Characterization of Occult Hepatitis B Infection Among Injecting Drug Users in Tehran, Iran

Abstract

BackgroundHepatitis B virus (HBV) infection is a major health problem worldwide.ObjectivesThe aim of this study was to investigate the frequency of occult hepatitis B infection (OBI) and its associated risk factors, together with the molecular characterization of the virus in injecting drug users of Tehran.Patients and MethodsThe study consisted of 229 injecting drug users. Serum samples were collected and tested for the presence of hepatitis B core antibody (HBcAb) and hepatitis B surface antigen (HBsAg) by an enzyme-linked immunosorbent assay (ELISA). HBV B virus DNA was extracted from the serum samples, and a fragment of the S gene was amplified using the nested polymerase chain reaction. The genotype, subgenotypes, subtype, and S gene mutation of HBV were determined by direct sequencing. A phylogenetic tree was constructed using the neighbor-joining method.ResultsSixty-four (28%) participants were HBcAb positive, 59 cases were HBcAb positive and HBsAg negative, and 5 cases were HBsAg positive. Hepatitis B DNA was found in three HBsAg-positive cases. Thirteen of 59 (22%) individuals were hepatitis B DNA positive. The phylogenetic tree of hepatitis B DNA showed the existence of genotype D. The only significant correlation was between sharing a syringe and OBI.ConclusionsIn comparison with the rate of HBcAb positivity reported in other Iranian studies, the rate was higher in the present study. There were a few variations, genotypes, and subtypes among the infected injecting drug users. Further investigations are needed to unravel the molecular characterization of OBI.

Epidemiology, risk factors, and molecular characterization of occult hepatitis B infection among anti‐hepatitis B core antigen alone subjects

“…40 Although, in previous studies non-DI subgenotypes, such as D2 and D3, have been rarely reported from Iran. 19 Almost all samples of this project had viral loads lower than 1.3 × 10 3 copies/mL, which is in line with most of previous studies that reported very low and undetectable viral loads 26,27,39 ; OBI usually defined with viral loads lower than 1000 copies/mL. 41 This is mainly related to long-standing persistence of viral cccDNA, presence of replication-competent isolates and intense suppression of viral activity.…”

“…This could be due to neighboring with Afghanistan; there is a heterogeneous distribution of HBV in Afghanistan . Although, in previous studies non‐DI subgenotypes, such as D2 and D3, have been rarely reported from Iran …”

“…Various reports are available on different population types that have been conducted in Iran. Most of them focused on high‐risk populations and showed varied results: 0% in blood donors, 22% among drug users, and 30% among hemodialysis and HIV‐positive people . Corresponding data is inadequate across anti‐HBc positive cases; 2.72% out of 110 patients in Zahedan city, 28.57% out of just 14 anti‐HBc positive cases in Isfahan, and in Tehran HBV‐DNA was detected among 12.2% out of 131 anti‐HBc samples…”

Persons with Intellectual Disability: A Potential Reservoir of Invasive Strains of Hepatitis B Virus

“…The detection of HBV genotype D is in line with previous epidemiological studies in Iran (29,30) and the neighbouring countries (8,31,32). Although HBV D1 is the major subgenotype circulating in Iran (33), partial S gene sequences in the present study did not provide enough data for HBV subgenotyping (34).…”

Occult Hepatitis B Infection in Hepatitis C Patients with Hematological Disorders

“…The gold standard for diagnosis of OBI is liver biopsy and detecting the presence of HBV DNA in hepatocytes (1)(2)(3). An alternative method for diagnosis of OBI is detecting HBV DNA in peripheral blood samples.…”