title: Sequence-based genotyping of hepatitis B virus in general population.
abstract: BACKGROUND
  Hepatitis B Virus (HBV) causes acute and chronic liver disease worldwide. HBV has eight genotypes (A to H) which is the reflection of its genome with their characteristic geographical distribution. Each genotype could have different pathogenic and therapeutic characteristics. There have been few records on HBV genotyping in general population from our region. This study aimed to determine hepatitis B genotypes using sequencing in the general population of Shahrekord, a Southwestern region of Iran.
  
  
  METHODS
  A total of 3000 serum samples (cluster sampling method) were enrolled from general population tested for HBsAg using ELISA. Using appropriate extraction kit, HBV DNA was extracted from HBsAg positive samples and each was subjected to nested PCR for detection of HBV DNA. Finally, using sequencing, the samples were used for HBV genotyping. Data were analyzed by SPSS 19 using descriptive statistics, chi square, and Fisher's exact test. P-value < 0.05 was considered as the level of significance.
  
  
  RESULTS
  Out of 3000 serum samples, 40 (1.3%) were positive for HBsAg. HBV DNA was detected in 10 out of 40 (25%) of the samples studied. Genotype D was the predominant HBV type found in all of these 10 HBV positive samples.
  
  
  CONCLUSIONS
  Genotype D is probably the predominant HBV type in our region.
authors.affiliation: Associate Professor, Medicinal Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran. alikarimi72@skums.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Karimi
authors.affiliation: Assistant Professor, Department of Community Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran. lmoezzi@yahoo.com.
authors.forename: Ma'soumeh
authors.initials: M
authors.lastname: Moezzi
authors.affiliation: Associate Professor, Department of Infectious Diseases, Shahrekord University of Medical Sciences, Shahrekord, Iran. rastabi966@gmail.com.
authors.forename: Reza
authors.initials: R
authors.lastname: Imani
keywords: Chronic hepatitis B; genotyping; nested polymerase chain reaction