Korean J Intern Med.  2011 Sep;26(3):255-261. 10.3904/kjim.2011.26.3.255.

Molecular Epidemiology of Hepatitis B Virus

• Kao JH

• KMID: 1022164
• DOI: http://doi.org/10.3904/kjim.2011.26.3.255

Abstract

Although safe and effective vaccines for hepatitis B virus (HBV) have been available for nearly three decades, this virus kills at least 600,000 people annually worldwide and remains the leading global cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Because the HBV reverse transcriptase lacks a proofreading function, many HBV genotypes, subgenotypes, mutants, and recombinants exist. At least 10 HBV genotypes (HBV-A through J) with distinct geographic distributions have been identified; by definition, their complete genomic sequences diverge by more than 8%. HBV genotype is increasingly becoming recognized as an important factor in the progression and clinical outcome of HBV-induced disease. Infections by HBV-C or -D are significantly more likely to lead to cirrhosis and hepatocellular carcinoma than are infections by HBV-A or -B. Additionally, the hepatitis B e antigen seroconversion response to standard or pegylated interferon is more favorable in patients with HBV-A or -B than in those with HBV-C or -D. However, therapeutic responses to nucleos(t)ide analogues are generally comparable among HBV genotypes. In conclusion, genotyping of HBV is useful in identifying chronic hepatitis B patients who are at increased risk of disease progression, thereby enabling physicians to optimize antiviral therapy for these patients.

Keyword

Antiviral agents; Genotype; Hepatitis B virus; Hepatocellular carcinoma; Molecular epidemiology

MeSH Terms

Antiviral Agents/therapeutic use
Drug Resistance, Viral/genetics
Genotype
Hepatitis B/diagnosis/drug therapy/*epidemiology
Hepatitis B virus/drug effects/*genetics/pathogenicity
Humans
Molecular Epidemiology
Phenotype
Prognosis