Hepatite E suína : estudo epidemiológico e desenvolvimento de ferramentas para o uso em diagnóstico

Abstract

Hepatitis E is an acute liver disease caused by hepatitis E virus (HEV). This virus is a member of family Hepeviridae, whose genome consists of a single-stranded RNA surrounded by a non-enveloped capsid. The HEV has four genotypes (genotypes 1-4), the genotypes 1 and 2, are found only found in humans, and genotypes 3 and 4 are considered as zoonotic. The pigs appear to be the main animal reservoir for zoonotic genotypes, although the virus has been identified in other animals. The concern of public health agencies with this infection has increased considerably due to its zoonotic potential. To evaluate the presence of HEV in confined pigs and wild boars, the enzyme immunoassay (ELISA) was used to identify anti-HEV IgG antibody in these animals. Among all samples in the present study, wild boar samples were negative (100%) for the presence of this antibody, whereas 50% of domestic pigs were positive. Although diagnostic methods have been developed and applied in the investigation of swine HEV infection, the available kits are imported and expensive to be use in research and routine laboratories. To contribute for the development of tools for diagnosis, this work also performed the cloning and expression methods in Escherichia coli bacteria system of a segment gene encoding the capsid HEV. The protein was expressed and purified although in small quantities. This work is the first serologic report about the HEV in wild boars from Brazil. These results confirm the circulation of HEV in Brazilian herds of domestic pigs and demostrates that the virus is not circulating among wild boars. This study shows that the risk of zoonotic transmission exist. Also, contributes to the HEV epidemiology studies in Brazil and to the development of biotechnological tools in the HEV infection.