Prevalence and distribution of hepatitis B virus genotype D in Galicia (northwest of Spain): influence of age, sex and origin

Introduction. Phylogenetically, hepatitis B virus (HBV) is classified into genotypes and subgenotypes used for epidemiological studies. The aim of this study is to know the distribution of HBV subgenotypes D in our environment. Patients and methods. From 401 patients HBV surface antigen positive, HBV DNA-positive, partial HBV-DNA S gene was amplified, sequenced and analysed using geno2pheno (hbv) (Max-Planck Institute) on line application. Results. We found 259 (64.6%) patients with HBV genotype D: 53 not subgenotypable, 9 (4%) D1, 61 (30%) D2, 15 (7%) D3 and 121 (59%) D4. Patients with D1 subgenotype were, on average, 23 years younger (p = 0.0001), with a higher proportion of women (p < 0.05). Conclusions. HBV subgenotype D4 was the most prevalent in our area. Patients with D1 subgenotype came from abroad were younger than the other subgenotypes and mostly women. These results show the interest of conducting studies at HBV subgenotype level.