Seroprevalence of Hepatitis B Virus and Hepatitis C Virus in Monte Negro in the Brazilian Western Amazon Region

Abstract

PURPOSE: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.CONCLUSION: 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.

Prevalence and genotyping of hepatitis C virus in blood donors in the state of Pará, Northern Brazil

“…Epidemiological studies on the prevalence of antibodies to HCV have been conducted in certain populations in the Northern region of Brazil (Soares et al 1994, Ferrari et al 1999, De Paula et al 2001, Tavares-Neto et al 2004, El Khouri et al 2005. We found a seroprevalence of antibodies to HCV of 0.22%.…”

“…In Northern Brazil, the seroprevalence among blood donors has been determined in the states of Acre (AC) (5.9%), Pará (PA) (0.5-2%), Roraima (1.2%) and Amazonas (AM) (0.8%) (GESBH 1999, Da Fonseca & Brasil 2004. Epidemiological studies conducted of indigenous, riverside and immigrant populations in Northern Brazil indicate a range of 0.38-2.4% seroprevalence (Soares et al 1994, Ferrari et al 1999, De Paula et al 2001, Tavares-Neto et al 2004, El Khouri et al 2005.…”

Hepatitis B and C virus infection among Brazilian Amazon riparians

“…Epidemiological research carried out among indigenous, riparian, and immigrant populations in the Brazilian Amazon has indicated that HBV seroprevalence may range from 0% to 20.6%, and for HCV, it may range from 0.4% to 4.8% 3,5,7,[11][12][13] . Northern Brazil has the highest HCV seroprevalence (2.1%), with a high frequency of genotype 1 [14][15][16] .…”

Imunogenicidade da vacina brasileira contra hepatite B em adultos

“…Preliminary results of the National Survey of Viral Hepatitides have provided estimated prevalences of 0.11% and 0.5% among 10-to 19-year-olds and 20-to 69-year-olds, respectively, in the Northeast Region and of 0.17% and 0.75% in these same age groups in the Center-West Region. 1,4,5,16 Despite such reductions in prevalence, however, hepatitis B remains an important public health concern in Brazil.…”