title: Epidemiology, risk factors and genotypes of HBV in HIV-infected patients in the northeast region of Colombia: high prevalence of occult hepatitis B and F3 subgenotype dominance.
abstract: BACKGROUND
  Chronic hepatitis B virus (HBV) infection is an increasing cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected individuals. HIV-positive patients are commonly co-infected with HBV due to shared routes of transmission.
  
  
  OBJECTIVE
  Our aim was to determine the risk factors, prevalence, genotypes, and mutations of the Surface S gene of HBV, and occult hepatitis B infection (OBI) among patients infected with HIV in a northeastern Colombian city.
  
  
  METHODS
  A cross-sectional study was conducted with 275 HIV-positive patients attending an outpatient clinic in Bucaramanga, Colombia during 2009-2010. Blood samples were collected and screened for serological markers of HBV (anti-HBs, anti-HBc and HBsAg) through ELISA assay. Regardless of their serological profile, all samples were tested for the HBV S gene by nested-PCR and HBV genotypes were determined by phylogenetic inference. Clinical records were used to examine demographic, clinical, virological, immunological and antiretroviral therapy (ART) variables of HIV infection.
  
  
  RESULTS
  Participants were on average 37±11 years old and 65.1% male. The prevalence of HIV-HBV coinfection was 12% (95%CI 8.4-16.4) of which 3.3% had active HBV infection and 8.7% OBI. The prevalence of HIV-HBV coinfection was associated with AIDS stage and ART treatment. Sequence analysis identified genotype F, subgenotype F3 in 93.8% of patients and genotype A in 6.2% of patients. A C149R mutation, which may have resulted from failure in HBsAg detection, was found in one patient with OBI.
  
  
  CONCLUSIONS
  The present study found a high prevalence of HIV-HBV coinfection with an incidence of OBI 2.6-fold higher compared to active HBV infection. These findings suggest including HBV DNA testing to detect OBI in addition to screening for HBV serological markers in HIV patients.
authors.affiliation: University of Santander (UDES), Bacteriology and Clinical Laboratory Program, Department of Health Sciences, CliniUDES Research Group, Laboratory for Biomedical and Biotechnological Research (LBBR) Bucaramanga, Santander, Colombia.
authors.forename: Henry
authors.initials: H
authors.lastname: Bautista-Amorocho
authors.affiliation: University of Santander (UDES), Bacteriology and Clinical Laboratory Program, Department of Health Sciences, CliniUDES Research Group, Laboratory for Biomedical and Biotechnological Research (LBBR) Bucaramanga, Santander, Colombia.
authors.forename: Yeny Zulay
authors.initials: YZ
authors.lastname: Castellanos-Domínguez
authors.affiliation: Industrial University of Santander (UIS), Department of Public Health, School of Medicine, Research Group on Demography, Public Health and Health Systems (GUINDESS), Bucaramanga, Santander, Colombia.
authors.forename: Laura Andrea
authors.initials: LA
authors.lastname: Rodríguez-Villamizar
authors.affiliation: University of Santander (UDES), Bacteriology and Clinical Laboratory Program, Department of Health Sciences, CliniUDES Research Group, Laboratory for Biomedical and Biotechnological Research (LBBR) Bucaramanga, Santander, Colombia.
authors.forename: Sindi Alejandra
authors.initials: SA
authors.lastname: Velandia-Cruz
authors.affiliation: University of Santander (UDES), Bacteriology and Clinical Laboratory Program, Department of Health Sciences, CliniUDES Research Group, Laboratory for Biomedical and Biotechnological Research (LBBR) Bucaramanga, Santander, Colombia.
authors.forename: Jeysson Andrey
authors.initials: JA
authors.lastname: Becerra-Peña
authors.affiliation: University of Santander (UDES), Bacteriology and Clinical Laboratory Program, Department of Health Sciences, CliniUDES Research Group, Laboratory for Biomedical and Biotechnological Research (LBBR) Bucaramanga, Santander, Colombia.
authors.forename: Ana Elvira
authors.initials: AE
authors.lastname: Farfán-García
mesh_terms: D000328:Adult; D003105:Colombia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000150:complications*; D006509:Hepatitis B / Q000150:complications / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D015995:Prevalence; D012307:Risk Factors