Prolonged incubation period of hepatitis B in a recipient of a nucleic acid amplification test-negative hepatitis B virus window donation.

BACKGROUND: The occurrence of transfusion-transmitted hepatitis B virus (HBV) infection has fallen dramatically due to continuous improvements in pre-transfusion laboratory testing. However, the characteristics of transfusion-transmitted HBV infection caused by individual donor nucleic acid amplification test (ID-NAT)-negative blood products are unclear. CASE PRESENTATION: A 76-year-old woman with acute myeloid leukemia was diagnosed with transfusion-transmitted HBV infection after receiving apheresis platelets derived from an ID-NAT-negative blood donation. This case was diagnosed definitively as transfusion-mediated because complete nucleotide homology of a 1556 bp region of the HBV Pol/preS1-preS2-S genes and a 23 bp region of the HBV core promoter/precore between the donor and recipient strains was confirmed by PCR-directed sequencing. The case is uncommon with respect to the unexpectedly prolonged HBV-DNA incubation period of nearly 5 months after transfusion (previously, the longest period observed since the recent implementation of ID-NAT pre-transfusion laboratory testing in Japan was 84 days). Slow-replicating HBV genotype A2 may contribute to the prolonged incubation period; also, the quantity of apheresis platelets delivered in a large volume of plasma, and/or the immune response of the recipient suffering from a hematological neoplasm, may have contributed to establishment of HBV infection in the recipient. This was supported by analysis of three previously documented cases of transfusion-transmitted HBV infection by blood products derived from ID-NAT-negative donations in Japan. CONCLUSION: Continuous monitoring of HBV infection for longer periods (>3 months) may be required after transfusion of blood components from an ID-NAT-negative HBV window donation.

Changing trends in seroprevalence rates of transfusion-transmitted diseases among blood donors in Jordan.

BACKGROUND: Hepatitis B and C infections and transmission are a serious challenge to all healthcare systems. We studied seroprevalence rates of Transfusion Transmitted Diseases (TTD) among blood bank donors in Jordan from 2014 to 2019 as a follow-up study of our previously published work. In addition, we wanted to explore the efficacy of the mandatory vaccination of infants against hepatitis B virus (HBV) which was implemented by the Ministry of Health since 1995 for the eradication of HBV infection in Jordan. METHODS: We reviewed blood bank donors' records at King Hussein Cancer Center (KHCC) from January 1st, 2014, until December 31st, 2019. Results of seropositivity prevalence rates for HBsAg, anti-HBcore, and anti-HCV, using Enzyme-Linked ImmunoSorbent Assay (ELISA) were compared to seropositivity rates from our previously published data. In addition, our results were compared to data obtained from other blood banks in Jordan, as well as compared to published information from blood banks in neighboring countries. RESULTS: The prevalence rates (%) of seropositive blood donors for viral hepatitis for the years 2014, 2015, 2016, 2017, 2018, and 2019, were as follows: HBsAg rates were 0.3386, 0.2108, 0.1801, 0.1898, 0.2068, and 0.2741; anti-HBcore rates were 4.1112, 3.2271, 2.9748, 2.8405, 2.6879 and 3.0986; and anti-HCV rates were 0.1129, 0.0486, 0.0548, 0.0654, 0.0782, and 0.0839, respectively. There was a significant increase in the prevalence of HBsAg, Anti-HBcore and Anti-HCV antibodies in 2019 (one sample z-score test, p < 0.00001). CONCLUSIONS: Prevalence rates of hepatitis B and C infections among Jordanian blood bank donors showed a steady decline between 2009 and 2017, and these rates were much lower in Jordan than in neighboring countries. However, an increase in the prevalence rates of hepatitis B and C infections among blood bank donors was documented in 2019. While the reasons for this increase are not clear yet, these findings highlight the importance of renewed efforts to increase public health awareness of HBV and implement effective measures to prevent the transmission and infection with HBV, including national vaccination programs.

Thalassemia Patients from Baluchistan in Pakistan Are Infected with Multiple Hepatitis B or C Virus Strains.

There are an estimated 2,000 children with ß-thalassemia in the province Baluchistan of Pakistan. These children are at high risk of acquiring transfusion-transmitted infections (TTIs) due to their need of regular blood transfusions for survival. Therefore, we investigated the frequencies of TTIs among these multi-transfused patients in a region where the WHO guidelines for blood safety are not always followed. Sera from 400 children (mean age 7.7 ± 4.70 years) treated at two thalassemia centers in Baluchistan were investigated for TTIs. Eleven (2.8%) were hepatitis B surface antigen positive, and 72 (18.3%) had anti-hepatitis C virus (HCV), two of which were infected with both viruses. Only 22% of the children had been reached by the program for universal hepatitis B virus (HBV) vaccination which started in 2004. Half (51%) of the HCV infected had also been HBV infected. The HBV- and HCV-infected patients were older and had received more blood transfusions than the uninfected patients (P < 0.001). Molecular characterization of the viral strains revealed the presence of several genetically different strains in at least three HBV- and seven HCV-infected children. This is the first study to demonstrate infections with multiple HBV or HCV strains simultaneously infecting thalassemia patients. These may become the source for new emerging recombinant viruses of unknown virulence. The high prevalence of anti-HCV-positive children, and the presence of HBV infections among children who should have been vaccinated, highlights an urgent need for improvements of blood safety in this region of Pakistan.

Prevalence, incidence and residual risk of transfusion transmitted viruses (HBV, HCV and HIV infections) in Lithuanian blood donors from 2004 to 2018: The incidence/window-period model study.

INTRODUCTION: Estimation of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) transfusion risk in blood donors is essential for monitoring the safety of the blood supply and the impact of new screening tests. Due to improvements in donor selection and continuing progress in screening assays, residual risk of virus transmission has significantly decreased over the past years. It is not practical and sometimes even not possible to measure residual risk in blood donors directly and mathematical models are used. The aim of this study was to calculate the prevalence, incidence rates of HBV, HCV and HIV infections and analyse evolution of their transmission residual risk from 2004 to 2018 at the National Blood Center of Lithuania. MATERIALS AND METHODS: Data from the archives of the National Blood Center of Lithuania from 2004 to 2018 was retrospectively analysed. The residual risk was calculated for each virus and year by applying the incidence/window-period model suggested by World Health Organization. For the analysis of the residual risk yearly trends a linear regression was used. RESULTS: A total of 754,755 blood donors and 1,245,568 donations were included in the analysis and represented a 2.06 donations per donor over 15 years. Average residual risk for HBV, HCV and HIV respectively was 570.04, 807.14 and 35.72 per 1,00,000 donations. During the study period, there was statistically significant downward trend in the residual risk for every analysed virus. DISCUSSION: Residual risk of virus transmission has been steadily decreasing over past 15 years in Lithuanian donors, but the current risk remains quite high. It is difficult to establish how much the risk is affected by statistical assumptions or virus prevalence in general population. However, results of this study indicate the need of the population screening program of transfusion transmitted viruses.

New HIV infections from blood transfusions averted in 28 countries supported by PEPFAR blood safety programs, 2004-2015.

BACKGROUND: To quantify the impact of the US President's Emergency Plan for AIDS Relief (PEPFAR) on the risk of HIV transmission through infected blood donations in countries supported by PEPFAR blood safety programs. METHODS: Data reported to the World Health Organization Global Database on Blood Safety were analyzed from 28 countries in sub-Saharan Africa (SSA), Asia, and the Caribbean during 2004-2015. We used the Goals model of Spectrum Spectrum System Software, version 5.53, to perform the modeling, assuming laboratory quality for HIV testing had 91.9% sensitivity and 97.7% specificity irrespective of testing method based on results of two external quality assurance and proficiency testing studies of transfusion screening for HIV in SSA blood centers. We calculated the number of new HIV infections from the number of transfusions and the prevalence of HIV infection acquired from blood transfusions with infected blood donations. We determined the impact of laboratory testing programs by estimating the number of new HIV infections averted since PEPFAR implementation. RESULTS: Assuming that HIV testing would not be performed in any of these countries without PEPFAR funding, the number of new HIV infections acquired from blood transfusions averted by laboratory testing increased over time in all 28 countries. The total number of HIV infections averted was estimated at 229 278 out of 20 428 373 blood transfusions during 2004-2015. CONCLUSION: Our mathematical modeling suggests a positive impact achieved over 12 years of PEPFAR support for blood safety. Standardized HIV testing of donated blood has reduced the risk of HIV transmission through blood transfusions in SSA, Asia, and the Caribbean.

HIV, HCV, and HBV incidence and residual risk in US blood donors before and after implementation of the 12-month deferral policy for men who have sex with men.

BACKGROUND: In December 2015, the men who have sex with men (MSM) deferral was reduced to 12 months in the United States. We compared human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) incidence and residual risk before and after this policy change using data from >50% of the US blood supply. STUDY DESIGN AND METHODS: Three estimation intervals from the Transfusion-Transmissible Infections Monitoring System were compared: 15-months pre- and two consecutive, nonoverlapping 15-month post-MSM deferral implementation. Repeat, first-time, and weighted all-donor incidences were estimated. Residual risk was calculated for all incidence estimates using the incidence/window-period method. RESULTS: HIV repeat donor incidence was 1.57 per 100 000 person-years (phtpy) in the second 15-month post change and not significantly different from pre-MSM incidence of 2.19 phtpy. Similar values were seen for HCV (1.49 phtpy vs 1.46 phtpy) and HBV (1.14 phtpy vs 0.97 phtpy). In some cases, higher estimated incidence, but without significant change from pre-MSM to the second post change period occurred for males and first-time donors (eg, first-time donors, second post change period: 6.12 phtpy HIV, 6.41 phtpy HCV and 5.34 phtpy HBV). Estimated per donation residual risk was 1:1.6 million for HIV, 1:2.0 million for HCV and 1:1.0 million for HBV based on weighted incidence for all donors. CONCLUSIONS: Repeat, first-time, and overall donor incidence did not vary significantly comparing pre-MSM to either of the post-MSM estimation intervals. Residual risk estimates vary by study, but all yield residual risks in the United States of ≤1 per million, and thus far have not shown increasing risk with the 12-month MSM policy change.

Transfusion-related Epstein-Barr virus (EBV) infection: A multicenter prospective cohort study among pediatric recipients of hematopoietic stem cell transplants (TREASuRE study).

BACKGROUND: Epstein-Barr virus (EBV) is carried in the blood of most adults, and transfusion-related infections have been reported. EBV is particularly deleterious in immunosuppressed transplant patients. The aim was to determine if EBV transmission occurred through leukodepleted blood product transfusion in pediatric recipients of hematopoietic stem cell transplants (HSCT). STUDY DESIGN AND METHODS: This prospective Canadian multi-center cohort study includes 156 allogeneic HSCT pediatric recipients. The association between EBV and transfusion was analyzed using Cox regressions. EBV infection, defined by a PCR+ test in the blood of seronegative recipients of an EBV-negative graft, was monitored in order to correlate the recipient EBV strain with that of the blood donors. EBV genotypes were determined by PCR amplification followed by DNA sequencing at two loci (EBNA3b and LMP1). RESULTS: No statistically significant associations were found between transfusions and EBV. One case of post-transplant EBV infection was identified among the 21 EBV-seronegative recipients receiving an EBV-negative graft. A total of 22 blood donors were retraced to determine whether the recipient's EBV strain matched that of a donor. One donor strain showed 100% sequence homology at the EBNA3b locus, but differed by one or two point mutations and by a 132-bp deletion at the LMP1 locus. The blood donor in question was alone among the 22 donors to show amplifiable virus in plasma. Blood from this donor readily produced an immortalized lymphoblastoid cell line in culture. CONCLUSION: While considered a rare event, EBV transmission through transfusion may occur in the context of severe immunosuppression.

High Risk of HBV Infection Among Vaccinated Polytransfused Children With Malignancy.

AIM OF THE STUDY: The national Egyptian hepatitis B virus (HBV) vaccination program coverage of all infants started in 1992. The study aimed to assess immunity against HBV and occurrence of HBV breakthrough infections in vaccinated polytransfused children with malignancies. PATIENTS AND METHODS: Eighty-nine polytransfused children with malignancies were recruited; 37 were on chemotherapy (male:female 20:17; mean age 7.7±4.0 y), and there were 52 naive patients (male:female 31:21; mean age 7.6±3.2 y). In addition, 162 age-matched and sex-matched healthy controls were recruited. Patients' sera were tested for quantitative anti-hepatitis B surface (HBs) (enzyme-linked immunoassays technique), hepatitis B surface antigen (HBsAg), total anti-hepatitis B core, and HBV-DNA (nested polymerase chain reaction for surface, core, and x-regions). RESULTS: There was a significant lower percentage of having protective anti-HBs (10 to 100 IU/L) level among those receiving chemotherapy (13.5%) than those without (44.2%) and controls (32.1%). Twenty-one (67.7%) of those on chemotherapy were HBsAg positive compared with 10 (32.2%) of those without. Overall, 46 patients were HBV-DNA positive; 38 were c-region positive, 5 were s-region positive, 2 positive for the c-region and the s-region, and 1 tested positive for the c-region and the x-region. Of 46 patients, 20 were also positive for HBsAg (overt infection), while 26 had occult HBV infection (HBsAg-negative). Anti-HBs ≥10 IU/L co-existed among 45% of patients with overt infection and in 50% of those with occult infection. There was nonsignificant impact of receiving chemotherapy on the level of HBV-DNA. CONCLUSIONS: Vaccinated children with malignancies, especially those under chemotherapy, are at a significant risk of HBV infection. The co-existence of anti-HBs with HBsAg and/or HBV-DNA may represent a possible residual transfusion-transmission risk with mutant HBV strains.

Trends and epidemiological analysis of hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and human T-cell lymphotropic virus among Iranian blood donors: strategies for improving blood safety.

BACKGROUND: Blood transfusion is associated with potential risks of transfusion-transmitted infections (TTIs). Different strategies are needed to monitor blood safety and screen the donors' efficacy, such as evaluation of the prevalence and trends of TTIs. This study was conducted to evaluate the prevalence and trends of TTIs, including hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and human T-cell lymphotropic virus (HTLV 1/2), and the impact of the donors' characteristics such as age, sex, and donor status on the prevalence of TTIs in blood donors in seven large provinces of Iran from 2010 to 2018. METHODS: This study was conducted on the data collected from all blood donations in seven Iranian Blood Transfusion Centers including Ardabil, Alborz, Guilan, West Azarbaijan, North, Razavi, and South Khorasan from April 2010 to March 2018. Demographic characteristics, number of donations, donor status, and screening and confirmatory serological results of all blood donations were collected from Iranian Blood Transfusion Organizations (IBTO) national database. The prevalence and trend of HBV, HCV, HIV, and HTLV 1/2 infections were reported according to the donation year and donor's characteristics. RESULTS: The analysis of the prevalence and trend of TTIs in 3,622,860 blood donors showed a significant decreasing trend in first-time and regular donors. Additionally, compared to first- time donors, regular donors made safer blood donations with lower risks of HBV, HIV, HCV and HTLV 1/2 (P < 0.0001). Although the prevalence of HTLV 1/2 and HBV was higher in females, TTIs had a significant decreasing trend in males and females. Finally, it was found that the prevalence of HBV and HTLV 1/2 increased with age up to 40-49 years and then decreased thereafter. CONCLUSIONS: The decreasing trends of TTIs in Iranian donors during 9 years may indicate that the various strategies implemented by IBTO have been effective in recent years. Other factors such as a decrease in the prevalence of specific TTIs in the general population might have also contributed to these declines.

Seroprevalence and Trend of HBV, HCV, and HIV Infections among Blood Donors of Fars Province, Iran (2006-2018).

BACKGROUND: Blood transfusion is a life-saving procedure; millions of lives are saved each year. However, blood transfusions are associated with certain risks that can lead to adverse consequences. This study aimed to survey the prevalence and trend of hepatitis B virus (HBV), hepatitis C virus (HCV), and Human immunodeficiency virus (HIV) among blood donors of Fars province, Iran (2006-2018). METHODS: This retrospective cross-sectional study was conducted by reviewing the records of the blood transfusion organization of Fars province. A total of 1952478 blood units were screened for transfusion-transmitted infections (TTIs). Then, data were entered into SPSS software (Negare. version 25). Chi-square test was used to compare the sof TTIs among blood donors. Chisquare test for trend was used to analyze the variations in trends of TTIs during this period. Finally, p-values less than 0.05 were considered statistically significant. GraphPad Prism software was used for the depiction of the graphs. RESULTS: Among the 1952478 blood donations within the 13-years, 4479(0.229 %) of donors were HBsAg, HCV Ab, and HIV Ag-Ab positive. The seroprevalence of HBV, HCV, and HIV was 2684(0.137%), 1703(0.087 %), and 92(0.0047%), respectively. CONCLUSION: The current study showed that the overall prevalence of TTIs among blood donors was low and had a descending trend over the years of study.

Blood transfusion is unlikely to be a source for hepatitis E virus transmission in India.

INTRODUCTION: Transmission of hepatitis E virus (HEV) through transfusion has been reported from countries where genotype 3 virus is predominant. Data from countries with predominantly genotype 1 HEV, such as India, are limited. We studied the risk of HEV transmission following transfusion of blood or blood components in India. METHODS: Adult patients undergoing cardiac surgery who received transfusion of blood or blood products in the peri-operative period and who lacked history of any transfusion or surgery in the preceding 1 year were studied. A pre-transfusion blood specimen was collected for IgG anti-HEV antibody test. For the participants who were seronegative for anti-HEV, follow up specimens were collected at every 2-3-month intervals for up to 6 months after surgery and were tested for IgM and IgG anti-HEV antibodies. RESULTS: Of the 335 participants originally enrolled, 191 (57%) could be followed up. Of them, 103 (53.9%) were seropositive for HEV IgG at baseline and were excluded. Of the remaining 88 participants (age 42 ± 14.1 years; 55 [63%] male), none reported hepatitis-like illness during the follow up period of 81 ± 23 days. Also, none of these 88 participants was found to have seroconversion to anti-HEV IgM or IgG positivity in the follow up specimens. CONCLUSION: Transfusion-mediated transmission of HEV was not observed in our cohort and may be infrequent in the Indian population, where genotype 1 is the predominant HEV type.

SARS-CoV-2 asymptomatic and symptomatic patients and risk for transfusion transmission.

Oral swabs, sputum, and blood samples from 18 asymptomatic and symptomatic patients with SARS-CoV-2 infection were examined using RT-PCR testing in order to assess the risk of transfusion-related transmission. In asymptomatic patients as well as patients with flu-like symptoms and fever, no SARS-CoV-2 RNA could be detected in the blood or serum despite a clearly positive result in all throat swabs. As patients with symptoms of infectious disease will not be admitted to blood donation, the risk for transfusion transmission of SARS-CoV-2 seems to be negligible.

Seroprevalence and Seroconversion of Cytomegalovirus in a Large Group of Healthy, German Blood Donors: Potential Contribution to Transfusion Transmitted Infections.

BACKGROUND: Immunocompromised patients are at increased risk of morbidity and mortality due to transfusion transmitted cytomegalovirus (CMV) infections. To avoid or minimize such risk, clinicians working in the field continually monitor the changing epidemiology of CMV infections. MATERIALS AND METHODS: A total of 234,192 blood donations obtained from 44,779 donors were tested. CMV seroprevalence and antibody conversion rates were determined over a 3-year period. RESULTS: A significant percentage (37.5%) of all male and female blood donors tested seropositive. Both age and gender were risk factors for CMV infection. A total of 177 seroconversions (0.4% of donors) were identified. The highest antibody conversion rate occurred among men between 30 and 39 years of age; women did not experience a similar peak in antibody conversion rate. Approximately 10% of infected blood donors were identified by CMV DNA testing prior to seroconversion. CONCLUSIONS: The high rates of seroprevalence and seroconversion and the identification of a significant number of CMV DNA-positive (infected) blood donors prior to seroconversion indicate that the routine testing of blood samples for CMV DNA could reduce the potential risk of CMV transmission to high-risk patients.

Transfusion-transmitted cytomegalovirus: behaviour of cell-free virus during blood component processing. A study on the safety of labile blood components in Switzerland.

BACKGROUND: Nowadays, most blood products are leukocyte-reduced. After this procedure, the residual risk for transfusion transmitted cytomegalovirus (TT-CMV) is mostly attributed to cell-free viruses in the plasma of blood donors following primary infection or viral reactivation. Here, objectives are: 1) to study the behaviour of cell-free CMV through the blood component processing; 2) to determine the anti-CMV seroprevalence, the level of viremia, the window-period in blood donor population; and 3) to identify cases of TT-CMV in bone marrow transplant (BMT) recipients. MATERIALS AND METHODS: Cell-free CMV was injected into blood bags originating from regular donors. Blood components were processed according to either the CompoSelect® or the CompoFlow® (Fresenius Kabi AG) techniques. Samples were analysed at each step for presence of virus DNA using quantitative polymerase chain reaction (PCR). The anti-CMV seroprevalence in our donor population was taken from our donor data system. The viremia was assessed in pooled plasmas samples from routine donations by quantitative PCR. Medical charts of 165 BMT anti-CMV seronegative recipients/anti-CMV seronegative donors who received CMV-unscreened blood products were reviewed. RESULTS: Cell-free CMV passes without any decrease in viral load through all stages of blood processing. The anti-CMV seroprevalence was 46.13%. Four DNA positive samples out of 42,240 individual blood donations were identified (0.009%); all had low levels of viremia (range 11-255 IU/mL). No window-period donation was identified. No TT-CMV was found. DISCUSSION: Cell-free CMV remains a concern with current blood component processing as it passes through all the processes. However, since low levels of CMV DNA were identified in the donations tested, and no BMT recipients had TT-CMV, the residual threat of TT-CMV after leukocyte reduction appears to be very low.

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.

Type 1 IFN signaling critically regulates influenza-induced alloimmunization to transfused KEL RBCs in a murine model.

BACKGROUND: Only a fraction of red blood cell (RBC) transfusion recipients form alloantibodies, and variables determining responsiveness or nonresponsiveness are poorly understood. We and others have previously shown in animal models that pretreatment with toll-like receptor agonists that mimic different types of infections impacts the magnitude or frequency of RBC alloantibody responses. We hypothesized that influenza infection, coexistent with transfusion, would impact responses to transfused RBCs in a manner dependent on Type 1(α/ß) interferon (IFN) signaling and tested this in a murine model. STUDY DESIGN AND METHODS: Wild-type mice or mice lacking the ability to respond to Type 1 IFN were infected with influenza prior to the transfusion of transgenic murine RBCs (K1) expressing the human KEL glycoprotein or the triple fusion HOD protein. Alloantibody responses were measured longitudinally after transfusion by flow cytometric crossmatch, and posttransfusion RBC recovery and survival was evaluated. RESULTS: Influenza-infected mice transfused with K1 RBCs developed robust anti-KEL alloantibodies, whereas animals transfused in the absence of infection remained nonresponders; influenza-associated RBC alloimmunization was also observed after transfusion of HOD RBCs. Recipient Type 1 IFN production was critical to the mechanism of action of influenza-induced RBC alloimmunization, with alloimmunization being significantly decreased in mice unable to sense Type 1 IFN (through antibody blockade or genetic approaches). CONCLUSION: These and other data suggest that Type 1 IFN responses to toll-like receptor agonists or infections regulate RBC alloantibody responses. Studies investigating whether such a correlation exists in humans may be informative.

Nucleic acid amplification test: Bridging the gap in blood safety & re-evaluation of blood screening for cryptic transfusion-transmitted infection among Indian donors.

Background & objectives: : Nucleic acid amplification test (NAT) in blood donor screening not only detects window period (WP) donors but also those with chronic occult infections which are negative by routine serological screening. This study was conducted to determine the time trend of NAT positivity and seroprevalence of transfusion-transmitted infections (TTIs) through a period of six years and evaluate the strength of NAT as a supplementary test in identifying the cryptic carriers in blood donor population. Methods: : A total of 1,01,411 blood donations were screened between January 2011 and December 2016 by the ELISA and individual donor (ID) NAT Procleix Ultrio Plus Assay. Additional molecular and serological assays were done on the NAT yield samples to differentiate the type of cryptic carriers. Results: : NAT yields comprised 0.05 per cent (50/101411) of the total samples tested with a yield rate of 1/2028. Hepatitis B virus (HBV) contributed to 80 per cent of the total NAT yields and the rest 20 per cent due to hepatitis C virus (HCV). Majority of HBV NAT yields (75%) were from chronic occult donors and 25 per cent were WP donors. Both HBV and HCV NAT yields had a wide range of viral count. There was no HIV NAT yield. A significant decline in the prevalence rate of TTIs through the study period of six years was observed. Interpretation & conclusions: : The cryptic infections found in blood donors increase the risk of TTIs. Blood screening by both serology and NAT can reduce this threat.

A microarray-based pathogen chip for simultaneous molecular detection of transfusion-transmitted infectious agents.

BACKGROUND: New and emerging transfusion-transmitted infections remain a threat to the blood supply. Blood donors are currently screened for less than half of known agents, primarily by individual tests. A screening platform that could simultaneously detect all known transfusion-transmitted pathogens and allow rapid addition of new targets would significantly increase blood safety and could improve the response to new agents. We describe the early stage development and validation of a microarray-based platform (pathogen chip) for simultaneous molecular detection of transfusion-transmitted RNA viruses. METHODS: Sixteen RNA viruses that pose a significant risk for transfusion-transmission were selected for inclusion on the pathogen chip. Viruses were targeted for detection by 1769 oligonucleotide probes selected by Agilent eArray software. Differentially concentrated positive plasma samples were used to evaluate performance and limits of detection in the context of individual pathogens or combinations to simulate coinfection. RNA-viruses detection and concentration were validated by RT-qPCR. RESULTS: Hepatitis A, B and C, Chikungunya, dengue 1-4, HIV 1-2, HTLV I-II, West Nile and Zika viruses were all correctly identified by the pathogen chip within the range of 105 to 102 copies/mL; hepatitis E virus from 105 to 104. In mixtures of 3-8 different viruses, all were correctly identified between 105 and 103 copies/mL. CONCLUSIONS: This microarray-based multi-pathogen screening platform accurately and reproducibly detected individual and mixed RNA viruses in one test from single samples with limits of detection as low as 102 copies mL.