Search Results (54)

Chronic hepatitis B virus (HBV) and Occult HBV infection (OBI) remain a health burden in sub-Saharan Africa. This study investigated HBV prevalence, circulating genotypes, and associated risk factors with HBV exposure among HIV-positive adults on antiretroviral therapy and pregnant women in southwestern Cameroon. A total of 233 HIV patients and 190 third-trimester pregnant women were screened for HBV DNA, viral load, serological markers (HBsAg, anti-HBc, and anti-HBs), and HBV genotypes were determined by partial sequencing of the S gene. HBV DNA was detected in 10% of HIV-positive patients and 4% of pregnant women, with an overall prevalence of 7%. OBI accounted for 9% and 3%, respectively. Anti-HBc seroprevalence was high (75% in HIV, 46% in pregnant women), while self-reported vaccination coverage was low (1% and 11%). Genotypes A, B, D, and E were identified, with genotype B reported for the first time in Cameroon. Immune escape mutations and the adefovir resistance mutation rtA181V were detected. Self-reported alcohol use was associated with HBV exposure in HIV patients (aOR = 2.08; p = 0.028) and inversely associated with tertiary education in pregnant women (aOR = 0.18; p = 0.038). This study highlights a significant burden of HBV and OBI among vulnerable populations in Cameroon. Full article

Hepatitis B virus (HBV) represents a significant global health challenge, affecting over 254 million individuals and contributing to 1.1 million deaths from liver-related complications in 2022. The World Health Organization has set ambitious targets to reduce HBV infections and mortality by 2030. However, only a small proportion (13%) of infected individuals receives timely diagnosis and treatment. HBV elimination efforts necessitate substantial improvements in HBV diagnosis, particularly in identifying early-stage infections, occult HBV infections (OBI), and breakthrough cases. The hepatitis B surface antigen (HBsAg) is a key biomarker in HBV diagnosis, serving as a reliable indicator of infection status and treatment response. Conventional HBsAg assays, with a lower limit of detection (LoD) between 0.03 and 250 IU/mL, often fail to detect OBI and HBV reactivation. In contrast, ultrasensitive HBsAg assays, with an LoD as low as 0.005 IU/mL, can improve the identification of low concentration levels of HBsAg, facilitating earlier diagnosis, monitoring of therapeutic response, and assessment for functional cure. Research confirms the superiority of ultrasensitive assays in detecting HBV in cases missed by conventional assays, detecting NAT-yield samples, and enabling earlier detection of HBV reactivation. This review examines the challenges in HBV diagnostics and the clinical utility of ultrasensitive HBsAg assays in improving progress toward global HBV elimination. Full article

The Amazon Basin was historically hyperendemic for HBV and HDV, associated with severe outcomes like fulminant hepatitis. Brazil initiated its hepatitis B vaccination in 1989. This study assessed the current prevalence in this endemic region to evaluate the impact of vaccination. A cross-sectional population-based survey enrolled 1100 urban and rural residents. HBsAg prevalence was 1.5%, with no cases in individuals under 20 years, demonstrating interrupted vertical and horizontal transmission. Anti-HBc positivity (30.9%) indicated past exposure, predominantly in those over 30 years. Isolated anti-HBc (10.3%) included two occult HBV infections. HDV coinfection occurred in 25% of HBsAg-positive cases, with HDV RNA detected in two. Anti-HDV positivity was exclusive to adults over 30. Vaccination coverage was poorly documented, but 23.7% had protective anti-HBs titers. HBV vaccination has reduced HBsAg prevalence from high to low endemicity in the region, eliminating chronic infections in younger generations. Persistent HDV in older age groups underscores the need for targeted screening. Despite vaccination record gaps, the findings highlight the program’s success in interrupting transmission and support continued efforts toward HBV/HDV elimination. Full article

Hepatitis B virus (HBV) remains a major global health concern, as it is not only one of the most common hepatotropic viruses but also ranks as the seventh leading cause of mortality worldwide. The most significant routes of infection include vertical transmission (from mother to child before, during, or after birth, including transplacental infection) and horizontal transmission in early childhood through close household contact with infected parents. The aim of our study was to assess the prevalence of chronic and occult hepatitis B virus infection among pregnant women in St. Petersburg (Russia), including molecular characterization. We analyzed plasma samples from 1368 local pregnant women. ELISA screening for HBV markers included qualitative detection of HBsAg, anti-HBs IgG, and anti-HBcore IgG. HBV DNA was identified using highly sensitive nested PCR, followed by whole-genome sequencing for HBV DNA-positive cases. Our study evaluated the prevalence of serological and molecular HBV markers and their association with age, vaccination status, and number of pregnancies. Serological markers HBsAg, anti-HBs IgG, and anti-HBcore IgG were detected in 1.9%, 63.8%, and 12.9% of participants, respectively. HBV DNA was found in 4.7% of pregnant women, including 2.8% with occult HBV infection (OBI). We observed a positive correlation between anti-HBcore IgG and age, but an inverse correlation with anti-HBs IgG; an inverse correlation between anti-HBcore IgG and vaccination status, while anti-HBs IgG showed a positive correlation; and a positive correlation between HBsAg, anti-HBcore IgG, and HBV DNA with the number of pregnancies. We also analyzed the prevalence of clinically significant mutations, including drug resistance mutations, escape mutations (affecting diagnostic detection and vaccine efficacy), and mutations associated with disease progression. The detection of HBsAg-negative HBV infection was linked to circulating viral variants carrying escape mutations, which evade HBsAg detection in diagnostic assays and neutralization by vaccine-induced antibodies. The predominance of HBV isolates in pregnant women harboring dual-threat mutations (those causing diagnostic failure via HBsAg negativity, reduced vaccine/immunoglobulin efficacy, viral reactivation, disease progression) poses a significant public health risk and warrants further investigation. Full article

Occult hepatitis B infection (OBI) is a serious public health issue. Although a number of effective hepatitis B vaccines are available, hepatitis B still poses a threat to global public health. Patients with OBI are usually asymptomatic, but there may be active HBV DNA present in their blood, leading to the risk of virus transmission during blood transfusions or organ transplantation, constituting a hazard to the health of recipients and increasing the risk of liver cirrhosis and liver cancer. Although China has progressed in the development of blood-screening technology, OBI is still a significant hidden danger to blood transfusion safety. Therefore, in blood screening and blood transfusion, strengthening the monitoring and management of OBI is crucial to ensure blood safety and protect public health. Full article

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

Background/Objectives: Immunization with the hepatitis B vaccine is the most effective means of preventing acute HBV infection. However, whether the primary vaccination of infants confers lifelong immunity remains controversial. Therefore, the ongoing surveillance of vaccine recipients is required. Methods: A longitudinal study was carried out based on LongAn county, one of the five clinical trial centers for hepatitis B immunization in China in the 1980s. Serum samples were collected and tested for HBV serological markers and DNA. Results: A total of 637 subjects born in 1987–1993 were recruited, including 503 males and 134 females. The total prevalence of HBsAg was 3.9%. The prevalence in females (8.2%) was significantly higher than that in males (2.8%) (p = 0.004). The prevalence of anti-HBc in females (52.2%) was also significantly higher than that in males (41.2%) (p = 0.021). The prevalence of anti-HBs was 42.7% and did not differ significantly between males (41.7%) and females (46.3%) (p = 0.347). Compared to data from surveillance over the last ten years, the positivity rate of HBsAg did not increase. The positivity rate of anti-HBs decreased significantly (p = 0.049) while that of anti-HBc increased significantly (p = 0.001). The prevalence of occult HBV infection (OBI) in 2024 (6.0%) was significantly higher than that in 2017 (1.6%) (p = 0.045). Subjects diagnosed with OBI in 2017 maintained occult infection in 2024. Conclusions: Neonatal HBV vaccination maintained effective protection for at least 37 years. However, the prevalence of OBI increases with age in those vaccinated at birth, raising a new issue of how to prevent and control OBI in the post-universal infant vaccination era. Full article

In the 1980s, Poland was a medium-endemic country, with one of the highest incidences of hepatitis B in Europe (45/10⁵ inhabitants). Pursuant to the WHO guidelines, obligatory vaccination was introduced in 1994–1996 (as a part of hepatitis B prophylaxis for newborns), and in 2000–2011, all 14-year-olds were vaccinated. To prevent transfusion-transmitted HBV infection (TT-HBV), since the 1970s, each donation has been tested for HBsAg and, since 2005, additionally for the presence of HBV DNA. Based on the data from the Blood Transfusion Centers, changes in HBV detection in Polish blood donors were analyzed, starting from the introduction of mandatory NAT screening until 2019. During the period under analysis, a total of 11,625 HBV-infected donors were identified: 97.95% were seropositive (confirmed HBsAg) and 2.05% were seronegative (NAT yields). The detection frequency for both categories of infections was significantly (p = 0.05) higher for men than for women (Residual Risk RR = 1.4 and RR = 2.63, respectively). Seropositive infections were detected more frequently (p < 0.05) in first-time donors than in repeat donors (RR = 360), while no significant differences were observed in the category of seronegative infections. A downward trend in HBsAg detection was observed in both first-time and repeat donors (Spearman’s coefficient R = −0.98 and R = −0.90, respectively). The frequency of HBsAg in first-time donors decreased 5-fold, and, in repeat donors, 30-fold. In both subpopulations, the largest decrease occurred in the age group ≤ 20 years (i.e., donors born between 1985 and 2001). The incidence of window period (WP) infections in the repeat donor group demonstrated a downward trend (R = −0.54, p < 0.05), and in the first-time donor group, no significant trend was recorded. For occult hepatitis B infection (OBI), no significant trend was observed in either donor subpopulation. WP infections were detected significantly more often in donors aged 21–50 years than in donors ≤20 years, most often in the 41–50 age group. The frequency of OBI increased with donor age and was the highest in the 51–60 age group. A spectacular decrease in the frequency of HBsAg(+) infections was observed in current study, indicating the effectiveness of the hepatitis prevention strategy applied in Poland. We expect that the improvement in the epidemiological situation among blood donors causes a reduction in the risk of TT-HBV. Confirmation of this hypothesis by the analysis of residual risk should be a subject of further studies. Full article

Background: Hepatitis B is an infectious disease of worldwide importance and of great interest to transfusion medicine. The Amazon region has areas of high endemicity, outlining a worrying scenario for transfusion and epidemiological safety. Objective: To analyze the profiles of serological and molecular markers for HBV of blood donors from HEMOAM. Methods: Blood donors with different patterns of reactivity in serological and molecular screening for HBV were tested for viral load by the qPCR method at the reference center for liver diseases in the state of Amazonas. Results: A total of 230,591 donors were tested, with 3104 (1.34%) found reactive for HBV and 2790 (89.9%) found reactive for isolated anti-HBc. Viral load was not detected in 100% of donors reactive only to HBsAg, while 100% of donors with positive anti-HBc and positive HBsAg or HBV NAT demonstrated a detectable viral load. We also detected one case of occult hepatitis B (0.03%) only with reactive HBV NAT and five donors (0.2%) with positive anti-HBc and HBV NAT. Conclusions: With this result, the great importance of the anti-HBc test for the unsuitability of blood donors was verified, as well as the fundamental introduction of the HBV NAT test in screening for hepatitis B in Brazilian blood banks, as this was the only way to detect the viral infection burden in asymptomatic donors who previously would not be treated, which contributed to the maintenance of the endemicity of hepatitis B in the Brazilian Amazon. Full article

This study aims to characterize the molecular profile of the hepatitis B virus (HBV) among socially vulnerable immigrants residing in Brazil to investigate the introduction of uncommon HBV strains into the country. Serum samples from 102 immigrants with positive serology for the HBV core antibody (anti-HBc) were tested for the presence of HBV DNA by PCR assays. Among these, 24 were also positive for the HBV surface antigen (HBsAg). The full or partial genome was sequenced to determine genotype by phylogenetic analysis. Participants were from Haiti (79.4%), Guinea-Bissau (11.8%), Venezuela (7.8%), and Colombia (1%). Of the 21 HBV DNA-positive samples, subgenotypes A1 (52.4%), A5 (28.6%), E (9.5%), F2 (4.8%), and F3 (4.8%) were identified. Among the 78 HBsAg-negative participants, four were positive for HBV DNA, resulting in an occult HBV infection rate of 5.1%. Phylogenetic analysis suggested that most strains were likely introduced to Brazil by migration. Importantly, 80% of A5 sequences had the A1762T/G1764A double mutation, linked to an increased risk of hepatocellular carcinoma development. In conclusion, this study is the first report of HBV subgenotype A5 in Brazil, shedding new light on the diversity of HBV strains circulating in the country. Understanding the genetic diversity of HBV in immigrant communities can lead to better prevention and control strategies, benefiting both immigrants and wider society. Full article

Liver damage can progress through different stages, resulting in cirrhosis or hepatocellular carcinoma (HCC), conditions that are often associated with viral infections. Globally, 42% and 21% of cirrhosis cases correlate with HBV and HCV, respectively. In the Americas, the prevalence ranges from 1% to 44%. The WHO has the goal to eliminate viral hepatitis, but it is important to consider occult HBV infection (OBI), a clinical condition characterized by the presence of HBV genomes despite negative surface antigen tests. This review aims to provide an overview of recent data on OBI, focusing on its role in the development of hepatic diseases and its significance in the WHO Viral Hepatitis Elimination Plan. Specific HBV gene mutations have been linked to HCC and other liver diseases. Factors related to the interactions between OBI and mutated viral proteins, which induce endoplasmic reticulum stress and oxidative DNA damage, and the potential role of HBV integration sites (such as the TERT promoter) have been identified in HCC/OBI patients. Health initiatives for OBI research in Latin American countries are crucial to achieving the WHO’s goal of eradicating viral hepatitis by 2030, given the difficulty in diagnosing OBI and its unclear association with hepatic diseases. Full article

Viral hepatitis is a systemic infectious diseases caused by various hepatitis viruses, primarily leading to liver damage. It is widely prevalent worldwide, with hepatitis viruses categorized into five types: hepatitis A, B, C, D, and E, based on their etiology. Currently, the detection of hepatitis viruses relies on methods such as enzyme-linked immunosorbent assay (ELISA), immunoelectron microscopy to observe and identify viral particles, and in situ hybridization to detect viral DNA in tissues. However, these methods have limitations, including low sensitivity, high error rates in results, and potential false negative reactions due to occult serum infection conditions. To address these challenges, we have designed an AuNPs-DNA walker method that uses gold nanoparticles (AuNPs) and complementary DNA strands for detecting viral DNA fragments through a colorimetric assay and fluorescence detection. The DNA walker, attached to gold nanoparticles, comprises a long walking strand with a probe sequence bound and stem-loop structural strands featuring a modified fluorescent molecule at the 3′ end, which contains the DNAzyme structural domain. Upon the addition of virus fragments, the target sequence binds to the probe chains. Subsequently, the long walking strand is released and continuously hybridizes with the stem-loop structural strand. The DNAzyme undergoes hydrolytical cleavage by Mg²⁺, breaking the stem-loop structural strand into linear single strands. As a result of these structural changes, the negative charge density in the solution decreases, weakening spatial repulsion and rapidly reducing the stability of the DNA walker. This leads to aggregation upon the addition of a high-salt solution, accompanied by a color change. Virus typing can be performed through fluorescence detection. The innovative method can detect DNA/RNA fragments with high specificity for the target sequence, reaching concentrations as low as 1 nM. Overall, our approach offers a more convenient and reliable method for the detection of hepatitis viruses. Full article

(1) Background: Hepatitis B virus (HBV) sequencing data are important for monitoring HBV evolution. We aimed to molecularly characterize HBV sequences from participants with HBV surface antigen-positive (HBsAg+) serology and occult hepatitis B infection (OBI+). (2) Methods: We utilized archived plasma samples from people living with human immunodeficiency virus (PLWH) in Botswana. HBV DNA was sequenced, genotyped and analyzed for mutations. We compared mutations from study sequences to those from previously generated HBV sequences in Botswana. The impact of OBI-associated mutations on protein function was assessed using the Protein Variation Effect Analyzer. (3) Results: Sequencing success was higher in HBsAg+ than in OBI+ samples [86/128 (67.2%) vs. 21/71 (29.2%)]. Overall, 93.5% (100/107) of sequences were genotype A1, 2.8% (3/107) were D3 and 3.7% (4/107) were E. We identified 13 escape mutations in 18/90 (20%) sequences with HBsAg coverage, with K122R having the highest frequency. The mutational profile of current sequences differed from previous Botswana HBV sequences, suggesting possible mutational changes over time. Mutations deemed to have an impact on protein function were _tpQ6H, _surfaceV194A and _preCW28L. (4) Conclusions: We characterized HBV sequences from PLWH in Botswana. Escape mutations were prevalent and were not associated with OBI. Longitudinal HBV studies are needed to investigate HBV natural evolution. Full article

Although a combination of immunoprophylaxis and antiviral therapy can effectively prevent mother-to-child transmission (MTCT) of hepatitis B virus (HBV), a considerable number of infants born to highly viremic mothers still develop occult HBV infection (OBI). To uncover the virological factor and risk predictor for OBI in infants, we found that the diversity and complexity of maternal HBV quasispecies in the case group were lower than those in the control group. Mutations with significant differences between the two groups were most enriched in the NTCPbd and PreC regions. Genetic distance at the amino-acid level of the PreC region, especially the combination of three amino-acid mutations in the PreC region, could strongly predict the risk of OBI in infants. HBV quasispecies in OBI infants were highly complex, and the non-synonymous substitutions were mainly found in the RT and HBsAg regions. The sK47E (rtQ55R) and sP49L mutations in OBI infants might contribute to OBI through inhibiting the production of HBV DNA and HBsAg, respectively. This study found the potential virological factors and risk predictors for OBI in infants born to highly viremic mothers, which might be helpful for controlling OBI in infants. Full article

SARS-CoV-2 and blood-borne viral coinfections are well reported. Nevertheless, little is known regarding the seroprevalence of SARS-CoV-2 and coinfection with blood-borne viruses in hematologic malignancy patients in Ethiopia. We aimed to assess the seroprevalence of SARS-CoV-2 and associated infections with hepatitis B and other viruses among adolescent and adult acute leukemia patients at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia. A cross-sectional study was conducted from July 2020 to June 2021. Blood samples were tested for the presence of anti-SARS-CoV-2, HBV, HCV, and HIV with ELISA kits and occult hepatitis B infection with a real-time polymerase chain reaction assay. Out of a total 110 cases, the SARS-CoV-2 seroprevalence was 35.5%. The prevalence showed a significant increment from July 2020 to the end of June 2021 (p = 0.015). In 22.7% and 2.7% of leukemia cases, HBV and HIV, respectively, were detected. No HCV was identified. The rate of SARS-CoV-2 coinfection with HBV and HIV was 28% (11/39) and 2.6% (1/39), respectively; however, there was no statistically significant association between SARS-CoV-2 seropositivity with HBV and HIV (p > 0.05). There is a need for viral screening in leukemia cases to monitor infections and inform management. Full article