A method for estimating incidence rate of infectious diseases among first-time blood donors

BACKGROUND: In certain circumstances, there is no method for estimating incidence based on testing results on a single blood sample from first‐time blood donors, severely limiting the ability to assess the residual risk of blood‐borne infections among this donor subpopulation. STUDY DESIGN AND METHODS: Incidence rates were estimated for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) among first‐time donors using the formula (P₂ ? P₁)/D, where P₁ is the prevalence among blood donations from first‐time donors of the minimum eligible ages for donation, P₂ is the prevalence among donations from first‐time donors of an older age group, and D is the age difference (in years) between the older and younger donor groups. RESULTS: Estimating incidence among first‐time donors using the proposed method based on a single test for anti‐HCV produced similar results to those based on HCV nucleic acid test (NAT) yield cases, by sex and in different periods. Comparison of the proposed method with HIV NAT yield also showed similar results although the small number of HIV NAT yield cases limits interpretation. CONCLUSIONS: The proposed method provides an alternative way for estimating incidence of certain blood‐borne infections among first‐time donors, provided that our assumptions are met. It helps residual risk assessment in donor populations where first‐time donors account for most of the donations and only one test result is available for each donor.     

A survey of the incidence of Miltenberger antibodies among Hong Kong Chinese blood donors

BACKGROUND: The ready availability of red cells of the Miltenberger (Mi) class III phenotype (6.28%) prompted the study of Mi antibodies among Chinese blood donors in Hong Kong, 98 percent of whom are descended from inhabitants of Guangdong Province in southern China. STUDY DESIGN AND METHODS: Red cells of the Mi class III phenotype were used to conduct a survey of the frequency of Miltenberger antibodies in 56,161 random Chinese blood donors, over a period of 12 months, using a microplate technique. RESULTS: Sera from 32 donors (0.057%) were found to contain Mi antibodies: sera from 22 contained anti-Mur + Hut; sera from 4 contained anti-Vw + Mur + Hut; sera from 4 had monospecific anti- Mur; and sera from 2 had monospecific anti-Hil. The immunoglobulin isotypes of 24 sera were mixtures of IgM and IgG, 4 were pure IgM, and 4 were pure IgG. CONCLUSION: The majority of Mi antibodies detected were naturally occurring. This survey proved useful for mass screening of random donors for the procurement of valuable Mi antisera.     

互助献血与无偿献血血清学标志物对比分析

目的：对互助献血和无偿献血的血清学指标进行分析对比,研究探讨互助献血的风险。方法2006年1月至2012年12月,对符合献血条件的1834例互助献血者以及217323例无偿献血者进行了血液采集和留取 ETDA 抗凝样本,进行 ALT、HBsAg、Anti-HCV、Anti-HIV、梅毒共5个项目的初复检。结果互助献血（8.67％）的总阳性率要高于无偿献血组（6.31％）,但两组的ALT 阳性率差异无统计学意义,互助献血组的HBsAg、Anti-HCV、梅毒均高于无偿献血组。结论无偿献血群体的血清学安全指标优于互助献血组,是血源性传播疾病较低的低危人群,应该是血液供应的主要来源群体;对互助献血采取合理的干预措施后,能确保其安全指数与无偿献血等同,可作为无偿献血的有益补充。     

不同核酸检测方法对献血者隐匿性乙肝病毒感染的研究

目的了解无偿献血者中隐匿性乙肝病毒感染情况,并比较不同核酸检测方法对隐匿性乙肝病毒感染检测能力的差异。方法分别采用nested-PCR和Procleix Ultrio全自动核酸检测系统对无偿献血者血浆标本进行HBV核酸检测,对核酸阳性标本进行HBV DNA序列分析。结果在总计9 209例次标本的检测中,共有9 159例为HBsAg(-);HBsAg(-)标本中nested-PCR方法检出18例HBV DNA阳性(0.19%,18/9 159),而Procleix Ultrio检出7例(0.076%,7/9 159),两者间差异有统计学意义(P<0.05);测序结果显示隐匿性HBV感染者中C基因型所占的比例(64.7%,11/17)明显高于HBsAg阳性的HBV感染者(23.1%,6/23,P<0.01)。结论闽南地区无偿献血者中存在较高比例的隐匿性乙肝病毒感染;不同核酸检测方法对献血者隐匿性乙肝病毒感染的检测能力存在差异。     

Current methods for detection of anti-erythrocytic antibodies in blood donors

Erythrocytic antibody screening in donors aids in reducing the risk of posttransfusion reactions and complications; donors with serum immune antibodies are taken from donation of plasma and transferred to that of erythrocyte-containing media. The application of highly sensitive tests for antibody screening permits detection of antibodies of wide range and various specificity and immunogenicity. The antibody identification technique makes it possible to establish a priority scale of transfusionally dangerous erythrocytic antigens.     

Current incidence and residual risk of hepatitis B infection among blood donors in the United States

BACKGROUND: This study used two approaches to estimate the current incidence of hepatitis B virus (HBV) in a US donor population.
METHODS: HBV incidence was estimated through the hepatitis B surface antigen (HBsAg) yield approach and the seroconversion method. Residual risk was estimated by the incidence–window period model. HBsAg yield refers to an HBsAg confirmed-positive, antibody against hepatitis B core antigen (anti-HBc)–nonreactive donation, adjusted for false-positive neutralization results. The number of HBsAg-seroconverting repeat donors divided by total number of person-years of evaluation or the HBsAg yield rate divided by HBsAg yield window gave rise to incidence estimates.
RESULTS: The seroconversion and the yield approach, respectively, gave an incidence estimate of 3.41 or 3.43 per 10⁵ person-years. Using a revised infectious window period of 38 or 30 days for current HBsAg assays, the current residual risk for HBV was respectively estimated for 2006 to 2008 at 1 in 282,000 or 1 in 357,000 donations from the seroconversion approach and 1 in 280,000 or 1 in 355,000 donations from the yield approach. With the same database and methods, this is a decrease from 1 in 86,000 to 1 in 110,000 observed in 1997 to 1999.
CONCLUSIONS: Current HBV incidence and residual risk are lower than earlier estimates, especially in the youngest donors, but remain higher in the absence of HBV nucleic acid test than those for human immunodeficiency virus or hepatitis C virus (HCV). In addition to the exclusion of HBsAg false-positive donors, the reduction could reflect shortened window periods and decreased incidence rates due to vaccination or other reasons.     

Multicenter comparison of serologic assays and estimation of human herpesvirus 8 seroprevalence among US blood donors

BACKGROUND: As part of assessing the possibility of transfusion transmission of human herpesvirus 8 (HHV-8 or Kaposi's sarcoma-associated herpesvirus), HHV-8 seroprevalence was estimated among US blood donors, the performance of HHV-8 serologic tests was compared, and the presence of HHV-8 DNA was tested for in donated blood. STUDY DESIGN AND METHODS: Replicate panels of 1040 plasma specimens prepared from 1000 US blood donors (collected in 1994 and 1995) and 21 Kaposi's sarcoma patients were tested for antibodies to HHV-8 in six laboratories. HHV-8 PCR was performed on blood samples from 138 donors, including all 33 who tested seropositive in at least two laboratories and 22 who tested positive in at least one. RESULTS: The estimated HHV-8 seroprevalence among US blood donors was 3.5 percent (95% CI, 1.2%-9.8%) by a conditional dependence latent-class model, 3.0 percent (95% CI, 2.0%-4.6%) by a conditional independence latent-class model, and 3.3 percent (95% CI, 2.3%-4.6%) by use of a consensus-derived gold standard (specimens positive in two or more laboratories); the conditional dependence model best fit the data. In this model, laboratory specificities ranged from 96.6 to 100 percent. Sensitivities ranged widely, but with overlapping 95 percent CIs. HHV-8 DNA was detected in blood from none of 138 donors evaluated. CONCLUSIONS: Medical and behavioral screening does not eliminate HHV-8-seropositive persons from the US blood donor pool, but no viral DNA was found in donor blood. Further studies of much larger numbers of seropositive individuals will be required to more completely assess the rate of viremia and possibility of HHV-8 transfusion transmission. Current data do not indicate a need to screen US blood donors for HHV-8.     

High incidence of defective high-shear platelet function among platelet donors

BACKGROUND: Because single-donor plateletpheresis concentrates now account for a large percentage of PLT concentrates, the PLT quality of individual donations is increasingly important. There has been little previous work on PLT function in blood donors. STUDY DESIGN AND METHODS: The aim of this study was to investigate the prevalence of defective PLT function among 100 healthy UK PLT donors on 3 consecutive donation days. Citrated blood samples were taken before plateletpheresis. High-shear PLT function testing was performed by a PLT function analyzer (PFA-100, Dade Behring), within both collagen-ADP (CADP) and collagen-epinephrine (CEPI) cartridges. RESULTS: Sixteen percent of PLT donors (mainly over the 3 donating days) had prolonged CEPI closure times (CTs) only, indicative of an aspirin-like pattern; 9 percent had a severe defect with prolonged CEPI CTs between 200 and 300 seconds, and 4 percent had maximal CEPI CTs of greater than 300 seconds. The majority of prolonged CEPI CTs appeared transient in nature. CONCLUSION: PLT dysfunction as detected by the PFA-100 is surprisingly common within a voluntary PLT donor population. The majority of CEPI defects appeared transient in nature and are indicative of surreptitious intake of cyclooxygenase inhibitors (e.g., aspirin). Identification of defective PLT function within donors would provide a simple means to eradicate defective PLTs from being clinically utilized.     

无偿献血者HIV假阳性献血员去留的探讨

目的探讨无偿献血者HIV确认为阴性的献血者是否保留、归队为献血者。方法无偿献血者标本（HIV两种试剂检测）仅一种试剂有反应,且A值小于1,乙型肝炎病毒表面抗原、丙型肝炎病毒抗体、梅毒抗体均阴性,转氨酶正常的献血者,于献血后12个月再采集标本做献血常规检测。结果共收集到46份标本,检测结果仅有1份标本进口试剂有反应性,国产试剂均无反应性,将有反应性标本送省疾病预防控制做确认实验,结果为阴性。结论无偿献血者HIV两种试剂检测（一种国产、一种进口）仅有一种试剂有反应性,且A值小于1者,其他项目均正常的献血者,HIV反应性多是假阳性,进一步检测之后,HIV无反应性或确认为阴性的献血者可以保留。     

Multiple unconfirmed-reactive screening tests for viral antibodies among blood donors

BACKGROUND: In December 1991, the United States Food and Drug Administration received reports of blood donations with unconfirmed reactivity on screening tests for antibodies to human immunodeficiency virus, human T-lymphotropic virus type I, and hepatitis C virus (HCV). Of 91 donors with these test results, 57 (63%) reported a recent influenza vaccination. STUDY DESIGN AND METHODS: To determine the extent of unconfirmed reactivity, the time at which it began, and its association or nonassociation with specific manufacturers' tests, a nationwide survey of blood centers was conducted. A case-donation was defined as a blood donation that was repeatedly reactive, but not confirmed positive, on at least two of the three tests from May 1990 through December 1991. RESULTS: Among 14 million donations screened by 110 centers, 582 case-donations were identified. An increase in case- donations was evident in the fall of 1990 (2.8/100,000 donations). In 1991, rates increased from 0.9 per 100,000 donations in the first quarter to 1.3, 3.2, and 19.7 in subsequent quarters. A significantly higher rate of case-donations was observed among donations tested with one of the two available anti-HCV screening tests (8.0 vs. 1.2/100,000 donations; risk ratio = 6.8; 95% CI = 5.4-8.5). CONCLUSION: Although unconfirmed reactivity on multiple screening tests appeared to be seasonal, its documentation prior to the availability of influenza vaccine in 1991 and higher rates among donations tested with one manufacturer's anti-HCV test indicated that test-specific factors were also involved.     

献血者三种病毒感染血液学筛查分析

目的探讨献血者单纯疱疹病毒(HSV)、巨细胞病毒(CMV)、风疹病毒(RV)感染状况及其血液学筛查的意义,进一步提高所供血液的质量。方法采用荧光定量聚合酶链反应技术,检测献血者血液中三种病毒的特异核酸载量。其中有偿献血者140例,(男、女各70例);无偿献血者140例(男、女各70例)。结果有偿献血者HSV感染男、女阳性率分别为1·4%,2·8%;CMV感染男、女阳性率分别为2·8%,5·7%;RV感染男、女阳性率分别为0·0%,1·4%。无偿献血者HSV感染男、女阳性率分别为0·0%,1·4%;CMV感染男、女阳性率分别为0·0%,2·8%;RV感染男、女阳性率均为0·0%。结论有偿献血者三种病毒感染阳性率高于无偿献血者。     

健康献血者不规则抗体筛查在临床输血中的意义

目的探讨健康献血者不规则抗体筛查在临床输血中的意义。方法收集2011年8月至2012年10月3 029名健康献血者的血液标本,采用盐水介质法和抗人球蛋白法进行不规则抗体筛查,抗体筛查阳性者做进一步鉴定,分析抗体特异性。结果对新疆维吾尔族自治区农三师图木舒克市中心血站3 029例健康献血者进行不规则抗体筛查阳性17例(0.56%),其中抗-D阳性9例,抗-E阳性4例,抗-e阳性1例,抗-M阳性2例,抗A1阳性1例。男性不规则抗体阳性率为0.43%(6/1 397),女性不规则抗体阳性率为0.67%(11/1 632),差异无统计学意义(P>0.05)。有输血史或妊娠史的健康献血者不规则抗体阳性率显著高于无输血史或妊娠史者(1.48%vs0.10%,P<0.05)。结论常规对健康献血者血液标本进行不规则抗体筛查和鉴定,对保障临床用血安全、预防溶血性输血反应具有极其重要的意义。