Individual-donation Nucleic Acid Testing Research Articles

Cost-benefit analysis of serological and nucleic acid testing for hepatitis B virus in blood donors in southern China

BackgroundMost Chinese blood centers have implemented mini pool (MP) HBV nucleic acid testing (NAT) together with HBsAg ELISA in routine blood donor screening for HBV infection since 2015, and a few centers upgraded MP to individual donation (ID) NAT screening recently, raising urgent need for cost-benefit analysis of different screening strategies. In an effort to prevent transfusion-transmitted infections (TTIs) for HBV, cost-benefit analyses of three different screening strategies: HBsAg alone, HBsAg plus MP NAT and HBsAg plus ID NAT were performed in blood donors from southern China where HBV infection was endemic.MethodsMP-6 HBV NAT and ID NAT were adopted in parallel to screen blood donors for further comparative analysis. On the basis of screening data and the documented parameters, the number of window period (WP) infection, HBV acute infection, chronic hepatitis B infection (CHB) and occult hepatitis B infection (OBI) was evaluated, and the potential prevented HBV TTIs and benefits of these three strategies were predicted based on cost-benefit analysis by an estimation model.ResultsOf 132,323 donations, the yield rate for HBsAg-/DNA + screened by ID NAT (0.12%) was significantly higher than that by MP NAT (0.058%, P < 0.05). Furthermore, the predicted transfusion-transmitted HBV cases prevented was 1.25 times more by ID NAT compared to MP-6 NAT. The cost-benefit ratio of the universal HBsAg screening, HBsAg plus ID NAT and HBsAg plus MP NAT were 1:58, 1:27 and 1:22, respectively.ConclusionsUniversal HBsAg ELISA screening in combination with HBV ID NAT or MP-6 NAT strategies was highly cost effective in China. To further improve blood safety, HBsAg plus HBV DNA ID NAT screening should be considered in HBV endemic regions/countries.

Clinical significance of viral markers testing by ELISA and Individual Donation Nucleic Acid Testing (ID-NAT) for blood screening in blood bank: Single center study in Egypt

Prevention of transfusion-transmitted viral infections and insurance of safe blood transfusion are the main goals of all blood banks worldwide. Despite the high sensitivity and specificity of currently used enzyme linked immunosorbent assay (ELISA) for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) testing, viral transmission could still occur during the window period. Introducing viral individual donation nucleic acid testing (ID-NAT) can greatly decrease such risk providing an additional layer in securing blood transfusion. We aimed to assess the clinical significance of viral markers testing by ELISA and ID-NAT for blood screening in the Blood Bank of Suez Canal University Hospital. We studied all donations (2132) collected during a two-months period. Blood donor samples were screened by ELISA and ID-NAT tests for HBV, HCV, and HIV. Serological testing results for HCV by ELISA revealed 2,122 (99.5 %) negative donations compared to 2,131 (99.95 %) negative donations by ID-NAT testing. Of the positive ELISA samples, only one was NAT positive. For HBV ELISA testing, 2,115 (99.2 %) donations were negative, also by ID-NAT testing 2,115 (99.2 %) donations were HBV DNA negative. Out of the negative ELISA samples, two samples were ID-NAT reactive donors which were missed by serology assay being in the window period. HIV ELISA testing revealed negative 2,130 (99.9 %) donations while ID-NAT testing showed 2,131 (99.95 %) negative donations and one positive donation. In conclusion, this is the first study carried out in the Suez Canal and Sinai region, Egypt to assess the importance of ID-NAT implementation. The introduction of ID-NAT in blood banks is an effective method for increasing safety of the blood transfusion.

NAT yield in blood donors: An observational study.

Individual donation nucleic acid testing (ID-NAT) is considered as highly sensitive technology for viral transfusion-transmissible infections (TTIs) in blood donors. The present study was aimed to analyze the results of ID-NAT with special reference to different types of donors, their age, gender, blood group ranges in a tertiary care center in north India. The present study was done from 24th June 2019 to 31st December 2021 in Blood Center, Department of Immunohematology and Blood Transfusion, SMS Hospital, Jaipur. A total of 18313 apparently healthy adult donors were included in present study. In 2019 Combined NAT yield was 1 in 754, in 2020 it was 1 in 2368 and in 2021 it was 1 in 741. With Total NAT yield was 1 in 1017 (0.09 %) over a period of study. NAT yield in HBV is 1 in 1077, in HCV 1 in 18313 and no NAT Yield in HIV. NAT testing for hepatitis B provides additional safety because ELISA does not pick up occult hepatitis. The non-seroconverting or delayed seroconverting disease is missed by ELISA alone and can be picked up by NAT.

Evaluating the cost-effectiveness of low-level HBV DNA screening in occult hepatitis B infection donors: A study from Shandong Blood Center, China

ObjectiveThis study aimed to assess the efficacy of individual-donation nucleic acid testing (ID-NAT) in detecting occult hepatitis B virus infection (OBI) among anti-HBc positive blood donors, compared to minipool nucleic acid testing (MP-NAT). MethodsThe present study analyzed data from the Shandong Blood Center in China during the period from January 2018 to June 2022, where HBsAg-negative blood donors were screened using the 6-sample minipool nucleic acid testing (6-sample MP NAT) method. NAT-positive samples underwent subsequent anti-HBc and anti-HBs testing. Approximately 5000 samples that passed the nucleic acid mixing test were randomly selected for anti-HBc testing, and over 100 anti-HBc positive samples underwent individual donor nucleic acid testing (ID-NAT). Any HBV DNA positive samples detected by ID-NAT were subsequently confirmed using alternative nucleic acid testing methods. ResultsAmong 220,445 HBsAg-negative blood donors, the positivity rate of HBV DNA detection using the 6-sample minipool nucleic acid testing (MP NAT) method was found to be 0.031% (69/220,445). Of the 67 HBV DNA positive samples, 55 (82.09%) and 25 (37.31%) were found to be positive for anti-HBc and anti-HBs, respectively, using the supplementary chemiluminescent microparticle immunoassay (CMIA). Among the 4797 HBsAg-negative/MP NAT-negative samples, 909 (18.95%) tested positive for anti-HBc. Further NAT testing was performed on 164 arbitrarily selected anti-HBc-positive/MP HBV DNA-negative samples, revealing a HBV DNA positivity rate of 1.22% (2/164). ConclusionUsing individual donation nucleic acid testing can significantly increase the detection rate of occult hepatitis B virus infection in anti-HBc-positive blood donors, resulting in a detection rate of 0.22% (1.22 × 0.1895). This rate is 8.10 times higher than the detection rate achieved by mixed testing methods (0.031%) [calculated as (0.22 + 0.031)/0.031]. Therefore, it is recommended to perform single HBV DNA testing on anti-HBc-positive blood donors, discard plasma with weakly positive or negative anti-HBs but positive anti-HBc, or avoid transfusing anti-HBc-positive plasma to recipients with weakly positive or negative anti-HBs to prevent HBV infection.

Donated Blood Screening for HIV, HCV and HBV by ID-NAT and the Residual Risk of Iatrogenic Transmission in a Tertiary Care Hospital Blood Bank in Puebla, Mexico.

Hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B virus (HBV) can be transmitted by blood transfusion. Most transmission occurs during the acute viremic phase (AVP), before antibody development. To reduce transmission risk, individual donor nucleic acid testing (ID-NAT) is used. In Puebla, Mexico, serological tests and ID-NAT have been applied to screen blood donors and detect individuals in AVP. In the present study, 106,125 blood donors' data in two periods (2012-2015 and 2017-2019) were analyzed. The residual risk (RR) values were calculated considering ID-NAT results. The RR for HIV was 14 in 1 million donations or 1 in 71,428, the RR for HVC was 6.8 in 1 million donations or 1 in 147,058 and, for HBV, it was 156 in 1 million donations, or 1 in 6410. Previously, it was predicted that the transmission RR of these viruses would be reduced in Mexico through better screening with NAT. The use of ID-NAT has, indeed, increased the safety of blood reserves for HIV and HCV. However, more research is needed to determine why the residual risk of HBV did not decrease as much over the study period. ID-NAT is an important complementary tool for blood donor screening that should be implemented.

Prevalence of occult hepatitis B virus infection among the blood donors in Golestan province: cross-sectional study.

Despite the increased sensitivity of screening tests, the HBV can be transmitted during the window period and occult hepatitis B infection. The purpose of this study was to evaluate HBV markers and prevalence of OBI among HBsAg negative blood donors in Golestan province. Anti-HBc (IgM and IgG), anti-HBs and anti-HBe tests on 4313 serum samples (HBsAg negative) were performed by ELISA method. Also, all samples for the presence of HBV-DNA were tested by using NAT methods. SPSS software and chi-square test were used for data analysis. Of the 4313 samples, 384 (8.9%) sera were anti-HBc positive. Also, of 384 anti-HBc positive samples, 302 (78.65%) were anti-HBs positive and 152 (39.6%) were anti-HBe positive. Thirty-nine (0.90%) samples were anti-HBc positive, anti-HBs negative and anti-HBe negative. HBV-DNA was not detected in any of specimens. Based on the results of retesting the isolated anti-HBc samples that after one year recalling, had undetectable HBV-DNA and for the prevention of the decreasing of healthy blood donation (due to false positive anti-HBc) and preservation of the blood supplies; Individual Donor Nucleic Acid Testing (ID-NAT) along with the anti-HBc testing for the improving blood safety is recommended.

Experience of individual donor nucleic acid testing on screening of blood donors for human immunodeficiency virus, hepatitis c virus, and hepatitis b virus at an Apex blood bank of Northern India

Experience of individual donor nucleic acid testing on screening of blood donors for human immunodeficiency virus, hepatitis c virus, and hepatitis b virus at an Apex blood bank of Northern India

An economic reappraisal of hepatitis B virus testing strategy for blood donors in Taiwan.

Taiwan is among the few hepatitis B virus (HBV) high-endemic countries that implement universal mini-pool nucleic acid testing (MP-NAT) and hepatitis B surface antigen (HBsAg) testing together with confirmatory individual donor nucleic acid testing (ID-NAT) for its blood supply since 2013. The aim of this study was to reappraise the value of HBsAg test in Taiwan's HBV testing strategy. A Markov model was constructed, and cost-effectiveness analysis was conducted in order to reappraise the existing HBV screening strategy in Taiwan. The incremental cost-effectiveness ratio (ICER) for the current testing strategy in Taiwan was estimated to be $US 443154 per quality-adjusted life year (QALY) gained. This is almost six times the willingness-to-pay (WTP) threshold that reflects local preferences. Universal HBsAg and MP-8-NAT together with confirmatory ID-NAT testing prevents a significant amount of HBV infections from entering the Taiwan blood supply. However, this comes at a disproportionate increase in cost.

NАТ technology – a step forward in hepatitis C screening in Bulgaria

Introduction: Globally, blood transfusions are the cause of transmissible infections in between 10% and 15% of all patients. Currently, the testing of donor blood for transmissible infections is utilizing enzyme-linked immunosorbent assay ELISA and chemiluminescence method CLIA for screening and detection of hepatitis C (HCV Ag/Ab). Since February, 2020 all donor samples of blood taken in the 5 centers for transfusion hematology in Bulgaria have been tested for markers of transmissible infections, including HCV, by nucleic acid testing (NAT). Aim: We have set the goal to analyze data produced by the implementation of NAT testing of donor blood for the period of 4 months (from 10th of February to 16th of June, 2020) regarding HCV infected samples. Materials and Methods: We present our experience of using NAT and data produced by its implementation for testing of donor blood for a period of 4 months, from the time NAT technology was implemented in Bulgaria. Results and Discussion: The performance of the multiplex Procleix Ultrio Elite assay as individual donor nucleic acid test for the detection of HCV is evaluated in a retrospective study. An advantage of the method is that it not only allows for timely identification of infected donor blood and saves lives of the recipients but also saves the lives of donors, as treatment of chronic hepatitis C continues to progress and is now effective in clearing the virus in more than half of the patients. In terms of safety and security of diagnosis and blood products obtained, the method has no alternative. Conclusion: A recommendation is drafted: to adopt a strategy to increase the quality of healthcare by introducing a one-time HCV screening for adults aged 18 and above, for individuals at risk and for pregnant women to reduce further the risk of incidental transmission of the hepatitis C virus.

Anti-HBc screening - is it worth the effort? Results of a 10-year surveillance programme covering more than 30 million donations in Germany.

Antibodies to hepatitis B core antigen (anti-HBc) testing were added to hepatitis surface antigen (HBsAg) screening in Germany in 2006 to prevent hepatitis B virus (HBV) transmissions by chronically infected donors. Wereport the results of a national surveillance of anti-HBc-reactive and HBsAg-negative donations and assess the resulting gain in blood safety and the donor loss. Donations were tested for anti-HBc, and if reactive, by sensitive individual donation nucleic acid testing (ID-NAT) and for antibodies to HBsAg (anti-HBs). Data from the national anti-HBc surveillance from 2006 to 2015 determined the proportion of anti-HBc-reactive donations stratified for donor type, sex, anti-HBs concentration and NAT-positivity. Donor loss due to anti-HBc-reactive results was quantified. Of 31562556 donations screened, 70671 were anti-HBc reactive but HBsAg negative (0.22%). The proportion of repeat donors with these test results decreased significantly from 0.25% in 2007 to 0.08% in 2015. In the entire study period, 82 HBV-NAT-positive donations were identified. Of these, 47 donations were only identified by ID-NAT. A total of 54203 anti-HBc-reactive units were discarded either due to possible infectiousness (NAT positive or anti-HBs concentration <100IU/l) or because no further testing was performed. Anti-HBc screening has improved blood safety in Germany. HBV-NAT-positive donations were identified after ID-NAT was triggered by the initial reactive anti-HBc result. The observed loss of donations was sustainable for maintaining an adequate blood supply in Germany.

Predictive model for Zika virus RNA minipool nucleic acid testing in outbreak scenarios.

Zika virus (ZIKV), a mosquito-borne flavivirus, causes asymptomatic infections in blood donors and can be transmitted by transfusion. During the 2016 US outbreak, universal individual-donation nucleic acid testing (ID-NAT) was used to screen the blood supply for ZIKV. Testing pooled samples from multiple donations with minipool (MP)-NAT is less sensitive than ID-NAT, which raised questions about its utility in ZIKV outbreaks. A mathematical model and computer simulation determined the risk of missing ID-NAT-reactive and immunoglobulin (Ig) M-negative donations in a ZIKV outbreak if MP-NAT is used initially instead of ID-NAT. The model calculated the time required for ZIKV RNA to replicate to a concentration detectable by testing donations individually or in pools of 6 (MP6) or 16 (MP16). A computer simulation then randomly selected infection times to determine the probability of detection by the candidate tests. The probability of detecting the first ID-NAT-reactive unit in an outbreak is 92% (2.5th-97.5th percentile, 79%-99%) by MP6 and 85% (2.5th-97.5th percentile, 67%-99%) by MP16. When one donation is detected by MP-NAT, the model predicts that the chance of having missed one or more ID-NAT-reactive donations is 8% to 15%. The probability of missing a unit by MP-NAT is constant over the course of the outbreak (8% by MP6, 15% by MP16). The model predicts that the probability that a candidate MP-NAT will detect the first ID-NAT-reactive unit in a ZIKV outbreak is 85% to 92% and remains constant over time.

Screening the Blood Supply for Zika Virus in the 50 U.S. States and Puerto Rico: A Cost-Effectiveness Analysis.

In 2016, universal individual donation nucleic acid testing (ID-NAT) of donated blood for Zika virus began in U.S. states and territories. To assess the cost-effectiveness of universal ID-NAT in the first year of screening compared with alternatives for the 50 states and separately for Puerto Rico. Microsimulation that captured Zika-related harms to transfusion recipients, sexual partners, and their infants. National testing results compiled by AABB and costs, utilities, and outcome probabilities estimated from the literature. Transfusion recipients. Lifetime. Societal. Universal ID-NAT, universal mini-pool NAT (MP-NAT), and ID-NAT exclusively for components transfused to women of childbearing age. Seasonally targeted strategies in Puerto Rico and geographically targeted strategies in the 50 states were also considered. Costs, quality-adjusted life-years (QALYs), and outcomes. In Puerto Rico, MP-NAT exclusively during high mosquito season was cost-effective at $81123 per QALY (95% CI, -$49138 to $978242 per QALY). No screening policy was cost-effective in the 50 states. Universal ID-NAT cost $341 million per QALY (CI, $125 million to $2.90 billion per QALY) compared with no screening in the 50 states. In Puerto Rico, MP-NAT only during the season of high mosquito activity was most cost-effective in 64% of probabilistic sensitivity analysis iterations. In the 50 states, no intervention was cost-effective in 99.99% of iterations. Cost-effectiveness was highly dependent on the rate of assumed infectious donations. Data were limited on the component-specific transmissibility of Zika and long-term sequelae of infection. Screening was cost-effective only in the high mosquito season in Puerto Rico, and no evaluated screening policy was cost-effective in the 50 states. During periods with lower rates of Zika-infectious donations, the cost-effectiveness of screening will be even less favorable. None.

Initial trends of individual donation nucleic acid testing in voluntary & replacement donors from a tertiary care centre in north India.

Background & objectives:Individual donation nucleic acid testing (ID-NAT) is considered as sensitive technology to assess blood safety from viral transfusion-transmissible infections (TTIs) in blood donors. The present study was aimed to analyze the results of ID-NAT for three years (2013-2015) with special reference to different types of donors and their age ranges in a tertiary care centre in north India.Methods:The results of ID-NAT for three years were retrospectively analyzed at our centre. A total of 168,433 donations were tested with ID-NAT, of which 10,467 were tested with Procleix® Ultrio® reagents and 157,966 were tested with Procleix® UltrioPlus® reagents, and the results were compared with those of serology to calculate the NAT yield in voluntary, replacement, first-time and repeat donors.Results:A combined NAT yield was observed as one in 1031 out of 167,069 seronegative donations with HBV yield as one in 1465, HCV yield as one in 3885 and HIV-1 as one in 167,069. Yield for co-infection (HCV and HBV) was one in 41,767. A high NAT yield was observed in replacement donors (1 in 498) as compared to voluntary donors (1 in 1320).Interpretation & conclusions:Addition of NAT to serology improved the blood safety in our centre interdicting possibility of 150 TTIs annually. It has also reemphasized the safety of voluntary over replacement donors. The results also highlight the need of proper counselling, notification and referral guidelines of NAT yield donors in our country and other countries which lack them.

Recent and occult hepatitis B virus infections among blood donors in the United States.

Characteristics of US blood donors with recent (RBI) or occult (OBI) hepatitis B virus (HBV) infection are not well defined. Donors with RBI and OBI were identified by nucleic acid and serologic testing among 34.4 million donations during 2009-2015. Consenting donors were interviewed and their HBV S-gene sequenced. The overall rate of HBV-infected donors was 7.95 per 100,000; of these, 0.35 per 100,000 and 1.70 per 100,000 were RBI and OBI, respectively. RBI (n = 120) and OBI (n = 583) donors constituted 26% of all HBV-infected (n = 2735) donors. Detection of HBV DNA in 92% of OBI donors required individual donation nucleic acid testing. Donors with OBI compared to RBI were older (mean age, 48 vs 39 years; p < 0.0001) with lower median viral loads (9 vs. 529 IU/mL; p < 0.0001). A higher proportion of OBI than RBI donors were born or resided in an endemic country (39% vs. 5%; p = 0.0078). Seventy-seven percent of all RBI and OBI donors had multiple sex partners, an HBV-risk factor. Of 40 RBI and 10 OBI donors whose S gene was sequenced, 33 (83%) and 6 (60%), respectively, carried HBV subgenotype A2; 18 (55%) and 2 (33%), respectively, shared an identical sequence. Infection with 1 or more putative HBV-immune-escape mutants was identified in 5 (50%) of OBI but no RBI donors. RBI and OBI continue to be identified at low rates, confirming the importance of comprehensive HBV DNA screening of US blood donations. HBV-infected donors require referral for care and evaluation and contact tracing; their HBV strains may provide important information on emergent genotypes.

Assessment of HIV transfusion transmission risk in South Africa: a 10-year analysis following implementation of individual donation nucleic acid amplification technology testing and donor demographics eligibility changes.

In 1998 we estimated that 34/million infectious window period donations were entering the blood supply at the South African National Blood Service. Selective use of donations based on donor race-ethnicity reduced this risk to 26/million donations but was deemed unethical. Consequently, in 2005 South African National Blood Service eliminated race-ethnicity-based collection policies and implemented individual-donation nucleic acid testing (ID-NAT). We describe the change in donor base demographics, human immunodeficiency virus (HIV) detection rates, and transfusion-transmissible HIV risk. In ten years 7.7 million donations were tested for anti-HIV and HIV RNA. Number of donations, HIV prevalence, ID-NAT yield rate, serology yield rate and residual transfusion-transmissible HIV risk were analyzed by donor type, race-ethnicity, age, and sex. Multiple regression analysis was performed to investigate the determinants of HIV-positive and nucleic acid testing yield donations. The combined strategy of increasing donations from black donors and implementing ID-NAT increased the proportion of donations from black donors from 6% in 2005 to 30% in 2015 (p < 0.00001), and reduced the transfusion-transmissible risk from 24 to 13 per million transfusions. ID-NAT interdicted 481 (1:16,100) seronegative window period donations, while one transfusion-transmissible case (0.13 per million) was documented. Race-ethnicity and donor type were highly significant predictors of HIV positivity, with adjusted odds ratio for first-time donors of 12.5 (95% confidence interval, 11.9-13.1) and for black race-ethnicity of 31.1 (95% confidence interval, 28.9-33.4). The proportion of serology yields among HIV-infected donors increased from 0.27% to 2.4%. ID-NAT enabled the South African National Blood Service to increase the number of donations from black donors fivefold while enhancing the safety of the blood supply.

Prevalence of Hepatitis B and C Viral Markers in Blood Donors Deferred from Donating Blood on the Basis of a History of Jaundice of Unknown Origin

The aim of the present study was to know the prevalence of viral hepatitis markers among blood donors deferred on the basis of a history of jaundice of unknown origin and to predict the impact of this deferral on blood safety. Observational study included 200 blood donors deferred on the basis of a history of jaundice of unknown origin and carried out serology and Individual Donation Nucleic Acid Testing (ID-NAT) for hepatitis B and hepatitis C. Five (2.5%) out of 200 blood donors deferred on the basis of history of jaundice were reactive on ELISA. Three out of five were reactive for HBsAg; whereas two for anti-HCV antibodies. Out of the 12 ID-NAT initial reactive, 10 samples discriminated on further testing; 4 for HBV, 5 for HCV and 1 was co-infection (HBV+HCV). The odds of being picked up as sero reactive on ELISA was 2.53 (95% CI; 1.04-6.19) and being picked up as ID-NAT yield was 13.08 (95% CI; 5.29-32.37) in donors deferred on a history of jaundice of unknown origin as compared to selected donors without a history of jaundice, with the difference in means achieving statistically significance at P=0.03 and <0.001 respectively.The potential of deferral on a history of jaundice of unknown origin has a capacity to interdict 2-3 HBV and/or HCV reactive blood donors on serology and 5 HBV and/or HCV reactive blood donors on ID-NAT from entering the quarantine blood supply per 100 donors. The findings of the present study support that a deferral for a history of jaundice of unknown origin after attaining the age of 12 years in the present scenario of transfusion transmissible infectious disease screening in India.

Cost projections for implementation of safety interventions to prevent transfusion-transmitted Zika virus infection in the United States.

In August 2016, the Food and Drug Administration advised US blood centers to screen all whole blood and apheresis donations for Zika virus (ZIKV) with an individual-donor nucleic acid test (ID-NAT) or to use approved pathogen reduction technology (PRT). The cost of implementing this guidance nationally has not been assessed. Scenarios were constructed to characterize approaches to ZIKV screening, including universal ID-NAT, risk-based seasonal allowance of minipool (MP) NAT by state, and universal MP-NAT. Data from the 2015 National Blood Collection and Utilization Survey (NBCUS) were used to characterize the number of donations nationally and by state. For each scenario, the estimated cost per donor ($3-$9 for MP-NAT, $7-$13 for ID-NAT) was multiplied by the estimated number of relevant donations from the NBCUS. Cost of PRT was calculated by multiplying the cost per unit ($50-$125) by the number of units approved for PRT. Prediction intervals for costs were generated using Monte Carlo simulation methods. Screening all donations in the 50 states and DC for ZIKV by ID-NAT would cost $137 million (95% confidence interval [CI], $109-$167) annually. Allowing seasonal MP-NAT in states with lower ZIKV risk could reduce NAT screening costs by 18% to 25%. Application of PRT to all platelet (PLT) and plasma units would cost $213 million (95% CI, $156-$304). Universal ID-NAT screening for ZIKV will cost US blood centers more than $100 million annually. The high cost of PRT for apheresis PLTs and plasma could be mitigated if, once validated, testing for transfusion transmissible pathogens could be eliminated.

Comparison of two algorithms to confirm and discriminate samples initially reactive for nucleic acid amplification tests.

BACKGROUND:Blood centers in India have published individual donor nucleic acid testing (ID-NAT) data based on an algorithm (Algorithm A) where serologically negative, NAT reactive sample was subsequently tested with discriminatory NAT (d-NAT), and on the basis of d-NAT, initial reactive samples were classified as “NAT yield” or inconclusive. We followed Algorithm B based on replicate testing and Ultrio Plus assay and compared the results with Algorithm A with Ultrio assay.MATERIALS AND METHODS:Results of ID-NAT using two algorithms were analyzed.RESULTS:A total of 88,583 (31,844 with Algorithm A and 56,739 with Algorithm B) samples were tested. Among serology nonreactive donations, NAT inconclusive results came down from 95.2% in Algorithm A to 73.1% in Algorithm B (P = 0.0001). Discriminated yield (DY) rate went up from 4.7% in Algorithm A to 21.9% in Algorithm B (P = 0.001).CONCLUSION:The study data suggest that replicate testing strategy and Ultrio Plus reduce the number of “inconclusive results” seen with earlier commonly used algorithm. We recommend a replicate testing strategy in ID-NAT testing since it will increase the DY and will eliminate the unnecessary discriminatory tests.

A study of centralized individual donor nucleic acid testing for transfusion transmitted infections to improve blood safety in Karnataka, India

Introduction: Karnataka state has a total of 176 blood banks, with a total collection of around 650,000 units annually. From January 2014, all units under the Department of Health and Family Welfare services are tested at NAT Lab established at the Central facility and from September 2014, standalone Regional Blood Transfusion Centre was included in the State Government project. Aim and Objective: The aim of the study is to analyze the nucleic acid testing (NAT) for our donor population and demonstrate consolidation of blood transfusion service through a centralized testing center for NAT and also to assess safety benefits of implementing individual donor NAT (IDNAT). Materials and Methods: We collect nearly 40,000 units annually from voluntary donors with 30% repeat donations. The donors undergo strict predonation counseling, donor questionnaire, and medical examination. The units collected are tested for human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) by ECI using VItros 3600. All the units are tested by NAT at Central NAT Lab, screened by Procleix® Panther System by Grifols. Results: From September 2014 to March 2016, total 50,903 samples tested for NAT. Of 50,903 samples, 588 samples (1.15%) were reactive by Chemiluminescence including 265 for HBV, 188 for HCV, and 135 for HIV. Total NAT reactive samples were 254, out of this 11 reactive for HIV-1 (0.02%), 2 reactive for HCV (0.003%), 235 (0.46%) reactive for HBV. There was one HIV and 10 HBV infection cases that were not detected by serology but reactive by NAT. The yield detected is 0.021% or one in 5000. Conclusion: The IDNAT project has helped in preventing window period infections thus reducing the treatment cost and burden on healthcare. It has added benefits in blood safety and should be considered along with the basic quality assured blood transfusion system such as volunteer base for blood donation, provision of donor self-deferral, donor notification, and quality assured sensitive serological methods.

Detection of occult hepatitis B and window period infection among blood donors by individual donation nucleic acid testing in a tertiary care center in South India

With the introduction of highly sensitive hepatitis B surface antigen immunoassay, transfusion associated HBV infection have reduced drastically but they still tend to occur due to blood donors with occult hepatitis B infection (OBI) and window period (WP) infection. Sera from, 24338 healthy voluntary blood donors were screened for HBsAg, HIV and HCV antibody using Vitros Enhanced Chemiluminescent Immunoassay. The median age of the donor population was 30 (range 18–54) with male preponderance (98%). All serologically negative samples were screened by nucleic acid testing (NAT) for viral DNA and RNA. NAT-positive samples were subjected to discriminatory NAT for HBV, HCV, and HIV and all samples positive for HBV DNA were tested for anti-HBc, anti-HBs, HBeAg. Viral load was determined using artus HBV RG PCR Kit. Of the 24,338 donors screened, 99.81% (24292/24338) were HBsAg negative of which NAT was positive for HBV DNA in 0.0205% (5/24292) donors. Four NAT positive donors had viral load of <200 IU/ml making them true cases of OBI. One NAT positive donor was negative for all antibodies making it a case of WP infection. Among OBI donors, 75% (3/4) were immune and all were negative for HBeAg. Precise HBV viral load could not be determined in all (5/5) NAT positive donors due to viral loads below the detection limit of the artus HBV RG PCR Kit. The overall incidence of OBI and WP infections was found to be low at 1 in 6503 and 1 in 24214 donations, respectively. More studies are needed to determine the actual burden of WP infections in Indian blood donors.