Detection of hepatitis B virus genotypes in a group of hepatitis B virus-infected patients in central and northern Sri Lanka.

Introduction. Hepatitis B infection causes a spectrum of clinical diseases varying from asymptomatic infection to severe or fulminant acute hepatitis, chronic liver disease, cirrhosis and hepatocellular carcinoma. Hepatitis B virus (HBV) genotypes appear to influence transmission dynamics, clinical outcomes and responses to antiviral therapy. However, hepatitis B genotyping has been poorly investigated in Sri Lanka. This study intended to determine hepatitis B genotypes in a group of HBV-infected people in central and northern Sri Lanka. Methodology. The study was a laboratory-based descriptive cross-sectional study. Initial detection of HBV DNA in 100 EDTA blood samples was done by using a commercially validated quantitative real-time PCR kit. Hepatitis B genotyping was performed by in-house conventional semi-nested multiplex PCR using genotype-specific primers (for genotypes A-F). The serological profile was determined using a commercially validated ELISA/chemiluminescence immunoassay. The results were evaluated for genotype prevalence, viral load association and hepatitis B e antigen (HBeAg) expression in the study population. Results and conclusion. The study detected that genotype C (n=38) is most prevalent and infections with multiple genotypes (n=52, 52%) were commoner than mono-genotype (n=23, 23%) infections. In total, 25% of patients had no detectable genotype among genotypes A-F. The mean viral load in asymptomatic patients with a single genotype was 3.28 log₁₀ copies ml^-1 and in multiple genotypes was 4.18 log₁₀ copies ml^-1 before treatment. Statistical significance was not detected in mean viral loads and HBeAg expression in these two groups. In the future, chronic HBV infection may be effectively treated and managed according to the infected genotype.