Identification of a new hepatitis B virus (HBV) genotype from Brazil that expresses HBV surface antigen subtype adw4

Naumann, Heike; Schaefer, Stephan; Yoshida, Clara Fumiko Tachibana; Gaspar, Ana; Repp, Reinald; Gerlich, Wolfram H.

doi:10.1099/0022-1317-74-8-1627

Cited by 126 publications

(90 citation statements)

References 39 publications

(15 reference statements)

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“…Genotype F is subdivided into two subgenotypes, F1 and F2, where subgenotype F1 is the most encountered in Central America and F2 principally in South America. Genotype F subgenotype F2 was identified primarily in Brazil [34]. Other authors [35] corroborate the present study with regard to the predominance of genotype A in Brazilian regions; however, in other studies, genotype F has greater frequency among isolated tribes of Amazonia who do not maintain contact with whites.…”

Section: Clinico-epidemiological Manifestationssupporting

confidence: 80%

Characterization of HBeAg-negative chronic hepatitis B in western Brazilian Amazonia

Victoria¹,

Oliveira²,

Victoria³

et al. 2008

Braz J Infect Dis

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The present study was conducted with 55 patients native from western Brazilian Amazonia, who were HBV-DNA positive after seroconversion of HBeAg. It is a descriptive case study, with the patients separated into two groups: with hepatitis and without hepatitis on histological examination. The aim of the present study was to describe the clinical and molecular characteristics of patients who are chronic carriers of HBsAg. The prevalence of hepatitis was 63.64%, with a predominance of males (41.82%) and a mean age of 42.5 years, occurring mostly in natives of the southeast sub-region (32.73%). Time was a variable proportional to the course of the disease and the most frequent symptoms were: dyspepsia, asthenia and loss of libido with the majority of the patients having history of prior contact with HBV or positive family history. Splenomegalia was the most frequent sign (40%). Among the tests, platelet count, serum albumin and prothrombin activity were significant in the diagnosis of hepatitis. Alphafetoprotein was greater in patients with hepatitis, and hepatocellular carcinoma was detected in 3.63% of the patients with hepatic cirrhosis. Three types of HBV genotypes were diagnosed: A, D and F in the samples amplified for gene S. Genotype A (AA) was observed in 54.54% of the cases with hepatitis, in contrast to other studies showing the predominance of genotype F in this region. We observed mutations in 36.36%, with a predominance of the mutations in the core promoter region (31.81%), due to the greater prevalence of genotype A in this study. Key-Words: HBeAg-negative chronic hepatitis B, western Brazilian Amazonia, mutations.Western Brazilian Amazonia is considered a region of high endemicity for hepatitis B virus (HBV), where a large part of the population is infected in perinatal period and during infancy. The prevalence of chronic carriers of HBV surface antigen (HBsAg) in these areas varies between 5% and 15% and approximately 50% to 95% of the population show serologic evidence of past infection with HBV [1,2,3]. Various factors are implicated in the development and outcome of HBV infection, but the progression to chronic hepatitis is proportionally greater in individuals infected by the vertical route or during the perinatal period [4]. Chronic hepatopathies related to HBV are seen in two forms: HBeAg positive and HBeAg negative. The HBeAg-negative chronic forms are represented by two groups of patients: chronic inactive HBsAg carriers and chronic hepatitis B (CHB) patients. The distinction between these two forms is difficult, particularly in patients with biochemical and intermittent virologic activity. It is estimated that in the world there are approximately 350 million inactive HBsAg carriers, and of these, 7% to 30% are infected with mutant forms of HBV, which despite the presence of anti-HBe antibody continue to be HBV-DNA positive [5]. Chronic HBsAg carriers who show HBeAg-negative/antiHBe-positive serologic status and have serum HBV-DNA detectable by PCR and active hepatic disease characterized by ...

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Section: Clinico-epidemiological Manifestationssupporting

confidence: 80%

Characterization of HBeAg-negative chronic hepatitis B in western Brazilian Amazonia

Victoria¹,

Oliveira²,

Victoria³

et al. 2008

Braz J Infect Dis

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“…The DNA sequence of Brazilian strain w4B (accession no. X69798; Naumann et al, 1993) was chosen arbitrarily as the outgroup, and 500 bootstrap operations were done. A to D refers to subgroup designation (Okamoto et al, 1988).…”

Section: Phylogenetic Analysismentioning

confidence: 99%

The hepatitis B virus X gene: analysis of functional domain variation and gene phylogeny using multiple sequences

Kidd‐Ljunggren

Öberg

Kidd

1995

Journal of General Virology

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“…HBV genotypes differ by at least 8% [2] . Since the first definition of the genotypes A, B, C and D [2] , genotypes E [3] , F [4] , G [5] and H [6] have been The isolates from the South-East-Asian apes, gibbon and orang-utan, are categorized into two genotypes, i.e., HBVgbn and HBVoru, respectively. These genotypes diverge by 8%.…”

Section: Introductionmentioning

confidence: 99%

Hepatitis B virus taxonomy and hepatitis B virus genotypes

Schaefer¹

2007

WJG

303

229

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Hepatitis B virus (HBV) is a member of the hepadnavirus family. Hepadnaviruses can be found in both mammals (orthohepadnaviruses) and birds (avihepadnaviruses). The genetic variability of HBV is very high. There are eight genotypes of HBV and three clades of HBV isolates from apes that appear to be additional genotypes of HBV. Most genotypes are now divided into subgenotypes with distinct virological and epidemiological properties. In addition, recombination among HBV genotypes increases the variability of HBV. This review summarises current knowledge of the epidemiology of genetic variability in hepadnaviruses and, due to rapid progress in the field, updates several recent reviews on HBV genotypes and subgenotypes.

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Identification of a new hepatitis B virus (HBV) genotype from Brazil that expresses HBV surface antigen subtype adw4

Cited by 126 publications

References 39 publications

Characterization of HBeAg-negative chronic hepatitis B in western Brazilian Amazonia

Characterization of HBeAg-negative chronic hepatitis B in western Brazilian Amazonia

The hepatitis B virus X gene: analysis of functional domain variation and gene phylogeny using multiple sequences

Hepatitis B virus taxonomy and hepatitis B virus genotypes

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