Molecular epidemiology of hepatitis B and hepatitis delta viruses circulating in the Western Amazon region, North Brazil

Abstract

BackgroundHepatitis B virus (HBV) and hepatitis D virus (HDV) represent important public health problems in the Western Amazon region with reported cases of fulminant hepatitis. This cross sectional study describes HBV and HDV genotypes circulating in the Brazilian Amazon region.MethodsHBsAg positive individuals (n = 224) were recruited in Manaus/Amazonas State (130 blood donors from the Hematology and Hemotherapy Foundation from Amazonas/HEMOAM; 60 subjects from outpatient clinic) and in Eirunepe city (n = 34) from 2003–2009. Most participants (n = 153) lived in Manaus, 63 were from 20 remote isolated municipalities, 8 lived outside Amazonas State. Genotyping was based on PCR products: HBV genotype A-F specific primers, restricted length polymorphism for HDV. HDV isolates were directly sequenced (delta antigen 405 nucleotide fragment) and phylogenetic analysis performed (MEGA; neighbor-joining, Kimura’s two parameter).ResultsMost participants were young adult males and HBV mono-infection predominated (70.5%, 158/224). Among blood donors, outpatient subjects and individuals from Eirunepe, HBV/A prevailed followed by HBV/D and F (p > 0.05). HBV/A was more frequent in blood donors (p < 0.05). HBV-HDV coinfection rate was 8.5% in blood donors (11/130), 65.0% (39/60) in outpatient subjects and 47.0% (16/34) in individuals from Eirunepe. Compared to blood donors, coinfection was higher in outpatient subjects (65.0% versus 8.5%; RR = 5.0; CI 3.4-7.9; p < 0.0001) and in subjects from Eirunepe (47.0% versus 8.5%; RR = 5.5; CI 3.0-9.9; p < 0.0001). HBV-HDV coinfection rates were higher in patients from highly endemic remote cities. Only HDV genotype 3 was detected, HBV/F-HDV/3 predominated (20/38; 52.7%), followed by HBV/A-HDV/3 (31.6%; 12/38) and HBV/D-HDV/3 (15.8%; 6/38).ConclusionsThe description of HBV and HDV genotypes circulating in the western Amazon can contribute to a better understanding of their relevance on the regional epidemics. These infections are highly endemic in the Amazon where their control is challenged by its vast territorial dimension with small, hard-to-reach municipalities dispersed into the jungle and populated by diverse ethnic groups.

Hepatitis delta virus: From biological and medical aspects to current and investigational therapeutic options

“…Recent evaluations of HDV prevalence are consistent with high endemicity, with HDV seropositivity rates ranging from 8,5% of HBsAg-positive asymptomatic blood donors to 65% in HBsAg-positive hospital outpatients (120). High HDV prevalence rates are also reported in the Amazonian areas of Venezuela and Colombia, where the infection is, as in Brazil, caused by HDV-3 and associated with fulminant hepatitis outbreaks (121).…”

Epidemiology of HBV subgenotypes D

“…Genotype C HBV was associated with more adverse outcomes than genotype B in chronic HDV infection. In a study from Amazon region, only HDV-3 and HBV genotype A, D and F were identified [98,99]. A recent study compared the infectivity of HBV genotypes in HDV coinfection.…”

Hepatitis Delta

“…6,14 The incidence of HBV is increasing dramatically in northern and central Europe because of infected individuals emigrating from endemic regions as well as increased rate of IV drug abuse. 15 Co-infection with HDV is common in Africa and Middle east however in USA coinfection with HDV is restricted to individuals with IV drug abuse or others at high risk.…”