Hepatitis B Virus Subgenotype A1: Evolutionary Relationships between Brazilian, African and Asian Isolates

Abstract

Brazil is a country of low hepatitis B virus (HBV) endemicity in which the genotype A of HBV (HBV/A) is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase), and one (Phe17) in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an ‘Asian-American’ clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300–400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.

A novel hepatitis B virus subgenotype D10 circulating in Ethiopia

“…A study in Haiti suggests that A1 was introduced from eastern Africa to Haiti during the slave trade around the turn of the 18th century . Another study in Brazil revealed the close relatedness of the Brazilian, Asian and Somalian isolates and suggests that the Brazilian A1 strains originate from South‐East Africa at the middle of the 19th century . Moreover, in the recent subgenotype A1 of HBV‐tracing human migrations in and out of Africa, the coclustering of Somalian and Latin American strains and the plausible sites of A1 origin and dispersal routes to Asia and Latin America are presented .…”

Epidemiological and molecular analysis of hepatitis B virus infection in manicurists in Central Brazil

“…These two genotypes are commonly detected in Brazil . The genotype A1 was brought to America during the slave trade, so it was commonly found in African descendants . The genotype F2 is Native American with origins in indigenous populations .…”

“…16,26,34,35 The genotype A1 was brought to America during the slave trade, so it was commonly found in African descendants. 17,35 The genotype F2 is Native American with origins in indigenous populations. 34,36 The viral loads found in the three samples submitted for quantification of DNA did not represent a significant risk for developing cirrhosis and hepatocellular carcinoma.…”

“…Full-length HBV genome was amplified by using a previously described method. 17,18 The PCR products were purified using the Wizard SV Gel and PCR Clean-Up System (Promega, Fitchburg, WI).…”

Genetic Variants of Hepatitis B Virus in Primary Donors in Astana, Kazakhstan

“…Широкое распростране-ние ВГВ субтипа A1 описано также в Бразилии, что, по всей видимости, является следствием бо-лее поздней «миграционной» волны, так как вы-является преимущественно у чернокожих и му-латов [8], подтверждая предположение о завозе вируса с пленниками, вывезенными из Юго-Восточной Аф рики в середине XIX в. [14].…”