Abstract:
Background: HBV and HIV share similar transmission routes. Concurrent infection with the two viruses usually
results in more severe and progressive liver disease, and a higher incidence of cirrhosis, liver cancer and mortality.
Further, this co-infection may lead to cross-resistance between HIV and HBV drugs and increased liver injury, either
due to direct hepatotoxicity or drug-related immune-reconstitution hepatitis. These challenges necessitate
continuous surveillance for HBV among HIV infected individuals to guide patient management. We conducted this
study to understand the serologic and genotypic characteristics of HBV among HIV/HBV infected patients in South
West and Littoral Regions of Cameroon.
Methods: Plasma samples were screened for HBsAg, HBeAg, Anti-HBs and anti-HBc using ELISA followed by DNA
extraction from all HBsAg positive samples. A 366 bp region covering the overlapping surface/polymerase gene was
amplified by a nested PCR and the product sequenced using Big Dye sequencing chemistry. The resulting
sequences were then analyzed for genotypes and both escape and drug resistance mutations.
Results: Of the 455 samples in this study, 25.5 % (n = 116) were HBsAg positive and 46 of these had their DNA
successfully amplified. Genotype E was found in 32 samples (69.6 %) and genotype A in the rest of the samples.
Escape mutations associated with failure of diagnosis (Y100C, R122K and Q129H) and with vaccine escape (Q129R
and T131N) were detected in varying frequencies in the population. Polymerase mutations implicated in resistance
to lamivudine and other ʟ-nucleoside analogues were detected in seven patients (15.2 %), while all the samples
lacked mutations associated with resistance to adefovir and tenofovir.
Conclusions: These findings suggest the endemicity of HBV and the predominance of genotypes A and E in the
study population. Also, drug resistance findings support the use of tenofovir based ART regimens among HIV/HBV
co-infected persons. There is need for continuous HBV screening and monitoring in HIV infected individuals in
these regions
