Hepatitis B virus genotyping, core promoter and precore/core mutations among Afghan hepatitis B infected individuals: a preliminary report

Abstract number: r2187

Amini-Bavil-Olyaee  S., Alavian  S., Adeli  A., Sarrami-Forooshani  R., Sabahi  F., Sabouri  E., Tavangar  H., Azizi  M., Mahboudi  F.

Introduction: 

In spite of continuation of hepatitis B virus (HBV) vaccination, HBV infection remains as an important public health problem worldwide. Although the HBV genotype distribution has been determined in some parts of the South Central Asia, no survey has been conducted to clarify HBV genotype in Afghanistan.

Materials and methods: 

Twelve Afghan HBV infected patients living in Afghanistan were enrolled in this study. Partial HBsAg and basic core promoter, precore and core (BCP/preC/C) regions were amplified and subjected for direct sequencing. In parallel, precore G1896A mutation was also determined by an amplification-created restriction site method.

Results: 

Results revealed HBV genotype D (95% bootstrap value), sub-genotype D1 (98% bootstrap value) and subtype ayw2 in all Afghan isolates. Afghan isolates clustered in a separate branch in the D1 sub-genotype called D1', supported by 82% bootstrap value. The percentage of intra-genotypic distance among Afghan isolates was 1.05% and inter-genotypic distance with the other genotype D was 2.87% and with other genotypes was 7.50–11.1%. The wild type, mixed infection and precore mutant were found in six, two and four HBV isolates, respectively. The A1762T/G1764A BCP dual mutation was found in one isolate. Three isolates presented single mutation in the BCP dual mutation region, whereas two of them showed a novel G1764T mutation.

Conclusion: 

In conclusion, this preliminary study revealed HBV genotype D, sub-genotype D1, and subtype ayw2 of HBV among hepatitis B infected patients from Afghanistan. Further investigation should be carried out for better understanding of HBV genotype distribution in other virgin parts of the South Central Asia.