Automated nucleic acid amplification testing in blood banks: An additional layer of blood safety

Burden of hepatitis B in asymptomatic blood donor population of India: A systematic review & meta-analysis

Background & objectives India has been classified as an intermediate Hepatitis B Virus (HBV) endemic country, and the transmission is believed to mostly occur horizontally. However, community-based data on HBV prevalence among blood donors in India are limited. The burden of Hepatitis B Virus (HBV) is unknown in the asymptomatic blood donor population. We therefore conducted a meta-analysis to assess the prevalence of the HBV among the blood donor population in India. Methods We searched different databases for research articles on the prevalence of HBV in the blood donor population from India. Following the PRISMA guidelines, forty articles published between January 2013 and October 20, 2023, were selected for meta-analysis after removing duplicates and conducting a two-level screening process. Review Manager Version 5.3 (Rev Man 5.4) was used for statistical meta-analysis. The study has been registered with PROSPERO (number CRD42023487616). Results Forty articles were selected out of the 527 published manuscripts for meta-analysis, and a total of 22,22,736 blood donations were studied. Of these, 24,151 individuals (1.11%) were identified either as chronically infected with HBV or living with HBV infection. A pooled prevalence of approximately 1.11 per cent with a 95% confidence interval (CI) of (0.011; 0.0112) (common effect model) or 95% CI of (0.0079; 0.0116) (random effects model) was estimated. The included studies exhibited a high level of heterogeneity, probably due to different diagnostic approaches followed in different studies. Interpretation & conclusions The burden of hepatitis is profound, impacting public health, economies, and societies in India. The outcome of this study would help address such a burden and develop comprehensive strategies focused on prevention, early diagnosis, treatment, and necessary collaboration to achieve significant reductions in hepatitis-related morbidity and mortality.

NAT yield in blood donors: An observational study

Introduction

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.

Methodology

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.

Result

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.

Conclusion

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.

Economic Evaluation of Nucleic Acid Testing for Screening of Blood Donations for Thalassemia Patients (ECONAT) in Western India

Background

Transfusion Transmitted infections(TTI) are of significant concern for blood safety. The thalassemia patients who receive multiple transfusions are at an increased risk of TTIs and the Nucleic Acid Test (NAT ) has been advocated for safe blood. Though NAT can reduce the window period compared to serology, cost is a constraint.

Methods

The thalassemia patient and NAT yield data from the centralized NAT lab in AIIMS Jodhpur was evaluated for cost-effectiveness using the Markov model. The incremental cost-effectiveness ratio (ICER) was calculated by dividing the difference between the cost for NAT and the cost of medical management of TTI-related complications by the product of the difference in utility value of a TTI health state with time and Gross National Income(GNI) per capita.

Results

Out of the 48,762 samples tested by NAT, 43 samples were discriminated NAT yield all of which were reactive for Hepatitis B (NAT yield of 1:1134). There was no HCV and HIV NAT yield despite HCV being the most prevalent TTI in this population. The cost of this intervention was INR 5,85,14,400. The number of lifetime QALY saved was 1.38 years. The cost of medical management is INR 82,19,114. Therefore the ICER for intervention is INR 3,64,45,860 per QALY saved which is 274 times the GNI per capita of India.

Conclusions

The provision of IDNAT-tested blood for thalassemia patients in Rajasthan state was not found to be cost-effective. Measures to bring down the cost or alternative options to increase blood safety should be explored.

Adaptation of a Public–Private Partnership Model for the Implementation of Minipool Nucleic Acid Testing for Screening Routine Blood Donations and the Evaluation of Assay: A Multi-Center Study from Odisha, India

Background Nucleic acid amplification testing (NAT) for the screening of blood donations is known to improve blood safety. The decision to initiate NAT requires careful deliberation of infrastructure, skilled manpower, and financial resources. This report outlines the initiative of the Government of Odisha to implement NAT screening in government blood banks in the state of Odisha, India, through public–private partnership (PPP) and evaluates the incremental yield of minipool NAT screening over serology testing of blood donations.

Methods Blood donations collected between June 2016 and September 2018 were initially screened for HBV (HBsAg), HCV (anti-HCV), and HIV (anti-HIV-1 and HIV-2) by ELISA, and syphilis and malaria. Sero-nonreactive donations were further screened in pools of six by Roche cobas TaqScreen MPX test version 2.0 (MPX2) NAT.

Results On screening 3,39,472 blood donations, 1.34% seroreactive donations were detected. In all, 847 NAT-reactive donations (0.26%): 693 HBV, 58 HCV, and 96 HIV were detected. The NAT yields were 1:386 overall, 1:472 for HBV, 1:5642 for HCV, and 1:3409 for HIV.

Conclusion NAT testing using the highly sensitive MPX2 assay leads to incremental detection of TTIs over serology. Implementation of NAT along with serological testing in blood centers all over India will be an important step towards providing safe blood. Our study not only highlights the benefits of minipool NAT testing but also presents a scalable PPP model that can serve as a template for application across other states.

The Prevalence of Transfusion-transmitted Infections among Blood Donors in Hospital Universiti Sains Malaysia

Objectives

Blood bank centers routinely screen for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) to ensure the safety of blood supply and thus prevent the dissemination of these viruses via blood transfusion. We sought to evaluate the detection of transfusion-transmitted infection (TTI) markers using standard serological methods and nucleic acid testing (NAT) among blood donors in Hospital Universiti Sains Malaysia.

Methods

Donated blood units were assessed for the presence or absence of HBV, HCV, and HIV using two screening method: serology and NAT. Reactive blood samples were then subjected to serological confirmatory and NAT discriminatory assays.

Results

A total of 9669 donors were recruited from September 2017 to June 2018. Among these, 36 donors were reactive either for HBV, HCV, or HIV by serological testing and eight by NAT screening. However, only 10 (three for HBV and seven for HCV) donors tested positive using serological testing and five (two for HBV and three for HCV) by NAT discriminatory assays. Note that all five NAT positive donors detected in the NAT discriminatory assays were confirmed to be serologically reactive. Therefore, the prevalence of HBV, HCV, and HIV was 0.03%, 0.1%, and 0.0%, respectively, in our donor pool.

Conclusions

Both serological and NAT screening and confirmatory assays should be used routinely to reduce the risk of infection transmission via the transfusion of blood and blood components.

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.

Assessment of Blood Donation and Transfusion in Eastern Uganda: A Mixed-Methods Study

BACKGROUND

Blood and blood products are essential in the management of injuries, medical illnesses, and childbirth. Chronic shortages in the blood supply perpetuates the high levels of morbidity and mortality from injury and treatable diseases. Patients in low- and middle-income countries are frequently unable to access blood units necessary for transfusion in a timely manner.

OBJECTIVES

This study aimed to gain insight into the community and hospital factors that contribute to the observed insufficient supply of blood units available for transfusion at a regional referral hospital in rural Eastern Uganda.

METHODS

A mixed-methods approach was utilized; community members were surveyed on knowledge, attitudes, and practices of blood donation and health professionals were queried on hospital factors affecting blood transfusions. Transfusion records were prospectively collected and analyzed, and the pathway of a single blood unit was observed and recorded.

FINDINGS

Among the 82 community members that were surveyed, knowledge was poor (<50% correct) regarding age, weight, and volume of blood to be able to donate, but participants were overall knowledgeable on general characteristics that would exclude individuals from donating blood. Major themes elicited during qualitative interviews included a positive attitude towards and lack of information regarding blood donation. Health professionals expressed frustration in delayed testing of transfusion transmissible infections. The majority of blood transfusions were allocated to female patients (55.8%) and children under five years of age (33.2%).

CONCLUSIONS

Broadened inclusion and education of the general population in blood donation and increased outreach programs may be promising interventions to increase the blood supply at the Soroti Regional Referral Hospital. To reduce the current bottleneck seen in TTI testing, the feasibility and cost-effectiveness of local TTI testing technology should be investigated further.

What is the evidence for the change in the blood -donation deferral period for high-risk groups and does it go far enough?

In November 2017, the deferral on blood donations from high-risk groups in Great Britain was changed to 3 months from last at-risk sexual contact following recommendations from the Advisory Committee on the Safety of Blood, Tissues and Organs. This represented a reduction from 12 months for men who have sex with men, and from a lifetime ban for sex workers. This is a step forward for equality and for reducing stigma around these groups. However, one argument for deferral is the prevalence of infections, which may not be identified due to the fallibility of current testing approaches. Clearly it is vital that the welfare of blood transfusion recipients is prioritised and they are not exposed to unacceptable risks. However, with the increasingly sophisticated technology used to screen blood, it can be argued that the evidence shows that the reduction in deferral does not go far enough.

Development of a novel peptide aptamer-based immunoassay to detect Zika virus in serum and urine

Zika virus (ZIKV) has been identified as a cause of adverse outcomes of pregnancy, including microcephaly and other congenital diseases. Most people infected with ZIKV do not show any symptoms. Development of a method to discriminate dengue virus (DENV) and ZIKV infections has been challenging, and efficient assays for patient management are limited, attributable to high levels of cross-reactivity among co-circulating Flaviviruses. Thus, there is an urgent need for a specific high-throughput diagnostic assay to discriminate ZIKV infections from other Flavivirus infections. Methods: A novel epitope peptide of the ZIKV envelope protein was predicted using three immune epitope database analysis tools and then further modified. A molecular docking study was conducted using three-dimensional structures of the ZIKV envelope and peptide. Experimentally, interactions between the selected peptides and virus were assessed via a fluorescence-linked sandwich immunosorbent assay (FLISA), and performance of peptide-linked sandwich FLISA was evaluated in virus-spiked human serum and urine. Results: The Z_10.8 peptide (KRAVVSCAEA) was predicted to be a suitable detector, with a higher binding affinity than other candidates based on four criteria (binding affinity, root mean square deviation, position of amine residue of lysine at the N-terminus, and interactive site) in a docking study. Z_10.8 was significantly more efficient at detecting ZIKV than the other two peptides, as shown in the direct FLISA (P < 0.001). Further, the equilibrium dissociation constant (K_d) for the Z_10.8 peptide was 706.0 ± 177.9 (mean ± SD, nM), with specificity to discriminate ZIKV from DENV. The limit of detection for the sandwich FLISA was calculated as 1×10⁴ tissue culture infective dose (TCID)₅₀/mL. The presence of serum or urine did not interfere with the performance of the Z_10.8-linked sandwich FLISA. Conclusion: Four criteria are suggested for the development of an in silico modeled peptide aptamer; this computerized peptide aptamer discriminated ZIKV from DENV via immunoassay.

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.

Residual risk of transmission of human immunodeficiency virus and hepatitis C virus infections by blood transfusion in northern Brazil

BACKGROUND

Nucleic acid test (NAT) blood screening for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was introduced in northern Brazil in July 2012. There are several Brazilian articles that have evaluated transfusion transmission risks for HIV and HCV. However, to our knowledge, this article is the first to evaluate the impact of HIV and HCV NAT implementation for blood screening in northern Brazil. The aim of this study was to determine the prevalence and incidence rates of HIV and HCV among blood donors and to compare the residual risk of transfusion transmission of these infections, before (2009-2011) and after (2012-2014) NAT implementation.

STUDY DESIGN AND METHODS

HIV and HCV prevalence and incidence were calculated based on rates of confirmed positive samples. Residual risk estimates were based on the incidence and window model described previously. Logistic and Poisson regressions were used in the statistical analysis. A p value of not more than 0.05 was considered significant.

RESULTS

HIV and HCV prevalence were 209.9 and 66.3 per 100,000 donations, respectively. Residual risk for HIV and HCV decreased significantly throughout the two study periods, mainly for HCV in which the reduction was one in 169,492 to one in 769,231 donations. For HIV, the decrease was one in 107,527 to one in 769,231 donations. HIV and HCV incidence rates were 21.13 and 3.06 per 100,000 persons/year before NAT and 14.03 and 2.65 per 100,000 persons/year after NAT.

CONCLUSION

The HIV and HCV NAT implementation significantly increased the transfusion safety in northern Brazil, bringing benefits to recipients due to better quality of blood products produced.

Three-Year Experience in NAT Screening of Blood Donors for Transfusion Transmitted Viruses in Croatia

Background

Croatia implemented individual donation (ID)-NAT testing of blood donors in 2013 for three viruses HBV, HCV, and HIV-1 as a mandatory test for all blood donors. This study assessed the impact of NAT screening 3 years after its implementation.

Methods

A total of 545,463 donations were collected and screened for HBV, HCV, and HIV-1 using the Procleix Ultrio Plus Assay. All initially reactive (IR) NAT samples were retested in triplicate and, if repeatedly reactive (RR), NAT discriminatory assay (dNAT) was performed. ID-NAT positive donations were confirmed by RT-PCR on the COBAS AmpliPrep/TaqMan platform.

Results

Out of 545,463 samples tested, 108 (0.02%) were RR in NAT. There were 82 (75,9%) HBV reactive, 16 (14.8%) HCV reactive, and 10 (9.3%) HIV-1 reactive samples. 51 (47.2%) samples were ID-NAT positive only. Out of these 51 NAT yield cases, 1 window period HIV-1 and 50 occult HBV infections (OBI) were determined. There were only two potential HBV DNA transmissions from OBI donors.

Conclusion

The implementation of NAT screening for three viruses has improved blood safety in Croatia. During the 3-year period, 1 window period HIV-1 and a number of occult HBV donations were identified.

Assessment of semi-automated nucleic acid testing programme in a Regional Blood Transfusion Centre

BACKGROUND

Detection of human immunodeficiency virus type-1 (HIV-1), hepatitis-C (HCV) and hepatitis-B virus (HBV) in the blood donors is crucial. An efficient form of detection is nucleic acid testing (NAT) in blood screening. We assessed the suitability of commercial NAT testing in a developing country, focusing on the Altona RealStar assay and the method of Sacace Biotechnologies.

METHODS

We have standardised and validated commercially available NAT kits with a semi-automated system for detection of HBV, HCV and HIV-1 in blood donations. The MP-NAT (mini-pool) assay consists of pooling of sample, virus extraction, amplification and detection with commercially available NAT kits. An internal control (IC) is incorporated in the assay to monitor the extraction, target amplification and detection process.

RESULTS

The sensitivity of the Altona RealStar assay at 10-MP for each viral target was evaluated, HBV showed amplification in all diluted positive samples of 100, 50, 25, 10 and 5 IU/ml. HIV and HCV infected samples showed amplification in all diluted positive samples of 500, 100, 50 and 30 IU/ml. For HIV, out of six diluted samples of 30 IU/ml, five were amplified. A total of 14,170 seronegative blood samples were tested by RealStar PCR kit in 10-MP and 6 (0.042%) samples/pools were positive. A total of 65,362 seronegative blood donations were also tested by kits of Sacace Biotechnologies, in 10-MP and 45 (0.075%) pools were positive. The prevalence of combined NAT yield cases among routine donors was 1 in 1559 donations tested for all the 3 viruses.

CONCLUSION

The semi-automated combined system for NAT screening assays is robust, sensitive, reproducible, and this gives an additional layer of safety with affordable cost.

Deceased tissue donor serology and molecular testing for HIV, hepatitis B and hepatitis C viruses: a lack of cadaveric validated tests

Vital to patient safety is the accurate assessment and minimization of risk for human immunodeficiency virus (HIV), Hepatitis C (HCV), and Hepatitis B (HBV) virus transmission by deceased donor organ and tissue transplantation. The pathogens are tested by serological kits based on enzyme-linked immunosorbent assay (ELISA), chemiluminescence (CLIA) and eletrochemiluminescence (ECLIA) immunoassays. Organ transplantation is a highly successful life-saving treatment in Brazil, but the Brazilian Health Surveillance Agency currently mandates that all deceased organ donors are screened for HIV, HCV and HBV following living donor policies. In this review, six ELISA (Wama^®, Bio-Rad^®, Biomerieux^®, DiaSorin^®, Acon Biotech^® and Biokit^®), three CLIA (Abbott^®, Siemens^®, Diasorin^®) and one ECLIA (Roche^®) were utilized for evaluating the effectiveness of those serological tests for deceased donors in Brazil according to manufacturer's guidelines. NAT for HIV, HCV and HBV can assist with detection of pre-seroconversion for those infections, and only Cobas^® TaqScreen MPX^® test, the Tigris System^® Procleix Ultrio Assay^® and the Bio-Manguinhos^® HIV/HCV/HBV NAT are commercially available. Between all the tests, only the manufacturer Abbott^® and Cobas^® TaqScreen MPX^® test are currently validated for cadaver samples.