Nucleic Acid Testing Testing Research Articles

Impact of nucleic acid testing in double screening of blood donations in Northern India: A single-center experience

Objectives: The aim of our study is to assess the ability of nucleic acid testing (NAT) to detect hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) from donor blood samples which were declared sero-non-reactive. Materials and Methods: The whole blood donations were collected over the 6-year period from 2017 to 2023 which were initially screened for hepatitis B surface antigen, anti-HCV, anti-HIV-1/2, and p24 antigen and syphilis by electrochemiluminescence assays by Roche Diagnostics, Germany and malaria by Pan/Pf rapid test. Donations were declared nonreactive by these tests which were further subjected to NAT testing using minipool method. It was done in pool of 6 using cobas Taq Screen MPX version 2.0 on the cobas s201 platform. The NAT yields were quantitated for viral loads and followed up by serology. Statistical analysis: The data obtained was entered in Microsoft Excel and analyzed using descriptive statistics using the Statistical Package for the Social Science 21 version. Results: Out of 152,575 donations, 149,304 were sero-non-reactive and screened by NAT. Out of 82, 45 were reactive for HBV deoxyribonucleic acid and 37 for HCV ribonucleic acid. The NAT yield was 1:1831 overall, 1:3337 for HBV and 1:4059 for HCV. Viral load was quantitated in 65/82 NAT yields (35 HBV and 30 HCV). The viral loads of HBV samples were <20 IU/mL for 19/35 samples and the HCV sample viral loads ranged from 25.3 to 9.3 × 106 IU/mL. Eleven NAT-yield donors (4 HBV, 7 HCV) reported for follow-up showed sero-conversion between 90 and 210 days after NAT screening. Conclusions: This study confirmed the benefit of a highly sensitive minipool NAT (MP-NAT) in interdicting infectious donations undetected by conventional screening and illustrates the detection of donations with low viral loads using the MP-NAT polymerase chain reaction.

Epidemiology of HEV Infection in Blood Donors in Southern Switzerland.

From 2014 to 2016, the number of hepatitis E virus (HEV) infections in southern Switzerland increased dramatically and suggested food as a potential infection reservoir. We evaluated the effects of food control measures introduced to limit HEV infections, assessing anti-HEV IgG and IgM rates in blood donors before and after the implementation of food control measures in 2017. From 2012 to 2013, we screened 1283, and from 2017 to 2019, we screened 1447 donors for IgG and IgM antibodies. No statistically significant differences were detected for IgG (32.8% from 2012 to 2013 vs. 31.1% from 2017 to 2019, p = 0.337) or IgM rates (2.0% from 2012 to 2013 vs. 2.8% from 2017 to 2019, p = 0.21). Rural provenience and age > 66 are predictors for positive IgG serology. A total of 5.9% of 303 donors included in both groups lost IgG positivity. We also determined nucleic acid testing (NAT) rates after the introduction of this test in 2018, comparing 49,345 donation results from southern Switzerland with those of 625,559 Swiss donor controls, and only 9 NAT-positive donors were found from 2018 to 2023. The high HEV seroprevalence in southern Switzerland may depend on different food supply chains in rural and urban areas. Local preventive measures probably have a limited impact on blood HEV risk; thus, continuous NAT testing is recommended.

Cost-effectiveness of Hepatitis C virus self-testing in four settings.

Globally, there are approximately 58 million people with chronic hepatitis C virus infection (HCV) but only 20% have been diagnosed. HCV self-testing (HCVST) could reach those who have never been tested and increase uptake of HCV testing services. We compared cost per HCV viraemic diagnosis or cure for HCVST versus facility-based HCV testing services. We used a decision analysis model with a one-year time horizon to examine the key drivers of economic cost per diagnosis or cure following the introduction of HCVST in China (men who have sex with men), Georgia (men 40-49 years), Viet Nam (people who inject drugs, PWID), and Kenya (PWID). HCV antibody (HCVAb) prevalence ranged from 1%-60% across settings. Model parameters in each setting were informed by HCV testing and treatment programmes, HIV self-testing programmes, and expert opinion. In the base case, we assume a reactive HCVST is followed by a facility-based rapid diagnostic test (RDT) and then nucleic acid testing (NAT). We assumed oral-fluid HCVST costs of $5.63/unit ($0.87-$21.43 for facility-based RDT), 62% increase in testing following HCVST introduction, 65% linkage following HCVST, and 10% replacement of facility-based testing with HCVST based on HIV studies. Parameters were varied in sensitivity analysis. Cost per HCV viraemic diagnosis without HCVST ranged from $35 2019 US dollars (Viet Nam) to $361 (Kenya). With HCVST, diagnosis increased resulting in incremental cost per diagnosis of $104 in Viet Nam, $163 in Georgia, $587 in Kenya, and $2,647 in China. Differences were driven by HCVAb prevalence. Switching to blood-based HCVST ($2.25/test), increasing uptake of HCVST and linkage to facility-based care and NAT testing, or proceeding directly to NAT testing following HCVST, reduced the cost per diagnosis. The baseline incremental cost per cure was lowest in Georgia ($1,418), similar in Viet Nam ($2,033), and Kenya ($2,566), and highest in China ($4,956). HCVST increased the number of people tested, diagnosed, and cured, but at higher cost. Introducing HCVST is more cost-effective in populations with high prevalence.

Residual risk estimates of transfusion transmissible hepatitis B, hepatitis C and human immunodeficiency virus using nucleic acid testing yield/window period model in an Indian setting.

Estimation of residual risk (RR) is necessary to understand status of blood safety with current testing strategies and need to improve it further. These estimates from India are lacking till date. Present study was aimed to estimate RR and incident rate (IR) of transfusion transmitted infectious disease (TTIDs) in Indian setting. Blood donor demographic data, serological testing results and nucleic acid testing (NAT) screening results were collected retrospectively from January 2015 to June 2017. Mathematical modelling using NAT yield/window period model was done to estimate IR and RR of TTIDs. Data was compared between different groups based on age-group, gender, donation repeatability and type of donor. A total 106 119 blood donors donated 109 441 units with overall TTID reactivity of 2.22%. HBV was most prevalent TTID (1.26%) with RR of 16.1 per million followed by HCV and HIV with RR of 4.4 and 3.1 per million donations, respectively. NAT testing variably reduced RR ranging from 69.4% to 96.1% depending on TTID. Younger, repeat and voluntary donors had significantly lower prevalence of TTIDs compared to older, first time and replacement donors. Gaps in the blood safety could be bridged significantly by implementing NAT testing and using quality serological assays. Comparatively high RR despite using quality serological assays and ID-NAT testing highlights need to develop long term strategies to improve blood safety by focusing on improving donor pool by recruiting regular voluntary donors among youth and imparting knowledge of healthy practices.

Alternative hepatitis B virus DNA confirmatory algorithm identified occult hepatitis B virus infection in Chinese blood donors with non-discriminatory nucleic acid testing.

Multiplex viral nucleic acid testing (NAT) and a discriminatory testing algorithm have been used to detect viral infections in blood donors. Non-discriminated reactive (NDR) results may arise from low hepatitis B virus (HBV) DNA levels and are challenging for donor management by blood services. The aim of this study was to evaluate the performance and feasibility of alternative viral particle concentration methods to confirm and to characterise HBV infection status in NDR donors from Dalian, China, in order to improve routine donor management according to the potential residual risk estimate. Individual donations were tested with ULTRIO Plus, and discriminated when reactive. Virions were concentrated from 12 and 6 mL plasma samples by ultracentrifugation (UC) and polyethylene glycol (PEG) precipitation, respectively. HBV DNA was detected with four nested polymerase chain reactions (95% limit of detection: 5-25 IU/mL). Amplified products were sequenced for definitive confirmation. Anti-HBc and anti-HBs were tested. Of 77,556 donors, 79 (0.1%) were NAT NDR. After viral particle concentration by UC and PEG precipitation, HBV DNA was detected in 46 (58.2%) and 34 (43.0%) NDR donors, respectively, including 61.7% of samples that were repeatedly non-reactive with multiple NAT testing. Anti-HBc and anti-HBs (median titre: 37 mIU/mL) were detected in 87.3% and 46.8% of NDR donors, respectively. Sequencing confirmed HBV DNA in 65.8% of NDR donors, of whom 96.2% were occult HBV carriers with rare mutations in S and core proteins. A HBV DNA confirmatory procedure with limited technical constraints was implemented successfully. The majority of NDR donors had occult HBV infections with extremely low viral DNA levels, which may constitute a potential residual threat for blood safety. Only a minority of anti-HBc+ NDR donors had anti-HBs levels high enough to consider their reinstatement as donors. The data support the permanent deferral of NDR donors to ensure maximum blood safety in areas of high HBV endemicity.

Frequency of Sexually Transmitted Diseases in Pakistani Blood Donors

Objective: To determine the frequency of HIV and syphilis infection among Pakistani blood donors presenting to blood transfusion services of Shifa International Hospital (SIH) Islamabad through serological testing and to determine accuracy of serological testing for Human Immunodeficiency Virus (HIV) taking nucleic acid testing (NAT) as gold standard. Methodology: Present study was a descriptive cross-sectional, conducted at SIH Islamabad over a period of six months (July- December 2016). A total of five thousand one hundred and seven (n=5,107) adult blood donors were enrolled and underwent serological testing for syphilis. For HIV, serology was performed followed by NAT screening. Results: There were 1.3% (n=68/5107) donors came out to be serologically positive for syphilis with a yield of 1:75 or 14686 donors per million. There were 0.2% (n=12/5107) donors came out to be serologically HIV positive with a yield of 1:426 or n=2350 donors per million. All HIV patients on NAT testing proved to be negative for HIV. Conclusions: A remarkable proportion of blood donors presented at our institute during the study period harbored STD, which can be detected through meticulous and stringent screening of blood donors. NAT has an incremental value in identifying false positive HIV cases on serological testing.

An Overview of Nucleic Acid Testing for the Novel Coronavirus SARS-CoV-2.

In this note we analyze the problems in the nucleic acid testing (NAT) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and we also give some suggestions for improving the accuracy of NAT diagnosis. NAT testing is considered to be the diagnostic “gold standard”; at present there are few reviews on NAT for SARS-CoV-2. Moreover, many false-negative results always appear in the procedure of detecting, which has affected early diagnosis of the disease and brought a great challenge to mitigation and containment of the pandemic. In conclusion, comprehensive analyses of serological and imaging findings should be performed to guide the formulation of an accurate clinical diagnosis, treatment plan, and monitoring therapeutic efficacy, in an effort to achieve early diagnosis, containment, and treatment of the disease, thereby effectively reducing progression of the pandemic. This article presents a literature overview of SARS-CoV-2 nucleic acid testing, aiming to provide support for clinicians.

Antibody dynamics to SARS-CoV-2 in asymptomatic COVID-19 infections.

BackgroundThe missing asymptomatic COVID‐19 infections have been overlooked because of the imperfect sensitivity of the nucleic acid testing (NAT). Globally understanding the humoral immunity in asymptomatic carriers will provide scientific knowledge for developing serological tests, improving early identification, and implementing more rational control strategies against the pandemic.MeasureUtilizing both NAT and commercial kits for serum IgM and IgG antibodies, we extensively screened 11 766 epidemiologically suspected individuals on enrollment and 63 asymptomatic individuals were detected and recruited. Sixty‐three healthy individuals and 51 mild patients without any preexisting conditions were set as controls. Serum IgM and IgG profiles were further probed using a SARS‐CoV‐2 proteome microarray, and neutralizing antibody was detected by a pseudotyped virus neutralization assay system. The dynamics of antibodies were analyzed with exposure time or symptoms onset.ResultsA combination test of NAT and serological testing for IgM antibody discovered 55.5% of the total of 63 asymptomatic infections, which significantly raises the detection sensitivity when compared with the NAT alone (19%). Serum proteome microarray analysis demonstrated that asymptomatics mainly produced IgM and IgG antibodies against S1 and N proteins out of 20 proteins of SARS‐CoV‐2. Different from strong and persistent N‐specific antibodies, S1‐specific IgM responses, which evolved in asymptomatic individuals as early as the seventh day after exposure, peaked on days from 17 days to 25 days, and then disappeared in two months, might be used as an early diagnostic biomarker. 11.8% (6/51) mild patients and 38.1% (24/63) asymptomatic individuals did not produce neutralizing antibody. In particular, neutralizing antibody in asymptomatics gradually vanished in two months.ConclusionOur findings might have important implications for the definition of asymptomatic COVID‐19 infections, diagnosis, serological survey, public health, and immunization strategies.

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.

Serologic Detection of SARS-CoV-2 Infections in Hemodialysis Centers: A Multicenter Retrospective Study in Wuhan, China

Rationale & ObjectivePatients receiving maintenance hemodialysis (MHD) are highly vulnerable to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current study was designed to evaluate the prevalence of SARS-CoV-2 infection based on both nucleic acid testing (NAT) and antibody testing in Chinese patients receiving MHD.Study DesignCross-sectional study.Setting & ParticipantsFrom December 1, 2019, to March 31, 2020, a total of 1,027 MHD patients in 5 large hemodialysis centers in Wuhan, China, were enrolled. Patients were screened for SARS-CoV-2 infection by symptoms and initial computed tomography (CT) of the chest. If patients developed symptoms after the initial screening was negative, repeat CT was performed. Patients suspected of being infected with SARS-CoV-2 were tested with 2 consecutive throat swabs for viral RNA. In mid-March 2020, antibody testing for SARS-CoV-2 was obtained for all MHD patients.ExposureNAT and antibody testing results for SARS-CoV-2.OutcomesMorbidity, clinical features, and laboratory and radiologic findings.Analytical ApproachDifferences between groups were examined using t test or Mann-Whitney U test, comparing those not infected with those infected and comparing those with infection detected using NAT with those with infection detected by positive serology test results.ResultsAmong 1,027 patients receiving MHD, 99 were identified as having SARS-CoV-2 infection, for a prevalence of 9.6%. Among the 99 cases, 52 (53%) were initially diagnosed with SARS-CoV-2 infection by positive NAT; 47 (47%) were identified later by positive immunoglobulin G (IgG) or IgM antibodies against SARS-CoV-2. There was a spectrum of antibody profiles in these 47 patients: IgM antibodies in 5 (11%), IgG antibodies in 35 (74%), and both IgM and IgG antibodies in 7 (15%). Of the 99 cases, 51% were asymptomatic during the epidemic; 61% had ground-glass or patchy opacities on CT of the chest compared with 11.6% among uninfected patients (P < 0.001). Patients with hypertensive kidney disease were more often found to have SARS-CoV-2 infection and were more likely to be symptomatic than patients with another primary cause of kidney failure.LimitationsPossible false-positive and false-negative results for both NAT and antibody testing; possible lack of generalizability to other dialysis populations.ConclusionsHalf the SARS-CoV-2 infections in patients receiving MHD were subclinical and were not identified by universal CT of the chest and selective NAT. Serologic testing may help evaluate the overall prevalence and understand the diversity of clinical courses among patients receiving MHD who are infected with SARS-CoV-2.

Three Years of Shared Service HIV Nucleic Acid Testing for Public Health Laboratories: Worthwhile for HIV-1 but Not for HIV-2.

In 2016, HIV-2 nucleic acid testing (NAT) was added to a shared service program that conducts HIV-1 NAT for public health laboratories performing the recommended algorithm for diagnosing HIV. Here, we evaluate the usefulness of HIV-2 NAT in this program as compared with HIV-1 NAT. Specimens eligible for HIV-1 NAT were reactive on an HIV-1/2 antibody or antigen/antibody initial test and nonreactive or indeterminate on a supplemental antibody test or were reactive for HIV-1 antigen-only on an HIV-1/2 antigen/antibody initial test. Specimens eligible for HIV-2 NAT were reactive on an initial test, HIV-2 indeterminate or HIV indeterminate on a supplemental antibody test and had no detectable HIV-1 RNA or were reactive for HIV-2 antibody on an HIV-1/2 antigen/antibody test, and this reactivity was not confirmed with a supplemental antibody assay. All specimens were tested in a reference laboratory using APTIMA HIV-1 qualitative RNA and/or a validated qualitative HIV-2 RNA real-time PCR assay. During 2016 to 2019, HIV-1 RNA was detected in 234 (14%) of 1731 specimens tested. HIV-2 RNA was not detected in 52 specimens tested. Median time from specimen collection to reporting of HIV-1 and HIV-2 NAT results by year ranged from 9 to 10 days and from 22 to 27 days, respectively. Two specimens with HIV-2 indeterminate results on a supplemental antibody test had detectable HIV-1 RNA. A shared service model for HIV-1 NAT is both feasible and beneficial for public health laboratories. However, because no HIV-2 infections were detected, our data suggest that this program should reconsider the usefulness of HIV-2 NAT testing.

COVID-19: A global transplant perspective on successfully navigating a pandemic.

The COVID‐19 pandemic has rapidly evolved and changed our way of life in an unprecedented manner. The emergence of COVID‐19 has impacted transplantation worldwide. The impact has not been just restricted to issues pertaining to donors or recipients, but also health‐care resource utilization as the intensity of cases in certain jurisdictions exceeds available capacity. Here we provide a personal viewpoint representing different jurisdictions from around the world in order to outline the impact of the current COVID‐19 pandemic on organ transplantation. Based on our collective experience, we discuss mitigation strategies such as donor screening, resource planning, and a staged approach to transplant volume considerations as local resource issues demand. We also discuss issues related to transplant‐related research during the pandemic, the role of transplant infectious diseases, and the influence of transplant societies for education and disseminating current information.

Usefulness of nucleic acid testing among negative HBs Ag blood donors in Egypt

IntroductionHepatitis B viral infection has been transmitted from donors with HBV infections who have negative HBs Ag. Many countries have implemented nucleic acid testing (NAT) to screen donors with non- reactive HBs Ag for detection of HBV DNA and enhance safety of blood transfusion, while it is restricted to limited blood banks in Egypt. ObjectiveTo evaluate the significance of NAT technology in detection of HBV DNA in the Egyptian blood donors with HBs Ag non- reactivity. MethodsThe study included 36,584 collected blood samples from volunteer blood donors at the blood bank of Zagazig University Hospitals. Each specimen was tested for HBs Ag; non- reactive sera were further tested for qualitative detection of HBV-DNA by NAT testing. All positive HBV-DNA donors were tested for anti- HBc and anti- HBs by electro-chemiluminescence immunoassay and confirmed by quantitative RT-PCR. ResultsAmong 34,671 donors non-reactive to HBs Ag, 34,657 (99.96%) were tested negative for HBV- DNA and 14 specimens (0.04%) were positive for HBV via NAT testing. Among HBV NAT positive donors, HBs Ab reactive only in (2); HBc Ab reactive only in (3); HBs and HBc Abs reactive in (3) while HBs and HBc Ab non-reactive in (6). All tested sera 14 (100%) showed low viral load for HBV (<50 IU/ml) confirmed by RT- qPCR. ConclusionOur results highlighted the significance of the HBV NAT technique to reduce the potential risk of HBV transfusion-transmission and the critical need to enforce the usage of NAT technology in all blood banks in Egypt.

ASSESSING NUCLEIC ACID TESTING VERSUS ELIZA FOR BLOOD VIRUSES DETECTION IN SOME BLOOD BANKS

INTRODUCTION: The goal of any transfusion service is to provide adequate and safe blood and blood products that meet the needs of patients. Transfusion-transmissible viral infections, such as hepatitis C virus (HCV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV), remain a major public health problem in developing countries. Nucleic acid testing (NAT) is a molecular technique for screening blood donations to reduce the risk of transfusion transmitted infections (TTIs) in the recipients, thus providing an additional layer of blood safety. AIM OF THE WORK: To assess the importance of implementing NAT assay to detect donors during window period which are not detected with Enzyme-linked immunoassay (ELISA). SUBJECTS AND METHODS: This cross sectional study was conducted at the Egyptian Abbassia regional Blood Transfusion center (ARBTC) at Abbassia, Cairo. Blood donation collected from 10000 voluntary donors from January 2016 to June 2016 and tested with both ID NAT and ELISA assays for HBV, HCV and HIV. RESULTS: NAT testing has the potential to detect viral nucleic acids of HIV 1-2, HBV, and HCV earlier than current screening methods. CONCLUSION: The implementation of NAT screening for three viruses has improved blood safety and reduced transfusion-transmitted infections.

Brief Report: The Amsterdam Symptom and Risk-Based Score Predicts for Acute HIV Infection in Men Who Have Sex With Men in San Diego.

Dijkstra et al recently described a risk- and symptom-based score moderately predictive for HIV seroconversion in the preceding 6-12 months in men who have sex with men (MSM) in Amsterdam. Our objective was to determine whether this "Amsterdam Score" could also predict for acute HIV infection (AHI) in MSM. This study is a case-control analysis of a prospectively enrolled cohort of MSM who voluntarily presented for HIV testing in San Diego. The study sample was composed of MSM who screened HIV antibody-negative and then either tested positive with AHI [HIV nucleic acid test (NAT)-positive] or tested HIV NAT-negative. The Amsterdam Score was calculated for each participant in the study sample. Score performance was assessed using receiver operating characteristic curves and their area under the curve (AUC). An optimal cutoff was determined using the Youden index. Seven hundred fifty-seven MSM (110 AHI and 647 HIV NAT-negative) were included in the analysis. AHI and HIV-negative cases were similar in age [median 32 years (interquartile range 26-42) vs 33 (27-45), respectively, P = 0.082]. The Amsterdam Score yielded a receiver operating characteristic curve with an AUC of 0.88 (95% confidence interval: 0.84 to 0.91). An optimal cutoff of ≥1.6 was 78.2% sensitive and 81.0% specific. The risk- and symptom-based Amsterdam Score was highly predictive (AUC of 0.88) of AHI in MSM in San Diego. The Amsterdam Score could be used to target NAT utilization in resource-poor settings among MSM who test HIV antibody-negative, although the potential cost-savings must be balanced with the risk of missing AHI diagnoses.

Inclusion of Seromarkers to Exclude Hepatitis B Virus Infection via Transfusion in Voluntary Blood Donors

Introduction: Hepatitis B Virus (HBV) infection is a serious viral infection causes acute and chronic hepatitis. Transfusion of blood and blood products is the predominant route of transmission of HBV. As per NACO guidelines, in India, donor blood is screened for HBsAg, anti-HCV antibodies, anti-HIV antibodies; slide/card rapid screening for malarial parasites and VDRL for Syphilis.Blood banks in India are only equipped to carry out rapid card test or ELISA for routine screening of HBV, HCV and HIV infections. In developed countries use Nucleic Acid Testing (NAT) were in place for screening and diagnosis of viral infections during window period. NAT assays are highly sensitive, specific and robust but require skilled manpower and specialized infrastructure and thus may not be cost-effective.Objectives: To explore the current sero-prevalence of HBsAg, Anti-HCV antibodies and anti-HIV antibodies (and other relevant seromarkers) by routine screening tests in a cohort of voluntary blood donors and to determine the efficiency of NAT over the routinely used rapid card and ELISA tests. To include any additional seromarker of HBV infection to detect the antigen in the window period.Methods: In this cross-sectional observational study, 3160 voluntary blood donors were screened for HBsAg. Samples were also subjected to screening of additional seromarkers such as HbeAg, anti-HBs and anti-HBc antibodies. Thirty samples were randomly selected from each HBsAg positive and HBsAg negative groups and were subjected to HBV DNA PCR for viral load estimation.Results: ELISA testing is more specific than rapid card test in detecting HBV infection, whereas NAT testing was beneficial in identification of added HBV infection. Both ELISA and rapid card test methods were found to be equally sensitive and specific in diagnosing HCV and HIV infections. NAT testing did not yield any significant increase in positive results compared to serological/rapid methods. HBeAg was found to be positive in 2 samples which are tested negative for HBsAg. HBV DNA was also found to be positive in one sample which is negative for HBsAg (1 out of 30), which might be cryptic HBV infection.Conclusion: Though NAT would be the choice of screening for Hepatitis B, it not cost-effective. Therefore, inclusion of one or more seromarkers for screening HBV, such as HBeAg, might be helpful in preventing transfusion transmitted infection.

Is Kidney Donor Profile Index (KDPI) Valid for Hepatitis C Aviremic Kidneys?

The Kidney Donor Risk Index (KDRI) and Kidney Donor Profile Index (KDPI) assist clinicians with the selection of deceased donor kidneys. This scoring system is based on 10 donor factors including Hepatitis C virus (HCV) status from serological or NAT testing. The donor HCV status (i.e., having either a positive hepatitis C antibody (Ab) or nucleic acid testing (NAT) result) increases the hazard ratio for graft failure by 1.27 and the KDPI by approximately 20%. Whether this increase in KDPI is a true reflection of graft quality for HCV seropositive but not viremic donors is unknown. Further investigations are needed to maximize the use of these organs.

Organ Donation in the Era of the Opioid Crisis

Organ Donation in the Era of the Opioid Crisis

Optimal pooling strategies for nucleic acid testing of donated blood considering viral load growth curves and donor characteristics

ABSTRACTBlood products are vital to healthcare, and their safety, in terms of being free of transfusion-transmittable infections (TTIs), is crucial. Unlike serological assays that screen for antibodies and antigens, Nucleic Acid Testing (NAT) technology screens for genetic material, enabling an earlier detection of the infection. However, because NAT is more expensive than serological testing, most blood centers administer NAT to pools of blood samples from multiple donors. This reduces the testing cost, but also decreases the test's sensitivity due to a dilution effect. Further, first-time donors typically have higher prevalence rates than repeat donors, and therefore, a flexible, non-universal strategy which allows first-time donors to undergo more extensive screening may reduce the TTI risk in transfusion recipients. Since some donor characteristics are uncertain, we develop a chance-constrained model that determines the optimal NAT pool sizes for the various TTIs, considering both non-universal and universal (i.e., common testing for all donors) strategies, so as to minimize the TTI risk while remaining within the testing budget with a high probability. Our case study of the United States quantifies the risk reduction benefit of non-universal NAT testing schemes over current practice.

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.