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

Hepatitis B virus (HBV) infects nearly 300 million people and is the leading cause of hepatitis and hepatocellular carcinoma worldwide. Despite the high burden of HBV in sub-Saharan Africa, countries such as Mozambique have limited data available on circulating HBV genotypes and the presence of drug resistance mutations. Blood donors from Beira, Mozambique were tested for HBV surface antigen (HBsAg) and HBV DNA at the Instituto Nacional de Saúde in Maputo, Mozambique. Regardless of HBsAg status, donors with detectable HBV DNA were evaluated for HBV genotype. PCR was performed with primers amplifying a 2.1–2.2 kilobase fragment of the HBV genome. PCR products were submitted for next generation sequencing (NGS), and consensus sequences were evaluated for HBV genotype, recombination, and the presence or absence of drug resistance mutations. Of the 1281 blood donors tested, 74 had quantifiable HBV DNA. The polymerase gene could be amplified from 45 of 58 (77.6%) individuals with chronic HBV infection and 12 of 16 (75%) with occult HBV infection. Among these 57, 51 (89.5%) sequences belonged to HBV genotype A1, while 6 (10.5%) were HBV genotype E. All genotype E sequences were E/A recombinants, and clustered separately from other genotype E references. Genotype A samples had a median viral load of 637 IU/mL, while genotype E samples had a median viral load of 476,084 IU/mL. No drug resistance mutations were observed in the consensus sequences. The current study demonstrates the genotypic diversity of HBV in blood donors in Mozambique, but the absence of dominant (consensus) drug resistance mutations. Studies in other at-risk populations are essential for understanding the epidemiology, risk of liver disease, and likelihood of treatment resistance in resource-limited settings.

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“…Previous studies suggest that genotypes A and E are circulating in various at-risk populations in Mozambique [ 20 , 34 , 35 ]. Chambal et al .…”

Section: Discussionmentioning

confidence: 99%

Hepatitis B virus genotypes and drug resistance mutations circulating in blood donors in Beira, Mozambique

et al. 2023

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“…Our NAT results in HBsAg negative samples showed occult Hepatitis B virus frequency of 0.98% (14/16) and a frequency of samples in immunological window period of 0.13% (2/16). These results reveal the relevance of occult hepatitis B as a contemporary risk during blood transfusion in Mozambique [ 29 ].…”

Section: Discussionmentioning

confidence: 95%

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

et al. 2022

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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.

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“…HBsAb is usually indicative of immunity after HBV infection. In some developed countries, blood is considered safe when HBsAb reaches a specific titer (21). In HBsAg-negative/HBcAb-positive patients, when HBeAb is positive, both the prevalence of patients with detectable serum HBV DNA (15.61%) and the viral load (43.5 IU/mL) are at the highest levels.…”

Section: Discussionmentioning

confidence: 99%

Prevalence and clinical characteristics of hepatitis B surface antigen-negative/hepatitis B core antibody-positive patients with detectable serum hepatitis B virus DNA

Cai¹,

Wu²,

Wu³

et al. 2022

Ann Transl Med

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Background: To determine the prevalence of detectable serum hepatitis B virus (HBV) DNA in patients who are hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (HBcAb)-positive. The correlation between HBV DNA viral load and serological markers, as well as liver and coagulation function indicators were investigated. Furthermore, the effects of immunosuppressive therapy on DNA replication were assessed. Methods: A total of 2,013 HBsAg-negative/HBcAb-positive patients admitted to our hospital between January and December 2019 were enrolled in this study. Patient clinical characteristics including serological markers, HBV DNA viral load, liver function and coagulation function indicators, and immune function status were analyzed.Results: In the Hunan province in China, the prevalence of detectable HBV DNA was 5.4% in HBsAgnegative/HBcAb-positive patients. However, the prevalence of detectable HBV DNA in HBsAg-negative/ HBcAb-positive patients may vary because of different HBV serological markers. In patients with detectable serum HBV DNA, the log10 HBV DNA value was positively correlated with alanine transaminase (ALT) and aspartate transaminase (AST) levels, and negatively correlated with antithrombin III (AT III) concentrations.Moreover, in patients receiving immunosuppressive therapy, ALT and AST levels were higher than those of patients who did not receive immunosuppressive therapy. The ALT and AST levels in hepatitis B e antibody (HBeAb)-positive patients were significantly higher than that observed in HBeAb-negative patients.Conclusions: For HBsAg-negative/HBcAb-positive patients, clinicians should pay attention to the patient's immune function status. In situations where HBV DNA cannot be detected, changes in serum ALT, AST, and AT III concentrations can be used to speculate on viral replication status to reduce the risk of HBV infection and transmission.

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

Cited by 13 publications

References 30 publications

Hepatitis B virus genotypes and drug resistance mutations circulating in blood donors in Beira, Mozambique

Hepatitis B virus genotypes and drug resistance mutations circulating in blood donors in Beira, Mozambique

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

Prevalence and clinical characteristics of hepatitis B surface antigen-negative/hepatitis B core antibody-positive patients with detectable serum hepatitis B virus DNA

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