High rate of occult hepatitis B virus infection in hemodialysis units of KwaZulu‐Natal, South Africa

Abstract

Occult hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV DNA in the liver with or without detectable HBV DNA in the serum of individuals testing HBV surface antigen (HBsAg) negative using currently available assays. The prevalence of OBI among patients receiving hemodialysis (HD) treatment remains poorly characterized in South Africa despite the high prevalence of HBV. We sought to determine the prevalence of OBI in HD units in tertiary hospitals of KwaZulu‐Natal and to characterize the HBV S gene mutations potentially responsible for OBI. A cross‐sectional descriptive study of residual diagnostic plasma samples from 85 HBsAg‐negative patients receiving HD treatment was included. The PreS/S gene was amplified with a nested HBV polymerase chain reaction for downstream next‐generation sequencing, to determine the viral genotype and identify S gene mutations associated with OBI. Nine of the 85 samples had OBI, based on detectable HBV DNA. The point prevalence of OBI was 10.6% (95% control interval: 5.5%‐19.1%). Phylogenetic analysis of the samples with OBI showed that all belonged to genotype A. Three (~33%) samples had mutations in the major hydrophilic region (MHR) within the S gene, three (~33%) had mutations within the S gene but outside the MHR, whilst the remaining three had no mutations observed. The prevalence of OBI in HBsAg‐negative patients undergoing HD was 10.6%, suggesting that OBI is a clinically significant problem in patients with HD in this region. The screening methods for HBV infection need to be revised to include nucleic acid testing.

Prevalence of occult hepatitis B infection among treatment-naive persons living with HIV in Ghana

“…in their study, PLHIV were on treatment for HBV [29] Similarly, a study by Dzudzor et. al., among chronic kidney patients on hemodialysis in Ghana in 2024 who were HBeAg negative but HBcAb positive, found 7.3% had detectable HBV DNA [30] The OBI prevalence found in this study was relatively lower compared to a study in South Africa (19.1%) [31][32][33], and significantly lower than another study among PLHIV in Morocco (68.4%) [34]. Nonetheless, a relatively lower prevalence has been reported elsewhere.…”

Occult Hepatitis B virus (HBV) infection and challenges for hepatitis elimination: A literature review

“…Overall, our literature review shows that it is currently challenging to estimate the exact prevalence of OBI, mainly due to the scarcity of studies in healthy populations and the lack of a standard diagnostic test. The reported prevalence varies widely from <1% to >50%, with higher rates found in Africa and Asia (Msomi et al, 2019;Ye, 2019) (Figure 1). Only one study has been published recently in Oceania and North America, showing that further epidemiological investigations in these areas would be important.…”

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

“…Substitutions V190 and F134I in genotype A samples have been reported in some studies, however their contribution to occult hepatitis has not yet been described. (18,28) Further studies are needed to determine effects of these and other variation we found in this study on HBsAg and HBV. In particular, T123A escape mutation located in the MHR of the S gene was distinctly present in one patient (sample BSM590).…”