Hepatitis B Virus Blood Screening: Need for Reappraisal of Blood Safety Measures?

Prevalence and Transfusion Risks of Occult Hepatitis B Infection Among HBcAb-Positive Blood Donors in a High-Endemic Region

Background: Hepatitis B virus (HBV) remains a significant global health concern, particularly in sub-Saharan Africa, where endemicity is high. Occult hepatitis B infection (OBI) presents a unique challenge to transfusion safety, as HBV DNA may persist in HBsAg-negative individuals. This study examines the prevalence of HBcAb positivity among blood donors at Usmanu Danfodiyo University Teaching Hospital (UDUTH), Sokoto, and assesses the risk of HBV transmission. Methods: A cross-sectional study was conducted among 200 blood donors. Samples were screened for HBsAg and HBV serological markers using a rapid assay and ELISA. HBcAb-positive samples were analyzed for HBV DNA using real-time polymerase chain reaction (qRT-PCR). Viral loads were quantified, and socio-demographic characteristics were recorded. Results: HBcAb was detected in 57 (28.5%) of the 200 donors. The most common serological pattern among donors was HBsAg-negative and HBcAb-negative (69%). Among these HBcAb-positive donors, HBV DNA was detected in three cases (1.5%), with viral loads of 753.1, 2.193 × 104, and 4.538 × 104 IU/mL. The presence of HBV DNA in these donors confirms the risk of OBI transmission through transfusion. Socio-demographic analysis revealed that 48.5% of donors were aged 26-35 years, 23.5% were aged 18-25 years, 23% were aged 36-42 years, and 2.5% were either 43-50 or above 50 years of age, of which 99.5% were male. These findings highlight a significant prevalence of HBcAb positivity and OBI, aligning with studies in similar high-endemic settings. Conclusions: HBcAb positivity and OBI represent significant transfusion risks in endemic regions. The presence of HBV DNA in 1.5% of HBcAb-positive donors in the study population highlights the limitations of HBsAg-based screening. Incorporating nucleic acid testing (NAT) into routine blood donor screening protocols is critical to enhancing transfusion safety. Further research is needed to evaluate the feasibility and cost-effectiveness of such interventions in resource-limited settings.

An agent-based model to simulate the transmission dynamics of bloodborne pathogens within hospitals

Mathematical models are powerful tools to analyze pathogen spread and assess control strategies in healthcare settings. Nevertheless, available models focus on nosocomial transmission through direct contact or aerosols rather than through blood, even though bloodborne pathogens remain a significant source of iatrogenic infectious risk. Herein, we propose an agent-based SEI (Susceptible-Exposed-Infected) model to reproduce the transmission of bloodborne pathogens dynamically within hospitals. This model simulates the dynamics of patients between hospital wards, from admission to discharge, as well as the dynamics of the devices used during at-risk invasive procedures, considering that patient contamination occurs after exposure to a contaminated device. We first illustrate the use of this model through a case study on hepatitis C virus (HCV) in Egypt. Model parameters, such as HCV upon-admission prevalence and transition probabilities between wards or ward-specific probabilities of undergoing different invasive procedures, are informed with data collected in Ain Shams University Hospital in Cairo. Our results suggest a low risk of HCV acquisition for patients hospitalized in this university hospital. However, we show that in a low-resource hospital, frequent device shortages could lead to increased risk. We also find that systematically screening patients in a few selected high-risk wards could significantly reduce this risk. We then further explore potential model applications through a second illustrative case study based on HBV nosocomial transmission in Ethiopia. In the future, this model could be used to predict the potential burden of emerging bloodborne pathogens and help implement effective control strategies in various hospital contexts.

Safety of Hepatitis B Virus Screening in Blood Donors from the Hospital Foundation of Hematology and Hemotherapy of the State of Amazonas (HEMOAM) in the Brazilian Amazon

BACKGROUND

Hepatitis B is an infectious disease of worldwide importance and of great interest to transfusion medicine. The Amazon region has areas of high endemicity, outlining a worrying scenario for transfusion and epidemiological safety.

OBJECTIVE

To analyze the profiles of serological and molecular markers for HBV of blood donors from HEMOAM.

METHODS

Blood donors with different patterns of reactivity in serological and molecular screening for HBV were tested for viral load by the qPCR method at the reference center for liver diseases in the state of Amazonas.

RESULTS

A total of 230,591 donors were tested, with 3104 (1.34%) found reactive for HBV and 2790 (89.9%) found reactive for isolated anti-HBc. Viral load was not detected in 100% of donors reactive only to HBsAg, while 100% of donors with positive anti-HBc and positive HBsAg or HBV NAT demonstrated a detectable viral load. We also detected one case of occult hepatitis B (0.03%) only with reactive HBV NAT and five donors (0.2%) with positive anti-HBc and HBV NAT.

CONCLUSIONS

With this result, the great importance of the anti-HBc test for the unsuitability of blood donors was verified, as well as the fundamental introduction of the HBV NAT test in screening for hepatitis B in Brazilian blood banks, as this was the only way to detect the viral infection burden in asymptomatic donors who previously would not be treated, which contributed to the maintenance of the endemicity of hepatitis B in the Brazilian Amazon.

Implementing pathogen reduction technology while discontinuing blood donor deferral criteria for sexual risk behaviors: A simulation study

BACKGROUND

Combining pathogen reduction technology (PRT) with blood screening may alleviate concerns over the risk of transfusion-transmitted infections (TTI) and support changes in blood donor selection to potentially increase blood availability. This study aimed to estimate the residual risk of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) transfusion-transmission in Canada after implementing PRT, while eliminating deferrals for sexual risk behaviors.

STUDY DESIGN AND METHODS

A probabilistic approach that combined Bayesian networks with Monte Carlo simulations was used to estimate the risk of transfusing HIV-, HBV-, or HCV-contaminated blood components. Different scenarios were considered to compare the current residual risk after PRT implementation, with and without donor deferral criteria for sexual risk behaviors. Donor profiles and blood component outcomes were simulated based on a literature review including the prevalence and incidence of HIV, HBV, and HCV in the Canadian blood donor population; the use of current blood screening assays; and HIV, HBV, and HCV blood donor viral loads.

RESULTS

In the universal PRT scenario (i.e., with PRT/without deferral criteria), the estimated risks of HIV, HBV, and HCV transmission were significantly lower than those in the currently observed scenario (i.e., without PRT/with deferral criteria).

CONCLUSIONS

This risk model suggests that PRT for platelets and plasma (and eventually for RBCs when available) significantly reduces the residual risks of HIV, HBV and HCV transfusion-transmission and could enable the removal of blood donor deferral criteria for sexual risk behaviors.

An overview of occult hepatitis B infection (OBI) with emphasis on HBV vaccination

Background

The prevalence of chronic hepatitis B virus (HBV) poses a significant threat to the lives of 257 million individuals globally, potentially resulting in severe outcomes such as liver cirrhosis or hepatocellular carcinoma. Among the existing preventive measures, yeast-derived vaccines have proven to be the most efficacious approach in combatting hepatitis B. Nonetheless, as scientific inquiries focus more on occult HBV infection (OBI) in vaccinated persons and the lingering risk of vertical transmission affecting 10-30 % of babies born to HBsAg-positive mothers, there is a growing apprehension regarding the inability of HBV vaccines to ensure complete immunity. This study aims to offer a more comprehensive understanding of the implications of widespread HBV vaccination initiatives on OBI while tackling the primary limitations associated with current vaccine formulations.

Methods

The exploration was conducted on PubMed, Scopus, and Web of Science databases to pinpoint research on OBI within vaccinated cohorts. A sum of 76 suitable studies was recognized.

Discussion

Multiple studies have documented the occurrence of OBI in fully vaccinated individuals, including both the general population and high-risk groups, such as newborns born to HBsAg-positive mothers. Factors contributing to vaccine failures include low-level anti-HBs antibodies, high maternal viral loads in mother-to-child transmission cases, as well as the presence of vaccine escape mutants and heterologous HBV genotypes. However, further research is needed to precisely understand the impact of active immunization on the emergence of OBI in vaccinated populations. Nonetheless, it is apparent that the advancement of more effective HBV vaccines could potentially lead to the extinction of HBV.

Seroprevalence of hepatitis C, hepatitis B, hiv and syphilis among blood donors at a tertiary care hospital in Mogadishu-Somalia in 2020-2022: a retrospective study

BACKGROUND

The safety of blood donation requires screening for transfusion-transmitted infections, including human immunodeficiency virus (HIV), syphilis, hepatitis B virus (HBV) and hepatitis C virus (HCV). This study aimed to determine the seroprevalence of HIV, HBV, HCV and syphilis in blood donors of Mogadishu Tertiary Care Hospital, Somalia from 2020 to 2022.

METHODS

The records of 109,385 blood donors who attended our blood center in Mogadishu-Somalia between 2020 and 2022 were examined retrospectively. Serum samples of donors; HBsAg, anti-HCV, anti-HIV and syphilisscreening tests were studied using the microparticleEnzyme-Linked ImmunoSorbent Assay (ELISA)(Vitros, Ortho-Clinical Diagnostics, U.S) method.The distribution of HBsAg, anti-HCV, anti-HIV and syphilis positivity rates of 109,385 blood donors according to years, gender and age were examined. Kolmogorov Smirnov, Skewness, Kurtosis tests and histogram were used for normality analysis. Chi-squared test (χ2) and Fisher Exact test were used to analyze categorical data. Categorical variables were expressed as frequency (percentage). Analysis of continuous data was performed with the Mann Whitney U test. P < 0.05 value was considered statistically significant.

RESULTS

HBsAg positivity was found in 0.6% of the donors, anti-HCV positivity in 0.01%, anti-HIV positivity in 0.03% and syphilispositivity in 0.3%. The results showed that among the blood donors, the prevalence of syphilis, HIV, Hepatitis B, and Hepatitis Cwas notably low.

CONCLUSION

The prevalence of HBV, HCV, HIV, and syphilis among blood donors in Somalia was found to be quite low. Even if our found seroprevalence rates are low, to guarantee the safety of blood for recipients, strict selection of blood donors and thorough screening of donors' blood using accepted procedures are strongly advised.

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

BACKGROUND

Most Chinese blood centers have implemented mini pool (MP) HBV nucleic acid testing (NAT) together with HBsAg ELISA in routine blood donor screening for HBV infection since 2015, and a few centers upgraded MP to individual donation (ID) NAT screening recently, raising urgent need for cost-benefit analysis of different screening strategies. In an effort to prevent transfusion-transmitted infections (TTIs) for HBV, cost-benefit analyses of three different screening strategies: HBsAg alone, HBsAg plus MP NAT and HBsAg plus ID NAT were performed in blood donors from southern China where HBV infection was endemic.

METHODS

MP-6 HBV NAT and ID NAT were adopted in parallel to screen blood donors for further comparative analysis. On the basis of screening data and the documented parameters, the number of window period (WP) infection, HBV acute infection, chronic hepatitis B infection (CHB) and occult hepatitis B infection (OBI) was evaluated, and the potential prevented HBV TTIs and benefits of these three strategies were predicted based on cost-benefit analysis by an estimation model.

RESULTS

Of 132,323 donations, the yield rate for HBsAg-/DNA + screened by ID NAT (0.12%) was significantly higher than that by MP NAT (0.058%, P < 0.05). Furthermore, the predicted transfusion-transmitted HBV cases prevented was 1.25 times more by ID NAT compared to MP-6 NAT. The cost-benefit ratio of the universal HBsAg screening, HBsAg plus ID NAT and HBsAg plus MP NAT were 1:58, 1:27 and 1:22, respectively.

CONCLUSIONS

Universal HBsAg ELISA screening in combination with HBV ID NAT or MP-6 NAT strategies was highly cost effective in China. To further improve blood safety, HBsAg plus HBV DNA ID NAT screening should be considered in HBV endemic regions/countries.

Low Prevalence of Anti-HBc Antibody and Lack of HBV DNA Among HBsAg-Negative Blood Donors in Iran: A Cross-sectional Study and Review of Literature

BACKGROUND

Occult hepatitis B infection (OBI) refers to the presence of hepatitis B virus (HBV) DNA in the serum or liver of individuals who tested negative for HBV surface antigen (HBsAg). This study aimed to determine seropositivity for antibodies against HBV core antigen (anti-HBc) and the frequency of OBI among the HBsAg non-reactive blood donors in Mashhad, northeastern Iran.

METHODS

In this cross-sectional study, serum samples of HBsAg-negative blood donors were examined for anti-HBc during June and August 2018. Anti-HBc-positive samples were tested for antibodies against HBsAg (anti-HBs), and those with negative results were classified as isolated anti-HBc cases. The presence of HBV DNA in the C, S, and X gene regions was assessed by a qualitative real-time polymerase chain reaction method in all HBsAg-negative samples. OBI subjects were detected by the presence of at least one HBV genomic region.

RESULTS

Of 540 HBsAg-negative donors, 29 (5.4%; 95% confidence interval: 3.6-7.6%) showed seroreactivity for anti-HBc, of whom 18 individuals were also seropositive for anti-HBs. All donors showed negative results for all three HBV genes regardless of their serum anti-HBc status.

CONCLUSION

Based on our findings, we suggest routine screening of Iranian blood donation volunteers for serum anti-HBc and anti-HBs but not HBV DNA.

Establishing a screening strategy for non-discriminatory reactive blood donors by constructing a predictive model of hepatitis B virus infection status from a single blood center in China

Background

When employing the transcription-mediated amplification method for screening blood donors, there are some non-discriminatory reactive results which are screening assay reactive but HBV-DNA discriminatory assay negative. This raises concerns regarding the possibility of false positives among donors, which may lead to permanent deferral of blood donors and affect blood supply. This study aimed to elucidate the infection status of these non-discriminatory reactive blood donors and develop and validate a model to predict individualized hepatitis B status to establish an optimal screening strategy.

Methods

Supplementary tests were conducted on initial non-discriminating reactive donations to determine their HBV infection status, including repeat testing, viral load, serological marker detection, and follow-up. Primary clinical variables of the donors were recorded. Based on the Akaike information criterion, a stepwise forward algorithm was used to identify the predictive factors for information and construct a predictive model. The optimal screening strategy was determined through cost-effectiveness analysis.

Results

At the Blood Center of Zhejiang Province, 435 cases of initial non-discriminatory reactive donations were collected over two successive periods and sub-categorized through repeated testing into the following three groups: non-repeated positive group, non-discriminated positive group, and non-repeated HBV-DNA positive group. The HBV discriminatory rate increased after repeated testing (110/435, 25.29%). According to supplementary tests, the HBV-DNA positivity rate was 65.52% (285/435), and occult HBV infection was a significantly different among groups (χ2 = 93.22, p < 0.01). The HBV serological markers and viral load in the non-repeated positive group differed from those in the other two groups, with a lower viral load and a higher proportion of false positives. The predictive model constructed using a stepwise forward algorithm exhibited high discrimination, good fit, high calibration, and effectiveness. A cost-effectiveness analysis indicated that utilizing repeated discriminatory testing and the predictive model is an extremely beneficial screening approach for non-discriminatory reactive blood donors.

Conclusion

Nearly two-third (65.52%) of the non-discriminatory reactive blood donors were HBV-DNA positive. Our innovative approach of constructing a predictive model as a supplementary screening strategy, combined with repeated discriminatory experiments, can effectively identify the infection status of non-discriminatory reactive blood donors, thereby increasing the safety of blood transfusions.

Occult Hepatitis B Infection among Blood Donors in Northwestern Greece

Background: Occult hepatitis B virus infection (OBI) is characterized by the presence of HBV DNA in individuals who test negative for hepatitis B surface antigen (HBsAg). It poses diagnostic challenges and contributes to chronic liver diseases. Understanding its epidemiology, pathogenesis and clinical outcomes remains essential. This study aimed to assess the prevalence and characteristics of OBI in Northwestern Greece. Methods:Serum samples were prospectively collected from 702 blood donors at the University Hospital of Ioannina, Greece, between February 2018 and September 2022. The investigation focused on the presence of hepatitis B virus (HBV) markers, utilizing the Abbott Architect HBsAg and HBcAb HB Qualitative II kit for the detection of HBsAg and anti-HBc, respectively. Further analysis was conducted on serum samples from individuals who tested negative for HBsAg but positive for anti-HBc, employing polymerase chain reaction (PCR) to detect HBV-DNA. In instances of OBI, sequencing and mutation analysis of the HBV pre-S/S gene were carried out for comprehensive characterization. Results:Screening revealed 56 cases (7.9%) with active HBV infection (HBsAg positive) and identified 144 cases (20.5%) indicative of past HBV infection (HBsAg negative, anti-HBc positive). Additionally, a prevalence of 5.4% (38/702) of OBI was detected. Among these, 36 cases exhibited a low HBV DNA load of less than 225 IU/mL. Notably, one OBI patient was co-infected with HIV. Furthermore, two cases of OBI with high HBV-DNA levels exceeding 200,000 IU/ml were detected. Sequencing analysis unveiled S- and pre-S mutations in four cases of OBI, including both instances with elevated HBV-DNA levels. Conclusion:In a region with a high proportion of immigrants from countries where HBV is endemic, a high prevalence of HBV infection and occult HBV infection (OBI) has been detected. Furthermore, mutations in the S gene were found to be associated with cases of OBI with high levels of HBV-DNA. However, additional research is needed to validate the results and understand the clinical relevance of specific OBI mutations for disease progression and treatment efficacy.

Occult Hepatitis B Infection among Blood Donors in Northwestern Greece

Background: Occult hepatitis B virus infection (OBI) is characterized by the presence of HBV DNA in individuals who test negative for hepatitis B surface antigen (HBsAg). It poses diagnostic challenges and contributes to chronic liver diseases. Understanding its epidemiology, pathogenesis and clinical outcomes remains essential. This study aimed to assess the prevalence and characteristics of OBI in Northwestern Greece. Methods:Serum samples were prospectively collected from 702 blood donors at the University Hospital of Ioannina, Greece, between February 2018 and September 2022. The investigation focused on the presence of hepatitis B virus (HBV) markers, utilizing the Abbott Architect HBsAg and HBcAb HB Qualitative II kit for the detection of HBsAg and anti-HBc, respectively. Further analysis was conducted on serum samples from individuals who tested negative for HBsAg but positive for anti-HBc, employing polymerase chain reaction (PCR) to detect HBV-DNA. In instances of OBI, sequencing and mutation analysis of the HBV pre-S/S gene were carried out for comprehensive characterization. Results:Screening revealed 56 cases (7.9%) with active HBV infection (HBsAg positive) and identified 144 cases (20.5%) indicative of past HBV infection (HBsAg negative, anti-HBc positive). Additionally, a prevalence of 5.4% (38/702) of OBI was detected. Among these, 36 cases exhibited a low HBV DNA load of less than 225 IU/mL. Notably, one OBI patient was co-infected with HIV. Furthermore, two cases of OBI with high HBV-DNA levels exceeding 200,000 IU/ml were detected. Sequencing analysis unveiled S- and pre-S mutations in four cases of OBI, including both instances with elevated HBV-DNA levels. Conclusion:In a region with a high proportion of immigrants from countries where HBV is endemic, a high prevalence of HBV infection and occult HBV infection (OBI) has been detected. Furthermore, mutations in the S gene were found to be associated with cases of OBI with high levels of HBV-DNA. However, additional research is needed to validate the results and understand the clinical relevance of specific OBI mutations for disease progression and treatment efficacy.

Prevalence of occult hepatitis B virus infection and characterisation of hepatitis B surface antigen mutants among adults in western Croatia

INTRODUCTION AND OBJECTIVES

Occult hepatitis B virus (HBV) infection (OBI) is characterised by low levels of hepatitis B virus (HBV) DNA in the blood/liver of patients with negative hepatitis B surface antigen (HBsAg). This study aimed to determine the OBI prevalence and virological characteristics (viral genotypes and HBsAg mutants) in patients with an "anti-HBc only" serological profile.

MATERIALS AND METHODS

A total of 24 900 serum samples were routinely screened for hepatitis B markers over a five-year period. All anti-HBc-positive/HBsAg-negative/anti-HBs-negative sera were selected and analysed for the presence of HBV DNA. Mutational analyses of the HBs gene and polymerase gene sequences were performed.

RESULTS

1749 (7.02%) sera were anti-HBc positive, and 113 (0.45%) sera had an "anti-HBc only" serological profile (HBsAg/anti-HBs negative). HBV DNA was detected in 12/113 (10.61%) "anti-HBc only" positive sera, representing 0.048% of all routinely tested samples. Due to extremely low viremia, HBV genome was successfully sequenced in only two sera where subgenotype D3 was confirmed. Mutational analyses of the S gene revealed multiple missense mutations. In addition to the M133I, Y134F, and G145R mutations, already associated with diagnostic escape, we also found nine novel OBI-related S-gene mutations - S136Y, F158L, K160N, E164G, S167L, A168V, L175S, S210I and F212C.

CONCLUSIONS

We detected multiple known and novel S gene mutations in 2/12 (16.6%) OBI cases, nevertheless, further studies are required to determine their role in the pathogenesis of OBI. Understanding the frequencies of clinically relevant HBV mutations may contribute to improvement of diagnostic protocols.

An interesting case of isolated false-negative hepatitis B surface antigen in a blood donor

BACKGROUND AND OBJECTIVES

An important requirement for a hepatitis B surface antigen (HBsAg) screening assay is reliable detection of HBsAg mutant forms, especially in blood donation. Here we investigate and describe the case of an isolated false-negative result of commercial serology HBsAg screening assay of a blood donor.

MATERIALS AND METHODS

The current donation was routinely tested for HBsAg and hepatitis B virus (HBV) DNA in the mini-pool mode nucleic acid testing (MP-NAT of six samples), and further evaluated by individual donation ID-NAT. Finally, it was quantified and sequenced. All previous donations were found to have negative HBsAg and HBV DNA, as also the subsequent sample taken 3 months after the marked donation.

RESULTS

The current donation of the 53-year-old unvaccinated female with 14 previous donations was initially HBsAg negative and HBV DNA (MP-NAT) positive. Further testing showed HBsAg positive using other HBV serological assays, antibodies to HBV core antigen immunoglobulin M positive and HBV DNA ID-NAT positive, and contained 200 IU/mL of HBV DNA. The implicated donation carried genotype D strains, subtype ayw2 (F83S, V96A, V190A, L193S, I195T, L213S, F220L). The mutations in three positions, namely amino acids T118A, P120T, and P127T, were proven subsequently.

CONCLUSION

This unique mutation combination near the target epitope of one of the immunoassay monoclonals is a possible cause of the reduced analytical sensitivity of the serology assay.

Performance Evaluation of an Improved HBsAg Assay (HBsAg NEXT) for the Detection of HBsAg Levels

Objectives  Detection of hepatitis B surface antigen (HBsAg) plays an important role in the screening and diagnosis of hepatitis B virus (HBV) infections. There is a need of highly sensitive assays with an improved lower limit of detection (LoD). Here, we evaluate the performance characteristics of the HBsAg NEXT (HBsAg new) assay in the detection of HBsAg in clinical samples. Materials and Methods  This was a cross-sectional study conducted at a tertiary care liver center in North India. The study included 439 clinical samples. The HBsAg new assay was compared to the conventional chemiluminescence-based assay (HBsAg old assay, Architect, Abbott Diagnostics, United States). The analytical sensitivity of the HBsAg new assay was evaluated by checking its performance with the second World Health Organization (WHO) international standards for HBsAg. Results  Out of 439 blood samples that were retrieved from the departmental repository stored at -80°C, 100 samples were positive and 339 samples were negative for HBsAg as per the HBsAg old assay. The HBsAg new assay showed incremental detection of HBsAg in 11 additional samples. Out of these, 5 samples were confirmed as occult HBV infection and the remaining 6 were classified as "exposed-to-virus" samples (HBV core total antibody-positive). The HBsAg new assay demonstrated a high positive significant correlation with the HBsAg old assay ( r  = 0.881, p -value < 0.001). The HBsAg new assay could effectively detect the second WHO international standards to the level of 0.0033 IU/mL. Conclusion  The HBsAg NEXT assay is a highly sensitive assay with an improved lower LoD.

Correlation of serological and molecular markers in the screening for hepatitis B virus in blood bank in northern Brazil

INTRODUCTION

In Brazil, the blood donor screening for hepatitis B virus (HBV) includes laboratory testing for serological (HBsAg and Anti-HBc) and molecular (HBV DNA) markers. This study aims to correlate serology reactive results with HBV DNA detection among blood donors with at least one HBV infection marker detected in a blood bank in northern Brazil.

METHOD

A retrospective search for HBV reactive blood donor data from January 2017 to December 2019 was performed. Serological screening was performed by chemiluminescent microparticle immunoassays Architect HBsAg and Architect Anti-HBc, whereas molecular screening was performed by the HBV nucleic acid test (HBV NAT).

MAIN RESULTS

A total of 556 HBsAg reactive results were detected, between positive (47.66%) and inconclusive (52.34%). A total of 3,658 Anti-HBc reactive results were detected, between positive (83.71%) and inconclusive (16.29%). None of the inconclusive results were associated with HBV DNA detection. The HBV DNA detection rates were 47.55% among HBsAg positive samples and 4.08% among Anti-HBc positive samples. The signal-to-cutoff (S/CO) ratio median of HBV NAT positive samples was superior in comparison to HBV NAT negative samples (p < 0.0001). The thresholds found to optimize sensitivity and specificity were 404.15 for Architect HBsAg and 7.77 for Architect Anti-HBc. Three blood donors were in the window period and 1 occult HBV infection case was detected.

CONCLUSION

High S/CO ratios were more predictive of HBV DNA detection. However, a number of HBV NAT positive samples gave low values, while some HBV NAT negative samples showed high values, reaffirming the significance of molecular testing to enhance transfusion safety.

Seroprevalence and Associated Factors of HBV and HCV among Pregnant Women Attending Antenatal Care at Debre Tabor Comprehensive Specialized Hospital, Northwest Ethiopia: A Cross-Sectional Study

Background

Infections with the hepatitis B virus (HBV) and the hepatitis C virus (HCV) are worldwide problems that particularly place a heavy burden on developing nations. HBV and HCV infections during pregnancy have a high rate of vertical transmission and harmful consequences for both the mother and the child. Therefore, this study was carried out to assess the seroprevalence and associated factors of HBV and HCV infections among pregnant women attending antenatal care at Debre Tabor Comprehensive Specialized Hospital in Ethiopia.

Methods

A cross-sectional study was conducted from March 15th to September 16th, 2022, at the Debre Tabor Comprehensive Specialized Hospital antenatal care clinic. Five milliliters of venous blood were collected from 422 pregnant women selected using a simple random sampling method. Data on sociodemographic characteristics and risk factors were collected using a prestructured questionnaire. A chi-square test, bivariate, and multivariate analyses were used to evaluate the association between dependent and independent variables. p values less than 0.05 were considered statistically significant.

Results

The seroprevalence of HBV and HCV infections was found to be 13% and 0.5%, respectively. Undertaking blood transfusion (AOR = 14.2, CI = 5.81-34.526, p = 0.001), tattooing (AOR = 3.99, CI = 1.1-14.36, p = 0.034), and dental therapy (AOR = 4.9, CI = 1.41-17.025, p = 0.012) were significantly associated with HBV infection.

Conclusion

HBV infection in pregnant women was shown to have a high endemicity (13%) in this investigation, whereas the seroprevalence of HCV infection was low (0.5%). HBV infection was significantly associated with a history of blood transfusions, tattooing, and dental therapy. Screening pregnant women for HBV and HCV infections and providing effective therapy would ensure better outcomes for the newborn. In addition, health education must be used to increase knowledge of screening and modes of transmission.

Blood Donation Screening of Transfusion-Transmissible Viral Infection Using Two Different Nucleic Acid Testing (NAT) Platforms: A Single Tertiary Care Oncology Centre Experience

Nucleic acid testing (NAT) is used to screen transfusiontransmittable infections (TTIs) in donated blood samples and provide an additional layer of blood safety. In this study, we describe our experience in screening viral TTIs using two formats of NAT: cobas® MPX2 polymerase chain reaction- based minipool NAT (PCR MP-NAT) and Procleix Utrio Plus transcription-mediated amplificationbased individual donor-NAT (TMA ID-NAT). Data routinely collected as a part of blood bank operations were retrospectively analysed over a period of 70 months for TTIs. Blood samples were initially screened for HIV, HBV, HCV, syphillis by chemiluminescence and malaria by Rapid card test. In addition to serological testing, all samples were further screened by TMA-based ID-NAT (ProcleixUltrio Plus Assay) during Jan 2015-Dec 2016, and by PCR-based MP-NAT (Cobas® TaqScreen MPX2) during Jan 2017-Oct 2020. RESULTS: A total of 48,151 donations were processed over 70 months, of which 16,212 donations were screened by ProcleixUtrio Plus TMA ID-NAT and 31,939 donations by cobas® MPX2 PCR MP-NAT. Replacement donors and male donors outnumbered voluntary donors and female donors respectively. The overall NAT yield rate of MP-NAT was 1:2281 compared to 1:3242 with ID-NAT, during the respective time period. ID-NAT detected 5 HBV infections missed by serology, whereas MP-NAT detected 13 HBV infections and 1 HCV infection missed by serology. The proportion of donations that were both seroreactive and NAT reactive was higher with MP-NAT (59.8%) compared to ID-NAT (34.6%). Cobas® MPX2MP-NAT had higher overall NAT yield rate compared to ProcleixUtrio Plus ID-NAT and confirmed a higher proportion of seroreactive donations. Due to the ease of operation, simple algorithm, cobas® MPX2 PCR based MP-NAT can be an effective solution for blood screening in India.

Liver diseases: Perspective from the Philippines

Liver diseases are a major cause of morbidity and mortality globally. In the Philippines, a lower middle-income country in Southeast Asia, liver diseases accounted for 27.3 cases per 1000 deaths. In this review, we discussed the prevalence, risk factors, and management of hepatitis B, hepatitis C and other viral hepatitis, non-alcoholic fatty liver disease, alcohol-associated liver disease, liver cirrhosis, and hepatocellular carcinoma. The true burden of liver disease in the Philippines is likely underestimated due to limited epidemiological studies. Thus, surveillance of liver disease should be strengthened. Clinical practice guidelines tailored to the local needs of the country have been developed for important liver diseases. Multisectoral cooperation among different stakeholders is needed to manage the burden of liver disease in the Philippines.

Molecular and genetic characterization of the hepatitis B virus full-length genome sequences identified in HBsAg-negative blood donors in Ural Federal District

Introduction. The World Health Organization estimates that as of 2019, more than 296 million people were living with chronic hepatitis B virus (HBV) infection. The prevalence of HBsAg-negative, occult form of the disease in blood donors varies depending on the region of the world and the sensitivity of the methods of analysis used. Considering that the genetic diversity of viruses demonstrates space and time variations and taking into account that the genetic profile of isolates in key groups, which may turn into a source of the pathogen spread, is important for forecasting of the epidemiological situation, the attention should be given to identification of HBV genotypes currently circulating among regular blood donors in regions of the Russian Federation. The aim of this work was molecular and genetic characterization of HBV genomes identified in HBsAg-negative blood donors in the Ural Federal District. Materials and methods. The study material was 1400 plasma samples obtained from HBsAg-negative blood donors in Ural Federal District. The study included the testing for HBsAg, anti-HBs IgG and anti-HBcore IgG antibodies, HBV DNA. For all identified HBV DNA containing samples, sequencing and analysis of the nucleotide sequences of the complete HBV genomes were performed. Results. The prevalence of HBV DNA was 4.93%, including 4 (0.28%) cases of false occult hepatitis B. Among anti-HBcore IgG-positive samples, HBV DNA was found in 18.08% of cases, while in persons with detected HBV DNA the anti-HBcore IgG positivity rate was 46.38%. In 8.69% of the isolates, anti-HBs IgG antibodies and viral DNA were detected simultaneously in the absence of anti-HBcore IgG. Based on phylogenetic analysis, HBV subgenotypes distribution in HBsAg-negative blood donors was as follows: D3 53.62%, D2 21.74%, D1 18.84%, C2 5.8%. The high variability in the S, C, P regions of the virus genome in the examined group was shown. In all cases of HBsAg-negative chronic HBV infection identified in blood donors, viral sequences contained at least one amino acid substitution in positions, mutations in which are associated with immune escape. In 3 (4.35%) cases mutations in reverse transcriptase region of P gene that are associated with resistance to the following drugs were identified: lamivudine, telbivudine, entecavir. Mutations in the preCore/Core regions that contribute to the progression of liver disease were also identified. Conclusion. Occult HBsAg-negative chronic HBV infection poses a threat of HBV transmission through transfusion of blood and its components due to the extremely low viral load, which does not allow the virus to be detected using routinely used diagnostic kits. The situation can be exacerbated by the abundance and diversity of virus amino acid substitutions that we have identified, including immune escape mutations, drug resistance mutations, and mutations that contribute to the progression of the disease.

Prevalence of transfusion-transmitted infections in Saudi Arabia blood donors: A nationwide, cross-sectional study

OBJECTIVES

To establish a nationwide epidemiological profile of transfusion-transmittable infection (TTI) markers among seemingly healthy blood donors to update policies required to ensure blood safety.

METHODS

A nationwide, cross-sectional study was designed to examine donor demographics and TTI prevalence during 2020 using data provided by the Ministry of Health, Saudi Arabia.

RESULTS

Collectively, a total of 375,218 whole blood units were donated, of which 32,758 (8.7%) were excluded due to TTI-related risk. The exclusion was based on a positive nucleic acid amplification test (NAT) or seroreactivity to hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), human T-cell lymphotropic virus (HTLV-I/II), syphilis, or malaria. Notably, the central (37.6%) and southern (33%) regions were the epicenters of TTI-reactive blood donors. Hepatitis B virus markers accounted for 85.7% and were the overall most prevalent of TTI-positive donations, followed by HCV at 5.9% and syphilis at 5.6%. In particular, anti-HBc and HBsAg were most prevalent in the south, while HBV NAT was highest in the center.

CONCLUSION

Hepatitis B virus, HCV, and syphilis carry the greatest risk of TTI in Saudi Arabia. Including HBsAg screening is a necessary precautious measure to maintain blood safety.

Re-Entry Evaluation of Chinese Blood Donors with Unconfirmed Hepatitis B Screening Results

The hepatitis B virus (HBV) remains a high priority for Chinese blood banks due to the high prevalence of infection. HBV blood safety has been significantly improved by the implementation of highly sensitive and specific serological and molecular HBV screening assays. The multiplication of viral markers tested and the ever-increasing analytical sensitivity of the tests can make the interpretation of the results difficult. False-positive or indeterminate results may lead to permanent donor deferrals and conflicts between donors and blood banks. To avoid blood shortages, blood services aim to limit unnecessary donor losses by developing procedures for the re-entry of donors temporarily deferred due to an unconfirmed HBV reactivity. The development of such procedures based on donor follow-up and HBV confirmation remains limited. A review of the scarce data available revealed considerable heterogeneity in testing methods and re-entry algorithms, limited validation studies, and a lack of accurate assessment of the residual infectious risk potentially associated with donor re-entry. In conclusion, systematic and widely validated confirmatory testing and prolonged follow-up are essential for safe re-entry of temporary deferred donors. Standardization of HBV testing methods and the establishment of dedicated expert laboratories are needed because of the complexity of HBV infection in blood donors.

Insights on 21 Years of HBV Surveillance in Blood Donors in France

Hepatitis B virus (HBV) infection is the most frequent viral infection found in blood donors (BDs) in France. We analyzed the epidemiological and sero-molecular data on HBV infection gathered over the past two decades by the French haemovigilance surveillance network, blood screening laboratories, and the national reference center for transfusion infectious risks (NRC). Between 2000 and 2020, 6149 of the 58,160,984 donations (1.06/10,000) tested HBV positive, 98% of them from first-time blood donors (FTBDs). In addition, 2212 (0.0071%) of the 30,977,753 donations screened for HBV DNA tested DNA positive, of which 25 (1.1%) were positive only for this marker. HBV prevalence decreased by 2.8-fold and the residual risk for transfusion-transmitted HBV infection decreased 13-fold and was divided by 13. The major risk factor for HBV infection was the origin of donors (endemic country, 66.5%), followed by parenteral exposure (10.7%). In the whole HBV-positive BD population, genotype D was predominant (41.8%), followed by genotypes A (26.2%) and E (20.4%), reflecting the geographical origin of donors. The low and decreasing prevalence and incidence of HBV infection in French BDs, coupled with a screening strategy using three HBV markers (HBsAg, anti-HBc and DNA), ensures a high level of blood safety, further reinforced by the implementation of pathogen-reduction measures.

Global epidemiology of occult hepatitis B virus infections in blood donors, a systematic review and meta-analysis

This study aimed to assess the global prevalence of occult hepatitis B in blood donors. We searched PubMed, Web of Science, Global Index Medicus, and Excerpta Medica Database. Study selection and data extraction were performed by at least two independent investigators. Heterogeneity (I2) was assessed using the χ2 test on the Cochran Q statistic and H parameters. Sources of heterogeneity were explored by subgroup analyses. This study is registered with PROSPERO, number CRD42021252787. We included 82 studies in this meta-analysis. The overall prevalence of OBI was 6.2% (95% CI: 5.4-7.1) in HBsAg negative and anti-HBc positive blood donors. Only sporadic cases of OBI were reported in HBsAg negative and anti-HBc negative blood donors. The overall prevalence of OBI was 0.2% (95% CI: 0.1-0.4) in HBsAg negative blood donors. The prevalence of OBI was generally higher in countries with low-income economic status. The results of this study show that despite routine screening of blood donors for hepatitis B, the transmission of HBV by blood remains possible via OBI and/or a seronegative window period; hence there is a need for active surveillance and foremost easier access to molecular tests for the screening of blood donors before transfusion.

Occult Hepatitis B Virus Infection: An Update

Occult hepatitis B virus (HBV) infection (OBI) refers to a condition in which replication-competent viral DNA is present in the liver (with detectable or undetectable HBV DNA in the serum) of individuals testing negative for the HBV surface antigen (HBsAg). In this peculiar phase of HBV infection, the covalently closed circular DNA (cccDNA) is in a low state of replication. Many advances have been made in clarifying the mechanisms involved in such a suppression of viral activity, which seems to be mainly related to the host's immune control and epigenetic factors. OBI is diffused worldwide, but its prevalence is highly variable among patient populations. This depends on different geographic areas, risk factors for parenteral infections, and assays used for HBsAg and HBV DNA detection. OBI has an impact in several clinical contexts: (a) it can be transmitted, causing a classic form of hepatitis B, through blood transfusion or liver transplantation; (b) it may reactivate in the case of immunosuppression, leading to the possible development of even fulminant hepatitis; (c) it may accelerate the progression of chronic liver disease due to different causes toward cirrhosis; (d) it maintains the pro-oncogenic properties of the "overt" infection, favoring the development of hepatocellular carcinoma.

[Prevalence of viral hepatitis B markers among blood donors in the Republic of Guinea]

INTRODUCTION

The problem of transfusion safety in relation to parenteral viral hepatitis still remains relevant. Viral hepatitis B (HB) remains the most common viral infection transmitted through transfusion procedures. One of the natural phases of chronic hepatitis B (CHB) is occult hepatitis B infection (OBI), characterized by an undetectable HBsAg (regardless of the other serological markers content) in the presence of hepatitis B virus (HBV) DNA in the liver tissue and an extremely low, up to undetectable, level of viral load in the blood. In the Republic of Guinea, as in most countries on the continent, the prevention of HBV transmission through transfusion is still based on HBsAg serological testing of donors only. In this connection, OBI remains as a potential threat to blood transfusion safety. Detection of HBV DNA is a reliable preventive measure against transmission of the virus from donors with HBsAg-negative HBV infection, especially in highly endemic regions. In this regard, the study was conducted to substantiate recommendations for improving blood safety against the background of significant HBV prevalence in the Republic of Guinea.The aim of the work was the evaluation of serological and molecular markers of HBV infection in blood donors in the Republic of Guinea.

MATERIAL AND METHODS

We examined 250 blood samples obtained from donors living in Conakry, Republic of Guinea. Samples were tested for the presence of serological (surface antigen, HBsAg; antibodies (ABs) to surface (anti-HBs IgG) and core (anti-HBc IgG) antigens) and molecular (DNA) markers of HBV infection.

RESULTS AND DISCUSSION

The overall detection rate of hepatitis B markers was 83.2%; HBsAg was detected in 16.4% of all individuals. The high incidence of HBsAg in men (19.55%) compared to women (8.45%) was shown, the relative risk of HBV infection with the formation of HBsAg-positive chronic hepatitis B in males was also significantly higher. The prevalence of the HBV DNA in the study group was 30.4%, the OBI cases accounted for 15.6%. The prevalence of this form of the disease was shown in donors aged 30-49 years (24.78%), in the group of people younger than 30 years, the incidence was lower (8.73%), and at the age of over 50 years, OBI was not detected. Based on the phylogenetic analysis of 76 virus isolates, it was shown that genotype E prevails in the examined group (85.53%).Cases of pathogen DNA detection occurred in HBsAg-negative blood donors in the presence of anti-HBs IgG (n = 4), as well as in the simultaneous presence of ABs anti-HBs IgG and anti-HBc IgG (n = 7). The viral load exceeded 200 IU/ml in OBI samples. Escape mutations were detected by sequencing in each OBI sample, contributing to the virus escaping from diagnostic based on screening for HBsAg.

CONCLUSION

Assessment of the prevalence viral hepatitis B markers in blood donors, determination of genotypes and clinically significant mutations of virus variants are necessary to ensure safe medical manipulations, control and prevention of the spread of this infectious agent.

The Course of Anti-HBc Antibodies over Time in Immunocompromised Hosts

Hepatitis B virus infection results in the appearance of anti-HBc antibodies that normally persist lifelong. We analyzed the course of anti-HBc antibodies overtime, focusing on patients with a permanent loss or fluctuating anti-HBc antibodies. From 120,531 patients tested for anti-HBc antibodies (Architect, Abbott) from January 2006 to December 2020, ≥4 serial values were available in 8098 and permanent or intermittent anti-HBc loss was observed in 139 patients. It was relatively frequent in baseline anti-HBc positive, immunocompromised patients with available serial measurements of anti-HBc overtime (13% of hematologic/oncologic patients, 10% of solid organ transplant recipients, and 6% of HIV patients compared to 3% in patients with other diseases). In the same period, 12,607 samples were tested for HBsAg, anti-HBc antibodies, and HBV DNA—in nine cases we detected HBV DNA with undetectable anti-HBc and HBsAg. In four out of nine cases contamination of the PCR during processing was the likeliest cause, in another four, no further data were available, while in one the HBV DNA was later followed by a temporary anti-HBc seroconversion. In conclusion, permanent or intermittent anti-HBc loss is more common in immunocompromised hosts than in patients with other underlying diseases. Furthermore, anti-HBc and HBsAg assays can be safely used to exclude an active HBV infection, even in immunocompromised hosts.

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

BACKGROUND

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.

MATERIALS AND METHODS

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.

RESULTS

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.

DISCUSSION

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.

Comparative assessment of immunochromatography and ELISA diagnostic tests for HBsAg detection in PCR-confirmed HBV infection

INTRODUCTION AND AIMS

Viral hepatitis, which appears most frequently at birth or during childhood, is a disease whose transmission routes include tears, bile, sexual fluids, sweat, milk, urine, feces, and saliva. The aim of the present study was to analyze the specificity of the immunochromatographic and ELISA diagnostic tests for hepatitis B surface antigen and compare them with PCR testing.

MATERIALS AND METHODS

The study sample was made up of 140 men and 60 women referred to the Urmia Medical University hospital to undergo PCR testing for HBV diagnosis. The ELISA test was performed using the Pioneer Medicine Company kit (Tehran, Iran).

RESULTS

The results of the HBs-Ag rapid test and the ELISA test were compared with the PCR test. The HBs-Ag rapid test had 97% sensitivity and 91% specificity, whereas the ELISA test had 78% sensitivity and 76% specificity.

DISCUSSION AND CONCLUSION

According to our results, the immunochromatographic test was accurate for diagnosing HBs-Ag in blood and the ELISA test had acceptable sensitivity and specificity, compared with PCR testing.

Assessment of hepatitis B surface antigen negative blood units for HBV DNA among replacement blood donors in a hospital based blood bank in Nigeria

Background

Hepatitis B virus infection is one of the greatest threats to blood safety all over the world. The laboratory algorithm based on only the detection of hepatitis B surface antigen (HBsAg) leaves a gap for infected HBsAg negative donors to donate blood during the “window period” (WP) and late stages of infection.

Objective

To estimate the frequency of the presence of HBV deoxyribonucleic acid (DNA) in HBsAg negative blood units screened using two different assays for HBsAg in a high endemic region.

Methods

Frozen serum aliquot of 100 replacement blood donors who donated blood units that were HBsAg negative were retrieved and tested for HBV DNA. Sample positive for HBV DNA was sequenced by Sanger's method, genotyped and the viral load was determined.

Results

One sample (1%) was positive for HBV DNA. The HBV viral load of the sample was 768,000 IU/ml. The partial S-gene of the Hepatitis B virus isolated was genotype E using the NCBI viral genotyping tool.

Conclusions

There is still a risk of HBV infected blood unit escaping detection when donor testing is limited to HBsAg screening. The use of NAT which can substantially reduce HBV infected blood donors from the donor pool should be considered.

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.

Prevalence of HBV and HCV Infections in Iranian Blood Donors; An Updated Systematic Review and Meta-Analysis

BACKGROUND Awareness of the prevalence of hepatitis B (HBV) and hepatitis C virus (HCV) infections, as blood transmitted infections, among blood donors can help policymakers improve the guidelines, share experiences, and estimate the blood safety over the country and in the region. We aimed to determine the prevalence of HBV and HCV infection in Iranian blood donors based on the present published literature. METHODS A meta-analysis was carried out based on the results of an electronic literature search in the international and national databases for all articles published until October 2020. We selected studies that had appropriate sampling and valid statistical analysis as well as proper measurement methods. The heterogenic indices of the studies were determined using Cochran's (Q) and I-square (I2) tests. According to the heterogeneity results, a fixed or random-effects model was implemented to estimate the pooled prevalence of HBV and HCV. Meta-regression was conducted to explore the suspected sources of heterogeneity. RESULTS We included 61 and 58 eligible studies related to HBV and HCV, respectively. The pooled prevalence of HBV was 0.57% (95% confidence interval (CI): 0.47 - 0.67, I2: 99.9%) among the blood donors. The range of prevalence rates of HBV was between 0.10% and 2.34% in different areas of Iran. The pooled prevalence of HCV was 0.22% (95% CI: 0.20 - 0.24, I2: 98.64%) in blood donors, which varied between 0.02% and 1.09% in separate locations. Subgroup and meta-regression analyses revealed that the year of publication, geographical location, and quality of the studies probably generated the heterogeneity. CONCLUSION The prevalence of HBV and HCV decreased steadily in Iranian blood donors during the past two decades. It should be asserted that most of the health policies and safety measures taken in recent years in Iran have been effective and promising.

Challenges in transfusion-transmitted infection screening in Sub-Saharan Africa

In Sub-Saharan Africa, high clinical demand for transfusion faces endemic bloodborne infections and limited resources. Blood screening for transfusion-transmitted bloodborne pathogens is the cornerstone of blood safety. Although there have been substantial improvements over the years, challenges in transfusion-transmitted infection screening that have been identified repeatedly long ago still need to be addressed. Affordability and sustainability of state-of-the-art quality assessed serological and molecular assays, and associated confirmation strategies remain of real concern. In addition, limited resources and infrastructures hamper the development of adequate facilities, quality management, and staff qualification, and exacerbate shortage of reagents and equipment maintenance. It is also important to maintain effort in constituting pools of repeat voluntary non-remunerated donors. Alternative strategies for blood screening that take into account local circumstances might be desirable but they should rely on appropriate field evaluation and careful economic assessment rather than dogma established from high-resource settings.

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

BACKGROUND AND OBJECTIVES

Taiwan is among the few hepatitis B virus (HBV) high-endemic countries that implement universal mini-pool nucleic acid testing (MP-NAT) and hepatitis B surface antigen (HBsAg) testing together with confirmatory individual donor nucleic acid testing (ID-NAT) for its blood supply since 2013. The aim of this study was to reappraise the value of HBsAg test in Taiwan's HBV testing strategy.

MATERIALS AND METHODS

A Markov model was constructed, and cost-effectiveness analysis was conducted in order to reappraise the existing HBV screening strategy in Taiwan.

RESULTS

The incremental cost-effectiveness ratio (ICER) for the current testing strategy in Taiwan was estimated to be $US 443 154 per quality-adjusted life year (QALY) gained. This is almost six times the willingness-to-pay (WTP) threshold that reflects local preferences.

CONCLUSION

Universal HBsAg and MP-8-NAT together with confirmatory ID-NAT testing prevents a significant amount of HBV infections from entering the Taiwan blood supply. However, this comes at a disproportionate increase in cost.

The contribution of more sensitive hepatitis B surface antigen assays to detecting and monitoring hepatitis B infection

BACKGROUND

Hepatitis B surface antigen (HBsAg) remains the main viral marker for screening and monitoring hepatitis B virus (HBV) infection. The quantification limit of most current HBsAg assays is around 0.05 IU/mL. The Lumipulse-G-HBsAg-Quant assay (Fujirebio) claims to obtain a tenfold improvement in sensitivity. This study aimed to assess the performance of this assay in detecting low HBsAg levels in clinical samples.

METHODS

Three panels of stored frozen samples were selected on the basis of HBV-DNA and HBsAg values obtained previously with routine techniques. Panels 1 (n=13) and 2 (n=52) consisted of DNA-positive/HBsAg-negative samples from individuals in the window period and with occult HBV infection respectively. Panel 3 comprised 23 samples with low or discrepant HBsAg screening results. All these samples were tested retrospectively with the DiaSorin and Fujirebio HBsAg assays.

RESULTS

Sixteen out of 65 samples (25 %), initially screened HBsAg negative, were reactive only with the Fujirebio assay (median value= 0.015 IU/mL; IQR= 0.012): three (23 %) samples from panel 1 and 13 (25 %) from panel 2. Thirteen of these 16 (81 %) had HBsAg values below 0.03 IU/mL with the DiaSorin assay. In panel 3, 22 (96 %) samples were quantified successfully with the Fujirebio assay (median: 0.32 IU/mL; IQR: 1.20) and 19 (83 %) with the DiaSorin assay (median: 0.31 IU/mL; IQR: 0.65). Concentrations obtained with the two assays showed good correlations (r=0.893, Spearman).

CONCLUSIONS

HBsAg assays with enhanced analytical sensitivity could improve HBV serological profile interpretation with possible consequences on clinical management of infected patients, and on blood transfusion safety.

Comprehensive analysis of hepatitis B virus infections in blood donors in southern China that are surface antigen positive but nucleic acid testing negative

BACKGROUND

Hepatitis B virus (HBV) infection is one of the major concerns for the safety of blood transfusion in high-prevalent countries such as in China. Prior studies outside of China have shown hepatitis B surface antigen (HBsAg) false-reactive rate of 0.02% to 0.04%. Similarly, false-negative HBsAg and HBV DNA results may occur in infected donors. Our study analyzed HBsAg enzyme-linked immunosorbent assay (ELISA)-reactive but NAT-negative donations in Shenzhen Blood Center, China.

STUDY DESIGN AND METHODS

HBsAg ELISA-positive/NAT-negative plasma samples identified from screening 101,025 donations during 2017-2018 were analyzed by molecular and serologic tests including neutralization, chemiluminescence immunoassays, and various HBV DNA amplification assays. Molecular characterizations of HBsAg-positive/NAT-negative samples were determined by quantitative polymerase chain reaction (qPCR) and nested PCR amplification of the basic core and precore promotor regions (295 base pairs) and HBsAg (S) region (496 base pairs).

RESULTS

Screening of 101,025 eligible blood donations identified 157 (0.16%, 95% confidence interval, 0.13%-0.18%) HBsAg ELISA-positive/NAT-negative plasma samples; of those, 71 (45.2%) were HBsAg confirmed positive by further HBsAg testing and DNA positive by molecular tests with increased sensitivity. Of the 71, all but one was antibody to hepatitis B core antigen reactive without antibody to hepatitis B surface antigen, yielding one recent (window-period) HBV infection. Of the remaining donations, 80 (51%) were not considered as HBV-infected donors, and 6 (3.8%) were interpreted as indeterminate since HBsAg results were discordant with unconfirmed HBV DNA results. In the 71 confirmed positives, HBsAg levels ranged from 0.05 to 400 IU/mL and HBV DNA from 6 to 2654 IU/mL; however, the correlation between the two was weak (R² = 0.24).

CONCLUSION

Fewer than half of HBsAg ELISA-positive/NAT-negative samples were confirmed as HBsAg positive. Our study demonstrates that in highly HBV-endemic countries, assays with high sensitivity and specificity may be required.

Occult hepatitis B infections and anti-HBc prevalence at a resource-limited blood bank in Mexico

OBJECTIVES

To identify blood donors with occult hepatitis B infections (OBIs), determine the prevalence of antibody to hepatitis B core antigen (anti-HBc) positivity and estimate the impact of anti-HBc screening on donor deferral at CETS-Veracruz (Mexico).

BACKGROUND

Hepatitis B virus infection is a major concern in transfusion medicine. Mexican regulations only mandate screening for hepatitis B surface antigen (HBsAg), and there are no requirements regarding testing for anti-HBc or use of a nucleic acid test (NAT). There is, therefore, limited information about the prevalence of anti-HBc positivity and occult hepatitis B among blood donors in Mexico.

METHODS

This retrospective study examined individuals who donated blood to CETS-Veracruz from June 2014 to June 2017. All donors were serologically examined according to Mexican health regulations, and the prevalence of anti-HBc positivity was determined. A NAT was used to identify individuals with OBIs.

RESULTS

We analysed the data of 28 016 blood donors. Over 4 years, the average prevalence of anti-HBc positivity was 1.05%. The risk factors for anti-HBc positivity were low education and age over 50 years. There were nine donors with OBIs.

CONCLUSION

The presence of donors with OBIs in CETS-Veracruz and other Mexican blood banks highlights the need to mandate the implementation of anti-HBc screening in Mexico.

Performance characteristics of the high sensitivity Alinity i & ARCHITECT HBsAg Next Qualitative/Confirmatory assays

Despite improvement in vaccinations, Hepatitis B remains a major health concern due to the difficulty of prevention even in low endemic areas such as Europe. In this report we describe the performance characteristics of the new HBsAg Next Qualitative and HBsAg Next Confirmatory assays designed for blood screening and diagnostic purposes on the Alinity i and ARCHITECT fully automated systems. The new assays were evaluated in comparison to the ARCHITECT HBsAg Qualitative II and Confirmatory assays on seroconversion, analytical sensitivity, and mutant panels along with testing of over 400 clinical positive samples demonstrating excellent improvements in sensitivity. Additionally, specificity was shown to be improved with testing of over 6000 donors and 240 diagnostic specimens. Overall, the Alinity i & ARCHITECT HBsAg Next assays have taken a step forward in improving the detection of Hepatitis B virus.

Quality and safety measures in transfusion practice: The experience of eight southern/eastern Mediterranean countries

BACKGROUND AND OBJECTIVES

Blood transfusion is inherently associated with risks, and little is known regarding the available quality and safety measures in developing countries. No studies or census has been carried out, and therefore, no data on this compelling issue are available.

MATERIALS AND METHODS

Data emanating from eight Arabic eastern/southern Mediterranean countries who responded to five surveys were collected and tabulated.

RESULTS

Asepsis during phlebotomy, screening for serological and immuno-haematological parameters and appropriate storage conditions are maintained across all countries. Variations in blood component processing exist. Universal leucoreduction is systematically applied in Lebanon. Nucleic acid testing is only performed in Egypt. Aphaeresis procedure, leucoreduction and quality control for blood components are virtually inexistent in Mauritania. Written donor questionnaire is absent in Algeria and Tunisia. Most donor deferral periods for infectious agents are inconsistent with international standards.

CONCLUSION

Gaps in the processing and in the quality/safety measures applied to the manufacture of blood components are quite evident in most eastern/southern Mediterranean countries. The decision of establishing an effective collaboration network and an independent body - aside from WHO - composed of specialists that oversees all transfusion activities in these countries is certainly a crucial step towards ensuring an optimum level of blood safety.

THE IMPACT OF POSITIVE ANTI-HBC MARKER ON PERMANENT DEFERRAL OF VOLUNTARY BLOOD DONORS IN EASTERN CROATIA AND ESTIMATION OF OCCULT HEPATITIS B VIRUS INFECTION RATE

Recently an increase has been reported in the number of HBV transmissions from anti-HBc positive blood donors that were repeatedly negative in HBsAg and nucleic acid testing using the most sensitive tests available. The aim of the study was to show the effect of anti-HBc antibody testing performed in 2006 on permanent deferral of voluntary blood donors (VBDs), and to estimate occult hepatitis B infection (OBI) rate in this population after the introduction of mandatory molecular testing in the 2013-2016 period. More than 30,000 blood donations collected during the 2005-2007 period and more than 14,000 VBDs having donated blood during the 2013-2016 period after the introduction of molecular testing from eastern Croatia were included in the study. Serologic testing was performed with HBsAg assay throughout the study period, and anti-HBc assay was only performed in 2006. As part of the confirmatory algorithm testing, all HBsAg positive and unclear results were tested with molecular tests. Anti-HBc prevalence among VBDs in 2006 was 1.5%, with a rate of 1:197, whereas HBsAg prevalence was stable from 2005 to 2007 (0.04%, 0.1% and 0.1%, respectively). The calculated OBI rate from 2013 to 2016 was 1:30,250. Ten of 161 (12.4%) VBDs had serologic anti-HBc-only pattern. Anti-HBc testing in 2006 resulted in statistically more deferrals of VBDs compared to 2005 and 2007, and to the rest of Republic of Croatia. The strategy of universal anti-HBc testing of VBDs in addition to the existing HBsAg and molecular screening could be an additional measure to prevent HBV transmission by blood and blood components.

Follow-up program for blood donors with unconfirmed screening results reveals a high false-positive rate in Dalian, China

BACKGROUND

Chinese blood donors with unconfirmed serological and/or molecular screening results are deferred permanently. This study investigated the implementation and performance of a follow-up program aiming to improve the notification and management of deferred donors in Dalian, China.

STUDY DESIGN AND METHODS

From January 2013 to February 2018, 411,216 donations were tested for HBsAg, anti-HCV, anti-HIV/HIV antigen, and antibodies to Treponema pallidum. HBV, HCV, and HIV nucleic acid testing (NAT) was performed in mini-pools of six or in individual donations (IDs). Reactive donations were evaluated further with alternative serological assays and ID-NAT re-testing. A follow-up procedure was developed to evaluate a subset of deferred donors that were either potential NAT yield cases, serology non-reactive and NAT non-repeated reactive (NRR), or serology NRR irrespective of NAT result.

RESULTS

Serological and molecular routine, plus supplemental testing, identified HBV, HCV, HIV, and TP in 503 (0.12%), 392 (0.09%), 156 (0.04%), and 2041 (0.49%) donations, respectively. Overall, 683 of 4156 (16.4%) eligible donors and 205 donors deferred prior 2013 participated in the program. They included 664 serology NRR and 224 NAT yield cases, and 58.8% repeat donors. All markers combined, follow-up documented false reactivity, primary acute infections, and OBI in 61.9% (550/888), 3.3% (29/888), and 12.8% (114/888) of these donors, respectively. Isolated anti-HBc or anti-HBs reactivity was observed in 22% of cases.

CONCLUSION

Follow-up testing refined infection status in 78.0% (693/888) of deferred donors with unconfirmed screening results. This high false-positive rate encouraged to reevaluate the current screening strategies and to consider donor reentry.

Occult hepatitis B infection among blood donors from Yaoundé, Cameroon

BACKGROUND

In Cameroon, the prevention of hepatitis B virus (HBV) transmission by blood transfusion is still only based on hepatitis B surface antigen (HBsAg) screening. However, occult HBV infection (OBI) characterised by the absence of detectable HBsAg and low level of viral DNA remains a potential threat for blood safety. The prevalence of OBI was investigated in blood donors from Yaoundé to provide evidence-based recommendations to improve HBV blood safety.

MATERIAL AND METHODS

Blood donations from August 1st, 2016 to March 31st, 2017 were routinely screened for HBV, human immunodeficiency virus (HIV), and hepatitis C virus (HCV) infections (Murex HBsAg Version 3, Murex HIV Ag/Ab Combination, and Murex HCV Ag/Ab Combination [DiaSorin]). Additional HBV investigations were performed, including hepatitis B core antibody ([HBc] Monolisa Anti-HBc PLUS; BIO-RAD) and HBV DNA tested in minipools of two samples using the quantitative Cobas Taqman HBV assay (Roche; LoQ: 6 IU/mL) and HBV DNA genotyping by sequencing.

RESULTS

Of 1,162 donations analysed, 91 (7.8%) were reactive for HBsAg. All of them were also anti-HBc positive. Among the 1,071 HBsAg negative samples, 522 (48.7%) were reactive for anti-HBc. Six (0.56% of all donations) samples fulfilled the consensus definition of OBI and showed low HBV DNA loads (all <6 IU/mL). Following nested polymerase chain reaction amplifications, HBV DNA sequences were obtained for 4 of these samples (1 nearly whole genome [3123 nt], 2 Pre-S/S regions [1,356 nt], and 1 S region [445 nt]). Phylogenetic analysis identified genotype E in all samples.

DISCUSSION

Around 1 in 100 Cameroonian blood donors screened who resulted HBsAg negative and anti-HBc positive carried occult HBV infection. HBsAg alone for screening prospective donors is not sufficient to eliminate the risk of HBV transfusion transmission in Cameroon, and because anti-HBc screening does not seem to be feasible without compromising blood supply, implementation of HBV nucleic acid testing could be considered when possible.

Improved detection of early acute, late acute, and occult Hepatitis B infections by an increased sensitivity HBsAg assay

BACKGROUND

Hepatitis B surface antigen (HBsAg) is the primary marker for diagnosis of acute and chronic hepatitis B. Although HBsAg assays have undergone continuous improvement, gaps remain in the detection of early and late acute infection and occult hepatitis B infection (OBI).

OBJECTIVES

The performance of a prototype, improved sensitivity HBsAg assay run on the ARCHITECT and Alinity instruments was evaluated for detection of early and late acute infection and OBI.

STUDY DESIGN

Seventy seven early acute samples [positive only for hepatitis B viral DNA (HBV DNA)], twelve seroconversion panels spanning late acute infection, and 101 occult samples (HBsAg negative, positive for HBV DNA and anti-HBc) were tested with the prototype assay and ARCHITECT HBsAg Qualitative II. HBsAg gene sequencing was performed to determine genotype and mutations in the immunodominant region.

RESULTS

Compared with ARCHITECT HBsAg Qualitative II, the prototype assay showed increased detection of NAT yield samples (28/77, 36.4%,), late acute samples (≥13 days longer detection of HBsAg for 6/12 panels), and OBI samples (11/101, 10.9%). HBsAg sequence data were obtained for 62 samples. Genotypes represented were A1, A2, B2, B4, C1, C2, C5, D3, E, and H. HBsAg escape mutations were found in 4.8% of NAT yield and 38.9% of OBI samples sequenced. Prototype assay values for 188 samples were equivalent on the ARCHITECT and Alinity instruments.

CONCLUSIONS

The new prototype HBsAg assay will be of diagnostic value in providing improved detection of early acute, late acute, and occult HBV infections.

Update of the statements on biology and clinical impact of occult hepatitis B virus infection

In October 2018 a large number of international experts with complementary expertise came together in Taormina to participate in a workshop on occult hepatitis B virus infection (OBI). The objectives of the workshop were to review the existing knowledge on OBI, to identify issues that require further investigation, to highlight both existing controversies and newly emerging perspectives, and ultimately to update the statements previously agreed in 2008. This paper represents the output from the workshop.

Preventing Hepatitis B in the Dialysis Unit

Patients with end-stage renal disease are at risk for contracting hepatitis B virus (HBV) because of their exposure to blood products and compromised immune status. Despite a decrease in the incidence of HBV infection, continued vigilance in the form of surveillance is imperative in preventing the spread of this robust DNA virus. Regular review of serologic markers with isolation and decontamination practices as appropriate are paramount to maintaining a safe environment for dialysis to occur. Vaccination response rates are known to be suboptimal in the hemodialysis population. This has been attributed to altered cellular and humoral immunity. Vaccine response rates are improved with modification of the vaccine schedule. Explicit care must be taken to ensure patients are screened on entry to the dialysis unit especially after hospitalization, and periodically thereafter. This review discusses HBV in terms of epidemiology, prevention strategies, vaccination options, and identifying serologic markers. Finally, our experience with incorporation of an alert system incorporated within the electronic medical record that highlights markers of infection and immunity is described.

Performance characteristics of a fast real-time PCR assay for hepatitis B virus DNA quantification

Detection of hepatitis B virus (HBV) DNA is particularly important for detection of early acute and of occult HBV infection. On the other hand, HBV DNA detection and quantification are essential to diagnose and treat chronic HBV infection. In this study, we evaluated the performance of the real-time PCR SUMASIGNAL VHB (un paso) (Immunoassay Center, Cuba). The clinical and analytical specificity of the assay was 100%. Intra-assay and inter-assay coefficients of variation ranged from 0.50 to 2.53% and from 1.23 to 3.03%, respectively. A strong correlation (r=0.926; P<0.001) with the COBAS^® AmpliPrep/COBAS^® TaqMan^® HBV Test, v2.0 (Roche Molecular Systems, Inc.) was obtained. The limit of detection using the third WHO international standard for HBV DNA was 377.47 IU/mL. The test was able to detect the most prevalent HBV genotypes (A-G) equally well. In conclusion, the SUMASIGNAL VHB (un paso) is a sensitive, specific, precise and accurate assay for the quantification of serum and plasma HBV DNA. Thus, this simple and fast real-time PCR test can be used as an aid in diagnosing an HBV infection and monitoring drug efficacy.

New and Old Biomarkers for Diagnosis and Management of Chronic Hepatitis B Virus Infection

Tests to detect the presence and activity of hepatitis B virus (HBV) are the cornerstones of diagnosis and management. Assays that detect or measure serum levels of HB surface antigen, HB surface antibody, and HB core antibody are used to identify patients with exposure to HBV, whereas other tests provide information on the level of virus replication, presence of specific variants, and presence of virus reservoirs. Newer diagnostic tests, used only in research settings so far, aim to quantify levels of intrahepatic HBV replication. Other tests have been developed to detect HBV infection in resource-limited settings. We review point-of-care tests (essential in global screening efforts), standard diagnostic tests used in routine clinical management, and newer tests that might be used in clinical trials of agents designed to cure HBV infection.