The presence of hepatitis B virus (HBV) resistance mutations upon initiation or during antiretroviral therapy (ART) in HIV co-infected patients is an important determinant of treatment response. The main objective of the study was to determine the prevalence of HBV resistance mutations in antiretroviral treatment-naïve and treatment-experienced HBV-HIV co-infected Ghanaian patients with detectable HBV viremia.

HBV-HIV co-infected patients who were ART-naïve or had received at least 9 months of lamivudine (3TC)-containing ART were enrolled in a cross-sectional study. Demographic and clinical data were collected and HBV DNA quantified. Partial HBV sequences were amplified by PCR and sequenced bi-directionally to obtain a 2.1-2.2 kb fragment for phylogenetic analysis of HBV genotypes and evaluation of drug resistance mutations.

Of the 100 HBV-HIV co-infected study patients, 75 were successfully PCR-amplified, and 63 were successfully sequenced. Of these 63 patients, 27 (42.9%) were ART-experienced, and 58 (92.1%) had HBV genotype E. No resistance mutations were observed in the 36 ART-naïve patients, while 21 (77.8%) of 27 treatment-experienced patients had resistance mutations. All patients with resistance mutations had no tenofovir (TDF) in their regimens, and 80% of them had HIV RNA < 40 copies/mL. The 3TC resistance mutations rtL180M and rtM204V were observed in 10 (47.6%) of the 21 patients, while 5 patients (23.8%) had rtV173, rtL80I, and rtM204V mutations.

A high proportion of HBV-HIV co-infected patients with detectable viremia on 3TC-containing ART had resistance mutations despite good ART adherence as determined by HIV RNA suppression. This study emphasizes the need for dual therapy as part of a fully suppressive ART in all HBV-HIV co-infected patients in Ghana.