Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

BACKGROUND: This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T- lymphotropic virus via the transfusion of seronegative, infectious window-period blood. STUDY DESIGN AND METHODS: Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window- period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window- period donations is the number of post-screening HIV-infectious donations removed by STS. RESULTS: Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window- period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million. CONCLUSION: STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.     

Geographic risk factors for viral hepatitis and cytomegalovirus infection among United States Armed Forces blood donors

In an effort to determine whether residence in a foreign country increases the risk of hepatitis B and C and cytomegalovirus (CMV) infection in United States (US) Armed Forces blood donors, 5719 volunteer donors at four US Navy blood banks were evaluated. Most participants were repeat donors (68%) and were young (mean age, 25 years), male (88%), and white (80%), black (10%), or Hispanic (7%). Birth outside of the United States was reported by 6 percent of subjects, and 34 percent had lived in a foreign country for more than 3 months. Twenty (0.3%) subjects had hepatitis B surface antigen (HBsAg), and 100 (1.7%) had antibody to hepatitis B core antigen (anti-HBc). Thirty-four (0.6%) were repeatably reactive in enzyme-linked immunosorbent assay for antibody to hepatitis C virus (anti-HCV); 11 (0.2%) had anti-HCV in immumoblot assay. Of the 3484 donors tested for anti-CMV, 1117 (32.1%) were positive. When demographic characteristics were controlled for both anti-HBc and anti-CMV seropositivies were independently associated in male blood donors with residence in the Philippines. Geographic factors were not associated with HBsAg and anti-HCV positivity. These findings indicate that the prevalence of serologic markers for viral hepatitis is low in military blood donors, but that residence in the Western Pacific is a risk factor for hepatitis B and CMV infection.     

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.     

Age-related donor return patterns among first-time blood donors in the United States

BACKGROUND: Committed repeat donors are vital to the continued success of blood collections, yet the effect of age of first-time (FT) donation on return behavior is poorly described. Sixteen-year-old donors are increasingly allowed to donate and have the highest rates of adverse events, which negatively impacts return behavior.
STUDY DESIGN AND METHODS: Annual cohorts of allogeneic FT donors from 2005 and 2006 were selected within the American Red Cross system and followed for 25 and 13 months, respectively. Return and total yield rates among different age groups were compared.
RESULTS: A total of 2.3 million FT donors from 2005 and 2006 gave 4.2 million donations during the study. Sixteen- to 19-year old FT donors made up 41% of the FT donor base in 2005 and 16-, 17-, 18-, and 19-year-olds, respectively, had initial return rates of 62, 52, 35, and 28% and yield rates of 2.0, 1.76, 1.51, and 1.41 over 13 months. Multivariate analysis of FT yield rates shows that younger (16 and 17 years) and older (50+ years) donors, males, blood group O donors, and those without any initial adverse reaction are most likely to return. Increasing severity of donor adverse reactions correlated with a reduction in yield and return rates.
CONCLUSION: FT 16-year-old donors had the highest return and yield rates despite the negative impact of increased adverse event rates. Donation at young age is critical to building a cadre of committed repeat donors but donor reactions must be addressed to ensure the donors' well-being and to sustain return behavior.     

Hepatitis B core antibody (anti-HBc) in blood donors in the United States: implications for surrogate testing programs

In order to evaluate the operational implications of excluding donated blood with antibody to hepatitis B core antigen (anti-HBc), the American Red Cross tested 107,473 voluntary blood donations for anti-HBc in 72 test sites during a 1-week period. The system-wide prevalence of anti-HBc was 2.60 percent, with a range of 0.55 to 6.38 percent, depending on geographic region. For the American Red Cross, which collects approximately one-half of the blood supply in the United States, excluding donated blood with anti-HBc would result in a loss of approximately 159,500 units during the first year.     

NAT screening of viral infections in donors enhances blood safety

The first experience in introducing the nucleic acid amplification technique (NAT) in an Indian blood service as compared with the established European practice is analyzed. Examination of 12,224 donor blood samples revealed 217 (1.78%) persons with markers of infections, including 8 (0.065%) persons only with markers of viral genome, without serological signs of infections. In India, enzyme immunoassay-negative NAT-positive donations were tens of times more detectable than in the developed countries, which is associated with the epidemiological features and the large (more than 50%) proportion of paid donors. By taking into account the fact that 4.6% of the preserved blood doses are annually rejected as defective in the Russian Federation, as evidenced by the screening of markers of infections, the introduction of NAT may be expected to reveal a large proportion of donors in the period of both a "seronegative window" and chronic carriers of hepatitis B virus with its blood content. Both intralaboratory monitoring using the certified standards and the laboratory work quality system as a whole are a necessary condition for introducing NAT into a blood service.     

Hepcidin as a diagnostic marker of iron deficiency in blood donors

BackgroundBlood donors are prone to have iron deficiency. The aim of this study was to determine utility of serum hepcidin as an indicator of iron deficiency in blood donors.MethodsA total of 200 voluntary, healthy blood donors were included in the study. Donors were categorized into four groups according to the donation frequency. Group I: (n = 50) who donated for the first time, or those who have not donated in the past 2 years (reactivated donors). Group II: (n = 50), who donated blood for the second time and had donated once in the previous 12 months. Group III: (n = 50), who donated blood for third time and had donated twice in the previous 12 months. Group IV: (n = 50) who donated blood for the fourth time and had donated thrice in the previous 12 months. Sera of study participants were evaluated for serum ferritin and serum hepcidin levels based on enzyme linked immunosorbent assay.ResultsSerum hepcidin concentration ranged 2.36?15734 pg/mL. Serum hepcidin and serum ferritin were found to be lowest in group IV donors. When serum ferritin concentration of less than 15 ng/mL was considered as gold standard for diagnosing iron deficiency, AUCROC for serum hepcidin as a diagnostic test of iron deficiency was found to be 0.715. Serum hepcidin showed statistical significant correlation with donation frequency(p = 0 .005) and serum ferritin (p = 0.01). Sensitivity and specificity of serum hepcidin was found to be 77.8 %, 79.6 % respectively.ConclusionEffectiveness of Serum hepcidin as a diagnostic marker of iron deficiency still needs to be determined.     

Profile of blood donors with serologic tests reactive for the presence of syphilis in São Paulo, Brazil

BACKGROUND: Syphilis screening of blood donors is a common practice worldwide, but very little is known about the meaning of a positive serologic test for syphilis in blood donors and the risk profile of these donors. The aim of this study was to determine the demographic characteristics and risk behaviors of blood donors with recent and past syphilis and their implications for blood bank testing and deferral strategies.
STUDY DESIGN AND METHODS: Demographic characteristics, category of donation, number of previous donations, sexual behavior, and history of sexually transmitted diseases were reviewed comparing blood donors with recent and past syphilis from January 1, 1999, to December 31, 2003.
RESULTS: A total of 2439 interviews were reviewed, including 2161 (88.6%) donors with past and 278 (11.4%) with recent syphilis infection. Factors associated with recent infection included younger age (≤20 years odds ratio [OR], 36.5; 95% confidence interval [CI], 15.8-84.1), two previous donations (OR, 2.7; 95% CI, 1.9-3.9), male-male sex (homosexual OR, 8.2; 95% CI, 3.2-20.8; and bisexual OR, 11.4; 95% CI, 3.6-36.3), two or more partners in the past 12 months (OR, 2.3; 95% CI, 1.3-4.0), symptoms for syphilis (OR, 4.5; 95% CI, 2.8-7.1), and human immunodeficiency virus (HIV) seropositivity (OR, 39.6; 95% CI, 4.6-339.8). Community donors were also associated with recent syphilis infection (OR, 1.5; 95% CI, 1.2-1.9) compared to replacement donors.
CONCLUSION: Sexual history, including male-male sex and multiple partners, were strongly associated with recent syphilis infection, which in turn was strongly associated with HIV. Continuous and vigilant surveillance that includes assessing sexual history and other factors associated with syphilis are needed to guide blood safety policies.     

Evaluation of the Bio-Rad syphilis IgG test performed on the CODA system for serologic diagnosis of syphilis

The performance of the Bio-Rad Syphilis IgG EIA test as a "screen for syphilis" [testing first by EIA and then by the rapid plasma reagin (RPR) assay if the EIA was positive or equivocal] and as a confirmatory test was evaluated by comparing results to those obtained by CAPTIA Syphilis-G. Discrepancies were resolved by repeating both EIAs and/or the SeroDia TP-PA (a particle agglutination assay that replaced the microhemagglutination Treponema pallidum test). Both EIAs were totally automated, the Bio-Rad test using the AutoPrep instrument for pipetting and the CODA system to perform all of the steps required to complete the EIA and interpret results, and the CAPTIA test using the LabOTech(R) to accomplish both functions. Of 449 unselected sera submitted to "screen for syphilis," both EIAs agreed for 432 (96.2%) specimens: 395 negative, 36 positive, and one equivocal. Fifty-four specimens were positive or equivocal by one or both EIAs; 41 of these were RPR reactive. Three of these 41 were incorrectly called negative by Bio-Rad (sensitivity 92.7%), and there was 1 false-negative result by CAPTIA (sensitivity, 97.6%) (P, not significant). To further evaluate the Bio-Rad assay as a confirmatory test, 144 known RPR-reactive specimens were tested by both EIAs. Results agreed for 134 (93.1%): 123 positive, 11 negative. After resolving discrepancies, there were 3 false-negative and no false-positive results by Bio-Rad (sensitivity 97.8%, specificity 100%), and with CAPTIA there were no false-negative results and 1 false-positive (sensitivity 100%, specificity 91.7%) (P, not significant). The sensitivity of the Bio-Rad assay could be improved, without altering specificity, by lowering the cut-off value for equivocal results. In summary, the Bio-Rad Syphilis IgG EIA performed using the AutoPrep instrument and CODA system is a reliable, efficient method of syphilis testing.     

Predictive value of past and current screening tests for syphilis in blood donors: changing from a rapid plasma reagin test to an automated specific treponemal test for screening

BACKGROUND: This study evaluated the change from a rapid plasma reagin (RPR) test to an automated specific treponemal test (PK-TP) in screening for syphilis in blood donors. STUDY DESIGN AND METHODS: A cross-sectional seroprevalence analysis was performed on 4,878,215 allogeneic blood donations from 19 American Red Cross Blood Services regions from May 1993 through September 1995. Positive predictive values relative to the confirmatory fluorescent treponemal antibody absorption test (FTA-ABS) were calculated. Differences in seroprevalence were compared in RPR and PK-TP tests for 1) unconfirmed and confirmed tests, 2) first-time and repeat donors, and 3) "recent" versus "past" infections. Donation data from three additional Red Cross regions were evaluated for repeat donation patterns of blood donors who had a donation that was positive in a serologic screening test for syphilis. The value of RPR and PK-TP tests as surrogate markers for HIV infection was compared. RESULTS: Reactive rates were lower but the positive predictive values was higher for the PK-TP test than for the RPR test. Initially, donors screened by PK-TP were more likely to be confirmed as positive than were donors screened by RPR, but these rates became comparable. It is estimated that a single HIV window-period donation was removed by serologic testing for syphilis each year of this study period. CONCLUSIONS: The change to the PK-TP test resulted in a lower repeatedly reactive rate, better prediction that a confirmed-positive test for syphilis would occur in testing in the FTA-ABS, fewer donations lost, and comparable deferral rates. Because of the high rate of reactivity to serologic testing for syphilis among donors previously confirmed positive for syphilis, indefinite deferral after a confirmed-positive index donation may be warranted. Serologic testing for syphilis is ineffective as a marker of HIV-infectious window-period donations.     

湛江市无偿献血者血液检测结果分析

目的分析无偿献血者血液检测结果,为招募安全献血者提供依据及减少血液报废,确保临床用血安全。方法对湛江市近5年来无偿献血者血液检测情况进行回顾性统计分析。结果丙氨酸氨基转移酶(ALT)不合格率为4.11%,乙型肝炎病毒表面抗原不合格率为0.53%,丙型肝炎病毒抗体不合格率为0.40%,人类免疫缺陷病毒抗体不合格率为0.08%,梅毒抗体不合格率为0.65%;总检测不合格率为5.57%。结论 ALT阳性是血液报废的最主要因素,梅毒抗体的阳性率逐年增高,成为仅次于ALT阳性而造成血液报废的重要因素。     

重庆市无偿献血人群中HIV感染者的流行病学特征分析

目的了解重庆市无偿献血者H IV感染的特征,以降低输血传播H IV的风险。方法收集和整理重庆市2008、2009年无偿献血者中的H IV感染者和重庆市CDC报告的H IV感染者基本信息,分析其感染特征,包括性别、年龄和感染途径。结果重庆市2008、2009年无偿献血人群的H IV感染率分别为55.8/10万(51/91 399)和72.1/10万(72/108 205),高于全市估算的H IV感染率25.6/10万和37.0/10万,无偿献血人群的H IV感染者以18~29岁的年轻人为主,占65.89%,其他年龄段的比例分别为30~39岁占23.26%,40~49岁占7.75%,≥50岁占3.10%。感染途径以男-男性传播方式为最,占50%,异性性传播的比例为47.06%,静脉吸毒传播占2.94%。结论应结合本地区无偿献血人群中H IV感染者的特征,有针对性地加强无偿献血者献血前的咨询和对高危人群的甄别排查,从而确保血液的安全性。     

北京地区献血者梅毒检测情况调查分析

梅毒是由梅毒螺旋体引起的慢性传染病,病程发展过程中可侵及人体任何器官和组织,并产生多种多样的症状与体征,甚至危及生命.梅毒的传播途径主要是性接触传播,其次是母婴垂直传播.但不慎输注了含有梅毒螺旋体的新鲜血液也是传染梅毒的途径之一.清楚地了解本地区献血者中梅毒的发病情况,高发人群及流行趋势,加强在献血者中梅毒的检测,可有效地预防输血后梅毒的发生.为此,笔者对北京地区59646名献血者做了梅毒检测,现将结果报告如下.     

Absence of risk factors for false-positive test results in blood donors with a reactive test result in an automated treponemal test (PK-TP) for syphilis

BACKGROUND: Screening and confirmatory serologic tests for syphilis are known to generate false-positive results in low-risk populations, which include blood donors. This study assessed whether conditions previously reported to cause biological false-positive (BFP) test results for syphilis are relevant to contemporary syphilis testing of blood donors and the extent to which seropositive donors report a history of syphilis. STUDY DESIGN AND METHODS: A history of conditions reported to be associated with BFP syphilis tests or a history of syphilis infection was assessed by a case-control study of donors with reactive and nonreactive automated treponemal test results, using an anonymous mail survey. Analysis of cases was stratified by fluorescent treponemal antibody absorption (FTA-ABS) result. RESULTS: Adjusted ORs (95% CIs) for reported BFP-associated conditions were 1.3 (0.8-2.1) for FTA-ABS-positive cases and 0.8 (0.3-1.9) for FTA-ABS-negative cases. Among responding blood donors, syphilis history was reported in 78 (51%) of 153 FTA-ABS-positive cases, 0 of 142 FTA-ABS-negative cases, and 3 (0.4%) of 716 automated treponemal test (PK-TP)-negative controls. CONCLUSION: Approximately half of donors with FTA-ABS-positive test results reported a syphilis history. There was no difference between reported BFP conditions for FTA-ABS-positive or FTA-ABS-negative cases and controls. This information may be useful when providing donors with better predonation or post-test counseling information about syphilis testing.     

Evaluation of routine anti-HBc screening of volunteer blood donors: a questionable surrogate test for non-A, non-B hepatitis

Routine antibody to hepatitis B core antigen (anti-HBc) screening, recommended as a surrogate test to identify potential carriers of non-A, non-B hepatitis, was evaluated on 22,346 blood donors using currently available enzyme immunoassay (EIA) reagents. Of the 2 percent found reactive, the majority had cutoff-to-sample absorbance ratios less than 2.0 and less than one-half had anti-HBc when tested by a radioimmunoassay (RIA) method. Only one of 2877 units donated previously by the reactive donors was implicated in a transfusion associated hepatitis case. These results raise questions about the use of currently available anti-HBc reagents as a surrogate test for non-A, non-B hepatitis.     

Utilization of blood transfusion among older adults in the United States

BACKGROUND: While there have been epidemiologic studies of blood donors, the characteristics of individuals who receive transfusions have not been well described for the US population. STUDY DESIGN AND METHODS: Subjects were from the nationally representative Health and Retirement Study whose data were linked to Medicare files from 1991 through 2007 (n = 16,377). A cohort study was conducted to assess the frequency of transfusion in older Americans over time and to describe the characteristics of blood recipients. RESULTS: Thirty‐one percent (95% confidence interval [CI], 30%‐33%) of older Americans received at least one transfusion within a 10‐year period and 5.8% (95% CI, 5.4%‐6.2%) experienced repeated transfusion‐related visits within 30 days. The mean number of transfusion‐related visits was 2.3 over a 10‐year period (95% CI, 2.2‐2.4). Older Americans who lived in the South were most likely to receive a transfusion (34%), independent of demographic and health‐related factors, while those who lived in the western United States were the least likely (26%). Predictors of transfusion included smoking, low body mass index, and a history of cancer, diabetes mellitus, end‐stage renal disease, and heart disease. African‐Americans and Mexican‐Americans had greater rates of blood utilization than other races and other Hispanics (respectively). There were also differences in transfusion utilization by education, marital status, religion, and alcohol use. CONCLUSIONS: Transfusion is common in older Americans. Regional variations in blood use are not explained by patient characteristics alone.     

Prevalence of transfusion-transmissible viral infections in first-time US blood donors by donation site

BACKGROUND: Understanding the donor base, infectious disease prevalence, and donation loss at various blood donation sites will help maximize blood collection efforts and blood availability. STUDY DESIGN AND METHODS: Using donation data collected at five US blood centers, the prevalence of HIV, HTLV, HBsAg, and HCV in first-time whole-blood donations at 10 donation sites was evaluated: military, education, religious, professional, industry, services, community, health care, government, and fixed sites. Donation loss from screening test reactivity at each donation site was also evaluated. RESULTS: During the study, 1.2 million first-time whole-blood donations were collected. Military and education sites had a low prevalence of all viral markers, except for HBsAg, which was highest at education sites. Variations in viral marker prevalence among donation sites were partially explained by donor demographic differences. Donation loss varied by donation site, ranging from 3.3 percent at education sites to 6.4 percent at industry sites, indicating differential efficiency of blood collection efforts. CONCLUSION: Different rates of positive viral test results and donation loss in first-time whole-blood donors were observed at various types of donation sites. This information may be useful in estimating the yield of usable units from specific blood drives and in allocating resources to meet blood center collection goals.