title: Seroprevalence of hepatitis B virus and hepatitis C virus in Monte Negro in the Brazilian western Amazon region.
abstract: OBJECTIVE
  This study was carried out in Monte Negro (state of Rondônia), a village in the Brazilian western Amazon region, where a University of São Paulo Medical School program for medical student training in rural assistance took place. It aimed to determine the prevalence of hepatitis B virus and hepatitis C virus, to investigate risk factors for infection, and to evaluate the State immunization program against hepatitis B virus in the region.
  
  
  METHODS
  The study is a cross-sectional seroprevalence survey, comprising 267 volunteers who answered a comprehensive questionnaire and had blood samples collected, which were analyzed in São Paulo for the presence of antibodies against hepatitis B virus (Hbs Ag, anti-Hbs, and anti-Hbc) and hepatitis C virus using commercial kits. Data were stored in a specific data bank, and the association between seropositivity and potential risk factors was analyzed by means of uni-, bi-, and multi-variate analysis, considering +/- 5%.
  
  
  RESULTS
  The seroprevalence of hepatitis B virus was 61.79% and of hepatitis C virus was 0.38%. Statistical analysis on the data bank showed that the prevalence of hepatitis B virus rose significantly with age, especially after adolescence. Infection was higher in those coming from outside the state of Rondônia. Exposure to vaccination against hepatitis B virus was higher in younger individuals and in those who were born in Rondônia.
  
  
  CONCLUSIONS
  Monte Negro is a highly endemic region for hepatitis B virus but not for hepatitis C virus. Our results also provide indirect evidence indicating a significant improvement in the immunization program in Rondônia in recent years.
authors.affiliation: Laboratory of Infectious Disease and Central Laboratory Division, Hospital das Clínicas, Faculty of Medicine, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: El Khouri
authors.forename: Leandro Savoy
authors.initials: LS
authors.lastname: Duarte
authors.forename: Rafael Bernadon
authors.initials: RB
authors.lastname: Ribeiro
authors.forename: Luis Fernando Ferraz
authors.initials: LF
authors.lastname: da Silva
authors.forename: Luis Marcelo Aranha
authors.initials: LM
authors.lastname: Camargo
authors.forename: Vera Aparecida
authors.initials: VA
authors.lastname: dos Santos
authors.forename: Marcelo Nascimento
authors.initials: MN
authors.lastname: Burattini
authors.forename: Carlos Eduardo Pereira
authors.initials: CE
authors.lastname: Corbett
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D004812:Epidemiologic Methods; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000097:blood*; D006509:Hepatitis B / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000276:immunology; D006515:Hepatitis B virus / Q000276:immunology*; D006526:Hepatitis C / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D017589:Immunization Programs / Q000592:standards*; D008297:Male; D008875:Middle Aged; D015397:Program Evaluation; D012424:Rural Population; D012959:Socioeconomic Factors
chemical_list: D015415:Biomarkers; D006508:Hepatitis Antibodies; D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D018937:Hepatitis C Antibodies