RNA病毒载量高低水平出现的阳性率没有增加(P>0.05);HCV RNA阳性患者ALT异常率(46.46%)高于阴性患者(20.45%),差异有统计学意义(P<0.05);44例HCV RNA阴性(30.76%)患者中有33例的S/CO>10,且有9例ALT异常。结论ELISA法检测血清抗-HCV诊断丙型肝炎与荧光定量PCR检测法均存在假阳性或假阴性情况;荧光定量PCR法的阳性率低于ELISA法;在临床诊断中ELISA法抗-HCV初筛阳性的样本应同时进行HCV RNA及ALT的联合检测,以避免漏诊、误诊,也为临床抗病毒的有效评估提供可靠的实验室依据。     

无偿献血人群HCV感染的检测和输血残余风险分析

目的了解深圳地区无偿献血人群HCV感染状况,评估血液经EIA筛查抗-HCV后经血传播HCV感染的残余风险。方法采用两种EIA试剂对献血者血液进行抗-HCV筛查,采用核酸检测技术检测EIA检测"合格"标本中HCV RNA,对HCVRNA阳性标本进行荧光定量PCR检测病毒载量,并对PCR扩增产物进行测序和病毒基因亚型分析。结果共筛查1997～2009年期间的献血者254 570人份,发现抗-HCV阳性1401人份,阳性率为0.55%;对2002～2007年期间EIA检测"合格"的113639份献血者血液标本进行NAT检测,检测出1份HCV RNA阳性、抗-HCV阴性的血清转换窗口期感染的献血者血液,HCV残余风险高达1/113 639。结论 EIA筛查后血液安全性有了很好的保障,但由于HCV感染窗口期存在,经血传播HCV残余风险依然处于较高的水平,NAT应用对提高血液安全,降低输血传播HCV残余风险意义重大。     

无偿献血人群HCV感染的检测和输血残余风险分析

目的了解深圳地区无偿献血人群HCV感染状况,评估血液经EIA筛查抗-HCV后经血传播HCV感染的残余风险。方法采用两种EIA试剂对献血者血液进行抗-HCV筛查,采用核酸检测技术检测EIA检测＂合格＂标本中HCV RNA,对HCVRNA阳性标本进行荧光定量PCR检测病毒载量,并对PCR扩增产物进行测序和病毒基因亚型分析。结果共筛查1997～2009年期间的献血者254 570人份,发现抗-HCV阳性1401人份,阳性率为0.55%;对2002～2007年期间EIA检测＂合格＂的113639份献血者血液标本进行NAT检测,检测出1份HCV RNA阳性、抗-HCV阴性的血清转换窗口期感染的献血者血液,HCV残余风险高达1/113 639。结论 EIA筛查后血液安全性有了很好的保障,但由于HCV感染窗口期存在,经血传播HCV残余风险依然处于较高的水平,NAT应用对提高血液安全,降低输血传播HCV残余风险意义重大。     

血浆miR-122在抗-HCV阳性献血者中表达的动态分析

目的动态分析抗-HCV阳性献血者血浆miR-122的表达特点及与HCV感染诊断指标的关联。方法对133名抗-HCV阳性献血者、24名健康献血者及15名确证抗-HCV阳性追踪献血者血液标本抽提血浆miRNA,以实时荧光定量PCR法检测血浆miR-122,分析血浆miR-122相对表达量与HCV RNA、抗-HCV临界值指数(COI)等指标关联性。结果 ROC曲线分析:miR-122在抗-HCV+/HCV RNA+组和抗-HCV+/HCV RNA-组中诊断丙型肝炎的AUC(ROC曲线下面积)为0.830(95%CI:0.755-0.889),区分抗-HCV+/HCV RNA+组和抗-HCV+/HCV RNA-组的敏感性和特异性分别为74.7%和82.4%。追踪15例抗-HCV+/HCV RNA+献血者血浆miR-122表达明显降低(P0.05)。结论血浆miR-122与HCV感染密切相关,确证HCV RNA感染献血者血浆miR-122随时间迁移表达降低。     

深圳地区抗-HCVRIBA结果不确定献血者的随访研究

目的追踪随访深圳地区抗-HCV ELISA结果呈反应性、RIBA结果为不确定的献血者,研究分析其HCV转归情况,为抗-HCV ELISA呈反应性结果的无偿献血者召回提供理论基础和科学依据。方法追踪随访2年前32名抗-HCV RIBA结果为不确定的献血者,对其血液标本进行抗-HCV ELISA、HCV-RNA(NAT)、ALT以及HCV病毒载量检测,若HCV-RNA阴性则加做RIBA确证试验。结果 32例随访者血液标本中6例抗-HCV ELISA呈反应性,包含1例ALT升高同时HCV-RNA和病毒载量测定阳性;3例RIBA确证阳性。结论抗-HCV RIBA结果为不确定的献血者仍属于献血高危人群,存在一定的HCV输血传播风险。     

深圳地区2003～2012年间无偿献血者抗-HCV抗体与核酸检出情况分析

目的调查分析深圳地区2003~2013年献血者抗-丙型肝炎病毒(HCV)抗体/病毒核酸检测(NAT)阳性检出情况。方法献血者经乙型肝炎病毒表面抗原(HBsAg)、丙氨酸氨基转移酶(ALT)快速试纸条初筛后,使用进口与国产两种酶联免疫吸附试验(ELISA)及血液病毒NAT方法检测抗-HCV抗体、HCV RNA,对11年来献血者抗-HCV抗体、NAT阳性率流行趋势进行统计分析比较。结果深圳地区2003~2013年献血人数逐年增长,抗-HCV抗体阳性率呈M型检出走势,于2013年达到最低。献血者抗-HCV抗体阳性/NAT阴性检出率与抗-HCV抗体走势一致,而真实感染HCV的指标抗-HCV抗体与NAT双阳性组检出率则缓慢下降;对抗-HCV抗体阳性献血者在不同分类组别比较发现,31~45岁献血者组、初次献血者组的抗-HCV抗体检出率分别高于其他年龄组与重复献血者(P0.05);抗-HCV抗体阴性/NAT阳性献血者有3例(检出率为1/134 518)。结论NAT检测为常规酶联免疫方法的补充检测手段,缺一不可,能大大降低输血风险,而NAT阴性献血者的抗-HCV抗体阳性占多数的检测结果应引起重视,避免因假阳性导致此类献血者资格淘汰。     

Seroprevalence of hepatitis C virus (HCV) infection among blood donors: a hospital-based study.

Insofar as chronic hepatitis C virus (HCV) infection in many individuals is asymptomatic, and as the prevalence of antibodies to hepatitis C virus (anti-HCV) among blood donors in Lebanon is scarce, this study addressed the prevalence of anti-HCV in 5,115 blood donors. Data obtained were compared to other world regions. Of the blood donors screened, 57 were initially tested positive or doubtful for anti-HCV Ab. Subsequent testing by two-third generation enzyme immunoassays confirmed that, of the 57 initially tested positive/doubtful, only 18 were positive for anti-HCV giving a prevalence rate of 0.4%. While there was no difference in HCV prevalence with respect to age or gender, a higher rate was seen in non-Lebanese compared to Lebanese subjects (3.4% vs 0.3%, P < 0.001). These results demonstrate a low prevalence of HCV infection among Lebanese blood donors, which was comparable to those established for western countries.     

Application of a new enzyme-linked immunosorbent assay for detection of total hepatitis C virus core antigen in blood donors

Recent studies have shown that total hepatitis C virus (HCV) core antigen, both free and antibody bound, is an accurate indirect marker of viral replication that can be used in clinical practice. The aim of the present study was to evaluate the performance of a new total HCV core antigen enzyme-linked immunosorbent assay (ELISA) for detection and quantification of total core antigen in blood donors, testing positive for anti-HCV antibodies and for prospective low-risk population screening. A population comprising 257 samples, from blood donors detected reactive for anti-HCV antibodies [137 recombinant immunoblot assay (RIBA) positive and 120 RIBA indeterminate], were tested by using a new total HCV core antigen ELISA. HCV-RNA was quantified by using quantitative polymerase chain reaction (PCR) assays in all RIBA-positive samples and RIBA-indeterminate samples that were positive for the total core antigen. Specificity of the assay was studied in 1070 healthy blood donors negative for anti-HCV antibodies. Compared with quantitative PCR assays, the total HCV core antigen assay showed 97.37% sensitivity. The three HCV-RNA-positive samples, which tested negative for the total core antigen, had a low viral load (< 1.4 x 10(4) IU mL(-1)). All samples with more than 1.4 x 10(4) IU mL(-1) of viral RNA were positive for total core antigen, independent of the HCV genotype. Concentration of total core antigen correlated significantly with those of HCV-RNA (r = 0.614, P < 0.0001). Overall specificity in freshly collected blood donor specimens was 99.63%. Our data indicate that the total HCV core antigen ELISA has a sensitivity close to PCR assays in diagnosing HCV infection in blood donors with anti-HCV antibodies and shows an excellent specificity in volunteer donors. This assay, in combination with anti-HCV antibodies screening tests, could be an alternative to molecular assays for HCV infection screening in blood donors.     

Screening of blood donations by hepatitis C virus polymerase chain reaction (HCV-PCR) improves safety of blood products by window period reduction

Introduction of the nucleic acid amplification technique (NAT) as a screening test for blood donors to detect HCV RNA became mandatory on 1 April 1999. Few automated commercial systems are available for HCV RNA detection at the moment. The Cobas Amplicor HCV 2.0 System is able to perform fully automated amplification and detection of nucleic acids. A concentration of 98 IU HCV RNA/ml can be detected by the Cobas Amplicor HCV 2.0 System (n = 233, in 100% of the cases). With a pool size of 40 donor samples, the guidelines of the Paul-Ehrlich-Institute concerning sensitivity (5,000 IU HCV RNA per mL in a single donation) were followed. One whole blood donation was identified as HCV-RNA positive (anti-HCV IgG negative, GPT < 30 U/L) during a period of 5 months. No false positive test results could be observed. The internal control and the run control are primarily helpful to monitor methodological problems.     

The prevalence of anti-HCV among Chinese voluntary blood donors in Taiwan

In Taiwan, the prevalence of circulating anti-HCV is 2 percent among first-time voluntary Chinese blood donors, 10 percent among donors with elevated ALT levels (greater than 45 IU/L), and higher among older men. The carrier rate for HBsAg was 18.6 percent and the frequency of positive HBV marker(s) (HBsAg, anti-HBc, anti-HBs) was 86.4 percent among first-time donors. There is no significant correlation between HBV and HCV infections in Taiwan, because there is no significant difference in the frequency of anti-HCV among donors with or without HBV markers. The frequency of anti-HCV among qualified donors in Taiwan (ALT less than 45 IU/L, not tested for anti-HBc) is 1.8 percent, which is not significantly different from the frequency (1.6%) in donors with normal ALT and negative for HBV marker(s) (qualified donors by Western Standards). Therefore, ALT is the most important surrogate marker for HCV infection in Taiwan.     

抗病毒治疗对Ⅰb型慢性丙肝患者PBMC IL-10、IL-12水平变化影响的研究

目的研究派罗欣联合利巴韦林抗病毒治疗对Ⅰb型慢性丙肝患者外周血单个核细胞(PBMC)分泌IL-10、IL-12水平的影响,分析IL-10、IL-12水平变化与病毒学应答结果之间的相关程度,探讨IL-10、IL-12作为抗病毒疗效评价指标的可能性。方法选取血清HCV-RNA阳性的Ib型慢性丙肝患者60例,依据病毒载量将其分为3组,低病毒载量组(1.0×103IU/ml     

HCV胶体金与ELISA法在献血者体检中的应用比较

目的应用丙型肝炎病毒（HCV）胶体金法检测无偿献血者,并与抗-HCV ELISA法比较。方法对2008年1月～2009年12月的5830例无偿献血者,先应用HCV胶体金试纸条检测,再分别用试剂1、试剂2两种抗-HCV ELISA试剂进行常规初检、复检。对HCV胶体金法阳性的标本、试剂1初检、试剂2复检阳性的标本,再进行HCV RNA RT-PCR荧光定量检测。结果在被检测的5830份标本中,HCV胶体金法阳性有11份,抗-HCV ELISA试剂1初检阳性12份、试剂2复检阳性13份;其中初检、复检均阳性的11份,仅初检阳性1份和仅复检阳性2份,HCV RNA RT-PCR荧光定量检测阳性11份。结论本组检验HCV胶体金法与HCV RNA RT-PCR荧光定量法结果符合率为100.0%,HCV胶体金试纸法假阳性率低,操作简便、快速,适合无偿献血者抗-HCV筛选。     

维持性血液透析患者丙型肝炎病毒感染基因型及同源性分子流行病学研究

目的研究深圳市第二人民医院血液透析中心维持性血液透析(maintenance hemodialysis,MHD)患者丙型肝炎病毒(hepatitisCvirus,HCV)感染的基因型及同源性,结合临床流行病学资料,为血液透析中心HCV感染的防治提供依据。方法荧光定量聚合酶链反应(PCR)法测定抗-HCV阳性的MHD患者的HCV-RNA定量,对HCV-RNA定量≥1×103 IU/ml的MHD患者,通过巢氏反转录(RT)-PCR对5’UTR及NS5B区进行扩增,扩增产物通过Sequence Scanner v1.0导出峰图,Muscle进行序列比对,MEGA5.1构建进化树以确定基因分型,bootstrap1000检验进化树可靠性,Blat进行序列同源性分析。结果 183例MHD患者中,抗-HCV阳性13例,抗-HCV阳性率为7.1%。HCV-RNA定量≥1×103IU/ml者9例中,1b型7例,6a型2例。1b型中,PC1与PC2间的遗传距离为0.000,PBC17与PC2间的遗传距离为0.008,PC29与PBC31间的遗传距离为0.035,PC32与PBC34间的遗传距离为0.102;6a型中,PC11与PC20间的遗传距离为0.068。PC1与PC2的同源性为100%,PC2与PBC17的同源性为99.23%,PC29与PBC31同源性为96.63%,PC32与PBC34的同源性为90.64%,PC11与PC20同源性为93.63%。9例患者的平均感染时间为(67.4±26.3)月,平均透析时间为(81.5±38.1)月,4例(PC2、PC11、PC29和PBC31)为输入性HCV感染者,另5例(PC1、PBC17、PC20、PC32和PC34)是在本中心接受MHD后的8～77月间发现HCV感染。在本中心感染的5例患者中,2例(PC32和PC34)有输血史及更换透析单位,3例(PC1、PBC17、PC20)无输血、更换透析单位、肾移植等感染HCV危险因素,根据流行病学调查,具有同源性的病例PC1和PBC17与感染源(输入性感染者)PC2患者有多次同班或邻班、相邻机位、同一护士操作的血液透析记录。结论深圳市第二人民医院血液透析中心的抗-HCV阳性率为7.1%。1b型为深圳市第二人民医院血液透析中心HCV感染的最常见基因型,其次为6a型。其中3例1b型患者(样本PC1、PC2和PBC17)HCV感染为同一流行株,同源性达99%以上,结合流行病学资料确定1例患者(PC2)为输入性传染源,与之同源感染的PC1和PBC17患者的可能传播途径为,因当时未对HCV阳性和阴性患者分区治疗、同一护士同时操作HCV阳性和阴性患者、护士未规范手卫生、护士操作不同患者未更换手套、共用肝素等不规范操作。近3年,本中心将抗-HCV阴性及HCV感染、HBV感染者实行分房间(分区)、专用透析机治疗、专人管理阳性患者、严格实施卫生部《血液净化标准化操作规范》管理,未再发新的感染患者,表明上述措施可有效防止血液透析中心内的交叉感染。本研究为血液透析中心HCV医源性感染的防治提供了重要的科学依据。     

YS01Protective Effect of HLA‐B57 on HCV Genotype 2 Infection in a West African Population

Background Recovery from Hepatitis C virus (HCV) infection is considered infrequent (<20%) in western populations but reaches 50% in West Africa where genotype 2 infection is predominant (Candotti J Virol 2003; 77: 7914). Aim To investigate cellular immune responses as alternative diagnostic of HCV infection and the possible involvement of viral or host genetic factors in recovery. Methods Samples from 104 Ghanaian blood donors screened with anti‐HCV rapid tests and enzyme immunoassay were collected between 2000 and 2005. HCV antibody screening was confirmed using genotype 2 recombinant core, E2 and NS3 proteins by Western blot. HCV viral load and genotype were determined. Cellular response to recombinant HCV genotype 2 proteins was tested by IFN gamma ELISpot on frozen cells. HLA genotype was determined by sequence specific oligonucleotide probes. Results A total of 104 donors were stratified in 37 chronic, 35 recovered infections and 32 false positive. 81% of subjects with chronic infections with RNA detected carried genotype 2 HCV RNA. Cellular immune response was investigated in 35 frozen peripheral blood mononuclear cell (PBMC) samples suitable for interferon‐gamma ELISpot assay. 12 confirmed recovered, one chronically infected and no false positive controls reacted to at least one recombinant protein. The magnitude of response was considerably higher in recovered cases. HLA‐B*57 was significantly more frequent in the group which had recovered from HCV infection compared with chronically infected subjects (P < 0.01, OR = 8.02). This allele is significantly more frequent in West Africa than in Europe or North America. Discussion and conclusions Cases classified as recovered by serological means were confirmed by the presence of T‐cells stimulated by viral proteins. Genotype 2 HCV tends to have lower viral load and better response to anti‐viral treatment suggesting that the local genotype might be more susceptible to immune control. However, genetic factors of the host might also influence the clinical outcome. It could be hypothesised that HLA‐B*5703 is the HLA molecule most efficient at presenting peptides from genotype 2 HCV in this population.     

广州地区SARS流行期和非流行期献血人群SARS病毒抗体的流行病学调查

目的　分析广州地区SARS流行期和非流行期无偿献血人群中严重急性呼吸道综合征(SARS)病毒感染 情况,为制定预防输血传播SARS病毒措施提供科学依据。方法　采用酶联免疫吸附试验(ELISA)对无偿献血者血 液进行SARS病毒抗体筛查,对SARS病毒抗体阳性样本用荧光聚合酶链反应(PCR)法进一步检测SARS病毒核 酸。采用统一的个案调查表对20名SARS病毒抗体阳性无偿献血者进行电话咨询调查,同时对31名SARS康复献 浆者进行检测,分析相关数据作对照。结果　6120名无偿献血者中,共检测出SARS病毒抗体阳性56例,阳性率为 0.92%,31名SARS康复献浆者中,检测出SARS病毒抗体阳性30例,阳性率为96.77%;SARS流行期和非流行期 无偿献血者SARS病毒抗体阳性率分别为0.91%和0.92%,56名无偿献血者SARS病毒抗体阳性的平均S/CO值 (2.34)和抗体平均滴度(≤1∶2)均明显低于30名SARS康复献浆者的平均S/CO值(14.8)和抗体平均滴度(≤1∶ 32);56例SARS病毒抗体阳性无偿献血者血液样本均未检测出SARS病毒核酸;20例SARS病毒抗体阳性无偿献 血者的调查显示:献血者身体健康,无SARS患者密切接触史。结论　广州地区无偿献血人群中存在的低水平 SARS病毒抗体阳性率,是否表明SARS病毒抗体阳性献血者曾经感染过SARS病毒,尚需进一步