Treatment Outcome in Hepatitis B-Positive Patients Attending a Selected Clinic in Baringo County of Kenya

Background: Hepatitis B virus (HBV) is often associated with chronic hepatitis, cirrhosis and hepatocellular carcinoma. The World Health Organization (WHO) rolled out guidelines for treatment of HBV globally in 2015 and the Kenyan Ministry of Health started implementing these guidelines in 2018. About one thousand patients have been receiving the WHO-recommended treatment across the country. However, their treatment outcome has not been evaluated. Baringo County is one of the counties with high number of patients on treatment. The aim of this study, therefore, was to evaluate the treatment outcome of these patients. Methods: Forty-one HBV positive patients attending comprehensive care clinic in Marigat, Baringo County were randomly selected. Five millilitres of blood were drawn from each patient and processed into serum. Presence of hepatitis B surface antigen (HBsAg), surface antibodies (HBsAb), e-antigen (HBeAg), e-Antibodies (HBeAb) and core antibodies (HBcAb) were tested using lumiquick HBV-5 panel test kit (Diagnostic, lnc, USA). HBV DNA extraction was done using Qiagen extraction kit, amplified and visualized on 2% agarose gel. All positive extracts were sequenced. HBV viral load was done using TaqMan™.   HBV sequences obtained were aligned and phylogenetic trees developed. Genotypes were determined using geno2pheno software and mutations on the surface antigen and polymerase coding regions were determined from the aligned sequences. Finding: Out of 41 serum samples collected, 2.4% patient was HBsAg negative and the remaining (97.6%) positive. HBsAb positivity was 2.4%, all samples were negative for hepatitis B core antibodies (HBcAb), 14.6% tested positive and 35(85.6%) tested negative for HBeAg. The mean age (±SD) of patients was 33.59 ± 2.307 (8-80).  Ten (24.3%) samples were detectable in qPCR and their viral load ranged from 4.6×104 to 1.04×101 IU/ml with majority of them (85.6%) having HBeAg negative and 80.4% having HBeAb positive. Two genotypes, genotype D (50%) and genotype A (50%) were identified among the HBV isolates. Putative mutations: rtM129L, rtW153R, rtP237T, rtN238T, and rtN248H were detected in the RT domain and have been identified to be associated with drug resistance, but not yet been confirmed experimentally in vitro.