High prevalence of HBV/A1 subgenotype in native south Americans may be explained by recent economic developments in the Amazon.
Native American populations present the highest prevalence of Hepatitis B Virus (HBV) infection in the Americas, which may be associated to severe disease outcomes. Ten HBV genotypes (A–J) have been described, displaying a remarkable geographic structure, which most likely reflects historic patterns of human migrations. In this study, we characterize the HBV strains circulating in a historical sample of Native South Americans to characterize the historical viral dynamics in this population. The sample consisted of 1070 individuals belonging to 38 populations collected between 1965 and 1997. Presence of HBV DNA was checked by quantitative real-time PCR, and determination of HBV genotypes and subgenotypes was performed through sequencing and phylogenetic analysis of a fragment including part of HBsAg and Pol coding regions (S/Pol). A Bayesian Skyline Plot analysis was performed to compare the viral population dynamics of HBV/A1 strains found in Native Americans and in the general Brazilian population. A total of 109 individuals were positive for HBV DNA (~ 10%), and 70 samples were successfully sequenced and genotyped. Subgenotype A1 (HBV/A1), related to African populations and the African slave trade, was the most prevalent (66–94%). The Skyline Plot analysis showed a marked population expansion of HBV/A1 in Native Americans occurring more recently (1945–1965) than in the general Brazilian population. Our results suggest that historic processes that contributed to formation of HBV/A1 circulating in Native American are related with more recent migratory waves towards the Amazon basin, which generated a different viral dynamics in this region.
Genetics Department, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
Bibiane A
BA
Godoy
Laboratory of Tropical Gastroenterology and Hepatology "João Alves de Queiroz and Castorina Bittencourt Alves", Institute of Tropical Medicine, Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo, SP, Brazil.
Michele S
MS
Gomes-Gouvêa
Genetics Department, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; VIZLab - Advanced Visualization Laboratory, UNISINOS, São Leopoldo, RS, Brazil.
Marcelo
M
Zagonel-Oliveira
Laboratory of Tropical Gastroenterology and Hepatology "João Alves de Queiroz and Castorina Bittencourt Alves", Institute of Tropical Medicine, Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo, SP, Brazil.
Mónica V
MV
Alvarado-Mora
Genetics Department, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
Francisco M
FM
Salzano
Laboratory of Tropical Gastroenterology and Hepatology "João Alves de Queiroz and Castorina Bittencourt Alves", Institute of Tropical Medicine, Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo, SP, Brazil; Hospital Israelita Albert Einstein, São Paulo, SP, Brazil.
João R R
JR
Pinho
Genetics Department, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. Electronic address: nelson.fagundes@ufrgs.br.
Nelson J R
NJ
Fagundes
D001499:Bayes Theorem; D001938:Brazil / Q000453:epidemiology; D004279:DNA, Viral / Q000097:blood; D057217:Economic Development; D060005:Genotyping Techniques; D006509:Hepatitis B / Q000208:ethnology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification*; D063426:Human Migration; D006801:Humans; D007199:Indians, South American / Q000235:genetics; D010802:Phylogeny; D011157:Population Dynamics; D015995:Prevalence; D017422:Sequence Analysis, DNA
D004279:DNA, Viral
Amazon region; Hepatitis B virus; Molecular epidemiology; Native American populations