Os genótipos do vírus da hepatite B na África e no Brasil: evolução, disseminação e associação com a rota de escravos / The genotypes of hepatitis B virus in Africa and in Brazil: evolution, spread and association with the route of slaves

A infecção pelo vírus da hepatite B (HBV) representa um grave problema de saúde públicamundial, apesar da existência de uma vacina eficiente. Estima-se que cerca de 350 milhõesde indivíduos no mundo estejam cronicamente infectados, dos quais a maior parte seencontra em países em desenvolvimento. A heterogeneidade das sequências dos isoladosdo HBV permite a sua classificação em oito genótipos, A a H, baseada na divergência do genoma completo de mais de 7,5 por cento. A presente tese é composta principalmente de três manuscritos, sendo um trabalho publicado e dois outros em submissão, além de cinco trabalhos como colaboradora. Esses estudos se propuseram a investigar a evolução dos genótipos do HBV entre África e Brasil e associar a dispersão dos genótipos no Brasil com a rota de escravos. No primeiro trabalho, entitulado Analysis of Complete NucleotideSequences of Angolan Hepatitis B Virus Isolates Reveals the Existence of a SeparateLineage within Genotype E, realizamos a caracterização filogenética viral dos isolados circulantes em Angola e sua associação com os perfis sorológicos e moleculares existentes naquela população. Através dessas análises, identificamos a separação das amostrasangolanas como pertencentes a uma nova linhagem, composta por Angola, Namibia eRepublica Democratica do Congo, provisoriamente denominada pela nossa equipe, SWL(Southwest African Lineage). No segundo trabalho, entitulado HBV subgenotype A1:Relationships between Brazilian, African and Asian isolates, fomos em busca das históriaevolutiva do HBV/A1, e suas suas rotas de dispersão entre África e Brasil durante o período do tráfico negreiro. Surpreendentemente, observamos que todas as amostras brasileiras estão geneticamente relacionadas às amostras da Ásia, ao invés da África. Esse fato sugere quer que o HBV/A1 possa ter sido introduzino no Brasil a partir dos portos de Moçambique,no sudeste africano, ou diretamente atravpés da Índia por navegantes portugueses...

Hepatitis B virus (HBV) infection is one of the major global human health problems, despitethe existence of an effective vaccine. It is estimated that around 350 million people worldwideare chronically infected; most of them is in developing countries. The sequenceheterogeneity of HBV isolates has led to the classification of HBV into eight genotypes, A toH, based on full-length genomic divergence of more than 7.5 percent. This thesis is composedmainly of three manuscripts: One of them is already published and two others are insubmission. Five other manuscripts are listed as complementary production. These studieshave set out to understand the evolution of HBV genotypes between Africa and Brazil andassociate its dispersion with slave routes. In the first study, entitled Analysis of CompleteNucleotide Sequences of Hepatitis B Virus Isolates Angolan Reveals the Existence of aSeparate Lineage Within Genotype E , performed the phylogenetic characterization of viralisolates circulating in Angola and its association with serological and molecular profiles.Through these analyzes, we characterized a separated lineage composed by Angolan,Namibia and Democratic Republic of Congo, provisionally named by our team as SWL(Southwest African Lineage). In the second paper, entitled Hepatitis B virus subgenotypeA1: Relationships between Brazilian, African and Asian isolates we aimed investigate theevolutionary history and migration patterns of HBV/A1 from Africa to Brazil during the slavetrade. Surprisingly, was observed that all Brazilian samples are genetically related to Asianisolates, rather than the African ones. These finds suggest that Asia was the source ofHBV/A1 infection in Brazil, probably through Mozambique in southeastern Africa, or directlythrough India by Portuguese sailors...

Epidemiology and molecular characterization of hepatitis B virus in Luanda, Angola

An estimated 360 million people are infected with hepatitis B virus (HBV) worldwide. Among these, 65 million live in Africa. Despite the high levels of hepatitis B in Africa, HBV epidemiology is still poorly documented in most African countries. In this work, the epidemiological and molecular characteristics of HBV infection were evaluated among the staff, visitors and adult patients (n = 508) of a public hospital in Luanda, Angola. The overall prevalence of hepatitis B core antibody (anti-HBc) and hepatitis B surface antigen was 79.7 percent and 15.1 percent, respectively. HBV infection was higher in males and was more prevalent in individuals younger than 50 years old. HBV-DNA was detected in 100 percent of HBV "e" antigen-positive serum samples and in 49 percent of anti-hepatitis Be antibody-positive samples. Thirty-five out of the 40 HBV genotypes belonged to genotype E. Circulation of genotypes A (4 samples) and D (1 sample) was also observed. The present study demonstrates that HBV infection is endemic in Luanda, which has a predominance of genotype E. This genotype is only sporadically found outside of Africa and is thought to have emerged in Africa at a time when the trans-Atlantic slave trade had stopped.