Hepatitis B virus infection in post-vaccination South Africa: Occult HBV infection and circulating surface gene variants

Edina Amponsah-Dacosta, Ramokone L. Lebelo, J. Nare Rakgole, Selokela G. Selabe, Maemu P. Gededzha, Simnikiwe H. Mayaphi, Eleanor A. Powell, Jason T. Blackard, M. Jeffrey Mphahlele*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)

Abstract

Background and objective: The aim of this study was to investigate the prevalence of occult hepatitis B virus (HBV) infection and the HBV surface (S) gene variants circulating in the South African population after nearly two decades of universal hepatitis B vaccination. Study design: From a previous serosurvey, 201 serum samples with serological evidence of exposure to HBV were identified and these were stratified into post- and pre-vaccine introduction populations. For all samples, HBV DNA was screened and quantified using a real-time PCR assay and results analysed together with HBV serological markers. Where HIV results were available, subset analysis was performed. The HBV S gene was PCR-amplified and sequences analysed for a total of 37 isolates. Results: The prevalence of occult HBV infection reduced from 70.4% in the pre-vaccine introduction era to 66.0% post-vaccine introduction. There was an association between HIV infection and an increase in prevalence of occult HBV infection within the post-vaccine introduction population, although this was not statistically significant. Furthermore, sequence analysis revealed the following HBV subgenotypes; A1 (n= 34), A2 (n= 2) and a rare D4 isolate. HBV S gene variants, including diagnostic escape mutants were isolated. Conclusion: There was a decline in the prevalence of occult HBV infection in post-vaccination South Africa, although the disease burden remains significant in the HIV co-infected population. After nearly two decades of a universal hepatitis B vaccination programme, no positive selection of vaccine escape mutants were observed.

Original languageEnglish
Pages (from-to)12-17
Number of pages6
JournalJournal of Clinical Virology
Volume63
DOIs
Publication statusPublished - 1 Feb 2015
Externally publishedYes

Keywords

  • Diagnostic escape mutants
  • HIV infection
  • Hepatitis B vaccine
  • Occult HBV infection
  • Subgenotype D4

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