ABSTRACT
The prevalence and genotypes of hepatitis B virus (HBV) have distinct geographical distribution. In Brazil, some African-descendants have been maintained as small isolated communities since the slavery period. In this study, HBV infection among these communities of African origin was examined. Individuals (1,058) living in 12 communities were interviewed and serum samples screened for the presence of HBV markers. HBsAg-positive sera were tested for HBV DNA by PCR and positive samples were genotyped by restriction fragment length polymorphism (RFLP). The overall prevalence of HBV infection was 19.8% (95% CI: 17.5-22.3), ranging from 5.5% to 42.4%, depending on the communities studied. Multivariate analysis of risk factors showed that increasing age, family history of hepatitis, and sexual activity were associated significantly with this infection. HBsAg was detected in 23/1,058 (2.2%) individuals. HBV DNA was present in 2/2 of HBeAg-positive serum samples and in 18/21 (85.7%) anti-HBe-positive samples. All HBV isolates belonged to genotype A, subtype Aa. Three RFLP patterns were identified: AI (17 isolates), AIV (1 isolate), and AVI (2 isolates). These findings suggest a common introduction of HBV during the slave trade from Africa to Brazil.
Subject(s)
Hepatitis B/ethnology , Adolescent , Adult , Aged , Aged, 80 and over , Black People/statistics & numerical data , Brazil/epidemiology , Child , Child, Preschool , Female , Genotype , Hepatitis B virus/genetics , Humans , Infant , Male , Middle Aged , Odds Ratio , Prevalence , Risk FactorsABSTRACT
Furnas dos Dionísios is an Afro-Brazilian black community whose descendants were mainly fugitive slaves that established themselves in the State of Mato Grosso do Sul (MS), Brazil. The population is comprised mainly of low socioeconomic individuals who are engaged in agricultural activities. The objective of this study was to investigate the prevalence of hepatitis B (HB) and its correlation with epidemiological data obtained from the community. The studied population totaled 260 individuals with ages varying from 1 to 79 years (median 20). One hundred thirty-three (51.2%) were females and 127 (48.8%) were males. A high prevalence for anti-HBc was observed (42.7%), with present infection detected in 9.2% of the subjects who were also HB surface antigens (HBs Ag) positive; 27.3% were anti-HBc and anti-HBs reactive, and 6.2% had anti-HBc as only marker. The prevalence for anti-HBc was proportional to age, reaching its highest peak in age categories greater than 50. No serological marker was detected in children under the age of 2 years, however anti-HBc was present in 12 subjects with ages between 2 and 14 years, of these 8 (7.4%) were HBsAg positive. Among individuals over the age of 15 years, 99 were anti-HBc reactive, of these 16 (10.5%) were also HBsAg positive, thus suggesting an increased prevalence of HBV carriers among children and adolescents. The risk factors observed in this community that were significantly associated with anti-HBc positivity were age (over 20 years) and having an anti-HBc positive mother. Both HBeAg and anti-HBe were detected in 44.4% of the samples tested. HBsAg subtypes found in the studied population were adw2 (77.7%) and ayw2 (23.3%). While intrafamilial transmission was most likely responsible for HBV infection among children, other routes such as sexual contact might be considered for individuals with ages over 15 years.
Subject(s)
Hepatitis B/ethnology , Adolescent , Adult , Africa/ethnology , Aged , Brazil/epidemiology , Child , Child, Preschool , Epidemiologic Methods , Female , Hepatitis B/epidemiology , Hepatitis B Antibodies/blood , Hepatitis B Surface Antigens/blood , Hepatitis B virus/immunology , Hepatitis B virus/isolation & purification , Humans , Infant , Male , Middle AgedABSTRACT
Furnas dos Dionísios is an Afro-Brazilian black community whose descendants were mainly fugitive slaves that established themselves in the State of Mato Grosso do Sul (MS), Brazil. The population is comprised mainly of low socioeconomic individuals who are engaged in agricultural activities. The objective of this study was to investigate the prevalence of hepatitis B (HB) and its correlation with epidemiological data obtained from the community. The studied population totaled 260 individuals with ages varying from 1 to 79 years (median 20). One hundred thirty-three (51.2 percent) were females and 127 (48.8 percent) were males. A high prevalence for anti-HBc was observed (42.7 percent), with present infection detected in 9.2 percent of the subjects who were also HB surface antigens (HBs Ag) positive; 27.3 percent were anti-HBc and anti-HBs reactive, and 6.2 percent had anti-HBc as only marker. The prevalence for anti-HBc was proportional to age, reaching its highest peak in age categories greater than 50. No serological marker was detected in children under the age of 2 years, however anti-HBc was present in 12 subjects with ages between 2 and 14 years, of these 8 (7.4 percent) were HBsAg positive. Among individuals over the age of 15 years, 99 were anti-HBc reactive, of these 16 (10.5 percent) were also HBsAg positive, thus suggesting an increased prevalence of HBV carriers among children and adolescents. The risk factors observed in this community that were significantly associated with anti-HBc positivity were age (over 20 years) and having an anti-HBc positive mother. Both HBeAg and anti-HBe were detected in 44.4 percent of the samples tested. HBsAg subtypes found in the studied population were adw2 (77.7 percent) and ayw2 (23.3 percent). While intrafamilial transmission was most likely responsible for HBV infection among children, other routes such as sexual contact might be considered for individuals with ages over 15 years
