Fecal microbiota transplantation: current challenges and future landscapes.

SUMMARYGiven the importance of gut microbial homeostasis in maintaining health, there has been considerable interest in developing innovative therapeutic strategies for restoring gut microbiota. One such approach, fecal microbiota transplantation (FMT), is the main "whole gut microbiome replacement" strategy and has been integrated into clinical practice guidelines for treating recurrent Clostridioides difficile infection (rCDI). Furthermore, the potential application of FMT in other indications such as inflammatory bowel disease (IBD), metabolic syndrome, and solid tumor malignancies is an area of intense interest and active research. However, the complex and variable nature of FMT makes it challenging to address its precise functionality and to assess clinical efficacy and safety in different disease contexts. In this review, we outline clinical applications, efficacy, durability, and safety of FMT and provide a comprehensive assessment of its procedural and administration aspects. The clinical applications of FMT in children and cancer immunotherapy are also described. We focus on data from human studies in IBD in contrast with rCDI to delineate the putative mechanisms of this treatment in IBD as a model, including colonization resistance and functional restoration through bacterial engraftment, modulating effects of virome/phageome, gut metabolome and host interactions, and immunoregulatory actions of FMT. Furthermore, we comprehensively review omics technologies, metagenomic approaches, and bioinformatics pipelines to characterize complex microbial communities and discuss their limitations. FMT regulatory challenges, ethical considerations, and pharmacomicrobiomics are also highlighted to shed light on future development of tailored microbiome-based therapeutics.

Improved efficiency using sequential automated immunoassays for syphilis screening in blood donors.

Using sequential immunoassays for the screening of blood donors is well described for viral serology testing but not for the screening of syphilis. In this study, we report the evaluation results and 2-year sequential testing data using two highly sensitive automated serology assays, the Alinity s Syphilis chemiluminescent immunoassay for screening, with all repeatedly reactive samples then tested on the Elecsys Syphilis electrochemiluminescence immunoassay. We screened 1,767,782 blood donor samples between 7 July 2021 and 6 July 2023 and found the Alinity false-positive rate to be low at 0.08% (1,456/1,767,782). The common false-positive rate between the two assays was also low (3.83%, 58/1,514). Concordantly reactive samples were further tested using a Treponema pallidum particle agglutination test, a rapid plasma reagin test, and a fluorescent treponemal antibody absorption test. There were 262/1,376 concordantly reactive Alinity and Elecsys blood donor samples with reactivity on one or more of the confirmatory tests. A total of 26/1,376 donors had a current syphilis infection, 152/1,376 reported a past history of syphilis and had been treated, and 84/1,376 did not report a past history of syphilis. We suggest that future studies could explore the use of sequential immunoassays to aid in the serodiagnosis for syphilis. IMPORTANCE: The serodiagnosis for syphilis usually follows two methodologies-a "traditional" algorithm using a non-treponemal test followed by confirmation using a treponemal test, or a "reverse" algorithm using a treponemal test followed by a non-treponemal test. There are limited reports in the literature of using a modified reverse algorithm (treponemal test followed by a second treponemal test), and to the best of knowledge, there are currently no published articles using two highly sensitive automated immunoassays to aid the serodiagnosis of syphilis. In addition, the Treponema pallidum particle agglutination (TPPA) assay is commonly used as a confirmatory test for the diagnosis of syphilis. With the withdrawal of the TPPA assay from Australia and presumably from the global market also, alternative testing algorithms are now required. This study provides proof of concept for using sequential immunoassays in the diagnosis of syphilis.

The question of screening organ donors for hepatitis e virus: a case report of transmission by kidney transplantation in France and a review of the literature.

BACKGROUND: Hepatitis E is a potentially serious infection in organ recipients, with an estimated two-thirds of cases becoming chronic, and with a subsequent risk of cirrhosis and death. In Europe, transmission occurs most often through the consumption of raw or undercooked pork, more rarely through blood transfusion, but also after solid organ transplantation. Here we describe a case of Hepatitis E virus (HEV) infection transmitted following kidney transplantation and review the literature describing cases of HEV infection transmitted by solid organ transplantation. CASE PRESENTATION: Three weeks after kidney transplantation, the patient presented with an isolated minimal increase in GGT and hepatic cytolysis 6 months later, leading to the diagnosis of genotype 3c hepatitis E, with a plasma viral load of 6.5 log10IU/mL. In retrospect, HEV RNA was detected in the patient's serum from the onset of hepatitis, and in the donor's serum on the day of donation, with 100% identity between the viral sequences, confirming donor-derived HEV infection. Hepatitis E had a chronic course, was treated by ribavirin, and relapsed 10 months after the end of treatment. DISCUSSION: Seven cases of transmission of HEV by solid organ transplantation have been described since 2012 without systematic screening for donors, all diagnosed at the chronic infection stage; two patients died. HEV organ donor transmission may be underestimated and there is insufficient focus on immunocompromised patients in whom mild liver function test impairment is potentially related to hepatitis E. However, since HEV infection is potentially severe in these patients, and as evidence accumulates, we believe that systematic screening of organ donors should be implemented for deceased and living donors regardless of liver function abnormalities, as is already the case in the UK and Spain. In January 2024, the French regulatory agency of transplantation has implemented mandatory screening of organ donors for HEV RNA.

Advancing gender inclusivity for Two-Spirit, trans, nonbinary and other gender-diverse blood and plasma donors.

BACKGROUND AND OBJECTIVES: Two-Spirit, trans, nonbinary and other gender-diverse (2STGD) donors face challenges in donation. While many blood operators aim to address these challenges, to date, no empirical study with these donors has been conducted to guide their efforts. This paper reports 2STGD donors' views on a two-step approach asking donors their gender and sex assigned at birth (SAAB), and expanding gender options in donor registration. MATERIALS AND METHODS: A qualitative community-based study was conducted with 2STGD donors (n = 85) in Canada. Semi-structured, in-depth interviews were conducted from July to October 2022, audio-recorded and transcribed. Data were analysed using a thematic analytic framework. RESULTS: Participants were divided on their views of a two-step approach asking gender and SAAB. Themes underlying views in favour of this approach included the following: demonstrating validation and visibility, and treating 2STGD donors and cisgender donors alike. Themes underlying views not in favour or uncertain included potential for harm, compromising physical safety, and invalidation. All participants were in favour of expanding gender options if blood operators must know donors' gender. CONCLUSION: Results indicate that a two-step approach for all donors is not recommended unless the blood operator must know both a donor's gender and SAAB to ensure donor and/or recipient safety. Gender options should be expanded beyond binary options. Ongoing research and evidence synthesis are needed to determine how best to apply donor safety measures to nonbinary donors.

Trends in immunological markers of transfusion transmissible infections among blood donors in Mamfe District Hospital, Southwest Cameroon.

BACKGROUND: Blood transfusion is associated with exposure to blood Transfusion Transmissible Infection (TTIs). The threat posed by the blood-borne pathogens is disproportionately distributed in different healthcare facilities in Cameroon. Thus, there is a need for continuous surveillance of TTIs in the country. This study aimed to assess the screening procedure for blood transfusion and determine the trend in immunological markers of TTIs among blood donors at the Mamfe District Hospital. METHODS: A prospective descriptive, cross-sectional and analytical study was conducted at Mamfe District Hospital from March to May 2022. A total of 165 blood donors were recruited by the consecutive sampling method. Donors were screened using both Rapid diagnostic tests,T. pallidum haemagglutination test and indirect enzyme-linked immunosorbent assay (ELISA) for the detection of TTIs. Data generated was entered into an Excel spreadsheet and analysed using the statistical software R, version 4.2.0. Statistical analysis included descriptive statistics of percentages, means ± standard deviation, and student t-test was used to compare both diagnostic techniques, and was considered significant when p < 0.05. RESULTS: A hundred and sixty-five donors were enrolled in the study with a male preponderance giving a male-female sex ratio of 22.5 and a mean age of 32.23 ± 8.60 years. The majority (75.2%) of the donors were of the O-positive blood type, repeat donors (69.1%) and were mainly family replacement and paid donors as against the voluntary blood donors (39.4% and 37.0% vs. 23.6% respectively). overall TTIs prevalence was 18.78% (31/165) (), with HBsAg being the most predominant marker at 12.12% (20/165) followed by Treponema pallidum, HCV and HIV antibodies at 4.85 (8/165), 1.21%(2/165), 0.60% (1/165) respectively. Except for the HBV, The prevalence of TTIs was higher when using a single RDT than the ELISA test, and the difference was significant (p < 0.05). CONCLUSION: Bloodborne pathogens remain a major menace to safe blood transfusion practice in Mamfe district hospital and their detection could be easily missed if the RDT method alone is used for donor screening. Therefore, the donor screening protocol in Mamfe District Hospital should systematically incorporate a confirmation diagnostic test such as ELISA.

Risk and benefits of expanded donor screening: A viewpoint from Germany.

This review describes the risks and benefits of expanding screening for transmissible pathogens in deceased organ donors. The focus is on the experience and procedure in Germany to make a decision on how to proceed with a possible donor. Three issues are of interest in how screening policies impact the process with the aim of mitigating unexpected transmission risks: (1) Should we add universal or targeted nucleic acid testing to serological tests for common blood-borne viruses (BBVs; HIV, HBV, and HCV)? (2) Which tests should be added for screening in a geographically restricted region beyond testing for these BBVs? (3) Being faced with changes (e.g., climate and population) in the own geographically restricted region, what strategies are needed before implementing new tests, and which considerations apply for proper indication to do this? Testing may only be effective when during donor characterization the appropriate conclusions are drawn from the existing findings and screening tests are initiated. This statement overlaps the need to implement universal screening for a pathogen or targeted screening based on the risk that the donor has acquired the transmissible pathogen or is not as possible to identify by current methods of clinical judgment and/or specific tests.

The American Association of Tissue Banks tissue donor screening for Mycobacterium tuberculosis-Recommended criteria and literature review.

After two multistate outbreaks of allograft tissue-transmitted tuberculosis (TB) due to viable bone, evidence-based donor screening criteria were developed to decrease the risk of transmission to recipients. Exclusionary criteria, commentary, and references supporting the criteria are provided, based on literature search and expert opinion. Both exposure and reactivation risk factors were considered, either for absolute exclusion or for exclusion in combination with multiple risk factors. A criteria subset was devised for tissues containing viable cells. Risk factors for consideration included exposure (e.g., geographic birth and residence, travel, homelessness, incarceration, healthcare, and workplace) and reactivation (e.g., kidney disease, liver disease, history of transplantation, immunosuppressive medications, and age). Additional donor considerations include the possibility of sepsis and chronic illness. Donor screening criteria represent minimal criteria for exclusion and do not completely exclude all possible donor TB risks. Additional measures to reduce transmission risk, such as donor and product testing, are discussed but not included in the recommendations. Careful donor evaluation is critical to tissue safety.

A Multiplex Assay to Assess the Transaminase Activity toward Chemically Diverse Amine Donors.

The development of methods to engineer and immobilize amine transaminases (ATAs) to improve their functionality and operational stability is gaining momentum. The quest for robust, fast, and easy-to-use methods to screen the activity of large collections of transaminases, is essential. This work presents a novel and multiplex fluorescence-based kinetic assay to assess ATA activity using 4-dimethylamino-1-naphthaldehyde as an amine acceptor. The developed assay allowed us to screen a battery of amine donors using free and immobilized ATAs from different microbial sources as biocatalysts. As a result, using chromatographic methods, 4-hydroxybenzylamine was identified as the best amine donor for the amination of 5-(hydroxymethyl)furfural. Finally, we adapted this method to determine the apparent Michaelis-Menten parameters of a model immobilized ATA at the microscopic (single-particle) level. Our studies promote the use of this multiplex, multidimensional assay to screen ATAs for further improvement.

Alternatives to blood donor deferral of gay, bisexual, and other men who have sex with men: Acceptability of screening the sexual risk behavior of all blood donors.

BACKGROUND: Blood operators screen donors to reduce the risk of transfusion-transmitted infections (TTIs). Many are evolving screening procedures from those that defer all who have had a sexual interaction with gay, bisexual, or other men who have sex with men (gbMSM) to an approach that assesses individual donors' recent sexual risk behavior with any partner. STUDY DESIGN AND METHODS: A representative sample of current blood donors (N = 1194) was recruited online and randomized to complete either the existing (at the time of the study) Canadian Blood Services' donor questionnaire (DQ) that screens out those with recent gbMSM sexual experience, a modified donor questionnaire (MDQ) that assesses individuals' recent sexual behavior with any partner, or an MDQ that assesses individual sexual behavior with any partner and explains why these questions are asked. Respondents were asked for their perceptions concerning difficulty, comfort, and acceptability of these screening questionnaires. RESULTS: Across experimental conditions, current donors regarded screening questionnaire difficulty to be low; discomfort in responding was minimal; screening questionnaires were perceived to be relatively inoffensive and justified, and very few donors would cease donating if the screening questionnaire they responded to became the one in general use. Some minor sex differences were observed, and in some cases, perceptions of the MDQ with explanation were somewhat more positive than those of the DQ and MDQ without explanation. DISCUSSION: An individual risk behavior screening approach appears to be acceptable to current blood donors as an alternative to screening out all who have recently engaged in gbMSM sexual interactions.

Second hepatitis C virus transmission by blood components since introduction of mandatory NAT screening in Germany.

BACKGROUND: Viral safety of blood products in Germany has improved significantly over the last two decades. We describe the second documented transfusion-transmitted (TT) episode for the hepatitis C virus (HCV) in Germany since mandatory nucleic acid amplification techniques (NAT) screening was introduced in 1999. STUDY DESIGN AND METHODS: When a repeat donor who had tested negative for anti-HCV tested positive for HCV RNA by NAT in a minipool (MP) of eight, a look-back procedure was initiated. Qualitative, quantitative and genotyping assays were used to investigate the titers of the quarantined fresh frozen plasma (FFP) from the donor and a serum sample from the recipient of the pooled platelet concentrate (PPC). Amplified products of 5'UTR and HVR1 were used for sequence comparison to characterize the HCV genomic identity of donor and recipient samples. RESULTS: All NAT tests utilized in this procedure were able to detect a low HCV RNA titer (~15 IU/ml) in the FFP from the donation. Dilution of FFP by factor 8 was performed to mimic an MP, and the detection rate correlated well with the claimed sensitivity of the tests. Analysis of donor and recipient samples revealed genotype 3a viral transmission confirmed by sequence analysis. CONCLUSION: This TT HCV case could have been prevented by individual donation (ID) NAT. However, a low titer blood donation in the window period (WP) is very rare. Residual risk calculation for TT HCV in the WP revealed that, compared to MP-NAT testing, ID-NAT would improve blood safety only marginally.

Physical Examination of Potential Deceased Organ and Tissue Donors: An Overview of the European Landscape.

Physical examination (PE) of donors is essential to identify potential risks to the safety and efficacy of donated organs and tissues and is mandatory in the EU. However, no detailed guidance is available as to how PE should be performed. Health authorities (HA) and health professionals (HP) in member states of the European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) and observer countries completed surveys relating to the regulatory requirements for PE and the professional practice of PE in their countries for organ and tissue donors. The HA survey addressed regulatory aspects, and the HP survey addressed professional practices, training, and respondents' opinions on the value of PE. These surveys revealed significant inter-country variation in the regulatory approach to PE and the performance of PE by professionals. Most respondents opined that PE was important and yielded valuable information in identifying contraindications to donation. There is no consensus at a regulatory or professional level as to how PE should be performed on organ and tissue donors. There is a requirement for agreed best practice guidelines in this area.

Impact of Hepatitis E Virus Screening in the UK Deceased Organ Donor Population.

Universal Hepatitis E Virus (HEV) screening of deceased organ donors was implemented by the UK national organ procurement organisation in October 2017. Donor testing for HEV infection is done post-transplant; detection of HEV ribonucleic acid (RNA) in donor plasma is therefore not a contra-indication for organ donation, with the result being used to inform recipient management. Immediate post-transplant detection of donor HEV viraemia triggers notification to transplant centres. Follow up of liver and kidney recipients has shown that transmission through solid organs is very efficient, particularly through liver grafts, as expected; no other organ types were transplanted in this cohort. Although donors with higher plasma viral load (VL > 103 IU/mL) were invariably associated with recipient infection, transmission was also documented at lower VL levels. Knowledge of donor HEV status has led to identification of transmission of infection via solid organ grafts followed by close patient monitoring and informed clinical management decisions. The purpose of this strategy is to allow early detection of infection and recurrence and treatment to circumvent the risk of accelerated liver damage from chronic HEV infection due to undiagnosed, inadvertent donor-derived transmission of infection.

West Nile Virus Transmission by Solid Organ Transplantation and Considerations for Organ Donor Screening Practices, United States.

West Nile virus (WNV) is the most common domestic arbovirus in the United States. During 2018, WNV was transmitted through solid organ transplantation to 2 recipients who had neuroinvasive disease develop. Because of increased illness and death in transplant recipients, organ procurement organizations should consider screening during region-specific WNV transmission months.

Effect of Hepatitis E Virus RNA Universal Blood Donor Screening, Catalonia, Spain, 2017‒2020.

Hepatitis E virus (HEV) is the major cause of acute viral hepatitis in several countries in Europe. HEV is acquired mainly by consumption of contaminated pork but can also be transmitted through blood transfusion. HEV infection is usually self-limited but can become persistent in immunocompromised persons. During the first 30 months of HEV RNA universal screening of blood donations in Catalonia, Spain, we identified 151 HEV RNA-positive donations (1/4,341 blood donations). Most infected donors reported consumption of pates and sausages, and 58% were negative for HEV IgM and IgG. All HEV isolates belonged to genotype 3. All infected donors spontaneously resolved the infection, and no neurologic symptoms and reinfections were observed after 1 year of follow-up. Since the implementation of HEV RNA universal screening, no new cases of transfusion-transmitted HEV infection were reported. Our data indicate HEV screening of blood donations provides safer blood for all recipients, especially for immunosuppressed persons.

Risk of transfusion-transmitted hepatitis E virus infection from pool-tested platelets and plasma.

BACKGROUND AND AIMS: Immunocompromised patients are at risk of chronic hepatitis E which can be acquired by blood transfusions. Currently, screening of blood donors (BDs) for HEV RNA with a limit of detection (LOD) of 2,000 IU/ml is required in Germany. However, this may result in up to 440,000 IU of HEV RNA in blood products depending on their plasma volume. We studied the residual risk of transfusion-transmitted (tt) HEV infection when an LOD of 2,000 IU/ml is applied. METHODS: Highly sensitive individual donor testing for HEV RNA on the Grifols Procleix Panther system (LOD 7.89 IU/ml) was performed. HEV loads were quantified by real-time PCR. RESULTS: Of 16,236 donors, 31 (0.19%) were HEV RNA positive. Three BDs had viral loads between 710 and 2,000 IU/ml, which pose a significant risk of tt hepatitis E with any type of blood product. Eight BDs had viral loads of >32 to 710 IU/ml, which pose a risk of tt hepatitis E with platelet or plasma transfusions because of their higher plasma volume compared to red blood cell concentrates. Eight of these 11 potentially infectious BDs were seronegative for HEV, indicating a recent infection. Only 8 of 31 donors had viral loads >2,000 IU/ml that would also have been detected by the required screening procedure and 12 had very low HEV loads (<32 IU/ml). CONCLUSIONS: Screening of BDs with an LOD of 2,000 IU/ml reduced the risk of tt HEV infection by about 73% for red blood cell concentrates but by just 42% for platelet and fresh frozen plasma transfusions. Single donor screening (LOD <32 IU/ml) should lead to an almost 100% risk reduction. LAY SUMMARY: Immunocompromised patients, such as solid organ or hematopoietic stem cell recipients, are at risk of chronic hepatitis E, which can be acquired via blood transfusions. The risk of transfusion-transmitted hepatitis E in these patients may not be sufficiently controlled by (mini-)pool hepatitis E virus RNA screening of blood donors. Single donor screening should be considered to improve the safety of blood products.

Strategies to enhance immunomodulatory properties and reduce heterogeneity in mesenchymal stromal cells during ex vivo expansion.

Therapies using mesenchymal stromal cells (MSCs) to treat immune and inflammatory conditions are now at an exciting stage of development, with many MSC-based products progressing to phase II and III clinical trials. However, a major bottleneck in the clinical translation of allogeneic MSC therapies is the variable immunomodulatory properties of MSC products due to differences in their tissue source, donor heterogeneity and processes involved in manufacturing and banking. This variable functionality of MSC products likely contributes to the substantial inconsistency observed in the clinical outcomes of phase III trials of MSC therapies; several trials have failed to reach the primary efficacy endpoint. In this review, we discuss various strategies to consistently maintain or enhance the immunomodulatory potency of MSCs during ex vivo expansion, which will enable the manufacture of allogeneic MSC banks that have high potency and low variability. Biophysical and biochemical priming strategies, the use of culture additives such as heparan sulfates, and genetic modification can substantially enhance the immunomodulatory properties of MSCs during in vitro expansion. Furthermore, robust donor screening, the use of biomarkers to select for potent MSC subpopulations, and rigorous quality testing to improve the release criteria for MSC banks have the potential to reduce batch-to-batch heterogeneity and enhance the clinical efficacy of the final MSC product. Machine learning approaches to develop predictive models of individual patient response can enable personalized therapies and potentially establish correlations between in vitro potency measurements and clinical outcomes in human trials.

Screening of chlamydia trachomatis in non-partner donors: situation of stored donations and proposal for periodic screening.

RESEARCH QUESTION: Lack of guidance on the frequency of Chlamydia trachomatis screening in non-partner donors has led to heterogeneous testing protocols. C. trachomatis was checked in sperm donations unscreened for C. trachomatis to determine the risk for C. trachomatis infection in recipients using historic sperm donations unscreened for C. trachomatis. A C. trachomatis screening protocol is proposed to harmonize C. trachomatis screening, for which a cost evaluation is provided. DESIGN: Retrospective study of sperm donations carried out between 2009 and 2019 from healthy non-partner donors for whom at least one straw was available. A straw was selected from the still available donations that had not been tested for C. trachomatis in urine at the time of donation. These sperm samples were screened for C. trachomatis by nucleic acid amplification (NAT). RESULTS: Forty donors were included in the analysis. The 210 analysed straws tested negative for C. trachomatis. A C. trachomatis screening protocol following the European Centre for Disease Prevention and Control (ECDC) protocol for other sexually transmitted diseases (STD), i.e. NAT C. trachomatis screening of donor eligibility and first and last donation, provided these occur within 90 days, is cost advantageous compared with screening of all samples (approximately 75% reduction). CONCLUSION: A negligible risk for C. trachomatis infection was found in recipients when using historical sperm samples stored at the sperm bank. C. trachomatis screening following the ECDC protocol for other STDs is supported as it significantly reduces workload and cost compared with screening all samples.

Haemoglobin S testing using HEA BeadChip™ technology: Lifeblood comparison with clinical diagnosis.

BACKGROUND AND OBJECTIVES: Red cell antigen genotyping is commonly performed on patients requiring chronic transfusion support, such as sickle cell disease and thalassaemia. The Immucor HEA BeadChip™ test, in addition to assessing red cell antigen expression, can also detect the haemoglobin S (HbS) mutation. Our aim was to compare HbS results using HEA BeadChip™ performed at the Australian Red Cross Lifeblood with conventional haemoglobin studies. MATERIALS AND METHODS: Patients with thalassaemia and sickle cell trait (SCT) or disease (SCD) referred for red cell genotyping between 2017 and 2019 were assessed. The HbS result obtained from HEA BeadChip™ was compared with that obtained from high-performance liquid chromatography (HPLC) performed by the referring pathology provider. RESULTS: One-hundred and nineteen cases had comparable HPLC and HEA BeadChip™ results. On HEA BeadChip™ testing, 40 cases showed a negative HbS result, 31 cases showed HbS+ and 47 cases showed HbS++. There was one case with 'low signal' result. Of the negative HbS cases, there was none with SCT. The HbS+ group comprised a mixture of SCT and SCD due to compound heterozygosity for HbS and ß-thalassaemia mutations. The HbS++ group comprised predominantly SCD due to homozygosity for HbS. CONCLUSION: HEA BeadChip™ is an accurate screening test for the detection of HbS. There were no false positives or false negatives. The identification of donors with the HbS mutation through the targeted genotyping programme would enable early intervention, improved donor management and reduced wastage.

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.

BACKGROUND: 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. STUDY DESIGN AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Suitability of Different Diagnostic Platforms for Virological Testing of Blood Samples from Cornea Donors.

Background: To minimize the risk of disease transmission in cornea transplantation, donor screening for blood-derived viral infections is mandatory. Ideally, pre-mortem blood samples are used, but based on availability, cadaveric blood samples of cornea donors may also be used. However, serological and nucleic acid amplification tests (NATs) need to be validated for the use of cadaveric specimens. Methods: Hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV) 1/2, and Treponema pallidum (syphilis)-specific serological and/or NAT assays were validated on different platforms (Abbott Alinity i, Alinity m, Roche Cobas 6800, and Roche Cobas AmpliPrep/Cobas TaqMan (CAP/CTM)) using (un)spiked paired pre- and post-mortem cornea donor blood samples from the same individual (up to 23.83 h after death) of 28 individuals in accordance with the specifications of the German Federal Institute for Vaccines and Biomedicines (Paul-Ehrlich-Institut [PEI]). In addition, routinely HBV-, HCV- and HIV-PCR-negative tested post-mortem blood samples of 24 individuals were used to assess NAT specificity. Results: For the majority of serological parameters on the Abbott Alinity i (HBsAg, anti-HBc, anti-HBs, anti-HCV, anti-HIV, anti-HTLV 1/2, and anti-Treponema pallidum), ratios of generated test results of (un)spiked paired pre- and post-mortem blood samples differed ≤25%, with an agreement of qualitative pre- and post-mortem test results ranging from 91.2 to 100%. For NAT parameters (HBV, HCV, and HIV) on the Cobas 6800, Alinity m, and CAP/CTM, no significant deviation in virus concentrations (factor >5) of spiked pre- and post-mortem blood samples could be observed. Ct-values of corresponding internal controls did also not differ significantly (>1.5 Ct-values). In addition, no false-positive test results were generated when specificity was assessed. Conclusion: Overall, fluctuations of test results for serological and NAT parameters in pre- and post-mortem blood samples examined in this study, were only limited and within the range of what is also observed when routinely testing fresh patient specimens. We conclude that all examined assays are eligible for the screening of blood samples taken up to about 24 h after the occurrence of death.