Occult hepatitis B virus infection among blood donors in Colombia

Epidemiology and Genetic Diversity of Hepatitis B Virus and Hepatitis Delta Virus Infection in Indigenous Communities in Colombia

Despite the universal vaccination program, there are still regions and territories with a high prevalence of Hepatitis B Virus infection (HBV), such as the Amazon basin, where several indigenous communities live. Additionally, Hepatitis Delta Virus (HDV) is a defective that requires the hepatitis B surface antigen (HBsAg) for the assembly and release of de novo viral particles. Therefore, hepatitis D could be the result of HBV/HDV coinfection or HDV superinfection in individuals with chronic hepatitis B. Among the high prevalence HDV populations are indigenous communities of America. This study aims to describe and characterize the frequency of HBV and HDV infection, viral genotypes and HBV immune escape mutants in indigenous populations from different regions of Colombia. The diagnosis of hepatitis B and hepatitis D was confirmed by serological markers. Moreover, the HBV and HDV genome were amplified by PCR and RT-PCR, respectively, and, subsequently, the phylogenetic analysis was performed. We characterized 47 cases of chronic hepatitis B, 1 case of reactivation and 2 cases of occult hepatitis B infection (OBI). Furthermore, a high prevalence of HDV infection was identified in the study population (29.33%, 22/75) and the circulation of several HBV genotypes and subgenotypes (F1b, F3, F4, and D). Interestingly, this is the first report of the HDV genotype I circulation in this country. These findings demonstrated that HBV and HDV infections are still public health problems in indigenous communities in Colombia.

Nucleic acid testing identifies high prevalence of blood borne viruses among approved blood donors in Mozambique

Background

Although blood transfusion is an intervention that saves lives, it poses significant risks to the blood receivers, including the transmission of bloodborne pathogens. We aimed at determining the prevalence of Human Immunodeficiency Virus (HIV), Hepatitis B virus (HBV), and Hepatitis C virus (HCV) in candidates approved for blood donation, and in samples considered to be negative in reference blood banks in Mozambique.

Methods

A cross-sectional study was performed between November 2014 and October 2015 in Maputo and Beira cities. Demographic information was obtained from all consenting blood donors using a structured questionnaire. Plasma samples were screened for HIVAb/Ag combinations, HBsAg and Anti-HCV. Blood donors considered to be negative by serological testing were re-tested in pools of six plasma samples using nucleic acid testing (NAT).

Results

Most blood donors were male 2,320 (83.4%) with an age range of 18 to 34 years. The overall seroprevalence of HIV, HBV and HCV infections among blood donors approved for donation was 4.6% (127; 95% CI 3.8–5.4), 4.5% (124; 95% CI 3.7–5.3) and 0.4% (11; 95% CI 0.2–0.7), respectively. The overall frequency by NAT of HIV RNA, HBV DNA, and HCV RNA in serologically negative blood donor samples was 2.6 per 1000 blood donors (7; 95% CI 1.1–5.4); 12.5 per 1000 blood donors (33; 95% CI 8.6–17.5) and 2.6 per 1000 blood donors (6; 95% CI 1.0–5.7), respectively.

Conclusion

Our results show high seroprevalence of HIV and HBV infections in blood donors approved for donation, and high frequency of molecular biomarkers of HIV, HBV, and HCV in blood considered to be safe. These results suggest the need for a new blood screening policy in Mozambique, including the use of NAT to detect infectious blood donations during the immunologically negative window.

Occult Hepatitis B Virus Infection among β-Thalassemia Major Patients in Ahvaz City, Iran

Occult Hepatitis B Infection (OBI) is a critical risk factor for triggering post-transfusion hepatitis (PTH), cirrhosis, hepatocellular carcinoma, and hepatitis B virus (HBV) reactivation, which β-thalassemia major (BTM) patients are at risk of it due to multiple blood transfusions. This study was aimed at determining the prevalence of OBI among BTM patients from Khuzestan Province, Iran. In this cross-sectional study, 90 thalassemia patients, who have received blood 36 to 552 times, participated referred to the Shafa hospital of Ahvaz city from January 2018 to April 2019. ELISA for determining serological markers (HBsAg, anti-HBc, anti-HBs, and anti-HCV) and real-time PCR for detecting HBV-DNA were performed; Nested PCR was conducted for DNA sequencing and determining the genotype of OBI case. Phylogenetic and statistical analyses were done by R package. Of 90 subjects enrolled in this study; 95.5% (86/90) were HBsAg negative, and the frequency of OBI among them was 1.16% (1/86). The anti-HBs, anti-HBc, and anti-HCV were detected in 80.00%, 7.78%, and 12.2% of patients, respectively. HBV-DNA was assessed at four HBsAg-positive subjects as well, and all of them were negative. The phylogenetic analysis showed that the detected HBV DNA in the OBI case belongs to the genotype D. This research, for the first time, demonstrated that OBI is present among β-thalassemia patients in Iran. Also, further studies are necessary to determine the actual prevalence of OBI among BTM patients in Iran to decisions concerning OBI screening, especially in transfusion centers.

[Residual risk for transfusion-transmitted hepatitis B virus infection due to occult hepatitis B virus infection in donors living in Yaoundé, Cameroon]

Introduction

l´infection virale au virus de l´hépatite B reste la plus importante transmise par transfusion sanguine. Bien que la recherche de l´antigène de surface (AgHBs) du virus de l´hépatite B (VHB) dans les banques de sang ait considérablement réduit le risque de transmission de l´infection du virus par transfusion, il subsiste un risque résiduel transfusionnel de transmission dû aux donneurs porteurs d´une hépatite B occulte. Les poches de sang contenant l´AcHBc avec ou sans l´AcHBs et l´ADN viral peuvent être infectieuses et représenter une menace pour la sécurité transfusionnelle là où l´AcHBc n´est pas dépisté. L´objectif de cette étude était de déterminer le risque résiduel de la transmission par transfusion du virus de l´hépatite B à l´hôpital central de Yaoundé (HCY) et le Centre Hospitalier Dominicain Saint Martin de Porres (CHDSMP) à Yaoundé au Cameroun.

Méthodes

une étude transversale a été effectuée sur des donneurs de sang de l´Hôpital Central de Yaoundé (HCY) et le Centre Hospitalier Dominicain Saint Martin de Porres (CHDSMP) chez lesquels la recherche de l´AcHBc et/ou AcHBs était faite par immunochromatographie. La recherche de l´ADN du VHB sur les échantillons testés positifs aux AcHBc et/ou AcHBs était faite par PCR en utilisant des amorces spécifiques.

Résultats

sur les 193 donneurs de sang négatifs aux marqueurs sérologiques des infections à VIH, VHB (AgHBs), VHC et tréponème retenus dans cette étude, nous avons obtenu une séroprévalence globale des AcHBc et/ou AcHBs de 9,84% (19/193). Sur les 19 donneurs potentiellement infectieux, l´ADN du virus a été détecté chez 03 individus dont 02 porteurs de l´AcHBc et 01 porteur à la fois de l´AcHBc et de l´AcHBs, soit une prévalence de l´hépatite B occulte de 15,79% (3/19) [IC95% =3,38%-39,58%] et un risque résiduel de transmission par transfusion de l´infection à VHB de 1,55% (3/193) [IC95% = 0,32%-4,48%].

Conclusion

il ressort de cette étude que le risque résiduel de transmission par transfusion sanguine de l´infection du VHB est faible. Toutefois il est recommandé de rechercher les AcHBc et/ou AcHBs lors de la qualification des dons de sang.

Molecular and serological characterization of occult hepatitis B among blood donors in Maputo, Mozambique

BACKGROUND

Occult hepatitis B virus (HBV) - characterized by the absence of detectable HBsAg in the presence of HBV DNA - represents a potential threat for blood safety.

OBJECTIVES

This study was conducted with the aim to investigate the serological and molecular characterization of occult HBV infection (OBI) among blood donors in Mozambique.

METHODS

1,502 blood donors were tested for HBsAg. All HBsAg-negative individuals were tested for HBV DNA. Antibodies against HBV core, surface and HBe antigen (anti-HBc, anti-HBs, HBeAg) were measured in HBV DNA positive individuals.

FINDINGS

1435 serum samples were HBsAg negative and 16 positive for HBV DNA, 14 confirmed to have OBI, corresponding to a frequency of 0.98%. Of the 14 OBI infections identified, 13/14 (92.8%) were positive for anti-HBc, 4/14 (28.5%) for anti-HBs, and no samples were reactive for HBeAg. Of the 14 OBI cases, nine samples (64.2%) were sequenced for the S/P region. Eight samples (88.9%) belonged to genotype A1 and one (11.1%) to genotype E. One escape mutation (T123A) associated with OBI and various amino acid substitutions for genotype A1 and E were observed.

MAIN CONCLUSIONS

Our results show the importance of using nucleic acid amplification test to detect occult hepatitis B infection in blood donors in Mozambique.

Prevalence of hepatitis B/C viruses and associated factors in key groups attending a health services institution in Colombia, 2019

Both hepatitis B virus (HBV) and hepatitis C virus (HCV) are major sources of morbidity and mortality worldwide; however, their prevalence in key groups in Colombia is not yet known. We aimed to analyse the prevalence of HBV and HCV and its associated factors in key groups who were treated at an institution providing health services in Colombia during 2019. This was a multiple-group ecological study that included 2,624 subjects from the general population, 1,100 men who have had sex with men (MSM), 1,061 homeless individuals, 380 sex workers, 260 vulnerable young people, 202 drug users, 41 inmates and 103 people from the lesbian, gay, bisexual and transgender community. Prevalence of infection with a 95% confidence interval and its associated factors was calculated for each group. Confounding variables were assessed using logistical regression and SPSS 25.0 software. Prevalence of HBV and HCV in the general population was 0.15% and 0.27%, respectively; 0.27% and 2.09% in MSM; 0.37% and 2.17% amongst homeless individuals; 0.26% and 0.0% amongst sex workers; 0.39% and 0.0% amongst vulnerable youth; and 5.94% and 45.54 amongst injecting drug users. In the multivariate HBV model, the explanatory variables included the study group, city of origin and the type of health affiliation; for HCV they were group, origin, sex, age group, health affiliation, use of drugs and hallucinogen use during sexual intercourse. A high prevalence of HBV and HCV were evidenced for both viral infections, which was, consequently, much higher within the key groups. The main associated factors that were identified related to origin and type of health affiliation and demonstrated a double vulnerability, that is, belonging to groups that are discriminated and excluded from many health policies and living under unfavourable socioeconomic conditions that prevent proper affiliation and health care.

Epidemiology, risk factors, and molecular characterization of occult hepatitis B infection among anti-hepatitis B core antigen alone subjects

OBJECTIVES

Features of occult hepatitis B virus (HBV) infection among the anti-hepatitis B core antigen (anti-HBc) positives have yet to be described in more details. This study aimed to determine the molecular prevalence of occult HBV infection (OBI), and association to risk factors among seropositives for anti-HBc.

METHODS

This was part of a community-based screening project that included 5234 cases. All participants completed a questionnaire on demographic and socio-epidemiological information. Then, the blood samples were collected and tested for anti-HBc and HBsAg using ELISA method. To identify OBI, nested-polymerase chain reaction (PCR) assays were performed for HBV-S and X genes, and viral load was determined using an in-house real-time PCR. Sequencing and phylogenetic analysis have been implemented for genotyping.

RESULTS

Overall, 596 cases, positive only for anti-HBc were included in the study. OBI was detected among 61 cases (10.2%). The genotype and subgenotype of HBV among all of them was D1, except one that was D4. Most of them had low viral loads ranged from 1.2 × 10² to 1.34 × 10 ³  copies/mL; 19.6% had undetectable viral loads. Important mutations in surface protein and reverse transcriptase were sI92T, sQ129H, rtL80I, rtS85F, rtL91I. The prevalence of OBI was related to some risk factors, such as tattooing (P = 0.02), sexual activities (P = 0.009), and diabetes (P = 0.031).

CONCLUSION

Our study suggests that OBI should be considered among anti-HBc seropositive subjects. This form of HBV infection was accompanied with some mutations, risk factors, and diseases. However, further investigations are needed to determine virological importance of documented mutations.

Isolated anti-HBc: The Relevance of Hepatitis B Core Antibody-A Review of New Issues

Hepatitis B core antibody (anti-HBc) is considered the most sensitive serological marker for history of hepatitis B virus (HBV) infection. In a subset of anti-HBc carriers, anti-HBc is present in the absence of hepatitis B surface antigen and hepatitis B surface antibody-a serological pattern known as "isolated anti-HBc" (IAHBc). IAHBc has been of clinical interest over the past several years, with growing data to suggest its role as a serological marker for occult HBV infection (OBI). This article reviews the clinical significance and association of IAHBc with hepatitis C virus (HCV) co-infection, risk of HBV reactivation during direct-acting antiviral therapy for HCV as well as immune suppression, and development of hepatocellular carcinoma (HCC). Hepatitis B core-related antigen is also highlighted as an emerging laboratory assay that may identify OBI and predict HCC development in non-cirrhotic patients receiving nucleoside/nucleotide analog therapy.

Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia

Background

Hepatitis B virus (HBV) occult infection (OBI) is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease.

Methods

Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia). Samples obtained from patients who were negative for the surface antigen of HBV (n = 50) were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique.

Results

In five cases out of 50 patients (10%) the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3), genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X.

Conclusions

This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12) described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis.

Prevalence and characterization of occult hepatitis B infection among blood donors in central Saudi Arabia

OBJECTIVES

To evaluate the prevalence of occult hepatitis B viral infections (OBIs)  among blood donors considering the clinical and epidemiological importance of identifying OBIs.

METHODS

A cross-sectional study conducted at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2011 and January 2012. Blood donors (n=8501) were screened for Hepatitis B virus surface antigen (HBsAg) and hepatitis B core antibodies (HBcAb). All HBsAg-negative and HBcAb-positive samples were tested further for hepatitis B surface antibodies (HBsAb), hepatitis B virus (HBV)-DNA, and HBV genotyping.  

RESULTS

Of the 8501 serum samples tested, 56 (0.7%) were positive and 8445 (99.3%) were negative for HBsAg. Among the HBsAg-negative samples, 198 (2.3%) were positive for HBcAb and these patients were suspected to have OBIs. Among the HBcAb-positive samples, 119 (60.1%) were positive while 79 (39.9%) were negative for HBsAb. Analysis of HBV-DNA for the suspected OBIs showed that 17 out of 198 samples (8.6%) yielded positive results, and all of them were HBsAb-negative. The viral load was low (less than 20-186 IU/mL) in all OBIs. Hepatitis B virus genotyping showed that 15 out of 17 samples (88.2%) were genotype D, and the other 2 samples (11.8%) were genotype E. 

CONCLUSION

The prevalence of OBIs among blood donors in Riyadh was 0.2%. Therefore, it is recommended that HBV molecular testing should be incorporated with serological assays for screening of blood donors.

Analysis of hepatitis B virus genotypes by restriction fragment length polymorphism

<p><strong>Introducción.</strong> Se han descrito diez genotipos (A-J) del virus de la hepatitis B (HBV) que están distribuidos en todos los continentes. Una de las técnicas utilizadas para determinar el genotipo viral es el análisis del polimorfismo de longitud de los fragmentos de restricción, un método simple y económico, pero con algunas limitaciones.<br /><strong>Objetivo.</strong> El objetivo inicial del estudio fue identificar el genotipo del HBV mediante RFLP en muestras de suero obtenidas de pacientes y donantes de sangre. Sin embargo, por las discrepancias observadas en los patrones de RFLP fue necesario realizar análisis filogenéticos y un análisis in silico de secuencias del HBV.<br /><strong>Materiales y métodos.</strong> Se obtuvieron 56 muestras de suero. Tras la extracción de ADN, se amplificó un fragmento del ORF S del HBV mediante reacción en cadena de la polimerasa, cuyos productos se analizaron por RFLP con las enzimas <em>AlwI</em>, <em>BsrI</em>, <em>CfrI</em>, <em>HpaII</em> y <em>StyI</em>, y algunos se secuenciaron. Los patrones obtenidos se compararon con los reportados previamente. Se efectuó un análisis<em> in silico</em> de RFLP en consideración de las diferencias entre los patrones esperados y los observados.<br /><strong>Resultados.</strong> Se identificaron los genotipos A y F, subgenotipo F3, en las muestras. Este resultado coincide con lo descrito en estudios previos en los que se ha demostrado que el genotipo F, subgenotipo F3, es prevalente en la población de la región andina del país, en tanto que el genotipo A predomina en el occidente (departamento del Chocó). Con base en el análisis <em>in silico</em> de 229 secuencias virales obtenidas del GenBank y las 11 secuencias de este estudio, se caracterizó un nuevo patrón de RFLP específico para el genotipo F, subgenotipo F3, y se describieron algunas modificaciones en el patrón de RFLP del genotipo A, subgenotipo A1.<br /><strong>Conclusiones.</strong> Se caracterizó el patrón de genotipificación del genotipo F, subgenotipo F3, del HBV mediante RFLP, análisis in silico y secuenciación. Se requieren nuevos análisis in silico con un número mayor de secuencias para validar los patrones de RFLP de los genotipos y subgenotipos del VHB.</p>

Molecular Characterization of Pre-Core/Core and S Region of Hepatitis B Virus in Hemodialysis Patients With Occult Hepatitis B Infection

BACKGROUND

Occult hepatitis B infection (OBI) is a major public health problem worldwide, which harbors potential risk of hepatitis B virus (HBV) transmission through blood transfusion and transplantation. OBI is characterized by the presence of HBV-DNA in the blood or liver tissue without detectable hepatitis B surface antigen (HBsAg) in the serum. An important cause of OBI is the occurrence of mutations in the HBV genome, especially in the S region.

OBJECTIVES

The study aims to analyze mutations in S and pre-core/core regions of HBV-DNA in hemodialysis patients.

PATIENTS AND METHODS

Sera of 216 hemodialysis patients were tested for HBsAg and hepatitis B core antibody (HBcAb) by ELISA. Sera of patients that tested negative for HBsAg were evaluated by PCR for the detection of HBV-DNA in the S and pre-core/core regions. In total, six PCR products were sequenced, aligned, and compared with the HBV reference sequence. Amino acid deletion and nucleotide substitution were considered mutations in S and pre-core/core regions of HBV-DNA.

RESULTS

Among 216 patients, 203 (93.98%) and 175 (81.01%) sera samples tested negative for HBsAg and HBcAb, respectively. Among all HBsAg-negative samples, six (2.9%) tested positive for HBV-DNA, including four (1.97%) for S and two (0.98%) for pre-core regions. All four (1.97%) samples that tested positive for the S region belonged to HBV-subtype awy. The amino acid sequence of all four samples showed the YMDD motif in position 204 (rtM204). There were three amino acid substitutions in the S region (T127P, P153L, and F170S) and one substitution in the RT region (Y135S). Moreover, two (0.98%) pre-core/core positive patients had an unexpected stop codon in position 1896.

CONCLUSIONS

This study indicates that 2.9% of hemodialysis patients had OBI, which is considered as a major public health problem worldwide. Moreover, we observed three mutations in S region, including T127P, P153L, and F170S, which caused OBI. This study is first to report a mutation analysis of HBV in hemodialysis patients in southwestern Iran. These results indicate that current screening tests based on HBsAg detection are not reliable for detection of HBV infection in dialysis patients.

Hepatitis B virus infection among institutionalized mentally ill patients in Brazil

Objectives

The main objective was to evaluate HBV infection and occult HBV infection (OBI) cases in mentally ill patients based on serological and molecular profiles.

Material and methods

Serum samples of 333 long-stay mentally ill patients were tested for the prevalence of HBV markers by serological (ELISA) and molecular (PCR) assays. The PCR products were sequenced to determine viral genotypes.

Results

It was observed a global prevalence of 12.9% (43/333) for HBV infection markers, considering HBsAg and/or anti-HBc positivity. Fourteen samples tested positive for anti-HBs alone. All samples positive (n = 57) for any HBV serological markers were tested for HBV-DNA and six were positive: HBsAg/anti-HBc (n = 1), anti-HBc/anti-HBs (n = 1), anti-HBs alone (n = 1), and anti-HBc alone (n = 3). The rate of OBI was 9.2% (5/54) from samples that were anti-HBc and/or anti-HBs positive. All sequenced samples were characterized as genotype A.

Conclusion

The high rate of HBV infections found in this study suggests the possibility of HBV transmission due to risk factors displayed by some patients, and highlights the importance of vaccination of susceptible patients and the staff of that institution.

Genetic variability of hepatitis B virus in Uruguay: D/F, A/F genotype recombinants

Hepatitis B virus (HBV) infection is a serious global health problem. Approximately 2 billion people worldwide have been infected, and approximately 350 million individuals currently suffer from HBV-induced chronic liver infection, which causes 600,000 deaths annually from chronic hepatitis, cirrhosis and hepatocellular carcinoma. HBV is classified in eight genotypes (A-H), and two more have been proposed (I-J). In this paper, complete genome sequences of nine Uruguayan HBV are reported. Five samples belong to genotype F1b and one to genotype A2. Three HBV recombinants were detected: A1/F1b, A2/F1b and D3/F1b. The following mutations were detected: a G1896A substitution, a 33-nucleotide deletion from position 2896 to 2928 in the Pre-S1 region involving Pre-S1 residues 3-13, a 33-nt deletion in the Pre-S1 region involving nt 2913-2945 and Pre-S1 residues 9-19. More F genotypes strains than expected were detected in this study, supporting the hypothesis that there are more people of indigenous origin than declared in our population. Also, one third of the samples analyzed were recombinants. This cannot be explained by the low HBV prevalence in Uruguay, but a high HBV infection rate in drug addicts and dialysis patients could act in favor of multiple-genotype HBV infections that could lead to recombination.