title: Molecular epidemiology of hepatitis D virus circulating in Southwestern Nigeria.
abstract: BACKGROUND
  Hepatitis B virus (HBV) and hepatitis D virus (HDV) infections are major public health problems in sub-Saharan Africa. Whereas it is known that HBV infection is endemic in Nigeria, there is only little data about HDV prevalence available. Here, we assessed the HDV seroprevalence and determined the HDV and HBV genotypes distribution among HBsAg positive individuals in Southwestern Nigeria.
  
  
  METHODS
  This cross-sectional study involved 188 serum samples from HBsAg positive outpatients recruited at four tertiary hospitals in Southwestern Nigeria. Anti-HDV antibodies were detected by ELISA while HDV-RNA was detected by RT-PCR. Sequencing followed by phylogenetic analyses and HBV genotype-specific PCR were used to characterize HDV and HBV genotypes, respectively.
  
  
  RESULTS
  Out of 188 HBsAg positive serum samples, 17 (9 %) showed detectable HDV-RNA. Anti-HDV antibodies test was possible from 103 samples and were observed in 4.9 % (5/103) patients. There was no significant difference in HDV prevalence between four main cities across the country. 64.7 % of HDV-RNA positive samples were from males and 35.3 % from females (P < 0.05). No significant associations were observed with regard to HDV seroprevalence and available demographic factors. Phylogenetic analyses demonstrated a predominance of HDV genotype 1 and HBV genotype E among the HDV-RNA/HBsAg positive patients.
  
  
  CONCLUSIONS
  In conclusion, our study showed a high prevalence of HDV infection in HBsAg carriers and the predominance of HDV genotype 1 infection in Nigerian HBV endemic region. The findings contribute to a better understanding of the relevance of HDV/HBV co-infection and circulating genotypes.
authors.affiliation: Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
authors.forename: Oluyinka Oladele
authors.initials: OO
authors.lastname: Opaleye
authors.affiliation: Department of Microbiology, Obafemi Awolowo University, Ile Ife, Nigeria.
authors.forename: Oluwatoyin Margaret
authors.initials: OM
authors.lastname: Japhet
authors.affiliation: Department of Virology, College of Medicine, University of Ibadan, Ibadan, Nigeria.
authors.forename: Olubusuyi Moses
authors.initials: OM
authors.lastname: Adewumi
authors.affiliation: Institute of Child Health, College of Medicine, University of Ibadan, Ibadan, Nigeria.
authors.forename: Ewean Chukwuma
authors.initials: EC
authors.lastname: Omoruyi
authors.affiliation: Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
authors.forename: Olusola Anuoluwapo
authors.initials: OA
authors.lastname: Akanbi
authors.affiliation: Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
authors.forename: Adeolu Sunday
authors.initials: AS
authors.lastname: Oluremi
authors.affiliation: Department of Infectious Diseases, Division of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Seestr. 10, D-13353, Berlin, Germany.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Institute of Tropical Medicine, University of Tuebingen, Tuebingen, Germany.
authors.forename: Hoang van
authors.initials: Hv
authors.lastname: Tong
authors.affiliation: Institute of Tropical Medicine, University of Tuebingen, Tuebingen, Germany.
authors.forename: Thirumalaisamy P
authors.initials: TP
authors.lastname: Velavan
authors.affiliation: Department of Infectious Diseases, Division of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Seestr. 10, D-13353, Berlin, Germany. bockc@rki.de.
authors.forename: C-Thomas
authors.initials: CT
authors.lastname: Bock
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005838:Genotype; D006508:Hepatitis Antibodies / Q000097:blood*; D003699:Hepatitis D / Q000453:epidemiology*; D003698:Hepatitis Delta Virus / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009549:Nigeria / Q000453:epidemiology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D016036:Seroepidemiologic Studies; D055815:Young Adult
chemical_list: D006508:Hepatitis Antibodies; D012367:RNA, Viral
keywords: HBV infection; HDV genotype; Hepatitis D virus; Molecular epidemiology; Nigeria