Hepatitis E virus in swine and effluent samples from slaughterhouses in Brazil

Abstract

Hepatitis E is an infectious disease which virus (HEV) is highly disseminated in swine herd populations. Sporadic acute human hepatitis E cases have been associated to genotype 3 and 4 strains of HEV also reported in swine populations of endemic and non-endemic areas. With the aim to evaluate the incidence of animals with current infection of HEV, 115 bile samples were collected from three slaughterhouses under inspection by Animal Sanitary Protection Agency of Rio de Janeiro, Brazil. In parallel, effluent samples were collected from six sewage pipe exit sites of two slaughterhouses. HEV RNA was detected in 11 out of 115 (9.6%) bile samples collected and three waste samples from one slaughterhouse. Viral loads observed for bile samples varied from 10(1)-10(5) genome copies/mL and for effluent samples mean load was 10(2) genome copies/mL. Sequencing and phylogenetic analysis classified samples within genotype 3 subtype 3b closely related to the sample obtained from the first reported autochthonous human case and samples from swine of commercial herds in Brazil. Our data demonstrates that although most animals achieve slaughter age (around 20 weeks old) already immune to HEV, a significant number of animals are with current infection at commercial age. Further studies should be addressed to consider risk analysis and possible evaluation of inspection regulations considering food safety measures regarding hepatitis E zoonotic aspect in Brazil.

HEV infection in swine from Eastern Brazilian Amazon: Evidence of co-infection by different subtypes

“…We found that among pigs from this region 9.9% (15/151) were currently infected with HEV (HEV RNA positive); these findings confirm the circulation of HEV among pigs in Brazil, where pigs with HEV infection also has been reported in other three different regions of the country [14,15,27]. The prevalence of anti-HEV IgG found among pigs from Pará state was lower (8.6%; 13/151) than that previously reported among pigs from other Brazilian regions: in pigs from Mato Grosso state a high (81.2%) seroprevalence of anti-HEV IgG was found [28], whereas in the Rio de Janeiro state, at southeastern region, the seroprevalence was 24.3% [29].…”

“…HEV genotype 3 was also previously described in Brazil infecting pigs from other regions of the country [14,15,27] and involved in a human infection case [16].…”

Molecular Epidemiology of Hepatitis E Virus (Hev) in South America: Current Status

“…The data reported in this work clearly suggested a zoonotic origin for the infection. Furthermore, the newly detected swine HEV strains (Lopes dos Santos et al 2011) were classified within subtype 3b and also showed to be closely related to the sample obtained from the first reported autochthonous human case and the porcine HEV strains that were previously reported in Brazil.…”

Detection of hepatitis E virus genome in pig livers in Antioquia, Colombia

“…Chang et al (2009) found that at slaughter age, most pigs (> 70%) were immune (because of the presence of antibodies) to HEV, and did not have a history of clinical symptoms or abnormalities associated with viral infection. Studies in Brazil have demonstrated that this pattern is common in commercial pigs, as they contain high levels of anti-HEV antibodies at slaughter age; however, other studies showed that a significant percentage of animals exhibit viremia or have traces of HEV in their feces (dos Santos et al, 2011). The above the dynamic of viral excretion in pigs destined for human consumption should be further examined to determine whether these animals present a risk of active hepatic viruses at the moment of slaughter or if the presence of a viral genome exists only without infectious virions.…”

“…Villalba et al (2010) found a seroprevalence of 10% (469 patients) in positive samples for anti-HEV IgG in healthy humans with no history of viral hepatitis in Cuba, while human HEV antibodies have been detected in healthy individuals in Brazil as well as molecular evidence for HEV (dos Santos et al, 2011). Similar studies have been conducted in Uruguay, where the prevalence of anti-HEV in human donors was 1.2% (Cruells et al, 1997) and sporadic cases of infection with genotype 3 HEV were also reported (Mirazo et al, 2011).…”