Using RFLP -PCR and Direct Sequencing to Determine HBV Genotypes in Intravenous Drug User Prisoners in Tehran Province

Hepatitis B virus (HBV) infection is a global health problem. Current researches indicate that 500,000 to 1.2 million deaths per year are caused by chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC). HBV genotyping and subtyping provide epidemiological data that may contribute to vaccination and antiviral treatment strategies, diagnostic development, and determination of the course of the disease. Hereby we decided to evaluate the genotype of this virus in prisoners who are addicted to some kinds of injection drugs. Patients and In this cross- sectional study which was done in Tehran province in 2008, HBV genotypes of serum samples from 122 HBsAg positive intravenous drug user prisoners were determined using cost-effective and standard methods such as PCR and RFLP. Then direct sequencing was utilized to confirm and revaluate the results of PCR-RFLP. The phylogenetic tree was drawn by computer biosoftware (Bioedit,Mega,ClustalW) and the results were assessed by statistical analysis SPSS v.16 (P<0.05)as well. 115 samples were reported positive when analyzed by nested PCR. All of these positive samples were reported to be genotype D by RFLP using BsrI, StyI, EaeI, DpnI, and HpaI enzymes. In addition,phylogenetic tree drawn by Neighbor-Joining method in 100% of the subjects confirmed the existence of genotype D(subgenotype D1, subtype ayw2). 115 HBV isolates from prisoners represent homogenous genotypic diversity, and our results concur with other reports from Iran, all showing that genotype D is the only detectable genotype in this study.This genotype with a low rate of severe liver diseases caused by HBV (cirrhosis, hepatocellular carcinoma) is in accordance with our results.