Edina Amponsah-Dacosta1, Ramokone L Lebelo1, J Nare Rakgole1, Selokela G Selabe1, Maemu P Gededzha1, Simnikiwe H Mayaphi2, Eleanor A Powell3, Jason T Blackard3, M Jeffrey Mphahlele4. 1. HIV and Hepatitis Research Unit, Department of Virology, University of Limpopo (Medunsa Campus) and National Health Laboratory Service, Pretoria, South Africa. 2. Department of Medical Virology, University of Pretoria/Tshwane Academic Division of NHLS, Pretoria, South Africa. 3. Division of Digestive Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA. 4. HIV and Hepatitis Research Unit, Department of Virology, University of Limpopo (Medunsa Campus) and National Health Laboratory Service, Pretoria, South Africa. Electronic address: jeffrey.mphahlele@mrc.ac.za.
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.
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.
Authors: Joseph Torresi; Linda Earnest-Silveira; Georgia Deliyannis; Kristy Edgtton; Hui Zhuang; Stephen A Locarnini; Janet Fyfe; Tina Sozzi; David C Jackson Journal: Virology Date: 2002-02-15 Impact factor: 3.616
Authors: Azwidowi Lukhwareni; Rosemary J Burnett; S Gloria Selabe; M Olga Mzileni; M Jeffrey Mphahlele Journal: J Med Virol Date: 2009-03 Impact factor: 2.327