Genotype determination in Moroccan hepatitis B chronic carriers

BackgroundIn Morocco, chronic liver disease related to hepatitis B virus (HBV) is a public health burden. Treatment of chronic hepatitis B is often complicated by the appearance of escape mutants after treatment with nucleoside analogs, especially with genotypes responsible for the more severe form of the disease.ObjectivesIn the present study we investigate the prevalence of the different HBV genotypes in Morocco since no previous careful study has been attempted.MethodsEpidemiological data from 91 chronically infected patients (45 women and 46 men) were collected prospectively. Sera were tested for anti-HBc IgG, HBeAg, anti-HBe antibody and liver enzymes. Restriction Fragment Length Polymorphism (RFLP) analysis was confirmed by subsequent sequencing of the pre-S and S region of the viral genome in order to determine which HBV genotypes were prevalent among Moroccan patients.ResultsThe mean age was 41 ± 12.4 years. Ten patients (11%) were positive for hepatitis B e antigen (HBeAg) and 81 (89%) were positive for anti-HBe antibodies. By the RLFP method, genotype D, pattern D2, was found in the 77 cases where HBV was successfully amplified. Phylogenetic analysis based on pre-S/S sequences revealed that genotype D in Morocco differed from others D strains subgenotypes (D1, D2, D3 and D4). In addition, the pre-core mutant defined as HBeAg-negative/anti-HBe-positive and HBV DNA positive was detected in 86% of cases.ConclusionsOur results clearly show that genotype D and pre-core mutant are highly prevalent in Morocco.