Dataset Information

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

ABSTRACT:

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.

SUBMITTER: Mabunda N

PROVIDER: S-EPMC7523502 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Publications

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

Mabunda Nédio N Zicai Ana Flora AF Ismael Nalia N Vubil Adolfo A Mello Francisco F Blackard Jason T JT Lago Barbara B Duarte Vanessa V Moraes Milton M Lewis Lia L Jani Ilesh I

Memorias do Instituto Oswaldo Cruz 20200923

<h4>Background</h4>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.<h4>Objectives</h4>This study was conducted with the aim to investigate the serological and molecular characterization of occult HBV infection (OBI) among blood donors in Mozambique.<h4>Methods</h4>1,502 blood donors were tested for HBsAg. All HBsAg-negative individuals were tested for HBV DNA. Antibodies against HBV core ...[more]

PMID: 32997000

Similar Datasets

Project description:BackgroundOccult hepatitis B infection (OBI) is characterized by the presence of hepatitis B virus (HBV) DNA at low levels in serum (<200 IU/mL) with a negative hepatitis B surface antigen (HBsAg) test. OBI remains a major challenge to blood safety, particularly in HBV-endemic regions like Cameroon, where HBV detection relies solely on HBsAg testing. This cross-sectional study aimed to investigate the actual incidence and genotype characteristics of OBI in Cameroonian blood donors.MethodsBetween March and June 2023, samples were collected from 288 HBsAg-negative blood donors aged 18 to 55 years and analysed for antibodies against the HBV core (anti-HBc) and surface antigens (anti-HBs). Following DNA extraction from the serum samples, qualitative nested PCR and quantitative real-time PCR were used to detect HBV viral DNA and viral load respectively. For positive samples, sequencing of a fragment of the S gene was performed to identify the circulating HBV genotypes.ResultsThe findings revealed that 58% (n = 167/288) of blood donors tested positive for anti-HBc, 29% (n = 83/288) tested positive for anti-HBs, and 26% (n = 75/288) being positive for both anti-HBc and anti-HBs. Occult hepatitis was confirmed in 4.5% of the blood donors, all of whom belonged to either HBV genotypes A or E, which are predominant in Cameroon. The amino acid substitution sA184V associated with HBsAg detection failure in genotype E was observed in 70% of OBI sequences, and the HBsAg immune escape variants (sT131N and sS143L) implicated in OBI were also observed. The mutation rtN139K in the reverse transcriptase (RT) domain of the overlapping HBV polymerase (P) gene was present in 17% of OBI-positive sequences of genotype E, likely contributing to masking HBsAg secretion.ConclusionThe results suggest a considerable risk of transfusion-transmitted HBV in this region. Therefore, to ensure blood safety, nucleic acid testing (NAT) is recommended, as relying solely on HBsAg assays is insufficient to eliminate this risk.

Dataset Information

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

Background

Objectives

Methods

Findings

Main conclusions

Publications

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

Similar Datasets

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