Occult hepatitis B virus infection: implications in transfusion

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.

Reconstruction of the historic time course of blood-borne virus contamination of clotting factor concentrates, 1974-1992

Factor VIII and IX clotting factor concentrates manufactured from pooled plasma have been identified as potent sources of virus infection in persons with hemophilia (PWHs) in the 1970s and 1980s. To investigate the range and diversity of viruses over this period, we analysed 24 clotting factor concentrates for several blood-borne viruses. Nucleic acid was extracted from 14 commercially produced clotting factors and 10 from nonremunerated donors, preserved in lyophilized form (expiry dates: 1974-1992). Clotting factors were tested by commercial and in-house quantitative PCRs for blood-borne viruses hepatitis A, B, C and E viruses (HAV, HBV, HCV, HEV), HIV- types 1/2, parvoviruses B19V and PARV4, and human pegiviruses types 1 and 2 (HPgV-1,-2). HCV and HPgV-1 were the most frequently detected viruses (both 14/24 tested) primarily in commercial clotting factors, with frequently extremely high viral loads in the late 1970s-1985 and a diverse range of HCV genotypes. Detection frequencies sharply declined following introduction of virus inactivation. HIV-1, HBV, and HAV were less frequently detected (3/24, 1/24, and 1/24 respectively); none were positive for HEV. Contrastingly, B19V and PARV4 were detected throughout the study period, even after introduction of dry heat treatment, consistent with ongoing documented transmission to PWHs into the early 1990s. While hemophilia treatment is now largely based on recombinant factor VIII/IX in the UK and elsewhere, the comprehensive screen of historical plasma-derived clotting factors reveals extensive exposure of PWHs to blood-borne viruses throughout 1970s-early 1990s, and the epidemiological and manufacturing parameters that influenced clotting factor contamination.

The seroepidemiology of isolated core antibody against hepatitis B among Taiwanese adults - A large hospital-based study

BACKGROUND/PURPOSE

This study aims to investigate the prevalence of isolated core antibodies against hepatitis B (IAHBc) in different birth cohorts using a large medical record database.

METHODS

Hepatitis B viral serological test data were collected from a chart cloud database at a medical center in Taiwan between January 2006 and December 2018. The data collected included birth year, sex, hepatitis B viral markers (HBsAg, anti-HBs or anti-HBc), and hepatitis B vaccination records. Enrolled patients were grouped according to their birth year into three categories: ≤ 1986, 1987-1992, and ≥ 1993, which correspond to no neonatal hepatitis B immunization, plasma-derived HB vaccine (PDHBV), and recombinant hepatitis B vaccine (RHBV), respectively. Prevalence of hepatitis B viral seromarkers, including IAHBc, was calculated by sex, age groups, and birth cohorts. Those who underwent repeated hepatitis B serology tests were included for further analysis to follow up their serostatus.

RESULTS

A total of 117,335 adults with complete hepatitis B serologic data were analyzed. Among them, 6641 individuals (5.7 %) were found to have IAHBc. The prevalence of IAHBc was 11.4 %, 0.8 %, and 0.3 % among those born before 1986, between 1987 and 1992, and after 1992, respectively. Among the 690 subjects with repeated blood tests and complete hepatitis B serologic data, 551 cases (79.9 %) remained IAHBc. The other cases included resolved infection status (13.9 %), seronegativity for three HB seromarkers (3 %), and carrier of hepatitis B virus (2.3 %).

CONCLUSION

The management of individuals with IAHBc should be tailored to their age, vaccination status, and risk factors for occult hepatitis B viral infection.

Effect of S-region mutations on HBsAg in HBsAg-negative HBV-infected patients

BACKGROUND

Occult HBV infection (OBI) is a special form of hepatitis B virus (HBV) infection that may cause Liver cirrhosis and hepatocellular carcinoma, causing significant harm to patients. Given the insidious nature of OBI, it is usually not easy to be detected. Most of the samples currently studied are concentrated on blood donors, however, patients in this special state have not been fully studied. This project aimed to study the effect of HBV S region mutations on HBsAg in patients with clinical OBI.

METHODS

Collect 107 HBsAg-/HBV DNA + blood samples from Beijing Youan Hospital, Capital Medical University from August 2022 to April 2023. Next, the successfully extracted and amplified HBV DNA S regions were sequenced. Construct mutant plasmids to verify the cell function of the high-frequency mutation sites and explore the possible molecular mechanism.

RESULTS

Sixty-eight HBsAg-negative samples were sequenced, revealing high-frequency amino acid substitution sites in the HBV S protein, including immune escape mutations (i.e., sY100C、sK122R、sI126T、sT131P、and sS114T) and TMD (Transmembrane domain) region substitutions (i.e., sT5A、sG10D、sF20S、and sS3N). We constructed a portion of the mutant plasmids and found that sT5A, sF20S, sG10D, sS3N, sI68T, and sI126T single point mutations or combined mutations may decrease HBsAg expression or change the antigenicity of HBsAg leading to detection failure.

CONCLUSIONS

HBsAg-negative patients may show various mutations and amino acid replacement sites at high frequency in the HBV S-region, and these mutations may lead to undetectable Hepatitis B surface antigen (HBsAg), HBsAg antigenic changes or secretion inhibition.

Ultrasensitive PCR system for HBV DNA detection: Risk stratification for occult hepatitis B virus infection in English blood donors

Occult hepatitis B (HBV) infection (OBI), characterized by low viral loads, accounts for much of the risk of HBV transfusion-transmitted infection. With anticore antibodies (anti-HBc) screening introduced in England, the imperative to identify OBI donors has increased. We aimed to develop an ultra-sensitive PCR system and investigate risk factors for HBV DNA presence in blood donations. Seven extraction methods and three PCR assays were compared. The optimal system was sought to determine HBV DNA presence in anti-HBc-positive donations. Predictors of DNA positivity were subsequently investigated. Extraction from 5 mL of plasma increased sample representation and resulted in HBV DNA detection in low viral load samples (~0.5 IU/mL). Screening of 487 763 donations in 2022 identified two OBI donors and 2042 anti-HBc-positive donors, 412 of the latter with anti-HBs < 100 mIU/mL. Testing of 134 anti-HBc-positive donations utilizing the 5 mL extraction method identified two further HBV DNA-positive donations. Higher anti-HBc titer and anti-HBs negativity were significant predictors of DNA detectability in anti-HBc-positive donations. An ultrasensitive PCR assay identified potentially infectious donations increasing HBV DNA detection in anti-HBc-positive donors from 0.5% to 1.9%. Anti-HBc titers may further complement the risk stratification for DNA positivity in anti-HBc screening and minimize unnecessary donor deferral.

Occult hepatitis B in Iranian blood donors, an overview of the challenges: A narrative review

Background

Occult hepatitis B infection (OBI) is a transfusion-transmitted infection. Although, screening the hepatitis B virus among blood donors can play an important role in increasing the health of blood products, OBI screening in blood transfusion centers is still a challenge. This review study aimed to appraise the challenges of OBI screening and its associated do's and don'ts in blood transfusion centers.

Methods

In this review study, a search was conducted on the electronic databases of PubMed, Web of Science, Scopus, Ovid, Irandoc, and Magiran from January 1996 to December 2020. Also, cross-sectional studies that determined the prevalence of OBI or anti-HBc were included in the study. In addition, studies with incomplete data on the prevalence of OBI were excluded.

Results

The prevalence of OBI varies among Iranian blood donors. The rates reported by blood transfusion centers of Mashhad, Ahvaz, and Tehran were 0%, and Isfahan, Shiraz, and Kerman were 0.9%, 0.08%, and 2.36%, respectively. In areas with high prevalence of hepatitis B virus, OBI screening only by anti-HBc test led to the exemption of blood donors from donating blood. Avoiding OBI screening also effected the risk of virus transmission to blood recipients. Plasma products had a higher risk (85%) of virus transmission.

Conclusions

Determining an appropriate screening strategy based on prevalence status, the cost-effectiveness of screening tests, and the policies of each blood transfusion center is essential.

Prevalence and trends of transfusion transmissible infections among blood donors in Basra, Iraq

BACKGROUND

Despite saving millions of lives through blood transfusion, transfusion-transmissible infections (TTIs) still threaten the lives of patients requiring blood transfusion. Hence, screening blood donors and studying the prevalence of TTIs among blood donors may display the burden of these diseases among our population. The aim of this study was to assess the seroprevalence rates of transfusion transmitted infections among blood donors in Basra, Iraq from 2019 to 2021 as groundwork for providing safe blood transfusion in Iraq.

METHODS

A cross-sectional study was carried out in the blood banks in Basra, Iraq from 1 January 2019 to 31 December 2021. A total of 197 898 samples were collected and screened for hepatitis B surface antigen (HBsAg), anti-hepatitis B core (HBc), anti-hepatitis C virus (HCV) and syphilis immunologically.

RESULTS

The prevalence rates of seropositive of viral hepatitis for the year 2019, 2020, 2021 were as following: hepatitis B virus (HBV) rates 1.54%, 1.45% and 1.14% with significant declined trend by 26%; anti-HCV rates were 0.14, 0.12 and 0.11% with significant declined trend by 21.4%; and the syphilis rates were 0.38, 0.47, 0.36 with marked declined trend 5.3%, respectively.Of those donors showed HBV positive, 2503 (1.26%) had positive anti-HBc results, while only 173 (0.0874) showed positive test results for both anti-HBc and HBsAg.

CONCLUSION

Prevalence rates of viral hepatitis and syphilis showed a steady decline between 2019 and 2021, and these rates were much lower in Basra than in other parts of Iraq and neighbouring countries. The importance of using the anti-HBc test in the screening of blood donors was indicated in this study. These findings would contribute in improving the understanding of TTIs epidemiology and supporting health authorities controlling bloodborne diseases.

Haplotype-dependent HLA-DRB1-DQB1 susceptibility to occult HBV infection in Xi'an Han population

BACKGROUND

Occult hepatitis B virus (HBV) infection (OBI) is primarily characterized by the persistence of HBV-DNA in the liver tissues and/or in the serum without detectable HBsAg. Human leukocyte antigen (HLA) polymorphisms have been found to be strongly associated with HBV in different ethnic backgrounds. The association of HLA-DRB1-DQB1 haplotypes with OBI has not been previously reported in China. The aim of this study was to identify the potential association of HLA-DRB1-DQB1 haplotypes that may be involved in OBI genetic susceptibility.

METHODS

A case-control study was conducted between 107 OBI subjects and 280 healthy controls from the blood donors in the Shaanxi Province Blood Center. The HLA-DRB1, DQB1 loci were genotyped using polymerase chain reaction-sequence based typing (PCR-SBT). Based on the genotype data of the two loci, haplotype estimation was performed.

RESULTS

HLA-DRB1*07:01-DQB1*02:02 (pc = 0.344 × 10^-3 , OR = 3.489, 95%CI = 2.000-6.088) and HLA-DRB1*09:01-DQB1*03:03 (pc = 0.02, OR = 2.370, 95%CI = 1.450-3.873) serve as the possible risk and susceptibility haplotypes for OBI in Xi'an Han after Bonferroni correction.

CONCLUSIONS

This study demonstrated that HLA II haplotypes were significantly associated with OBI in the Xi'an Han population. To the best of our knowledge, this is the first study to associate HLA-DRB1-DQB1 haplotypes with OBI, which can provide valuable insights into the relationship between the various genetic factors and immune responses in the Xi'an population. The findings can also form the basis for future studies about the role of HLA in OBI.

Post-Vaccination and Post-Infection Immunity to the Hepatitis B Virus and Circulation of Immune-Escape Variants in the Russian Federation 20 Years after the Start of Mass Vaccination

A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 years ago, with catch-up immunization for adolescents and adults under the age of 60 years launched in 2006. Here, we have assessed the humoral immunity to HBV in different regions of Russia, as well as the infection frequency following 20 years of a nationwide vaccination campaign. We have also evaluated the role of immune-escape variants in continuing HBV circulation. A total of 36,149 healthy volunteers from nine regions spanning the Russian Federation from west to east were tested for HBV surface antigen (HBsAg), antibodies to HBV capsid protein (anti-HBc), and antibodies to HBsAg (anti-HBs). HBV sequences from 481 chronic Hepatitis B patients collected from 2018-2022 were analyzed for HBsAg immune-escape variants, compared with 205 sequences obtained prior to 2010. Overall, the HBsAg detection rate was 0.8%, with this level significantly exceeded only in one study region, the Republic of Dagestan (2.4%, p < 0.0001). Among the generation vaccinated at birth, the average HBsAg detection rate was below 0.3%, ranging from 0% to 0.7% depending on the region. The anti-HBc detection rate in subjects under 20 years was 7.4%, indicating ongoing HBV circulation. The overall proportion of participants under 20 years with vaccine-induced HBV immunity (anti-HBs positive, anti-HBc negative) was 41.7% but below 10% in the Tuva Republic and below 25% in the Sverdlovsk and Kaliningrad regions. The overall prevalence of immune-escape HBsAg variants was 25.2% in sequences obtained from 2018-2022, similar to the prevalence of 25.8% in sequences collected prior to 2010 (p > 0.05). The population dynamics of immune-escape variants predicted by Bayesian analysis have remained stable over the last 20 years, indicating the absence of vaccine-driven positive selection. In contrast, the wild-type HBV population size experienced a rapid decrease starting in the mid-1990s, following the introduction of mass immunization, but it subsequently began to recover, reaching pre-vaccination levels by 2020. Taken together, these data indicate that it is gaps in vaccination, and not virus evolution, that may be responsible for the continued virus circulation despite 20 years of mass vaccination.

The introduction of Laboratory testing for anti-HBcore in blood donors

Introduction. The introduction of screening testing for antibodies to the hepatitis B virus nuclear antigen (anti-HBcore) is designed to prevent the procurement of donated blood from individuals with the latent (occult) form of viral hepatitis B, in which surface HBsAg is not identified.

Aim – to evaluate the frequency of anti-HBcore markers’ occurrence in donors under the current regulatory and legal framework.

Materials and methods. This retrospective observational study was conducted with a follow-up period of one year among blood donors of the Blood Center (BC) of the Federal Medical-Biological Agency. The screening study for anti-HBcore in blood donors and its components was selective in accordance with the requirements of Appendix № 4 of Order № 1166n of October 28, 2020 of the Ministry of Health of Russia.

Results. During the study period, the BC was visited by 17,180 donors who donated blood and its components 35,840 times. There were 181 anti-HBcore tests (0.5 % of all blood samples) in 178 unique donors of blood and blood components (1.03 % of all donors). There were 14 positive, 2 questionable and 166 negative results on anti-HBcore tests. The probability of finding a positive result depending on the conditions was 9 % (7.3–14.7 %). There were no statistically significant differences in the detection of anti-HBcore in primary versus regular donors (OR = 2.539; 95% CI: 0.7321–8; p = 0.13), as well as for male donors compared with female donors (OR = 2.448; 95% CI: 0.7141–11.11; p = 0.17). 86.7 % of donors with a positive test for anti-HBcore previously had no signs of viral hepatitis B disease, the presence of questionable HBsAg was not detected, i. e. these cases may be associated with an occult form. Donors who did not previously have questionable results for various bloodborne infections during their donor career had a slightly higher probability of detecting a positive anti-HBcore test compared to donors who previously had these questionable results (OR = 1.24; 95% CI”: 0.42–3.69; p = 0.69). During the period of the donor career, 233 donations of blood and its components were made by donors with a positive result for anti-HBcore, 468 units of donor components were received, of which 365 units were given to medical institutions.

Conclusion. The probability of obtaining a positive test for anti-HBcore in the current regulatory environment is random and does not depend on the results of other infectious markers testing. It is recommended to perform anti-HBcore testing with each donation of blood and blood components.

Low Risk of Occult Hepatitis B Infection among Vietnamese Blood Donors

Occult hepatitis B infection (OBI) is characterized by the presence of low levels of hepatitis B virus (HBV) DNA and undetectable HBsAg in the blood. The prevalence of OBI in blood donors in Asia ranges from 0.013% (China) to 10.9% (Laos), with no data available from Vietnam so far. We aimed to investigate the prevalence of OBI among Vietnamese blood donors. A total of 623 (114 women and 509 men) HBsAg-negative blood donors were screened for anti-HBc and anti-HBs by ELISA assays. In addition, DNA from sera was isolated and nested PCR was performed for the HBV surface gene (S); a fragment of the S gene was then sequenced in positive samples. The results revealed that 39% (n = 242) of blood donors were positive for anti-HBc, and 70% (n = 434) were positive for anti-HBs, with 36% (n = 223) being positive for both anti-HBc and anti-HBs. In addition, 3% of blood donors (n = 19) were positive for anti-HBc only, and 34% (n = 211) had only anti-HBs as serological marker. A total of 27% (n = 170) were seronegative for any marker. Two of the blood donors (0.3%) were OBI-positive and sequencing revealed that HBV sequences belonged to HBV genotype B, which is the predominant genotype in Vietnam.

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.

Viral safety of recovered plasma for contract fractionation; an Iranian experience, 2006-2015

OBJECTIVE

The current study analysed the viral safety among Iranian blood donors.

BACKGROUND

Plasma products demand is increasing in the world. With contract plasma fractionation, the plasma wastage decreases and the access of patients to plasma-derived medicines (PDM) improves.

STUDY AND DESIGN METHOD

Screening results including hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV), and human immunodeficiency virus (HIV) Ag/Ab of 19 054 036 donations from 2006 to 2015 were analysed. The plasma for fractionation was tested for HBV DNA, HCV RNA, HIV RNA, HAV RNA, and Parvovirus B19 DNA by fractionators. New samples were collected from the positive donors and retested. The prevalence of serological and nucleic acid testing (NAT) markers per 10⁵ donations, 95% confidential interval (CI), and p-values were calculated.

RESULTS

The prevalence of markers was as follows: 250/10⁵ donations for HBsAg from 516 in 2006 to 116/10⁵ donations in 2015; 74/10⁵ donations for HCV, decreasing from 127 to 41/10⁵ and 3.6/10⁵ for HIV during current study. During 10 years, 5 713 641 units of recovered plasma were shipped for contract fractionation to produce PDM; 0.26/10⁵ donations for HBV DNA and 0.14/10⁵ for HCV RNA were reported positive. The results of five retested samples for HBV and one sample for HCV were negative.

CONCLUSION

The prevalence of HBV, HCV, and HIV in blood donations was extremely low. Thanks to the availability, high quality and safety of recovered plasma as a result of the improvements in the quality system at IBTO, this plasma could be used for the production of PDMPs.

Role of core protein mutations in the development of occult HBV infection

BACKGROUND & AIMS

Occult HBV infection (OBI) is associated with transfusion-transmitted HBV infection and hepatocellular carcinoma. Studies on OBI genesis have concentrated on mutations in the S region and the regulatory elements. Herein, we aimed to determine the role of mutations in the core region on OBIs.

METHODS

An OBI strain (SZA) carrying 9 amino acid (aa) substitutions in the core protein/capsid (Cp) was selected by sequence alignment and Western blot analysis from 26 genotype B OBI samples to extensively explore the impact of Cp mutations on viral antigen production in vitro and in vivo.

RESULTS

A large panel of 30 Cp replicons were generated by a replication-competent pHBV1.3 carrying SZA or wild-type (WT) Cp in a 1.3-fold over-length of HBV genome, in which the various Cp mutants were individually introduced by repairing site mutations of SZA-Cp or creating site mutations of WT-Cp by site-directed mutagenesis. The expression of HBcAg, HBeAg, and HBsAg and viral RNA was quantified from individual SZA and WT Cp mutant replicons in transfected Huh7 cells or infected mice, respectively. An analysis of the effect of Cp mutants on intracellular or extracellular viral protein production indicated that the W62R mutation in Cp had a critical impact on the reduction of HBcAg and HBeAg production during HBV replication, whereas P50H and/or S74G mutations played a limited role in influencing viral protein production invivo.

CONCLUSIONS

W62R and its combination mutations in HBV Cp might massively affect HBcAg and HBeAg production during viral replication, which, in turn, might contribute to the occurrence of OBI.

LAY SUMMARY

Occult hepatitis B virus infections (OBIs) have been found to be associated with amino acid mutations in the S region of the HBV, but the role of mutations in the core protein (Cp) remains unclear. In this study, an OBI strain (SZA) carrying 9 amino acid substitutions in Cp has been examined comprehensively in vitro and in vivo. The W62R mutation in Cp majorly reduces HBcAg and HBeAg production during HBV replication, potentially contributing to the occurrence of OBI.

Hepatitis B virus prevalence in first-time blood donors in Flanders, Belgium: Impact of universal vaccination and migration

BACKGROUND

Transfusion-transmissible infections such as hepatitis B virus (HBV) remain a major concern for the safety of blood transfusion. This cross-sectional study aimed to assess the trend of HBV prevalence and associated risk factors among a first-time donor population in a low endemic country.

STUDY DESIGN AND METHODS

Between 2010 and 2018, blood samples were collected from first-time donors presented at donor collection sites of Belgian Red Cross-Flanders. They were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (anti-HBc), and HBV DNA, HIV and hepatitis virus C (HCV) antibodies and RNA, and syphilis antibodies.

RESULTS

A total of 211,331 first-time blood donors (43.7% males, median age 25 years) were analyzed. HBsAg prevalence decreased from 0.06% in 2010 to 0.05% in 2018 (p = .004) and this declining trend was accompanied by an increased number of donors in the HBV vaccinated birth cohort (p < .001). HBsAg prevalence was 0.33% in foreign-born donors and 0.02% in Belgian natives (p < .001). Multivariate risk profiling showed that anti-HBc positivity was significantly associated with mainly foreign-born donors (odds ratio [OR] = 9.24) but also with older age (OR = 1.06), male gender (OR = 1.32), year of blood donation (OR = 0.94), and co-infections with HCV (OR = 4.31) or syphilis (OR = 4.91).

DISCUSSION

The decreasing trend in HBV prevalence could mainly be explained by the introduction of the universal HBV vaccination. Being born in endemic areas was the most important predictor for HBV infection while the co-infections with syphilis suggest unreported sexual risk contacts.

Occult and active hepatitis B virus detection in donated blood in São Paulo, Brazil

BACKGROUND

The present study determined the HBV antigen, antibody, and DNA status in blood donations deemed to be HBV positive. Individuals with an occult HBV infection (OBI), defined as being positive for HBV DNA but negative for HBV surface antigen (HBsAg), as well as those with active infection (HBsAg-positive), were identified and characterized.

STUDY DESIGN AND METHODS

From a total pool if 198,363 blood donations, we evaluated in a cross-sectional study, 1106 samples that were positive in screening tests for antibody to HBV core antigen (HBcAb), HBsAg, and/or HBV DNA by nucleic acid testing (NAT-HBV). The presence of genetic variants in the HBV pol/S gene in individuals with an active HBV infection was also determined.

RESULTS

OBIs were detected in six of 976 samples (0.6%) that were positive only for HBcAb. The rate of HBV active infection was 0.024% (48/198,363) and there was a predominance of HBV sub-genotype A1 (62.2%, 28/45), followed by D3 (17.8%, 8/45). Mutations in the S gene were found in 57.8% (26/45) and immune escape mutations in 37.8% (17/45) of active HBV-infected donors. Among them, T123N, G145A, and D144G high-impact immune escape mutations were identified.

CONCLUSION

Highly sensitive molecular tests improve the capacity to detect OBIs. When NAT is performed in pooled samples, HBcAb test has value in the detection of donors with OBI and improves transfusion safety. Mutations in the S gene are frequent in HBsAg-positive blood, including those associated with diagnostic failure and vaccine escape mutations.

Design of micromagnetic arrays for on-chip separation of superparamagnetic bead aggregates and detection of a model protein and double-stranded DNA analytes

Magnetically actuated lab-on-a-chip (LOC) technologies have enabled rapid, highly efficient separation of specific biomarkers and cells from complex biological samples. Nonlinear magnetophoresis (NLM) is a technique that uses a microfabricated magnet array (MMA) and a time varying external magnetic field to precisely control the transport of superparamagnetic (SPM) beads on the surface of a chip based on their size and magnetization. We analyze the transport and separation behavior of SPM monomers and dimers on four MMA geometries, i.e., circular, triangular, square and rectangular shaped micromagnets, across a range of external magnetic field rotation frequencies. The measured critical frequency of the SPM beads on an MMA, i.e., the velocity for which the hydrodynamic drag on a bead exceeds the magnetic force, is closely related to the local magnetic flux density landscape on a micromagnet in the presence of an external magnetic field. A set of design criteria has been established for the optimization of MMAs for NLM separation, with particular focus on the shape of the micromagnets forming the array. The square MMA was used to detect a model protein biomarker and gene fragment based on a magnetic bead assembly (MBA) assay. This assay uses ligand functionalized SPM beads to capture and directly detect an analyte through the formation of SPM bead aggregates. These beads aggregates were detected through NLM separation and microscopic analysis resulting in a highly sensitive assay that did not use carrier fluid.

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.

Occurrence of occult hepatitis B virus infection associated with envelope protein mutations according to anti-HBs carriage in blood donors

OBJECTIVES

Occult hepatitis B virus infection (OBI) carries a risk of hepatitis B virus (HBV) transmission and hepatocellular carcinoma. As previous studies have had a limited sample size, the characteristics of OBI with genotype B and C (OBI_B and OBI_C) mutations relating to hepatitis B surface antibody (anti-HBs) elicited by vaccination or a limited host immune response to HBV have not been fully explored.

METHODS

In this study, the occurrence of OBI_B or OBI_C strains associated with envelope protein (pre-S/S) amino acid substitutions obtained from 99 blood donors stratified according to anti-HBs carriage were characterized extensively.

RESULTS

According to the presence of anti-HBs within each genotype, the number and frequency of substitution sites specific for anti-HBs(-) OBI_B were higher than those specific for anti-HBs(+) OBI_B strains (67 vs 31; 117 vs 41), but the reverse pattern was found in OBI_C strains (3 vs 24; 3 vs 26). Mutations pre-s₁T68I and sQ129R/L were found uniquely in 15-25% of anti-HBs(+) OBI_B carriers and mutation pre-s₁A54E was found preferentially in anti-HBs(+) OBI_C, while 17 substitutions were found preferentially in 11-38% of anti-HBs(-) OBI_B strains. In the major hydrophilic region (MHR) region, mutations sS167 in OBI_B, sT118 in OBI_C, and sA166 in both genotypes were possibly immune-induced escape mutation sites.

CONCLUSIONS

Several mutations in pre-S/S of OBI appeared to be associated with carrier anti-HBs pressure, which might be risk factors for potential reactivation of viruses under anti-HBs selection in OBI carriers.

Pathogen reduction of blood components during outbreaks of infectious diseases in the European Union: an expert opinion from the European Centre for Disease Prevention and Control consultation meeting

Pathogen reduction (PR) of selected blood components is a technology that has been adopted in practice in various ways. Although they offer great advantages in improving the safety of the blood supply, these technologies have limitations which hinder their broader use, e.g. increased costs. In this context, the European Centre for Disease Prevention and Control (ECDC), in co-operation with the Italian National Blood Centre, organised an expert consultation meeting to discuss the potential role of pathogen reduction technologies (PRT) as a blood safety intervention during outbreaks of infectious diseases for which (in most cases) laboratory screening of blood donations is not available. The meeting brought together 26 experts and representatives of national competent authorities for blood from thirteen European Union and European Economic Area (EU/EEA) Member States (MS), Switzerland, the World Health Organization, the European Directorate for the Quality of Medicines and Health Care of the Council of Europe, the US Food and Drug Administration, and the ECDC. During the meeting, the current use of PRTs in the EU/EEA MS and Switzerland was verified, with particular reference to emerging infectious diseases (see Appendix). In this article, we also present expert discussions and a common view on the potential use of PRT as a part of both preparedness and response to threats posed to blood safety by outbreaks of infectious disease.

Nearly half of Ultrio plus NAT non-discriminated reactive blood donors were identified as occult HBV infection in South China

Background

Blood donor plasma samples were detected by the Ultrio Plus NAT system for HBV, HCV and HIV-1 in Shenzhen blood center, China. Reactive samples underwent further discriminatory testing of a single virus by the same methodology. A large number of cases of non-discriminated reactive (NDR) donors were found, leaving potential risk of transmitting HBV if not deferrals. This study identified those non-discriminated samples.

Methods

The NDR plasma samples from blood donation screening were detected and classified by additional molecular and serological tests. Molecular characterizations of DNA+ NDR were determined by sequencing analysis.

Results

A number of 259 (0.21%) NDR plasma samples from screening of 123,280 eligible blood donors were detected, which presented a higher rate (91.1%) of anti-HBc reactivity and nearly half (46.7%) of HBV DNA+ that classified as occult HBV infection (OBI). Most OBI strains were wild-type HBV, but some substitutions V168A, S174 N, V177A, Q129R/L/H, G145A/R in S region of genotype B (OBI_B) and T47K/V/A, P49H/L, Q101R/H/K, S174 N, L175S, V177A, T118 M/R/K, G145R/A/K/E, R160K/N in S region of genotype C (OBI_C) strains were identified in high frequency.

Conclusion

Nearly half of NDR blood samples were identified as OBI, in which a number of important mutations were detected. NDR donation might have potential risk for HBV transmission, but need to be further investigated.

Anti-HBc prevalence among Croatian blood donors in a 14-year period (2004-2017): Assessment of trends, risks and need for implementing routine testing

OBJECTIVES

The anti-HBc prevalence over a 14-years period (2004-2017), trends, infectivity, residual risk, and need for testing in blood donors (BD) of the Croatian Institute of Transfusion Medicine were assessed.

MATERIAL AND METHODS

Anti-HBc was tested in 19,969 BD serum samples collected in 2004 (N=7561), 2013 (N=7318) and 2017 (N=5090). All serums were initially screened for HBsAg, anti-HCV, HIV Ag/Ab, and anti-TP. 2013 and 2017 samples were also tested by ID-NAT.

RESULTS

Over a 14-years period, the anti-HBc prevalence significantly decreased among Croatian BD (5.24% in 2004, 2.56% in 2013, and 1.32% in 2017). Similarly, the prevalence of anti-HBc-only profiles decreased from 0.62% in 2004, 0.25% in 2013, and 0.21% in 2017. The 4-time decreasing trend was observed in all age groups of BD from 2017 but mostly among repeat donors (5.90% to 1.38%). First-time donors showed no significant difference in anti-HBc prevalence probably due to their younger age (<29 years) and HBV vaccine status. However, similar anti-HBs carriage rates (80.56%, 87.57%, and 82.09%) were reported in anti-HBc positive donors over the study period. HBsAg and HBV DNA were not detected. No OBI infection was found in the study despite an OBI frequency of 1:10,900 donations previously reported in Croatia. A HBV decreasing residual risks of 68, 88, and 12 per million donations were estimated for years 2004, 2013, and 2017, respectively.

CONCLUSION

Anti-HBc testing is an additional measure of preventing HBV infection by transfusion. Implementation of anti-HBc testing will result in the deferral of 1.3% BD and should be supported by cost-benefit analyses.

Prevalence of Hepatitis B Virus (HBV) Among Blood Donors in Eastern Saudi Arabia: Results From a Five-Year Retrospective Study of HBV Seromarkers

Background

Transfusion-transmissible hepatitis B virus (HBV) infection is a major problem worldwide. Recently, confirmatory nucleic acid tests (NATs) for HBV DNA have been employed in several countries. We assessed the prevalence and yearly trends of HBV infection in blood donors in the Eastern Province of Saudi Arabia, screening for HBV surface antigen (HBsAg), antibody against HBV core antigen (anti-HBc), and HBV DNA.

Methods

Between 2011 and 2015, a total of 22,842 donors were screenedfor HBsAg, anti-HBc, and HBV DNA using the HBsAg Qualitative II kit (Abbott, Ireland Diagnostics Division, Sligo, Ireland), ARCHITECT Anti-hepatitis B core antigen antibody (HBc) II Assay kit (Abbott GmbH & Co. KG, Wiesbaden, Germany), and NAT Procleix Ultrio Elite Assay kit (Grifols Diagnostic Solutions Inc., Los Angeles, CA, USA), respectively.

Results

A total of 739 (3.24%) donors were HbsAg(+), anti-HBc(+), or HBV DNA(+); 63 (0.28%) were HbsAg(+), anti-HBc(+), and HBV DNA(+). Twelve (0.05%) were anti-HBc(+) and HBV DNA(+) but HBsAg(−); they were considered to have occult infection. Further, 664 (2.91%) were HBsAg(−) but anti-HBc(+), indicating chronic or resolving infection. HBV prevalence increased significantly from 2011 to 2012, increased marginally till 2013, and showed a decreasing trend from 2013 (P>0.05).

Conclusions

The five-year prevalence of HBV infection among blood donors in the Eastern Province of Saudi Arabia (3.24%) is lower than that reported for other regions in the country. The occult HBV infection rate of 0.05% emphasizes the importance of NATs in isolating potential infectious blood units.

Real Time Polymerase Chain Reaction for Hepatitis B Screening in Donor Corneas in the Central Eye Bank of Iran

PURPOSE

The aim of this study was to report the results of the use of real-time polymerase chain reaction (PCR) for the diagnosis of hepatitis B virus (HBV) infection in cornea donors at the Central Eye Bank of Iran.

METHODS

Between 2014 and 2016, all cornea donors that had negative screening serologic results for hepatitis B (HB) surface antigen, HB surface antibody (Ab), hepatitis C virus Ab, human immune deficiency virus Ab, human T-cell leukemia virus Ab, and syphilis, and positive serology for HB core Ab were subjected to real-time PCR with a detection limit of 400 IU/mL to identify HBV DNA. Positive results for HBV DNA were considered occult HBV infections in these donors.

RESULTS

Over the 3-year period, 122 out of 10448 cornea donors had negative screening serologic tests outside of HB core Ab. Of which, 90 cases were subjected to real-time PCR. Occult HBV was detected in 11 cases (12.2%), resulting in the rejection of the corresponding corneas. The remaining 79 cases (87.8%) had negative results for HBV DNA and the corresponding corneas were used for transplantation.

CONCLUSION

Implementation of PCR for the detection of occult HBV in cornea donors is necessary to not only increase the security level of cornea donation but also minimize the rejection rate of donors that have isolated HB core Ab reactivity.

Characterization of efficacy and safety of pathogen inactivated and quarantine plasma in routine use for treatment of acquired immune thrombotic thrombocytopenic purpura

BACKGROUND

Auto-immune thrombotic thrombocytopenic purpura (TTP) is a morbid multi-organ disorder. Cardiac involvement not recognized in initial disease descriptions is a major cause of morbidity. Therapeutic plasma exchange (TPE) requires exposure to multiple plasma donors with risk of transfusion-transmitted infection (TTI). Pathogen inactivation (PI) with amotosalen-UVA, the INTERCEPT Blood System for Plasma (IBSP) is licensed to reduce TTI risk.

METHODS

An open-label, retrospective study evaluated the efficacy of quarantine plasma (QP) and IBSP in TTP and defined treatment emergent cardiac abnormalities. Medical record review of sequential patient cohorts treated with QP and IBSP characterized efficacy by remission at 30 and 60 days (d) of treatment, time to remission, and volume (L/kg) of plasma required. Safety outcomes focused on cardiac adverse events (AE), relapse rates, and mortality.

RESULTS

Thirty-one patients (18 IBSP and 13 QP) met study criteria for auto-immune TTP. The proportions (%) of patients in remission at 30 d (IBSP = 61·1, QP = 46·2, P = 0·570) and 60 d (IBSP = 77·8, QP = 76·9, P = 1·00) were not different. Median days to remission were less for IBSP (15·0 vs. 24·0, P = 0·003). Relapse rates (%) 60 d after remission were not different between cohorts (IBSP = 7·1, QP = 40·0, P = 0·150). ECG abnormalities before and during TPE were frequent; however, cardiac AE and mortality were not different between treatment cohorts.

CONCLUSIONS

Cardiac and a spectrum of ECG findings are common in TTP. In this study, IBSP and QP had similar therapeutic profiles for TPE.

The current incidence, prevalence, and residual risk of hepatitis B viral infections among voluntary blood donors in China

BACKGROUND

There are few data available on the prevalence, incidence, and residual risk of transfusion-transmitted HBV (TT-HBV) infections among Chinese blood donors. This study investigated the demographic characteristics of blood donors, as well as the prevalence, incidence, and residual risk (RR) of TT-HBV infections in six large blood centers in different regions of China.

METHODS

The demographic characteristics and HBV screening test results of blood donors from six blood centers in different regions in China were collected and analyzed. The hepatitis B surface antigen (HBsAg) yield approach was used to estimate the incidence of HBV. Then, the RR of TT-HBV infections was evaluated using the incidence-window period model.

RESULTS

The majority of donors were between 18 and 35 years old (including 35), with the exception of the Changzhi Blood Center where a majority of donors were between 35 and 55 years old (including 55). The prevalences of HBV were 0.13%, 0.078%, 0.16%, 0.07%, 0.20%, 0.25% in Hefei, Dalian, Changzhi, Kaifeng, Mianyang and Fujian, respectively. The estimated corresponding incidences were 213.44, 161.59, 989.80, 278.05, 125.31 and 352.19 per 10⁵ person-years. Using an infectious window period of 59 days, the RR for HBV was estimated to be 34.14, 25.85, 158.35, 44.48, 20.04 and 56.35 per 10⁵ person-years in Hefei, Dalian, Changzhi, Kaifeng, Mianyang and Fujian, respectively.

CONCLUSION

Despite the introduction of more sensitive assays in blood screening, our data revealed that the current residual risk of TT-HBV infection was still high (overall 56.53 per 10⁵ py). A continuous monitoring of the residual risk of transfusion-transmitted infections is crucial for safe blood management.

Advances in research on influencing factors of hepatitis B virus infection caused by blood transfusions

As one of the main factors affecting safe blood transfusion, hepatitis B virus (HBV) infection through blood transfer seriously endangers human health. Therefore, studies should focus on both reducing infection rate of HBV and accurately evaluating the risk of infection. This study discusses the main factors affecting HBV infection that results from blood transfusions, with the aim of gaining insights into reducing HBV infection.

Evaluation of clinical sensitivity and specificity of hepatitis B virus (HBV), hepatitis C virus, and human immunodeficiency Virus-1 by cobas MPX: Detection of occult HBV infection in an HBV-endemic area

BACKGROUND

Transfusion-transmitted infectious diseases remain a major concern for blood safety, particularly with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Nucleic acid testing (NAT) in donor screening shortens the serologically negative window period and reduces virus transmission. The cobas MPX (Roche Molecular Systems, Inc., Branchburg, New Jersey) is a recently developed multiplex qualitative PCR system that enables the simultaneous detection of HBV, HCV, and HIV with improved sensitivity and throughput using cobas 6800 and 8800 instruments.

OBJECTIVES

The aim of this study was to conduct an evaluation of the clinical sensitivity and specificity of cobas MPX detection of HBV, HCV, and HIV in clinical specimens.

STUDY DESIGN

Among samples referred for HBV, HCV, and HIV-1 quantification at Severance Hospital, Yonsei University College of Medicine, positive samples were selected to evaluate sensitivity. A total of 843 samples was tested using both cobas MPX and COBAS AmpliPrep/COBAS TaqMan Tests for HBV, HCV, and HIV-1 using the cobas 8800 system and a COBAS TaqMan 96 analyzer, respectively. Samples that showed discrepancies were confirmed by nested PCR.

CONCLUSIONS

The cobas MPX achieved excellent sensitivity and specificity for the detection of HBV, HCV, and HIV-1 in clinical samples. We found that the lower limit of detection (LOD) of blood screening by NAT actually improves clinical sensitivity, and occult HBV infection prevalence among healthy employees of the hospital was rather high.

Bloodstream Infections

Bacteremia and sepsis are conditions associated with high mortality and are of great impact to health care operations. Among the top causes of mortality in the United States, these conditions cause over 600 fatalities each day. Empiric, broad-spectrum treatment is a common but often a costly approach that may fail to effectively target the correct microbe, may inadvertently harm patients via antimicrobial toxicity or downstream antimicrobial resistance. To meet the diagnostic challenges of bacteremia and sepsis, laboratories must understand the complexity of diagnosing and treating septic patients, in order to focus on creating algorithms that can help direct a more targeted approach to antimicrobial therapy and synergize with existing clinical practices defined in new Surviving Sepsis Guidelines. Significant advances have been made in improving blood culture media; as yet no molecular or antigen-based method has proven superior for the detection of bacteremia in terms of limit of detection. Several methods for rapid molecular identification of pathogens from blood cultures bottles are available and many more are on the diagnostic horizon. Ultimately, early intervention by molecular detection of bacteria and fungi directly from whole blood could provide the most patient benefit and contribute to tailored antibiotic coverage of the patient early on in the course of the disease. Although blood cultures remain as the best means of diagnosing bacteremia and candidemia, complementary testing with antigen tests, microbiologic investigations from other body sites, and histopathology can often aid in the diagnosis of disseminated disease, and application of emerging nucleic acid test methods and other new technology may greatly impact our ability to bacteremic and septic patients, particularly those who are immunocompromised.

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

Background

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

Methods

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

Results

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

Conclusion

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

Prevalence and trends of hepatitis B virus, Hepatitis C virus, Human immunodeficiency virus 1, 2 and syphilis infections among blood donors in a regional transfusion center in Punjab, India: A 3 years study

Background:

Accurate estimates of the risk of transfusion-transmitted infectious diseases are essential for monitoring the safety of blood supply and evaluating the potential effects of new screening tests.

Objective:

The aim was to determine changes over time in blood donor population infection rates of hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV-1, 2) and syphilis.

Materials and Methods:

Changes in rates of HBV, HCV, HIV-1, 2, and syphilis infections were evaluated by comparing yearly prevalence rates for blood donors over 3 years, that is, between January 1, 2012 and December 31, 2014. Serological tests were done according to the standard operating procedures and manufacturer's instructions and included the following: tests for hepatitis B surface antigen; antibodies to HCV and HIV-1, 2 and rapid plasma reagin test for syphilis.

Results:

Nearly 2.54 of the total screened blood donors were reactive for one of the four transfusion transmitted infections (TTIs) with higher prevalence in replacement (3%) than voluntary donors (2.3%) and in male (2.54%) than female (2.3%) donors. TTI tend to be more (54.7%) in younger population of 18–30 years. HCV infection is the most common of all TTI (50%).

Conclusion:

The rising prevalence rates of HIV; HBV; HCV and syphilis among different groups suggests that blood transfusion is still very unsafe in this community and emphasis should be laid on donor education and donor self-exclusion, implementation of strict donor screening criteria, pre-donation counseling, and more sensitive screening methods. Furthermore, donors with a history of sexually transmitted infections should be totally excluded from all donations.

Characterisation and follow-up study of occult hepatitis B virus infection in anti-HBc-positive qualified blood donors in southern China

BACKGROUND

Most major Chinese blood centres look for hepatitis B surface antigen (HBsAg) and perform nucleic acid testing to screen blood for hepatitis B virus infection. The search for antibodies to the core of hepatitis B virus (anti-HBc) has not been implemented because it would lead to a high rate of discarded blood units. The aim of this study was to evaluate the prevalence of occult HBV infection among anti-HBc-positive qualified blood donors in southern China.

MATERIALS AND METHODS

We tested anti-HBc-positive blood donations negative for HBsAg and HBV DNA by standard NAT from Shenzhen for the presence of HBV DNA by sensitive nested and quantitative polymerase chain reactions. Anti-HBs titres were quantified. HBV DNA-positive donors were traced and followed-up.

RESULTS

Of the 1,033 qualified donors, 47.4% (95% CI: 44.4 to 50.5%) carried anti-HBc as evidence of exposure to HBV. The rate of anti-HBc positivity increased steadily with age, ranging from 32.6% in the age group <30 years to 69.8% in the age group <50 years (p<0.001). Of the 1,033 donors, 777 (75.2%; 95% CI: 72.4 to 77.8%) carried anti-HBs (>10 IU/L). HBV DNA was detected in 14 donors who were anti-HBc-positive, HBsAg-negative and negative by routine NAT. Seven of those 14 specimens had an anti-HBs titre above 100 mIU/mL. The prevalence of OBI in anti-HBc-positive qualified blood donors was 2.86% (95% CI: 1.57 to 4.75%). Eight of the 14 OBI cases were genotype B and one was genotype C; 7/14 cases were followed-up, one case converted to anti-HBe. HBV DNA became undetectable in all follow-up samples.

DISCUSSION

A small proportion of anti-HBc-positive qualified donors carry HBV DNA after HBsAg and NAT screening. This finding suggests the possibility of HBV transmission from asymptomatic donors, especially in areas of high HBV prevalence. More sensitive NAT rather than anti-HBc testing should be considered to improve blood safety.

Occult Hepatitis B virus infection in previously screened, blood donors in Ile-Ife, Nigeria: implications for blood transfusion and stem cell transplantation

BACKGROUND

Hepatitis B virus (HBV) transmission through blood transfusion is reduced by screening for hepatitis B surface antigen (HBsAg). However this method cannot detect the presence of occult hepatitis B virus infection. This study sought to determine the prevalence of occult hepatitis B virus infection among blood donors in Ile-Ife, Nigeria. For the first time in Nigeria we employed an automated real-time PCR- method to investigate the prevalence of occult HBV in blood donors.

METHODS

Blood donors screened with HBsAg immunochromatographic rapid test kits at the blood transfusion units of two hospitals and found to be negative were recruited into the study. Questionnaires to elicit risk factors for HBV infection were administered and then 10 ml of blood was collected from each donor. Plasma samples obtained from these HBsAg negative blood donors were screened again for HBsAg using an enzyme-linked immunosorbent assay (ELISA) method, and those found negative were screened for the presence of total antibody to the HBV core antigen (anti-HBc) using ELISA method. Those positive to anti-HBc were then tested for HBV DNA, using an automated real-time PCR method.

RESULTS

Five hundred and seven blood donors found HBsAg negative by immunochromatographic rapid test kits at both blood transfusion units, were tested for HBsAg using ELISA and 5 (1 %) were HBsAg positive. The 502 found negative were tested for anti-HBc and 354 (70.5 %) were found positive implying previous exposure to HBV and 19 (5.4 %) of the 354 anti-HBc positive had HBV DNA signifying occult HBV infection. No risk factors were found to be associated with the presence of HBV DNA among those who tested positive.

CONCLUSION

Occult HBV infection exists in blood donors in Ile-Ife, Nigeria and the use of HBsAg alone for screening prospective donors will not eliminate the risk of HBV transmission in blood transfusion or stem cell transplantation.

Occult hepatitis B virus infection among hepatitis C virus seropositive and seronegative blood donors in Alexandria, Egypt

BACKGROUND AND AIMS

Occult hepatitis B virus infection (OBI, serum hepatitis B surface antigen negative but hepatitis B virus DNA positive) is an emerging problem in the safety of blood transfusion. The introduction of hepatitis B surface antigen in the screening panel for blood bank donors has substantially reduced, but not entirely eliminated, the risk of hepatitis B virus infection. It has been suggested that infection with hepatitis C virus may inhibit hepatitis B virus replication. Therefore, this study aimed at estimating the prevalence and risk factors for OBI among blood donors and determining its relationship with hepatitis C virus infection.

SUBJECTS AND METHODS

Presence of hepatitis B virus DNA and hepatitis C virus RNA was investigated for among 508 hepatitis B surface antigen-negative blood donors in Alexandria, Egypt. Half of the donors were identified as hepatitis C virus antibody reactive.

RESULTS

OBI was detected in 21 donors (4.1%) from the studied population: eight were among hepatitis C virus antibody positive donors (3.2%), among whom seven (33.3%) had hepatitis C virus RNA in their serum, and 13 (5.1%) were among hepatitis C virus antibody negative donors, with no statistically significant difference. The only significant risk factor for OBI among the studied blood donors was visiting local barbers.

CONCLUSION AND RECOMMENDATIONS

OBI is a considerable risk in blood banks, making screening for hepatitis B virus infection only on the basis of surface antigenemia insufficient.

Genetic variation of occult hepatitis B virus infection

Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare.

Comparison of Procleix Ultrio Elite and Procleix Ultrio NAT Assays for Screening of Transfusion Transmitted Infections among Blood Donors in India

Background. Introduction of nucleic acid testing (NAT) has helped in decreasing window period donations, resulting in increased safety of blood supplies. NAT combines the advantages of direct and highly sequence-specific detection of viral genomes. We analysed the performance of newer Procleix Ultrio Elite (PUE) and Procleix Ultrio assay (PUA) for the screening of the viral markers in our donor population. Material and Methods. 10,015 donor samples were screened by routine immunoassays and both versions of NAT. NAT yields detected were subjected to viral load estimation and to other serological markers. Results. A total of 21 NAT yields were detected; three were positive by both NAT systems, whereas 18 samples were reactive by PUE only. NAT yields include 18 HBV and 3 HCV yields, of which 17 HBV yields were occult infections and 1 was window period (WP) infection. All 3 HCV yields were WP infections. No HIV-1/HIV-2 yield was found. Conclusion. Efficient target capture chemistry in the new TMA assay version significantly improved sensitivity. NAT is superior to serological immunoassays for screening of the viral markers; and the efficient target capture system in the newer TMA assay, namely, the PUE system, has significantly improved sensitivity over the earlier versions.

Occult HBV infection status among chronic hepatitis C and hemodialysis patients in Northeastern Egypt: regional and national overview

INTRODUCTION

Occult hepatitis B infection (OBI) is considered to be one of the major risks for patients suffering from end-stage renal disease (ESRD) on regular hemodialysis (HD) and patients with chronic hepatitis C virus (HCV) infection. This study compared the prevalence of OBI among these two high-risk groups in the Suez Canal region, Northeastern Egypt, to obtain a better national overview of the magnitude of OBI in this region.

METHODS

Serum samples were collected from 165 HD patients and 210 chronic HCV-infected patients. Anti-HCV antibody, hepatitis B surface antigen (HBsAg), total hepatitis B core (anti-HBc) antibody, and hepatitis B surface antibody (anti-HBs) were detected by enzyme-linked immunosorbent assay (ELISA). HCV RNA was detected using a quantitative real-time RT-PCR assay, and HBV was detected using a nested PCR.

RESULTS

All patients were negative for HBsAg. A total of 49.1% and 25.2% of the patients in the HD and HCV groups, respectively, were anti-HBc-positive. In addition, more anti-HBs-positive patients were detected in the HD group compared to the HCV group (52.1% and 11.4%, respectively). Three cases were positive for HBV DNA in the HD group, while eighteen positive cases were detected in the HCV group. Both study groups showed significant differences in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level as well as anti-HBc, anti-HBs and HBV-DNA positivity.

CONCLUSIONS

OBI was more prevalent among chronic HCV patients than HD patients in the Suez Canal region, Egypt, with rates of 8.5% and 1.8%, respectively. However, more precise assessment of this infection requires regular patient follow-up using HBV DNA detection methods.

Prevalence of hepatitis B seromarkers and hepatitis C antibodies in blood donors in Basra, Iraq

BACKGROUND

Transfusion-caused hepatitis remains a major problem in Iraq. Therefore, testing for hepatitis B surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc) and antibodies to hepatitis C antigen (anti-HCV) is a very important preventative measure. The objective of this study was to establish the prevalence of hepatitis B and C virus seromarkers among blood donors as a foundation for safe blood transfusion in Iraq.

METHODS

A cross-sectional observational study was conducted in the blood banks in Basra, Iraq from 1 January to 31 December 2013. Blood samples were collected and were tested for HBsAg, anti-HBc and anti-HCV using standard laboratory techniques.

RESULTS

A total of 69 915 blood donors were enrolled for the study. A total of 1625 (2.3%) donors have shown serological evidence for hepatitis B virus infection; of those donors, 125 (0.2%) showed a positive test result for both anti-HBc and HBsAg while 1475 (2.1%) had positive anti-HBc results as the only positive test for HBV infection. There was no significant difference between males and females (p=0.28). The prevalence of anti-HCV was 0.1%.

CONCLUSIONS

This is the first large population study of its kind in Basra, Iraq. The prevalence of hepatitis B and C among blood donors is very low in Basra. Around 2% of blood donors had anti-HBc as the only serological evidence of HBV infection. Inclusion of anti-HBc in routine screening of blood donors in Iraq should be encouraged.

T- and B-cell responses and previous exposure to hepatitis B virus in 'anti-HBc alone' patients

A serologic response to hepatitis B virus (HBV) defined as 'anti-HBc alone' is commonly observed, but its significance remains unclear. This study aimed to define the relationship between 'anti-HBc alone' serostatus and HBV infection, including HBV-specific T- and B-cell memory responses. We enrolled 31 'anti-HBc alone' patients. Total HBV DNA and cccDNA were tested by nested polymerase chain reaction (PCR) analysis in liver samples from 22 'anti-HBc alone' patients vs controls (chronic or resolved HBV infection), followed by HBsAg/HBcAg immunohistochemical (IHC) staining. IFN-γ secretion by HBV-specific T cells was compared in individuals who were 'anti-HBc alone' (n = 27), resolved HBV (n = 21), chronic HBV (n = 24) and 12 healthy controls using enzyme-linked immunospot (ELISpot) assays. An HBsAg-IgG B-cell ELISpot assay was performed in 'anti-HBc alone' patients before and after one dose of recombinant HBsAg vaccine. The majority (23/31, 74.2%) of the 'anti-HBc alone' individuals were co-infected with HCV. Infrequent intrahepatic total HBV DNA (2/22, 9.1%) and cccDNA (1/22, 4.5%) were detected in biopsies; HBsAg and HBcAg IHC staining was negative. HBV-specific T-cell responses were similar between 'anti-HBc alone' individuals and HBV resolvers. Circulating HBV-memory B-cell responses were detected in all 'anti-HBc alone' individuals, consistent with an HBsAg-specific memory pool. After one HBV vaccine dose, increased anti-HBs antibody levels were observed, accompanied by an expansion of HBsAg-specific memory B cells (P = 0.0226). 'Anti-HBc alone' individuals showed HBV-specific T-cell and memory B-cell responses typical of previous viral exposure and protective memory, suggesting a resolved infection.

Two years' experience of implementing molecular screening of hepatitis B virus, hepatitis C virus and human immunodeficiency virus 1, 2 in Riyadh blood donors

Molecular screening technologies have improved blood safety by reducing the number of window-period transmissions relative to serological screening. In the two years following the introduction of molecular testing in King Khalid University Hospital, Saudi Arabia, 25,920 donor samples were screened in parallel by both serological and molecular techniques for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV). No HCV or HIV NAT yields were detected. However, molecular screening enabled the interdiction of two confirmed HBV NAT yields. This is only the second report of confirmed HBV NAT yield in the Kingdom of Saudi Arabia, and amongst the few reports in the wider Middle East and North Africa region.

Hepatitis B surface gene variants isolated from blood donors with overt and occult HBV infection in north eastern Egypt

Background

Major hydrophilic region in genomic HBV extending from aa99 to aa169, clustered with a highly conformational epitope, is critical to the antigenicity of hepatitis B surface antigen (HBsAg) and may affect the diagnosis of HBV in HBV screening test. So, this study aimed to characterize variants of S gene product of hepatitis B virus (HBV) isolated from patients with overt or occult HBV infection in north-eastern Egypt.

Methods

The study included sera of two different groups of volunteer blood donors (VBDs), 82 with overt HBV that were positive for HBsAg and anti-HBc and 343 donors negative for HBsAg eligible for donation. Of the latter group, only 44 were positive for anti-HBc. All anti-HBc positive sera were subjected to HBV DNA detection and partial sequence analysis targeting the HBV S gene.

Results

HBV DNA was detected in 22.7 % of HBsAg-/anti-HBc + (10/44 patients) and in 90 % of HBsAg + donors (74/82 patients) with significant statistical difference (P = 0.0001). Phylogenetic analysis showed that HBV strains retrieved from both groups were of genotype D. Amino acid escape mutation T125M was detected in only 2 samples of the occult infection group and in none of the overt group (P = 0.01). Different amino acid substitutions were identified in overt infection group: S143L/T (16.2 %, 12/74) and P120T/S (2.7 %, 2/74). Q129R was significantly more frequent in cases with occult HBV infection (40 %, 4/10) than overt group (6.8 %, 5/74) (P = 0.01).

Conclusions

HBV genotype D predominated both in patients with overt and occult HBV infection. Different profiles of amino acid substitutions in the major hydrophilic region were seen in these two groups in Egypt.

Prevalence and clinical relevance of occult hepatitis B virus infection in patients on the waiting list for kidney transplantation

BACKGROUND

Occult hepatitis B virus (HBV) infection can be defined as the long-lasting persistence of viral genomes in the liver tissue, and sometimes also in the serum at low levels of viremia in individuals with undetectable HBV surface antigen (HBsAg). Viral replication can be reactivated by immunosuppressive therapies or immunologic diseases, leading to the development of typical hepatitis B.

METHODS

All patients on the waiting list for renal transplantation at the only 2 transplant centers in our region (Piemonte, Italy) were checked for the presence of occult HBV infection by an highly sensitive quantitative HBV-DNA polymerase chain reaction (PCR) assay (nested PCR); the only exclusion criterion was HBsAg-positivity. The enrollment lasted from October 1, 2006, to May 31, 2007. The prospective follow-up will continue for 5 years.

RESULTS

HBV-DNA sequences were detected in blood samples from 10 of 300 cases examined (3.3%), being more frequent among Asian (1/3; 33.3%) and African (1/16; 6.25%) subjects as compared with the Caucasians (8/281; 2.8%; P = .011), among anti-hepatitis C virus (HCV) positive versus HCV negative patients (3/32 [9.3%] vs 7/268 [2.6%]; P = .004) and mainly among patients with a previous history of overt liver diseases (3/22 [14%] vs 7/278 [2.5%]; P = .019). HBV-DNA sequences became undetectable at 1 month after renal transplantation in 3 patients; the follow-up is in progress for these and the other patients.

CONCLUSION

Occult HBV infection occurs in patients undergoing renal transplantation. Longer observation and prospective studies will clarify the clinical impact of this occult infection on transplant outcomes and the possibility of viral reactivation related to immunosuppressive therapy.