Detecção e caracterização do vírus da hepatite E em potenciais reservatórios silvestres

• Ano de defesa: 2022
• Autor(a) principal: Moraes, Danny Franciele da Silva Dias
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Faculdade de Medicina Veterinária (FAVET); UFMT CUC - Cuiabá; Programa de Pós-Graduação em Ciências Veterinárias
• Palavras-chave em Português: Vírus da hepatite E; Zoonoses; Saúde única; Animais silvestres; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA; Hepatitis E virus; Zoonosis; One health; Wild animals
• Link de acesso: http://ri.ufmt.br/handle/1/4547

The hepatitis E virus (HEV) is the etiologic agent responsible for the majority of acute hepatitis conditions worldwide. Although the evolutionary course of these conditions culminates in asymptomatic or self-limited patients, some groups such as pregnant women and immunocompromised patients may trigger severe acute and even chronic hepatitis. Hepatitis E has distinct epidemiological patterns: genotypes 1 and 2 have man as exclusive host and are associated to major outbreaks, genotypes 5 and 6 have the cycle exclusively in animals, while genotypes 3, 4, 7 and 8 have zoonotic character. In Brazil and Portugal, the autochthonous HEV occurs exclusively associated to genotype 3 and is transmitted mainly by pork meat (pigs and wild boars), however this virus has been reported in several wild reservoirs. Therefore, the aim of this study was to investigate potential reservoirs of HEV in wild animals in order to increase the epidemiological knowledge of this virus. Then a systematic review of all articles about HEV in Brazil was carried through, with searches in 5 indexed databases in order to detect possible gaps. With this work it was possible to identify that the epidemiological pattern of HEV in Brazil depends on the circulation of the genotype 3 of zoonotic transmission. In deer, we investigated the presence and characterisation of HEV in faeces from free-living deer in Portugal, namely red deer (Cervus elaphus) (n=95) and fallow deer (Dama dama) (n=35) by pan-genotypic nested RT-PCR followed by two-way sequencing and phylogenetic analysis. Two female red deer, sampled in central Portugal, were positive for HEV (2.1%; 95% confidence interval: 0.58-7.35). Sequencing and genetic characterisation showed that these two HEV samples were 98.96% identical, both being of the HEV3 genotype, subgenotype 3e. This subgenotype has recently been associated with severe infections in humans in Europe. This is the first report of HEV in deer from Portugal. The increasing number and distribution of deer in the region and the zoonotic characteristics of the circulating HEV3 subgenotype 3e genotype highlights the importance of continued surveillance directed at food-borne diseases, especially those involving wild animals and deer in particular. Finally, an investigation was conducted on the presence of HEV in faeces from Portuguese micro-mammals, namely the Mediterranean rat (Mus spretus) (n=26) and the white-toothed shrew (Crocidura russula) (n=14). Nested RT-PCR was performed for the ORF1 and ORF2 region, obtaining only amplification of one sample using the primer targeting ORF2, and the amplified sample was submitted to two-way genome sequencing. Among the 40 samples analyzed, only one sample from Mus spretus was positive (2.5%; 95% CI: 0.06-13.16), showing the occurrence of 3.85% (95%CI: 0.01-19.64) (1/26) for the species. After analysis by HEVtool, it was characterized as HEV3e. Although most scientific literature reports the occurrence of Orthohepesvirus C in rodents, in this study the occurrence of Orthohepesvirus A, HEV3 subgenotype 3e in Mus spretus is presented for the first time. The detection of this pathogen in synanthropic rodents reinforces the importance in the surveillance of potential hosts and increase the risk of spillover highlighting the unique health approach in the control and prevention of endemics.