Prevalence,incidence, and residual risk of human immunodeficiency virus and hepatitis C virus infections among United States blood donors since the introduction of nucleic acid testing

BACKGROUND: Nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was introduced for blood donation screening in the United States in 1999. This study analyzes temporal trends of these two infections since NAT introduction. STUDY DESIGN AND METHODS: Donation data from 1999 to 2008 were analyzed; each donation was tested for antibodies and viral RNA for HIV and HCV. Incidence for first‐time (FT) donors was derived by multiplying that among repeat (RP) donors by the ratio of NAT yield rates between FT and RP donors. Incidence for all donors was the weighted mean based on percentage of FT and RP donors. Residual risk (RR) was determined using the window‐period model. RESULTS: During the 10‐year period approximately 66 million donations were screened with 32 HIV (1:2 million) and 244 HCV (1:270,000) NAT yield donations identified. HCV prevalence among FT donors decreased by 53% for 2008 compared to 1999. HIV and HCV incidence among RP donors increased in 2007 through 2008 compared to 2005 through 2006. During 2007 through 2008, HIV incidence was 3.1 per 10⁵ person‐years (py), with an RR estimate of 0.68 per 10⁶ (1:1,467,000) donations; HCV incidence was 5.1 per 10⁵ py, with an RR estimate of 0.87 per 10⁶ (1:1,149,000). The increase in HIV incidence was primarily among 16‐ to 19‐year‐old, male African American donors and that in HCV was primarily among Caucasian donors of 50 or more years. Donors from the Southern United States had higher incidence rates. CONCLUSION: HCV prevalence decreased significantly since NAT introduction. The increase in HIV and HCV incidence in 2007 through 2008 warrants continued monitoring and investigation.     

Impact of individual-donation nucleic acid testing on risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus transmission by blood transfusion in South Africa

BACKGROUND: In 2005, the South African National Blood Service introduced individual-donation (ID) nucleic acid test (NAT) screening for human immunodeficiency virus (HIV) RNA, hepatitis C virus (HCV) RNA, and hepatitis B virus (HBV) DNA. At the same time the use of ethnic origin to prioritize the transfusion of blood according to a hierarchy of residual risk was discontinued.
STUDY DESIGN AND METHODS: ID-NAT (Ultrio on Procleix Tigris, Chiron) and serology (PRISM, Abbott) repeat test and confirmation testing algorithms were designed to enable differentiation between false-positive and true-NAT and -serology yields. After 1 year, the NAT and serology yield rates in first-time, lapsed, and repeat donors were analyzed and used to estimate the residual risk of HIV, HBV, and HCV infections by blood transfusion.
RESULTS: The HIV, HBV, and HCV ID-NAT window phase yield rates in 732,250 blood donations were 1:45,765, 1:11,810, and 1:732,200, respectively. Seven of 16 HIV window phase donations with viral loads above 16,000 copies/mL were HIV p24 antigen enzyme-linked immunosorbent assay positive. PRISM detected anti-HIV and hepatitis B surface antigen (HBsAg) in 89.4 and 73.9% of early infections in repeat donors. The Procleix assay detected viremia in 99.7 and 95.5% of anti-HIV– and HBsAg-positive first-time donors. In these donors, the occult HBV DNA carrier rate was 1:5200. The residual transmission risk of ID-NAT HIV, HBV, and HCV window phase donations was estimated at 1:479,000, 1:61,500, and 1:21,000,000 respectively.
CONCLUSION: One-year ID-NAT screening of 732,250 donations interdicted 16 HIV, 20 HBV, and 1 HCV window phase donations and 42 anti-hepatitis B core antigen–reactive infections during an early recovery or a later stage of occult HBV infection.     

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.     

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.     

Residual risk of transfusion-transmitted viral infections in Shenzhen, China, 2001 through 2004

BACKGROUND: There are no current estimates of the residual risks of transmission by blood of hepatitis B virus (HBV) or hepatitis C virus (HCV) and human immunodeficiency virus (HIV) in China. Such estimates are an essential prerequisite to monitoring and improving transfusion safety as well as supporting evidence based assessment of the value of implementing new screening interventions. STUDY DESIGN AND METHODS: Viral screening data for donors from Shenzhen, China, for the period 2001 to 2004, were retrospectively analyzed. The data were applied to a published model to estimate the residual risk of transmitting HIV, HBV, and HCV by blood transfusion in Shenzhen, as well as to assess the residual risk reduction value of various new tests. RESULTS: The point estimates for the combined 2003 and 2004 period calculate as 1 in 17,501 for HBV, 1 in 59,588 for HCV, and 1 in 903,498 for HIV. The predicted yield for improved hepatitis B surface antigen (HBsAg) assays, minipool (MP) nucleic acid testing (NAT), and individual-donation (ID) NAT was 6.9, 9.5, and 28.3 per million donations, respectively. The predicted yield for implementing a fourth-generation HCV (antigen-antibody) or MP NAT assay was 13.4 or 14.7 per million donations, respectively. For HIV, the predicted yield for implementing a fourth-generation HIV (antigen-antibody) or MP NAT assay was markedly smaller, 0.25 or 0.65 per million donations, respectively. CONCLUSIONS: Relative to that reported for Western blood systems, the prevalence and the residual risk of HBV and HCV are high, whereas HIV is comparable. Pending a formal cost-effectiveness study for NAT, implementing improved HBsAg and combination HCV antibody-antigen assays in Shenzhen would markedly reduce the residual risk.     

Residual risk of transfusion‐transmitted hepatitis B virus (HBV) infection caused by blood components derived from donors with occult HBV infection in Japan

BACKGROUND: Nucleic acid amplification testing (NAT) for hepatitis B virus (HBV) during blood screening has helped to prevent transfusion‐transmitted HBV infection (TT‐HBV) in Japan. Nevertheless, 4 to 13 TT‐HBV infections arise annually. STUDY DESIGN AND METHODS: The Japanese Red Cross (JRC) analyzed repository samples of donated blood for TT‐HBV that was suspected through hemovigilance. Blood donations implicated in TT‐HBV infections were categorized as either window period (WP) or occult HBV infection (OBI) related. In addition, we analyzed blood from 4742 donors with low antibody to hepatitis B core antigen (anti‐HBc) and antibody to hepatitis B surface antigen (anti‐HBs) titers using individual‐donation NAT (ID‐NAT) to investigate the relationship between anti‐HBc titer and proportion of viremic donors. RESULTS: Introduction of a more sensitive NAT method for screening minipools of 20 donations increased the OBI detection rate from 3.9 to 15.2 per million, while also the confirmed OBI transmission rate increased from 0.67 to 1.49 per million. By contrast the WP transmission rate decreased from 0.92 to 0.46 per million. Testing repository samples of donations missed by minipools of 20 donations NAT showed that 75 and 85% of TT‐HBV that arose from WP and OBI donations, respectively, would have been interdicted by ID‐NAT. The ID‐NAT trial revealed that 1.94% of donations with low anti‐HBc and anti‐HBs titers were viremic and that anti‐HBc titers and the frequency of viremia did not correlate. CONCLUSIONS: The JRC has elected to achieve maximal safety by discarding all units with low anti‐HBc and anti‐HBs titers that account for 1.3% of the total donations.     

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.     

Residual risk of transfusion-transmitted human immunodeficiency virus, hepatitis C virus, and hepatitis B virus infections in Italy

BACKGROUND: Estimating the risk of transfusion-transmitted infections (TTIs) is essential for monitoring blood safety. The residual risk of TTI was estimated for nearly 90 percent of the blood supply in Italy. STUDY DESIGN AND METHODS: Data were analyzed from 1,079,281 repeat donors, corresponding to 5,361,000 donations made in blood transfusion centers throughout Italy in the period 1999 through 2001. The residual risk of transfusion-transmitted human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) infections was estimated with the incidence rate-window period model. The denominator for the incidence rate (i.e., the number of person-years at risk) was estimated on a sample of 5850 donors. RESULTS: The risk of an infectious donation entering the blood supply, per 1 million donations, was 1.91 (probable range, 0.52-3.32) for HIV, 16.74 (9.57-24.01) for HCV, and 69.16 (43.12-102.70) for total HBV (adjusted for vaccination and hepatitis B surface antigen transience). CONCLUSION: In Italy, the estimated residual risk of TTI is apparently low, particularly for HIV infection. Although the estimated risks are higher for HCV and HBV, the introduction of mandatory viral detection tests for HCV in 2002 should account for an 80 percent reduction in the HCV risk. Moreover, the ongoing HBV vaccination program will contribute to reducing the risk of transfusion-transmitted HBV.     

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.     

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.     

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.     

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.     

Declining value of alanine aminotransferase in screening of blood donors to prevent posttransfusion hepatitis B and C virus infection. The Retrovirus Epidemiology Donor Study

BACKGROUND: Since the mid-1980s, blood banks in the United States have screened donors for elevated alanine aminotransferase (ALT) in an effort to prevent posttransfusion hepatitis. The present study was designed to quantitate the residual value of ALT screening following the implementation of hepatitis C virus (HCV) assays. STUDY DESIGN AND METHODS: Two approaches were used. First, a database of 2.3 million donations made by 586,507 volunteer blood donors between 1991 and 1993 was used to compare the incidence of seroconversion to hepatitis B virus (HBV) and HCV marker positivity in donors with elevated ALT values and with normal ALT values. Second, the duration of ALT elevation prior to HBV and HCV seroconversion was determined from 34 well-documented cases of posttransfusion HBV and HCV; elevated-ALT window periods were multiplied by rates of HBV and HCV incidence in donors to project the yield of ALT screening. Predictive value and cost- effectiveness analyses were also performed to compare the value of ALT screening before and after HCV screening was implemented. RESULTS: Both approaches indicate that ALT testing does not detect HBV in the window phase but does currently identify approximately 3 HCV window-phase donations per 1 million donations; this contrasts with ALT detection of approximately 1800 HCV-infectious units per 1 million donations prior to anti-HCV screening. Currently, only 8 in 10,000 donated units with elevated ALT (negative anti-HCV) are infected with HCV. The cost of continued ALT screening was estimated at $7,931,000 per quality- adjusted year of life saved. CONCLUSION: The yield, predictive value, and cost-effectiveness of ALT screening of blood donors have declined dramatically with the implementation of progressively improved anti-HCV assays. ALT screening of volunteer blood donors should be discontinued.     

Prevalence and trends of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus among blood donors in Iran, 2004 through 2007

BACKGROUND: Evaluation and monitoring the prevalence of transfusion-transmissible viral infections in blood donors is a valuable index of donor selection and blood safety. This study analyzed the trends of blood-borne infections among Iranian blood donations during 4 years.
STUDY DESIGN AND METHODS: Viral screening results of 6,499,851 allogeneic donations from 2004 through 2007 were analyzed. All donations were screened for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and syphilis. The prevalence of HBV, HCV, and HIV infections per 100,000 donations and 95% confidence interval was calculated. The p value was estimated by chi-square test.
RESULTS: The prevalences of HBV, HCV, and HIV decreased during the 4-year study from 2004 through 2007. The overall prevalence was 0.56% for HBV, 0.004% for HIV, and 0.13% for HCV. There was a significant and impressive decrease in hepatitis B surface antigen prevalence from 0.73% in 2004 to 0.41% in 2007. The prevalence of HIV appeared to have decreased from 0.005% in 2004 to 0.004% in 2007 although the decrease was not significant. HCV prevalence showed a slight decline in blood donations from 0.14% in 2005 to 0.12% in 2007.
CONCLUSION: The trends of transfusion-transmitted infection prevalence in Iranian blood donations suggest that most of the safety measures employed in recent years in Iran have been effective.     

Experience of German Red Cross blood donor services with nucleic acid testing: results of screening more than 30 million blood donations for human immunodeficiency virus-1, hepatitis C virus, and hepatitis B virus

BACKGROUND: The risk of transfusion-transmitted human immunodeficiency virus-1 (HIV-1), hepatitis C virus (HCV), and hepatitis B virus (HBV) infections is predominantly attributable to donations given during the early stage of infection when diagnostic tests may fail. In 1997, nucleic acid amplification technique (NAT)-testing was introduced at the German Red Cross (GRC) blood donor services to reduce this diagnostic window period (WP). STUDY DESIGN AND METHODS: A total of 31,524,571 blood donations collected from 1997 through 2005 were screened by minipool NAT, predominantly with pool sizes of 96 donations. These donations cover approximately 80 percent of all the blood collected in Germany during that period. Based on these data, the WP risk in the GRC blood donor population was estimated by using a state-of-the-art mathematic model. RESULTS: During the observation period, 23 HCV, 7 HIV-1, and 43 HBV NAT-only-positive donations were detected. On the basis of these data and estimated pre-NAT infectious WPs, the residual risk per unit transfused was estimated at 1 in 10.88 million for HCV (95% confidence interval [CI], 7.51-19.72 million), 1 in 4.30 million for HIV-1 (95% CI, 2.39-21.37 million), and 1 in 360,000 for HBV (95% CI, 0.19-3.36 million). Based on observed cases of breakthrough infections, the risk of transfusion-related infections may be even lower. CONCLUSION: The risk of a blood recipient becoming infected with HCV, HIV-1, or HBV has reached an extremely low level. Introduction of individual donation testing for HCV and HIV-1 would have a marginal effect on interception of WP donations.     

A comparison of human immunodeficiency virus,hepatitis C virus,hepatitis B virus,and human T‐lymphotropic virus marker rates for directed versus volunteer blood donations to the American Red Cross during 2005 to 2010

BACKGROUND: At most US blood centers, patients may still opt to choose specific donors to give blood for their anticipated transfusion needs. However, there is little evidence of improved safety with directed donation when compared to volunteer donation. STUDY DESIGN AND METHODS: The percentage of directed donations made to the American Red Cross (ARC) from 1995 to 2010 was determined. Infectious disease marker rates for human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), and human T‐lymphotropic virus (HTLV) were calculated for volunteer and directed donations made from 2005 to 2010. Odds ratios (ORs) were calculated to compare marker‐positive rates of directed donations to volunteer donations. RESULTS: The percentage of donations from directed donors declined from 1.6% in 1995 to 0.12% in 2010. From 2005 to 2010, the ARC collected 38,894,782 volunteer and 69,869 directed donations. Rates of HIV, HCV, HBV, and HTLV for volunteer donations were 2.9, 32.2, 12.4, and 2.5 per 100,000 donations, respectively; for directed, the rates were 7.2, 93.0, 40.1, and 18.6 per 100,000. After demographics and first‐time or repeat status were adjusted for, corresponding ORs of viral marker positivity in directed versus volunteer donations were not significant for HIV, HBV, or HTLV and significant for HCV (OR, 0.7; 95% confidence interval, 0.50‐0.90). CONCLUSIONS: Directed donations have declined by 92% at the ARC since 1995, but have higher viral marker rates than volunteer donations. The difference can be explained in part by the effects of first‐time or repeat status of the donors. Patients considering directed donation should be appropriately counseled about the potential risks.     

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.     

Relative sensitivities of licensed nucleic acid amplification tests for detection of viremia in early human immunodeficiency virus and hepatitis C virus infection

BACKGROUND: Screening donors for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) RNA is primarily performed on minipools (MPs) with one of two commercial nucleic acid amplification tests (NAT; Roche Molecular Systems; or Gen-Probe/Chiron). We compared these assays with respect to detection of RNA in early HIV and HCV infection. STUDY DESIGN AND METHODS: Twelve HIV plasma donor panels (116 serial samples) and 12 HCV panels (180 serial samples) were selected to optimally represent early viremia. Initial testing was performed in singlicate or triplicate on separately coded aliquots, both neat and at dilutions corresponding to MP screening (1:16 for Gen-Probe; 1:24 for Roche); 20 additional replicates were performed when discordant results were observed. Odds ratios (ORs) comparing detection of RNA by different assays were derived with logistic regression models. Differences in window-period closure and yields of assays in MP or individual-donation (ID) format were estimated. RESULTS: Differences in detection rates between Roche and Gen-Probe NAT assays were small and only observed with samples with very-low-level viremia. ORs for detecting RNA by the Gen-Probe versus the Roche assay were significant for HIV if conducted on MPs (1.8; 95% confidence interval [CI], 1.3-2.5) but not neat (1.0; 95% CI, 0.72-1.4). Odds of detecting HCV RNA were higher if the Gen-Probe assay was conducted either neat (2.3; 95% CI, 1.6-3.2) or on MPs (4.0; 95% CI, 2.8-5.8). These differences translated to <1 day window-period closure and 相似文献   

Mini-pool screening by nucleic acid testing for hepatitis B virus, hepatitis C virus, and HIV: preliminary results

BACKGROUND: The purpose of this study was to evaluate the feasibility of nucleic acid testing (NAT) of mini-pools as a blood donation screening test. STUDY DESIGN AND METHODS: The stepwise implementation of NAT of mini-pools began in January 1997. Since March 1997, all blood donations collected by the German Red Cross Blood Transfusion Service of Baden-Wurttemberg were tested for hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV nucleic acids. An extra barcoded serum sample is collected from each blood donor for NAT-based screening, which is performed only on hepatitis B surface antigen-, anti-HCV-, anti-HIV-, and anti-Treponema pallidum-seronegative donations. Samples are pooled to a maximum of 96. Positive results are resolved through intersecting subpools (a chessboard design). NAT-based screening does not include a virus concentration step before nucleic acid extraction. RESULTS: By the end of October 1997, 331, 783 donations in 3,779 pools had been screened. As yet, no viremic but seronegative blood donor has been found for the three markers. CONCLUSION: It is feasible to incorporate NAT-based screening of mini-pools into the routine virus diagnostics of a large blood transfusion service. It remains to be determined whether screening blood donations by NAT will indeed increase the safety of blood supply.