A pilot study for screening blood donors in Taiwan by nucleic acid amplification technology: detecting occult hepatitis B virus infections and closing the serologic window period for hepatitis C virus

BACKGROUND: Blood donors in Taiwan currently are screened for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection by immunoassay. The risk of enzyme immunoassay (EIA)-negative, nucleic acid amplification technology (NAT)-reactive donations is not well understood. This study aimed to screen for such donors in Taiwan by a multiplex test (cobas TaqScreen, Roche) on a commercially available NAT system (cobas s 201 system, Roche). STUDY DESIGN AND METHODS: NAT was performed on donors without prescreening in pools of six and NAT-reactive pools were then resolved to the single donation. Individual-donor NAT-reactive samples were discriminated by a commercially available polymerase chain reaction (PCR)-based diagnostic assay (COBAS AmpliScreen, Roche). Samples with EIA- and NAT-discordant results were investigated with supplemental serologic and confirmatory tests. Each sample taken from follow-up of HBV NAT yield cases was tested for HBV serologic profile, NAT, and viral load. The sensitivity and performance efficacy were also evaluated. RESULTS: The 95 percent limit of detection (LOD) for HBV, HCV, and HIV were 5.09, 11.83, and 62.53 IU per mL, respectively. Among 10,727 seronegative donations, 12 HBV NAT yield cases (0.11%) and 1 HCV NAT yield case (0.01%) were detected. Follow-up results for 1 to 8 months showed that the HCV yield case was a window case and all HBV NAT yield cases were occult carriers. CONCLUSION: The use of NAT detected occult HBV and reduced HCV window period. The yield rate, especially occult HBV, was 10- to 100-fold higher than that in developed, HBV nonendemic countries. Therefore, NAT implementation for routine donor screening in a more cost-effective manner should contribute to safer blood transfusion in Taiwan.     

Deferred donor care in a regional hospital blood center in Ghana

BACKGROUND: In sub-Saharan Africa, the viral marker burden in blood donor populations ranges between 10 and 30 percent. Deferred donors constitute a rare population of asymptomatic human immunodeficiency virus (HIV)- and hepatitis B virus (HBV)-infected individuals with high likelihood of long survival if cared for. Deferred donor care provides an opportunity for a public health impact on highly pathogenic infections.
STUDY DESIGN AND METHODS: Between 2004 and 2007, all candidate donors deferred before donation for reactivity of anti-HIV, hepatitis C virus antibody (anti-HCV), and hepatitis B virus surface antigen (HBsAg) rapid tests were informed and referred to a donor care program consisting of test confirmation, information, counseling, and potential referral for follow-up and therapy. Dedicated trained nurses supervised the program including alanine aminotransferase (ALT) level testing to identify liver disease.
RESULTS: In a 4-year period 51,100 donors were screened and 5778, 1578, and 227 candidate donors were deferred for reactivity to HBV, HIV, or HCV serologic markers, respectively. The rates of entry into the donor care program were 48, 14.3, and 22 percent of deferred donors, respectively. A total of 83 of 210 HBsAg-positive donors with elevated ALT levels were referred and 66 received antiviral treatment. A total of 89 of 516 confirmed anti-HIV–positive donors were referred to the hospital acquired immune deficiency syndrome clinic for follow-up.
CONCLUSIONS: With little additional expense, the deferred donor care program identified asymptomatic infections with high odds of benefiting from monitoring and therapy. In the local circumstances, this public health–limited but definite impact was permitted by the rapid-test predonation screening, and this impact could be increased if more resources were available.     

Cost-effectiveness of additional blood screening tests in the Netherlands

BACKGROUND: During the past decade, blood screening tests such as triplex nucleic acid amplification testing (NAT) and human T‐cell lymphotropic virus type I or I (HTLV‐I/II) antibody testing were added to existing serologic testing for hepatitis B virus (HBV), human immunodeficiency virus (HIV), and hepatitis C virus (HCV). In some low‐prevalence regions these additional tests yielded disputable benefits that can be valuated by cost‐effectiveness analyses (CEAs). CEAs are used to support decision making on implementation of medical technology. We present CEAs of selected additional screening tests that are not uniformly implemented in the EU. STUDY DESIGN AND METHODS: Cost‐effectiveness was analyzed of: 1) HBV, HCV, and HIV triplex NAT in addition to serologic testing; 2) HTLV‐I/II antibody test for all donors, for first‐time donors only, and for pediatric recipients only; and 3) hepatitis A virus (HAV) for all donations. Disease progression of the studied viral infections was described in five Markov models. RESULTS: In the Netherlands, the incremental cost‐effectiveness ratio (ICER) of triplex NAT is €5.20 million per quality‐adjusted life‐year (QALY) for testing minipools of six donation samples and €4.65 million/QALY for individual donation testing. The ICER for anti‐HTLV‐I/II is €45.2 million/QALY if testing all donations, €2.23 million/QALY if testing new donors only, and €27.0 million/QALY if testing blood products for pediatric patients only. The ICER of HAV NAT is €18.6 million/QALY. CONCLUSION: The resulting ICERs are very high, especially when compared to other health care interventions. Nevertheless, these screening tests are implemented in the Netherlands and elsewhere. Policy makers should reflect more explicit on the acceptability of costs and effects whenever additional blood screening tests are implemented.     

Hepatitis B virus (HBV) DNA screening of blood donations in minipools with the COBAS AmpliScreen HBV test

BACKGROUND: The risk of hepatitis B virus (HBV) transmission by blood transfusion (estimated at 1 in 63,000-1 in 205,000 units in the United States) exceeds that of hepatitis C virus (HCV) or human immunodeficiency virus (HIV). Reduction of window-period HBV transmissions through detection of HBV DNA-positive units by minipool nucleic acid testing (MP NAT) would be expected to decrease this risk. STUDY DESIGN AND METHODS: A large multicenter study of the COBAS AmpliScreen HBV test (Roche Molecular Systems) was conducted on minipools of 24 blood donation specimens. The yield of HBV DNA-positive, hepatitis B surface antigen (HBsAg)-negative window-period donations was determined relative to current and newly licensed HBsAg assays. Donors with selected HBV DNA, HBsAg, and anti-hepatitis B core antigen (HBc) results were further evaluated. RESULTS: The detection rate of window-period units was 1 in 352,451 (95% confidence interval, 1 in 2,941,176-1 in 97,561). Assay specificity was high (99.9964%). HBV DNA was detected in 84 percent of HBsAg-positive, anti-HBc-positive donations by MP NAT and in 94 percent when individual-donation (ID) NAT was added. HBV DNA was detected in 0.03 percent of HBsAg-negative, anti-HBc-positive donations by MP NAT and in 0.41 percent when ID NAT was added. CONCLUSIONS: Implementation of HBV MP NAT will provide an increment in safety relative to HBV serologic screening, similar to that for HCV and in excess of that for HIV. Our data indicate that the implementation of HBV MP NAT would likely interdict 39 HBV window-period units and prevent 56 cases of transfusion-transmitted HBV infection annually. The current data indicate that HBV MP NAT should not lead to discontinuation of anti-HBc testing but that discontinuation of HBsAg testing with retention of anti-HBc testing may be possible.     

Refinement of a viral transmission risk model for blood donations in seroconversion window phase screened by nucleic acid testing in different pool sizes and repeat test algorithms

BACKGROUND: In minipool nucleic acid test (MP‐NAT) screening protocols, the donations implicated in reactive test pools are released for transfusion when they are nonreactive in a repeat test on the individual samples, but in individual‐donation (ID)‐NAT screening algorithms the release of nonrepeatable reactive (NRR) donations is under discussion. STUDY DESIGN AND METHODS: A previously developed window phase (WP) transmission risk model for NAT‐screened blood transfusions has been refined to take the effect of repeat tests of initially reactive (IR) MP‐ or ID‐NAT results into account. The model has then been applied to simulate the effect of different screening algorithms with ULTRIO and the new‐generation ULTRIO Plus assay (Novartis Diagnostics) on transmission risk for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). RESULTS: We calculated WP risk‐day equivalents for MP16‐, MP8‐, and ID‐NAT with and without duplicate retesting of IR results of 3.1, 2.7, 1.5, and 1.3 days for HCV; 6.3, 5.5, 3.3, and 2.9 days for HIV; and 24.4, 22.2, 15.6, and 14.1 days for HBV, respectively. These latter infectious HBV WPs reduced to 20.4, 18.2, 11.6, and 10.3 days, respectively, with the more sensitive ULTRIO Plus assay. CONCLUSION: ULTRIO Plus ID‐NAT screening reduces the virus transmission risk in the WP by 54% to 58% compared to ULTRIO MP16‐NAT, while the incremental risk caused by releasing donations with duplicate ID‐NAT NRR results is 5% to 6%. To achieve maximum safety and specificity a similar repeat test algorithm can be applied to ID‐NAT as used for serologic assays.     

Limited effectiveness of donor deferral registries for transfusion-transmitted disease markers

BACKGROUND: Donor deferral registries (DDRs) detect repeat donations by previously deferred donors and prevent their release. The utility of DDRs has not been objectively demonstrated. STUDY DESIGN AND METHODS: A total of 10.2 million first-time donors to the American Red Cross from 1995 through 2002 were reviewed to identify donors deferred by screening tests for human immunodeficiency virus (HIV; 0.19% of donors), hepatitis C virus (HCV; 0.55%), and hepatitis B virus (HBV; 0.13%). All repeat-reactive (RR) donors were deferred despite confirmatory testing. Donors were notified and counseled about their test results and deferral. Their subsequent donation behavior was assessed. RESULTS: A total of 414 HIV-deferred donors (2.1%), 471 HCV-deferred donors (0.8%, p < 0.001 vs. HIV and HBV), and 222 HBV-deferred donors (1.6%, p < 0.01 vs. HIV) returned to donate despite their deferred status. For all three tests, confirmed-positive donors were less likely to return. Of donors originally confirmed positive, only 7 returning donors were negative by screening (thus the repeat donation interdicted from distribution by the DDR): 0 HIV RR donors, 2 of 36,092 HCV RR donors, and 5 of 8,404 HBV RR donors. Review of the laboratory results for the HCV donors and one HBV donor was consistent with originally false-positive confirmation tests. The four other HBV confirmed-positive donors were anti-hepatitis B core antigen-positive on their subsequent donation, which was discarded despite the DDR. CONCLUSION: Of 10.2 million donors, the DDR did not prevent the release of any potentially dangerous blood component due to inappropriate return of donors deferred for HIV, HCV, and HBV tests. The effectiveness of DDRs should be evaluated for other deferrals.     

Occult hepatitis B virus infection in Thai blood donors

BACKGROUND: An evaluation by the National Blood Center, the Thai Red Cross Society, of two commercial multiplex nucleic acid tests (NATs; the Chiron PROCLEIX ULTRIO test and the Roche Cobas TaqScreen MPX test) for screening Thai blood donors for hepatitis B virus (HBV), hepatitis C virus, and human immunodeficiency virus Type 1 identified 175 HBV NAT–reactive/hepatitis B surface antigen (HBsAg)‐negative donors. The classification of the HBV infection of these donors was confirmed by follow‐up testing. STUDY DESIGN AND METHODS: Index samples were tested for HBV serologic markers and HBV viral loads were determined. Donors were followed for up to 13 months and samples were tested with both NAT assays and for all HBV serological markers. RESULTS: Of 175 HBV NAT–yield donors, 72 (41%) were followed. Based on the follow‐up results, the majority of donors who were followed had an occult HBV infection (66.7%), followed by donors with a primary, acute infection (26.4%). The majority of donors in this latter group (20.8%) were in the window period. Three donors (4.2%), who were anti‐HBs positive, had a reinfection or breakthrough infection. CONCLUSION: The majority of donors detected during routine screening, who were HBsAg negative and NAT reactive, had an occult HBV infection, thus validating the decision to introduce NAT for blood donations in Thailand.     

Trends in prevalence,incidence, and residual risk of major transfusion‐transmissible viral infections in United Arab Emirates blood donors: impact of individual‐donation nucleic acid testing, 2004 through 2009

BACKGROUND: United Arab Emirates (UAE) has a heterogeneous population consisting of more than 160 nationalities and 85% of the population being non‐UAE. In 2007, Dubai Blood Donation Centre (DBDC), the major local supplier of blood in the UAE, introduced six‐minipool nucleic acid test (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV), which in 2008 upgraded to individual‐donation (ID)‐NAT. The aim of this study was to analyze the efficacy of the donor screening program in the UAE and evaluate the impact of NAT on the yield and residual risk of transfusion‐transmissible viral infections (TTVIs). STUDY DESIGN AND METHODS: A total of 169,781 blood donations collected at DBDC between 2004 and 2009 were screened for TTVIs. During the period 2008 through 2009, a total of 59,283 donations were tested with both ID‐NAT and serologic assays. The incidence, prevalence, and residual risk for each viral agent were estimated and analyzed. RESULTS: The individual prevalences of HBV, HCV, and HIV per 100,000 donation were 234.4, 110, and 4, respectively. Calculated residual risk per million donations for HBV was decreased from 1.41 in pre‐NAT period to 0.92 in post‐NAT period. These figures were decreased for HCV and HIV from 1.73 and 0.39 to 0 and 0.32, respectively. CONCLUSION: Incidence rates and estimated residual risk indicate that the current risk of TTVIs attributable to blood donation is relatively low in the UAE. The study recommends the parallel use of both serology and ID‐NAT TTVIs screening in blood donations and suggests the exclusion of antibody to hepatitis B core antigen–positive donations as this can eliminate the potential infectivity of these units with marginal effects on the blood stock in UAE.     

Two HBV DNA+/HBsAg− blood donors identified by HBV NAT in Shenzhen, China

Background

In order to further improve blood safety, mini-pool (MP) nucleic acid testing (NAT) was implemented to screen samples negative for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (anti-HCV), anti-human immunodeficiency virus (anti-HIV), syphilis (anti-Treponemal antibody) and with normal ALT.

Study design and methods

From August 2006 to February 2008, 41,301 donations were screened using commercial HIV/HCV RNA and HBV DNA Real-Time PCR NAT assays in pools of 8. Reactive pools were re-tested as individual samples using the appropriate screening test and confirmed using an alternate commercial NAT assay. Donors reactive on both NAT assays were considered ‘confirmed’ positive for the virus concerned and recalled for additional follow-up testing and counseling.

Results

Of the 41,301 samples screened, no HIV or HCV RNA-positive/seronegative donations were detected but two HBV DNA positive/HBsAg negative blood donors (Donors 1 and 2) were identified. Their respective hepatitis immunological markers were: Donor 1 - anti-HBc positive/anti-HBe positive/HBeAg negative/ALT normal and HBV DNA viral load of 112 IU/ml; Donor 2 - anti-HBc positive/anti-HBe negative/HBeAg negative/ALT normal and HBV DNA viral load 2750 IU/ml.

Conclusions

MP NAT identified two HBsAg negative donors with presumed occult infection but no HIV or HCV seronegative/NAT positive (yield) donors. The HBV yield rate of 1 in 20,650 (95%CI - 1 in 5663 to 1 in 75,303) is comparatively high, exceeds the predicted rate based on previous modeling for the population and demonstrates the incremental blood safety value of NAT in countries where HBV is highly epidemic. The low viral load of the two yield samples underscores the importance of optimizing the sensitivity of the HBV NAT assay selected for screening.     

Comparison of two automated nucleic acid testing systems for simultaneous detection of human immunodeficiency virus and hepatitis C virus RNA and hepatitis B virus DNA

BACKGROUND: Recently developed nucleic acid testing (NAT) assays incorporating simultaneous detection of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) have made HBV NAT screening more feasible for blood services. This study compared the performance of two "multiplex" NAT assays and their automated testing platforms. STUDY DESIGN AND METHODS: The HBV NAT yield rate was estimated by testing 10,397 Hong Kong (HK) donor samples concurrently on the PROCLEIX ULTRIO (Ultrio) assay as individual donor samples with the TIGRIS and on the cobas TaqScreen multiplex (cobas MPX) test in pools of 6 with the cobas s 201. Analytical sensitivity was assessed by probit analysis of diluted international standards and operational performance was compared. RESULTS: Each system detected two different HBV NAT yield samples for a combined rate of 0.04 percent. One additional sample was reactive on the cobas MPX test but remained unresolved. The 95 percent detection limits for HIV-1, HBV, and HCV were 42.2, 12.2, and 2.0 IU per mL, respectively, for Ultrio and 50.5, 8.4, and 6.0 IU per mL for the cobas MPX. The invalid test and failed run rates were 0.05 and 2.92 percent, respectively, for the TIGRIS and 2.39 and 5.53 percent for the cobas s 201. CONCLUSION: Clinical sensitivity for HBV in HK blood donors was equivalent, as was the analytical sensitivity for HIV-1 and HBV; however, the Ultrio assay had a higher analytical sensitivity for HCV. Despite a shorter downtime and mean time of repair for the cobas s 201, the TIGRIS demonstrated better overall operational performance.     

Impact of nucleic acid testing for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus on the safety of blood supply in Italy: a 6-year survey

BACKGROUND: Nucleic acid testing (NAT) for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) has been implemented in several European countries and in the United States, while hepatitis B virus (HBV) NAT is still being questioned by opinions both in favor and against such an option, depending on the HBV endemicity, health care resources, and expected benefits. STUDY DESIGN AND METHODS: This survey was aimed to assess the NAT impact in improving the safety of blood supply in Italy, 6 years after implementation. The study involved 93 Italian transfusion centers and was carried out in 2001 through 2006. A total of 10,776,288 units were tested for the presence of HCV RNA, 7,932,430 for HIV RNA, and 3,405,497 for HBV DNA, respectively. RESULTS: Twenty‐seven donations or 2.5 per million tested were HCV RNA–positive/anti‐HCV–negative; 14 or 1.8 per million units tested were HIV RNA–positive/anti‐HIV–negative; and 197 or 57.8 per million donations tested were HBV DNA–positive/hepatitis B surface antigen–negative. Of the latter, 8 (2.3/10⁶) were collected from donors in the window phase of infection and 189 (55.5/10⁶) from donors with occult HBV. Sixty‐eight percent of the latter donors had hepatitis B surface antibody, 74.5 percent of whom with concentrations considered protective (≥10 mIU/mL). CONCLUSION: NAT implementation has improved blood safety by reducing the risk of entering 2.5 HCV and 1.8 HIV infectious units per million donations into the blood supply. The yield of NAT in detecting infectious blood before transfusion was higher for HBV than for HCV or HIV. However, the benefit of HBV NAT in terms of avoided HBV‐related morbidity and mortality in blood recipients needs to be further evaluated.     

Evaluation of a multiplex human immunodeficiency virus-1, hepatitis C virus, and hepatitis B virus nucleic acid testing assay to detect viremic blood donors in northern Thailand

BACKGROUND: Screening of blood donors with nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) has been implemented recently in the United States. There are limited data, however, on the additional NAT yield of donors in developing countries in Asia where the prevalence of infection is higher. In addition, data on hepatitis B virus (HBV) NAT in high prevalence areas are minimal. STUDY DESIGN AND METHODS: A total of 5083 whole-blood donors at the Chiang Mai University Hospital, Thailand, blood bank were evaluated with a commercially available NAT assay (Procleix Ultrio, Gen-Probe, Inc.) to screen individual donations. RESULTS: No NAT yield cases were found for HIV-1 or HCV. There were 17 samples with discrepant HBV DNA NAT and hepatitis B surface antigen (HBsAg) tests, however. Seven of these were HBV DNA NAT-positive, HBsAg-negative; of these 7, 1 was NAT-positive at baseline, but negative on follow-up, and considered a false-positive, 1 had an acute infection, and 5 had chronic prevalent HBV infections, for a NAT yield of 6 in 4798 HBsAg negative donors (1:800). In addition there were 10 NAT-negative, HBsAg-positive serum samples. All were anti-hepatitis B core antigen immunoglobulin G-positive; on testing with a more sensitive NAT target capture assay, 5 were positive (1.8-20.6 IU/mL) and 5 were negative. CONCLUSION: Multiplex NAT screening of individual-donor serum samples in Northern Thailand detected approximately 1 per 800 HBV NAT-positive, HBsAg-negative donors. The especially high prevalence of HBV infection in Thailand and other Asian countries suggests that HBV NAT screening of donors will be more cost-effective than in other areas.     

上海地区无偿献血者乙肝病毒核酸检测分析

目的了解无偿献血者乙肝病毒核酸筛查(NAT)阳性人群特点,为血液安全策略提供参考。方法无偿献血者血液经Murex和科华HBsAg ELISA试剂检测,结果为阴性的血液使用cobas TaqScreen MPX试剂进行HBV DNA,HCV RNA,HIV RNA 3项联合核酸检测。对于MPX反应性标本,使用COBAS AmpliPrep/TaqMan进行核酸鉴别试验,同时使用罗氏ECL电化学发光检测系统进行乙肝补充血清学试验。结果 2011年11月1日～2012年1月31日3个月共有献血者86 375人(次),其中有63 351人(次)为初次献血者,HBsAg反应性为1.04%,23 024人(次)为重复献血者,HBsAg反应性为0.46%,两者差异有统计学意义(χ2=63.63,P0.05)。84 990份HBsAg、抗-HCV、抗-HIV1/2阴性血液进行MPX核酸检测,共发现52例(0.060%)HBV DNA阳性,均为低拷贝,含量为(20～200)IU/ml间,其中32例(0.051%)来自初次献血者,20例(0.087%)来自重复献血者,两者比例差异无统计学意义(χ2=3.65,P0.05),没有发现HCV RNA与HIV RNA阳性。结论重复献血者HBsAg反应性比率低于初次献血者;HBsAg阴性献血者HBV DNA阳性率为0.060%,重复献血者HBV DNA阳性率与初次献血者比较,两者差异无统计学意义;开展HBV核酸检测能够进一步保障血液安全。     

Prevalence of serologic markers for hepatitis B and C viruses in Brazilian blood donors and incidence and residual risk of transfusion transmission of hepatitis C virus

BACKGROUND: We evaluate the current prevalence of serologic markers for hepatitis B virus (HBV) and hepatitis C virus (HCV) in blood donors and estimated HCV incidence and residual transfusion‐transmitted risk at three large Brazilian blood centers. STUDY DESIGN AND METHODS: Data on whole blood and platelet donations were collected from January through December 2007, analyzed by center; donor type; age; sex; donation status; and serologic results for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti‐HBc), and anti‐HCV. HBV and HCV prevalence rates were calculated for all first‐time donations. HCV incidence was derived including interdonation intervals that preceded first repeat donations given during the study, and HCV residual risk was estimated for transfusions derived from repeat donors. RESULTS: There were 307,354 donations in 2007. Overall prevalence of concordant HBsAg and anti‐HBc reactivity was 289 per 100,000 donations and of anti‐HCV confirmed reactivity 191 per 100,000 donations. There were significant associations between older age and hepatitis markers, especially for HCV. HCV incidence was 3.11 (95% confidence interval, 0.77‐7.03) per 100,000 person‐years, and residual risk of HCV window‐phase infections was estimated at 5.0 per million units transfused. CONCLUSION: Improvement in donor selection, socioeconomic conditions, and preventive measures, implemented over time, may have helped to decrease prevalence of HBV and HCV, relative to previous reports. Incidence and residual risk of HCV are also diminishing. Ongoing monitoring of HBV and HCV markers among Brazilian blood donors should help guide improved recruitment procedures, donor selection, laboratory screening, and counseling strategies.     

The cost‐effectiveness of introducing nucleic acid testing to test for hepatitis B,hepatitis C,and human immunodeficiency virus among blood donors in Sweden

BACKGROUND: The purpose of this study was to estimate the cost‐effectiveness of using individual‐donor nucleic acid testing (ID‐NAT) in addition to serologic tests compared with the sole use of serologic tests for the identification of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) among blood donors in Sweden. STUDY DESIGN AND METHODS: The two strategies analyzed were serologic tests and ID‐NAT plus serologic tests. A health‐economic model was used to estimate the lifetime costs and effects. The effects were measured as infections avoided and quality‐adjusted life‐years (QALYs) gained. A societal perspective was used. RESULTS: The largest number of viral transmissions occurred with serologic testing only. However, the risks for viral transmissions were very low with both strategies. The total cost was mainly influenced by the cost of the test carried out. The cost of using ID‐NAT plus serologic tests compared to serologic tests alone was estimated at Swedish Krona (SEK) 101 million (USD 12.7 million) per avoided viral transmission. The cost per QALY gained was SEK 22 million (USD 2.7 million). CONCLUSION: Using ID‐NAT for testing against HBV, HCV, and HIV among blood donors leads to cost‐effectiveness ratios that are far beyond what is usually considered cost‐effective. The main reason for this is that with current methods, the risks for virus transmission are very low in Sweden.     

Rare detection of hepatitis B and hepatitis C virus genomes by polymerase chain reaction in seronegative donors with elevated alanine aminotransferase

BACKGROUND: Since screening for antibody to hepatitis C virus (HCV) was introduced in 1990, posttransfusion hepatitis has been reduced to nearly background levels. This has led to reconsideration of the value of testing donated blood for elevated alanine aminotransferase (ALT). The contribution of ALT testing in detecting seronegative infection was evaluated by the performance of polymerase chain reaction (PCR) for hepatitis B virus (HBV) or HCV in plasma from ALT-elevated blood units. STUDY DESIGN AND METHODS: Testing was performed on 375 units of plasma, derived from an equivalent of 47,500 blood donations, with a highly sensitive hemi-nested PCR procedure. Using a triplet of primers directed at the conserved regions of HBV DNA and 5'-noncoding regions of HCV RNA, the hemi-nested PCR assay can reliably amplify 10 viral molecules to levels detectable in ethidium bromide-stained agarose gels. Pools of plasma from groups of four donors were screened with hemi-nested PCR. For any reactive pools, the plasma from individual donors was retested twice on different aliquots. RESULTS: Two of 375 units, both with midrange ALT elevation, were repeatedly reactive in hemi-nested PCR (one each for HBV DNA and HCV RNA). However, samples from the two suspect donors tested 9 and 5 months later revealed no seroconversion, elevated ALT, or viral genomes in hemi-nested PCR. CONCLUSION: The lack of confirmed HBV or HCV infection in this study representing an estimated 47,500 voluntary blood donations suggests that routine ALT testing for further prevention of posttransfusion hepatitis after exclusion of HBV- and/or HCV-seropositive blood may be superfluous.     

Evaluation of the persistence and characteristics of indeterminate reactivity against hepatitis C virus in blood donors

BACKGROUND: A substantial number of individuals are excluded from blood donation due to indeterminate results in screening tests for hepatitis C virus antibody (anti-HCV). Disclosure of the characteristics of the indeterminate serologic pattern could optimize the testing and the management and care of blood donors.
STUDY DESIGN AND METHODS: Ninety-two former blood donors deferred from blood donation due to consistent reactivity in anti-HCV enzyme immunoassay and indeterminate HCV recombinant immunoblot assay (RIBA) results were retested for anti-HCV to examine the extent of disappearance of reactivity. In addition, they were screened for selected viral, immunologic, and inflammatory variables to detect possible causes of the test reactivity pattern.
RESULTS: After a median observation time of 75 months, 66 of 92 individuals had persistent indeterminate HCV RIBA results. Reactivity against the nonstructural NS5 antigen was the most frequent finding. A significant association was detected both between indeterminate reactivity in HCV RIBA and against the NS5 antigen independently and detectable antibody against adenovirus. Novel indeterminate reactivity showed increased prevalence during autumn and winter months.
CONCLUSION: Indeterminate HCV RIBA reactivity in blood donors persists over years. Increased prevalence during autumn and winter and association to detection of adenovirus antibody indicate that viral infection and cross-reactivity are etiologic factors in indeterminate HCV RIBA reactivity. Further prospective studies are needed to confirm the results.     

Seroprevalence of known and putative hepatitis markers in United States blood donors with ALT levels at least 120 IU per L

BACKGROUND: ALT testing of blood donors was initiated as a surrogate marker for non-A, non-B hepatitis. Increased sensitivity of subsequent HBV and HCV tests used for standard donor screening make any residual value of ALT testing questionable. STUDY DESIGN AND METHODS: A prospective study was conducted in 166 of 645 eligible blood donors from three American Red Cross regions whose ALT was > or =120 IU per L and whose standard donor screening tests were negative. Of these enrolled donors, 124 (75%) completed follow-up. Samples obtained from the index donation, at enrollment (1 month), and at follow-up (6 months) underwent the standard donor screening tests, as well as those for HCV RNA and HGV RNA (RT-PCR), antibodies to the virus envelope E2 protein of GB virus type C (GBV-C E2 antibody), and IgM antibody for CMV, parvovirus B19, EBV VCA, and HAV. Participants completed a brief demographic and exposure history questionnaire at follow-up. RESULTS: All study samples were negative in standard donor-screening tests. ALT levels were variable at return visits, with 80 to 86 percent <120 IU per L. No participants were positive for HCV RNA; 4 percent were positive for HGV RNA, and 10 percent were positive for GBV-C E2 antibody. Results of CMV, parvovirus B19, EBV VCA, and HAV testing were similar to published background rates. No demographic or exposure history variables had significant correlation with ALT or other testing results. CONCLUSION: These data suggest that an ALT > or =120 IU per L in blood donors with negative standard screening tests has questionable value as a surrogate marker for seronegative HBV or HCV infection. Continued ALT testing may contribute little, if anything, to the safety of blood components or plasma for further manufacture.     

Anti-HBc screening in Egyptian blood donors reduces the risk of hepatitis B virus transmission

summary .  Occult hepatitis B virus (HBV) in blood donors is considered as a potential risk for transmission of HBV infection. The aim of this study was to determine the prevalence of anti-hepatitis B core antibody (anti-HBC) positivity in Egyptian blood donations as well as to estimate the frequency of HBV-DNA in anti-HBc-positive donations. The study included 760 Egyptian healthy blood donors, representing 26 different Egyptian governorates screened according to routine practice for the presence of hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies (Abs), HIV-1/2 Abs and Treponema Abs. The accepted blood units for donation were tested for the presence of total anti-HBc Abs by two tests. Positive units for anti-HBc were further tested for HBV-DNA by polymerase chain reaction. According to routine screening, a total of 48/760 units (6·3%) were rejected [38 (5%) HCV-Ab-positive units, 9 (1·18%) HbsAg-positive units and 1 (0·13%) Treponema-Ab-positive unit]. Among the accepted blood units for donation, prevalence of anti-HBc was 78/712 units (10·96%). HBV-DNA was detected in 9/78 (11·54%) of the anti-HBc-positive units, and thus, occult HBV infection was detected in 9/712 (1·26%) of the accepted blood donations. Implementing anti-HBc test to the routine assay for the forthcoming two decades would certainly eliminate possible HBV-infected units. Rejection of these units will be beneficial to decrease the risk of HBV transmission with its potential consequences particularly in immunocompromised recipients.