The hepatitis delta genotype 8 in Northeast Brazil: The North Atlantic slave trade as the potential route for infection.

Hepatitis Delta virus (HDV) is not well known, even though HDV and Hepatitis B virus (HBV) co-infection leads to severe forms of acute and chronic liver diseases. HDV is endemic in the Western Amazon region. Recently, the HDV genotype 8 was found in chronic patients followed at the center for liver studies in the Northeast Brazil, Maranhão. Previous studies suggested that this genotype was introduced in Maranhão during the slave trade. The presence of HDV in that study, which was done outside the Amazon region, led us to investigate whether the virus is found infecting individuals in other regions of Maranhão as well. Thus, we screened ninety-two HBsAg positive individuals from five Municipalities of Maranhão for anti-HD antibody and eight were found positive (8.7%). These eight positive individuals were submitted to polymerase chain reaction (PCR) to investigate active HDV infection. Half of them were positive for a fragment sequence of the delta antigen; their sequence samples were submitted to genotype characterization by phylogenetic analysis. All sequences clustered in a unique branch of the tree separated from the other branch described in Africa. Our study confirmed the presence of HDV-8 in Maranhão. These infected individuals had no evidence of contact with African people. Furthermore, we found individuals infected with HDV-8 in two more different municipalities. More studies like ours are urgent because the co-infection HBV/HDV is more difficult to treat. Identification of the endemic regions and implementation of healthy policies for preventing this infection are urgent in this region.

High prevalence of hepatitis B virus subgenotypes A1 and D4 in Maranhão state, Northeast Brazil.

In this study, we determined the prevalence of HBV subgenotypes in Maranhão state, located in northeastern Brazil, where the population is heterogeneous, with a high proportion of African descendants. HBV was detected in 119 of 133 (89.5%) chronic hepatitis B patients, including 103 (86.5%) who were HBeAg-negative. Using phylogenetic analysis of the S/Polymerase region of HBV DNA, subgenotype A1 was found to be the most prevalent (67%), followed by genotype D (28%; subgenotype D4 was detected in 24%, D3 in 3%, and D2 in 1%). Genotype F, clustering with subgenotype F2a, was found in six (5%) patients. The topology of the phylogenetic tree showed that HBV/A1 sequences did not cluster together, suggesting that more than one strain was introduced into Maranhão. On the other hand, HBV/D4 sequences formed a monophyletic cluster, suggesting a single entry of this strain in this population. This study showed that HBV/A1 was the only subgenotype of HBV/A present in the population from Maranhão and indicated that in this region HBV/A1 was not restricted to an Afro-descendant community where it was previously reported, but is widely distributed among general population of HBV chronic carriers. Unexpectedly, we found a high frequency of HBV subgenotype D4. Together with previously reported data on the distribution of HBV/D4 in the world, these findings suggest that this subgenotype was more prevalent in the African continent in the past and may have been introduced in Maranhão by means of the slave trade during the late XVIII century, when the largest number of African slaves arrived to this region.