Screening For Hepatitis B Virus Surface Antigen Research Articles

Retraction.

Retraction: 'Infectivity of hepatitis B virus (HBV) surface antigen (HBsAg) positive plasma with undetectable HBV-DNA: Can HBsAg screening be discontinued in Egyptian blood donors?' by Magdy El Ekiaby, Junko Tanaka, Harry van Drimmelen, Jean-Pierre Allain, Nico Lelie, J Viral Hepat 2022, 29: 330-339. The above article, published online on 11 March 2022 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/full/10.1111/jvh.13666) has been retracted by agreement between the authors, the journal's Editor in Chief, Graham Foster, and John Wiley & Sons Ltd. The authors have informed the journal that a systematic calculation error was discovered subsequent to the publication. Following editorial assessment, all parties have agreed that the identified error could potentially have implications for public health decision-making and warrant retraction of the article in its present form. The authors have been recommended to submit a corrected version of the article for an independent evaluation.

Infectivity of hepatitis B virus (HBV) surface antigen (HBsAg) positive plasma with undetectable HBV-DNA: Can HBsAg screening be discontinued in Egyptian blood donors?

HBV infectivity data were reviewed and the 50% infectious dose (ID50 ) was reassessed in different HBsAg positive infection stages enabling modelling of transfusion-transmitted (TT)-HBV infection risk if HBsAg donor screening was replaced by individual donation nucleic acid amplification technology (ID-NAT). Quantitative HBsAg and HBV-DNA assays were performed against international standards to compare the ratio between potential infectious HBV virions and subviral HBsAg particles in Egyptian HBsAg positive blood donors as well as in Japanese chimpanzee samples of known infectivity. HBV-DNA load below the quantification limit of detection was estimated against a reference standard by replicate NAT testing (n=25). Infectivity of chimpanzee samples collected during ramp-up and declining viremic phase were tested in a human liver chimeric mice (HLCM) model and compared with published infectivity data from different HBsAg positive infection stages. Lowest estimates of ID50 in HBsAg positive plasma were 3-6 HBV virions in chimpanzee studies. Infectivity decreased approximately 10-100-fold in the declining viremic phase using HLCM. In acute-phase samples, HBV to HBsAg particle ratios varied between 1:102 -104 but in HBsAg positive blood donors this particle ratio reached 1:106 -1012 when viral load was below 100 HBV-DNA copies/ml. Modelled TT-HBV risk of an HBsAg positive/ID-NAT nonreactive blood transfusion was estimated at 9%-46% for components containing 20-200ml of plasma assuming an ID50 of 316 (point estimate between 100 and 1000) virions. In the Egyptian setting, discontinuation of HBsAg donor screening and reliance on ID-NAT alone seems to be unsafe.

Compliance of protocol-driven hepatitis B serological screening in patients receiving anti-CD20 monoclonal antibody therapy.

261 Background: The US Food and Drug Administration has issued a boxed warning for anti-CD20 monoclonal anti-bodies for the reactivation of Hepatitis B virus (HBV) infection. The National Comprehensive Cancer Network (NCCN) Non-Hodgkin Lymphoma and Infectious Diseases Society of America guidelines recommend routine serologic testing for all patients receiving anti-CD20 antibody therapy. NCCN specifies serologic screening of HBV surface antigen (HBsAg) and hepatitis B core antibody (HBcAb) should be completed prior to initiation of anti-CD20 therapy. In March 2018, UCHealth included HBV screening into the EHR oncology templates which include an anti-CD20 monoclonal antibody. The purpose of this study was to assess the impact of this template modification on compliance to guideline recommended screening for patients receiving anti-CD20 monoclonal antibody therapy. Methods: This was a retrospective chart review of patients who received an anti-CD20 monoclonal antibody for an oncologic indication between April 1, 2017 to November 30, 2017 (pre-template change) and April 1, 2018 to November 30, 2018 (post-template change) at any of the UCHealth Cancer Care and Hematology Centers. The primary objective was the composite compliance rate of HBsAg and HBcAb screening completed prior to receipt of treatment. Secondary objectives included compliance rate of each screening test, days between screening and treatment, screening for initial compared to relapse therapy, and rate of hepatitis C virus screening. Results: The addition HBV serologic screening to the EHR oncology templates containing an anti-CD20 agent improved screening compliance of HBsAg and HBcAb by 6.7% as a system (2017: 89.7% vs 2018: 96.4% [p = 0.133]). Secondary endpoints saw an increase in testing of each individual screening, testing for patients in the relapse setting, and HCV screening. Additionally, a reduction was seen in median days between screening and start of therapy (2017: 11 (4.5-30.3 IQR) vs 2018: 7 (2-14 IQR) [p = 0.008]). Conclusions: The addition of HBV serologic screening to EHR oncology templates increased compliance to guideline recommended screening for patients receiving anti-CD20 antibody therapy.

Hepatitis B Virus Surface Antigen Carriage Among Blood Donors in Ziguinchor, Senegal: Prevalence and Associated Factors

Introduction: Hepatitis B virus is endemic in Senegal, West Africa, however the prevalence of hepatitis B virus surface antigen (HBsAg) carriage in Ziguinchor, Senegal is unknown. This study was conducted in order to determine the prevalence of HBsAg carriage among blood donors in Ziguinchor and to identify factors associated with HBsAg carriage. Methodology: A retrospective study was conducted in the blood donation unit of the Ziguinchor Regional Hospital in 2013. Screening for HBsAg was performed with kits from Rapid Signal TM HBsAg Serum/Plasma Dipstrip (Orgenics ltd Israel). Results: A total of 2122 donors were included in this study, of which 1715 (80.8%) were male and 407 (19.2%) were female. The overall prevalence of HBsAg carriage among all donors was 12.1% (n=256). Carriage was higher among male donors, (n=223, 13%) compared to female donors (n=33, 8.1%) (p=0.04). Carriage was lower among regular voluntary donors (n=24, 5.8%) compared to new voluntary donors (n=101, 14.1%) and replacement donors (n=131, 13.2%) (p<0.001). Conclusion: This is the first study to report the prevalence of HBsAg carriage in Ziguinchor, Senegal. HBsAg carriage is highly prevalent among blood donors in Ziguinchor, especially among males and new voluntary or replacement donors.

Detection and identification of occult hepatitis B virus infection among blood donors

Background: Occult hepatitis B virus infection (OBI) is defined as the presence of circulating hepatitis B virus (HBV) DNA as detected by HBV nucleic acid test (NAT), in the absence of detectable HBV surface antigen (HBsAg), with or without antibodies to hepatitis B core antigen (anti-HBc) or hepatitis B surface antigen (anti-HBs). HBV infection is a continuing threat to transfusion safety, especially in developing counties like India where detection of HBV is primarily based on the screening for HBsAg as a marker of infection. Objective: To know the prevalence of OBI among blood donors and their serological and molecular characterization of NAT yield samples. Materials and Methods: A total of 41,090 blood donor’s samples from February 2014 to August 2015 were tested by individual donor-NAT (ID-NAT) apart from routine serological screening for anti-HIV 1-2, P24 antigen, anti-HCV, and Hepatitis B surface antigen (HBsAg) by Biomerieux (Vironostika® HIV Ag-Ab, Hepanostika® HCV Ultra, and HBsAg Ultra, France). All the samples were tested individually by Procleix® Utrio Plus® Assay (Novartis Emeryville, CA). Blood units that were HBsAg nonreactive but ID-NAT reactive (NAT yield) were further worked up with anti-HBc, anti-HBsAg, viral DNA load, and viral genotyping. Result: Of the 41,090 samples, 29 were reactive for HBV DNA (NAT yield). Among the 29 NAT yields, 24 were individual NAT yield, 4 were HBV–HCV NAT co-yield, and 1was HBV-HIV NAT co-yield. A total of 24 HBV individual NAT yield samples were further tested for OBI. A total of 11 samples were reactive for anti-HBc only, 3 samples carried both anti-HBc and anti-HBs, yielding a total of 14 (58.3%) samples that were classified as OBI and 1 (4.2%) sample was reactive for anti-HBs only. Nine samples (37.5%) did not have any serological marker owing to incomplete antibody, and they remained unclassified, as window period infection could not be excluded. Two HBV-NAT yield samples of genotype D, one with a window period and the second being an OBI had high viral load by qPCR. Conclusion: Blood products from donors with OBI carry a high risk of HBV transmission by transfusion. Because of multiple antigens and antibodies present in blood in response to HBV infection, at present there is no single test to detect the infection. In developing country such as India with high seroprevalence of HBV infection, combination of at least two tests would help us to improve the transfusion safety.

Rare transmission of hepatitis B virus by Dutch donors with occult infection.

To reduce the rate of transfusion-transmitted hepatitis B virus (HBV), HBV DNA testing was introduced for all Dutch blood donations in 2008, in addition to the existing screening for HBV surface antigen (HBsAg). This study describes the lookback results for repeat donors with an "HBV DNA-only" test result (HBV DNA-positive and HBsAg-negative). From November 2008 until June 2011, a total of 2.3 million blood donations were tested for HBV DNA and 22 donors showed the HBV DNA-only profile. Four donors had early preseroconversion HBV infection, two showed suppressed infection after vaccination, and 16 donors had occult chronic HBV infection (OBI). Potentially infectious donations were traced back as far as 1992. If possible the recipients were tested for current and past HBV infection. A total of 416 implicated donations could be traced in blood bank records, involving 448 issued blood products. For 170 (38%) of the recipients no information was obtained from the hospitals; 196 (44%) recipients had died, and 82 (18%) were tested for HBV. Six recipients tested positive for current (n = 4) or past (n = 2) HBV infection. For two recipients transfusion was ruled out as the source of infection. Three patients showed HBV DNA sequences matching with the HBV in one common OBI donor. Overall, in four of 82 tested recipients (5%) HBV transmission was likely. In our lookback study HBV testing was possible in only a minority (18%) of potentially exposed recipients. A low transmission rate (5%) was observed in recipients of blood components from donors with OBI.

Effectiveness of prevention of mother-to-child transmission practice in three provinces of Southern China

Vaccination in prevention mother-to-child transmission (PMTCT) of hepatitis B has been recommended since plasma-derived hepatitis B vaccines became available in China in 1986; however, less study evaluated practice effectiveness of PMTCT systematically. We conducted a prospective survey to evaluate the effectiveness of PMTCT practices in 3 provinces of southern China. We selected prefectures with low timely birth dose coverage in Yunnan, Guangxi, and Hunan provinces. Infants born to HBsAg positive mothers were evaluated at 7–12 months of age. We tested hepatitis B virus (HBV) surface antigen (HBsAg) and HBV e antigen (HBeAg) of mothers and tested HBsAg of infants born to HBsAg positive mothers using Enzyme-linked Immunosorbent Assay (ELISA) at provincial CDC laboratories. We used logistic regression analysis to analyze the risk factors for HBV infection. Among 3,094 infants born to HBsAg positive mothers, 172 were positive for HBsAg (5.6%). HBeAg status of pregnant women, timely birth dose (TBD) of hepatitis B vaccine were major predictors for HBV infection of infants. PMTCT practices greatly reduced the prevalence of HBsAg among infants born to HBsAg positive mothers China. However, the effectiveness of strategies used in PMTCT varied. HBsAg screening for pregnant women, monitoring of infants born to HBsAg positive mother should be enhanced to evaluate the effectiveness of program.

PTU-101 Rituximab and hepatitis b: are we doing it right?: Abstract PTU-101 Table 1

<h3>Introduction</h3> Rituximab is a potent immunosuppressant used to treat haematological malignancies, rheumatological diseases and autoimmune disorders. Patients with current or past infection with the hepatitis B virus (HBV) are at high risk of reactivation following treatment with rituximab and other immunosuppressants.¹HBV reactivation can cause liver failure and is associated with a 5–12% mortality. Guidelines advise screening for HBV surface antigen (HBsAg) and core antibody (anti-HBcAb) prior to initiating immunosuppression, and recommend antiviral prophylaxis for all found to be positive.² <h3>Method</h3> A baseline audit was conducted on all patients receiving rituximab in our Trust between Sept-Dec 2012 to determine the proportion of patients tested for HBsAg and anti-HBcAb. Data was also collected on prophylactic antiviral prescriptions. Following the baseline audit, a hospital guideline was developed and targeted education was conducted for rituximab prescribers. Two follow-up audits were conducted in Feb–April 2014 and Sept–Dec 2014. <h3>Results</h3> A summary of the baseline results and follow-up audits is shown in Table 1. The baseline audit showed very low rates of HBV testing; only 23% tested for HBsAg and 19% for anti-HBcAb. None were HBsAg positive, but 2 were anti-HBcAb positive and neither received antiviral prophylaxis. One of these patients experienced HBV reactivation and despite tenofovir treatment developed liver failure requiring a 3-week hospital admission. The rituximab prescriptions were mainly from our rheumatology (56%) and haematology (32%) departments. This audit highlighted the need for education of clinicians prescribing rituximab. A Trust protocol was introduced and targeted education sessions were delivered to the specialties using rituximab. A significant stepwise increase in HBV testing was seen in follow-up audits (Table 1). By Sept-Dec 2014, 79% of patients were tested for HBsAg. <h3>Conclusion</h3> In our Trust, introduction of a protocol and targeted education of clinicians has led to a dramatic increase in HBV screening prior to receiving rituximab (19% to 79%). However, reinforcement of the guidelines is needed to further increase testing rates and appropriate hepatology referrals. Importantly, prophylactic antiviral treatment was indicated for 5% of patients tested. <h3>Disclosure of interest</h3> None Declared. <h3>References</h3> EASL Guidelines: Management of chronic HBV infection. J Hepatol. 2012;57:167–185 NICE Hepatitis B guidelines, 2013

Sensitivity of individual donor nucleic acid testing (NAT) for the detection of hepatitis B infection by studying diluted NAT yield samples.

Screening blood donors for the presence of hepatitis B virus surface antigen (HBsAg) has been the backbone of blood safety. However, occult hepatitis B infection (OBI) in donors can be missed when only HBsAg screening is used. Nucleic acid testing (NAT) is capable of detecting OBI among donors. The aim of our study was to analyse the sensitivity of NAT for detecting OBI. The kits used during the study for serology testing were BioRad Monolisa™ HBsAg Ultra (HBsAg screening), Abbott Architect for anti-HBcAg (total) and anti-HBsAg testing, and Vitros® by Ortho Clinical Diagnostics for anti-HBcAg (IgM). Procleix Ultrio was used for individual donor-NAT (ID-NAT) and Abbott m2000 for estimation of HBV DNA. Out of 28,134 HBsAg non-reactive donors, 25 were ID-NAT-reactive. Of these 25 NAT yield samples, 18 were studied further at different dilutions from 1:2 to 1:16. The doubling dilutions were made with HBV non-reactive AB plasma. Undiluted samples were used for all serological tests and for HBV DNA estimation. Of the 18 samples studied, nine were NAT-reactive at a dilution of <1:4 and five out of these showed presence of antibody to core antigen (IgG+IgM). Antibody to surface antigen was present in only two of the nine NAT-reactive samples, one with antibody to core antigen and the other without. Six had a viral load in the range from <10 to 38 IU/mL whereas the viral load in the remaining three samples was not determined. Among the other nine samples which were NAT-reactive at dilutions≥1:4, antibody to core antigen (IgG+IgM) was present in seven. Our study showed that ID-NAT testing along with HBsAg screening could detect most potentially HBV infectious donors (including those with OBI). NAT screening for HBV on diluted samples could compromise blood safety because samples with a low viral load will escape detection.

Prevalence of Hepatitis B Virus Infection among Egyptian Pregnant Women - A Single Center Study

Background: Hepatitis B virus (HBV) infection still has a relatively high incidence and prevalence worldwide. In the post-vaccination era in developing countries, perinatal vertical transmission remains the most common mode of transmission. Prevention of mother-to-child transmission requires screening for HBV surface antigen (HBsAg) in pregnant women to identify which newborns that must be immunized. Aim: This study aimed to evaluate the prevalence of HBV infection among pregnant mothers who were attending outpatient clinic of the Obstetric Department, and Social and Preventive Medicine Center at Cairo University Hospital Campus, for routine antenatal care. Methods: A cross sectional study included 2,000 pregnant women. A rapid screening test for HBV “One Step HBsAg Rapid Test” was done for all women and all HBsAg-positive cases were confirmed by ELISA for HBsAg. A structured questionnaire for risk factors for HBV acquisition was filled for every pregnant mother positive for HBsAg and a control group of HBsAg negative mothers. Results: Out of 2,000 pregnant women, 35 (1.75%) were positive by the rapid test, out of whom 32/35 cases (91.43) were confirmed to be positive by the confirmatory test representing 1.6% of the study population. Family history of HBV, previous intravenous (IV) injections, medical clinic attendance, hospital admission, and surgeries were the risk factors for acquiring HBV infection (P-value=0.001, 0.003, 0.002, 0.000, and 0.011, respectively). Conclusion: HBV infection is prevalent among pregnant mothers attending our outpatient services. Therefore we recommend screening for HBV in all Egyptian pregnant mothers to prevent neonatal infection by immunoprophylaxis.

High Endemicity and Low Molecular Diversity of Hepatitis B Virus Infections in Pregnant Women in a Rural District of North Cameroon

BackgroundA program, supported by the GEMHEP (Groupe d'étude Moléculaire des Hépatites), was established in 2007 in the sanitary district of Tokombéré, to prevent perinatal transmission of hepatitis B virus (HBV). It comprises screening for HBV surface antigen (HBsAg) in all pregnant women and vaccinating the newborn if tests are positive.Methods/Principal Findings1276 women were enrolled in the study after providing informed consent. Demographic data and blood samples were available for 1267 of the enrolled patients. HBsAg was determined locally using a rapid test (Vikia HBsAg, Biomerieux). Tests for HBV and HDV virological markers (HBeAg, anti-HDV antibodies (Ab), HBV-DNA, HDV-RNA, HBV and HDV genotypes) were performed on the confirmed HBsAg-positive samples in the virology unit of the Angers University Hospital (France). HBsAg was found in 259 of the 1267 pregnant women (20.4%) between January 2009 and April 2010, of whom 59 were HBeAg-positive (22.7%) with high levels of HBV-DNA. Anti-HDV Ab were found in 19 (7.3%) of the HBsAg-positive women. The prevalence rates of HBsAg and HDV were not age-dependent whereas HBeAg carriers were statistically younger than non carriers. Basal core promoter (BCP) and precore (PC) mutations and genotypes were determined by sequencing. Of 120 amplified sequences, 119 belonged to HBV genotype E (HBV/E) and the 9 HDV strains belonged to HDV clade 1. In the PC region, 83/228 patients (36.4%) harbored a G1896A mutant or mixed phenotype virus. In the BCP region, the double mutation A1762T/G1764A and the G1757A substitution were detected respectively in 26/228 patients (11.4%) and 189/228 patients (82.8%).ConclusionsOur results confirm the high prevalence and low molecular diversity of HBV in Far Northern Cameroon; more than 20% of the infected women were highly viremic, suggesting a high rate of HBV perinatal transmission and supporting the WHO recommendation to vaccinate at birth against hepatitis B.

HBsAg, anti-HCV, anti-HIV 1/2 and syphilis seroprevalence in healthy volunteer blood donors in southeastern Anatolia

This study investigated the seroprevalence of hepatitis B virus surface antigen (HBsAg), antibody against hepatitis C virus (anti-HCV), antibody against human immunodeficiency virus type 1/2 (anti-HIV 1/2), and antibody against Treponema pallidum (anti-Treponemal or syphilis antibody) in healthy volunteer blood donors, and assessed their distribution according to the years and genders. HBsAg, anti-HCV, anti-HIV ½, and syphilis screening results of a total of 266,035 healthy volunteer blood donors who had been admitted for blood donation to the Regional Blood Center of Dicle University Hospital between January 2000 and December 2010 were evaluated, retrospectively. HBsAg, anti-HCV, and anti-HIV 1/2 screening were performed using a fully automated device with the microparticle enzyme immunoassay method (MEIA). Syphilis screening was performed by Rapid Plasma Reagin (RPR) carbon test between January 2000 and December 2009, and by using a fully automated device with the MEIA method between January 2010 and December 2010. Of 266,035 healthy volunteer blood donors, 259,384 (97.5%) were male and 6,651 (2.5%) were female. Statistically, there was not any significant difference between male and female genders for HBsAg, anti-HCV and syphilis seropositivities (P = 0.729, P = 0.748, and P = 0.861, respectively). HBsAg was found to be positive in 8,422 (3.17%), anti-HCV in 1,703 (0.64%), anti-HIV 1/2 in one (0.0004%) of 266,035 healthy volunteer blood donors, and syphilis antibody with RPR in 166 (0.07%) of 246,341 healthy volunteer blood donors. Blood donor forms should be carefully tailored to improve the identification of possible risks of transfusion-transmitted infections.

Infectivity of occult hepatitis B from two different points of view

Infectivity of occult hepatitis <scp>B</scp> from two different points of view

Viral Hepatitis and Rapid Diagnostic Test Based Screening for HBsAg in HIV-infected Patients in Rural Tanzania

BackgroundCo-infection with hepatitis B virus (HBV) is highly prevalent in people living with HIV in Sub-Saharan Africa. Screening for HBV surface antigen (HBsAg) before initiation of combination antiretroviral therapy (cART) is recommended. However, it is not part of diagnostic routines in HIV programs in many resource-limited countries although patients could benefit from optimized antiretroviral therapy covering both infections. Screening could be facilitated by rapid diagnostic tests for HBsAg. Operating experience with these point of care devices in HIV-positive patients in Sub-Saharan Africa is largely lacking. We determined the prevalence of HBV and Hepatitis C virus (HCV) infection as well as the diagnostic accuracy of the rapid test device Determine HBsAg in an HIV cohort in rural Tanzania.MethodsProspectively collected blood samples from adult, HIV-1 positive and antiretroviral treatment-naïve patients in the Kilombero and Ulanga antiretroviral cohort (KIULARCO) in rural Tanzania were analyzed at the point of care with Determine HBsAg, a reference HBsAg EIA and an anti-HCV EIA.ResultsSamples of 272 patients were included. Median age was 38 years (interquartile range [IQR] 32–47), 169/272 (63%) subjects were females and median CD4+ count was 250 cells/µL (IQR 97–439). HBsAg was detected in 25/272 (9.2%, 95% confidence interval [CI] 6.2–13.0%) subjects. Of these, 7/25 (28%) were positive for HBeAg. Sensitivity of Determine HBsAg was rated at 96% (95% CI 82.8–99.6%) and specificity at 100% (95% CI, 98.9–100%). Antibodies to HCV (anti-HCV) were found in 10/272 (3.7%, 95% CI 2.0–6.4%) of patients.ConclusionThis study reports a high prevalence of HBV in HIV-positive patients in a rural Tanzanian setting. The rapid diagnostic test Determine HBsAg is an accurate assay for screening for HBsAg in HIV-1 infected patients at the point of care and may further help to guide cART in Sub-Saharan Africa.

Economic Analysis of Hepatitis B Screening and Treatment

Economic Analysis of Hepatitis B Screening and Treatment

Significance of detecting anti-HBc among Egyptian male blood donors negative for HBsAg*

Screening for hepatitis B virus surface antigen (HBsAg) reduces the risk of transfusion-transmitted hepatitis B viral (HBV) infection. However, the absence of HBsAg in the blood of apparently healthy individuals may not be sufficient to ensure the lack of circulating HBV. Blood containing anti-hepatitis B core antibody (anti-HBc) without detectable presence of HBsAg might be infectious; therefore, screening for anti-HBc has been implemented in some countries resulting in a decrease in the risk of post-transfusion HBV infection. To study the seroprevalence of anti-HBc. The relationship between anti-HBc positivity and the presence of circulating HBV among healthy blood donors negative for HBsAg will be helpful to decide whether supplemental testing may bring additional safety to blood products. A total of 1026 serum samples collected from HBsAg-negative Egyptian healthy male donors were tested for the presence of anti-HBc (both IgM and IgG types) using the competitive enzyme-linked immunosorbent assay technique. Anti-HBc-positive samples were subjected to real-time polymerase chain reaction to confirm the presence of HBV DNA. Of the 1026 samples tested, 80 (7·8%) blood samples were found to be reactive to anti-HBc. Of those, HBV DNA was detected in five of the samples (6·25%). The levels of detected viraemia were variable among the five donors. This study shows the insufficient effectiveness of HBsAg screening in protecting blood recipients from HBV infection. Inclusion of anti-HBc testing should be considered in the screening of blood donors.

Detection and characterization of hepatitis B virus strains from wild-caught gorillas and chimpanzees in Cameroon, Central Africa

Previous epidemiological studies have reported a high prevalence of hepatitis B virus (HBV) infection in chimpanzees in Gabon and Congo, Central Africa. There is no data for this species from Cameroon. To date few cases of active HBV infection have been documented in gorillas and only one complete HBV sequence has been described from a wild-caught gorilla originating from Cameroon and housed in Germany. Since gorillas are apes found in Cameroon, we thus investigated the prevalence and genetic relationships of HBV infecting apes in this area. We subjected 185 wild-caught apes’ plasmas, including 159 from chimpanzees and 26 from gorillas to ELISA screening for HBV surface antigen (HBsAg). Subsequently, we detected HBV DNA, sequenced the whole HBV genome and performed phylogenetic analysis. Eleven (6.9%) chimpanzees and 3 (11.6%) gorillas plasma were found HBsAg positive, of which 8 and 3 were positive for HBV DNA, respectively. Phylogenetic analyses revealed that the 3 new gorilla HBV sequences grouped together with the single available HBV sequence from gorilla. Evidence of recombination between HBV Pan troglodytes troglodytes and Pan troglodytes vellerosus was observed in two of the Cameroonian strains. Findings from our study show that HBV infection is endemic in wild-born gorillas and chimpanzees in Cameroon, and that there is evidence of recombination between HBV strains circulating in chimpanzees. We demonstrated the existence of gorillas’ specific HBV strains distinct but related to those found in chimpanzees living in the same habitat in Cameroon, providing substantial evidence of species association of HBV in NHPs.

Symptomatic Hepatitis B Virus (HBV) Reactivation despite Reduced Viral Fitness Is Associated with HBV Test and Immune Escape Mutations in an HIV‐Coinfected Patient

Two sequential hepatitis B virus (HBV) strains obtained before and during an icteric flare-up of an occult HBV infection in a patient coinfected with human immunodeficiency virus revealed HBV surface antigen (HBsAg) test escape mutations, although the patient had never received hepatitis B-specific immunoglobulin. In contrast to the high HBV DNA loads, recurrence of HBsAg, and resulting icteric hepatitis, phenotypic analysis of the mutated HBV strains revealed significantly reduced replication efficacies in vitro, compared with wild-type HBV. Therefore, immune escape in the transiently anti-HBs-positive patient appeared to be crucial for persistence and reactivation. Immune escape mutants evolved even without exogenous selective pressure, hampered detection in HBsAg screening, and might be transmitted during reactivation with high HBV loads.

Rapid Detection of Hepatitis B Virus Surface Antigen by an Agglutination Assay Mediated by a Bispecific Diabody against Both Human Erythrocytes and Hepatitis B Virus Surface Antigen

Bispecific antibodies have immense potential for use in clinical applications. In the present study, a bispecific diabody against human red blood cells (RBCs) and hepatitis B virus surface antigen (HBsAg) was used to detect HBsAg in blood specimens. The bispecific diabody was constructed by crossing over the variable region of the heavy chains and the light chains of anti-RBC and anti-HBsAg antibodies with a short linker, SRGGGS. In enzyme-linked immunosorbent assays, this bispecific diabody showed specific binding to both RBCs and HBsAg. When this bispecific diabody was mixed with human blood specimens in the presence of HBsAg, the dual binding sites of the diabody caused agglutination of human RBCs. This diabody-mediated agglutination assay was then used to test 712 clinical blood specimens and showed 97.7% sensitivity and 100% specificity when the results were compared with those of the conventional immunoassay, which was used as a reference. This autologous RBC agglutination assay provides a simple approach for rapid screening for HBsAg in blood specimens.

Frequency of hepatitis B virus ‘a’ determinant variants in unselected Spanish chronic carriers

The prevalence in the population of hepatitis B virus (HBV) surface antigen (HBsAg) variants that may impair diagnosis, or allow the virus to escape vaccine-induced immunity or passive immunoglobulin therapy is unknown. A genome fragment encoding HBsAg amino acids 112-212 was amplified and sequenced from the sera of 272 unselected DNA-positive, HBV-chronic carriers from Spain. The genotype and the HBsAg subtype were predicted from the sequences. Analysis of amino-acid positions 112-157 revealed single or multiple substitutions in 39% of the carriers studied. Mutations were not detected for residues 121, 135, 137, 139, 140, 141, 142, 146, 147, 148, 149, 151, 152, 153, 155, 156, and 157. Substitutions reported previously to be in association with failures of diagnostic tests or with vaccine or immunoglobulin therapy escape were found in 12.5%, 6.6%, and 9.2% of carriers, respectively. Met133Thr (2.2%); Gln129His, Met133Ile, Phe/Tyr134Asn (1.8%); Phe/Tyr134Leu, Gly145Ala (1.5%), and Pro120Thr (1.1%) were the most frequent. Other substitutions, including Gly145Arg (0.4%), were found at a frequency of less than 1%. Samples containing HBV mutants were tested with three commercial assays for HBsAg screening. Almost all the mutants reacted to the upper cut-off values of the assays, but six samples with weak reactivity with one or more of the methods were also found. Thus, HBV mutants with a potential impact on clinical and public health issues are moderately frequent among chronic carriers from Spain, although their influence on the performance of diagnostic tests seems to be slight.