Detection of anti-HEV antibodies and RNA of HEV in pigs from a hyperendemic Italian region with high human seroprevalence

Abstract

Background Pigs are considered the main reservoir of genotypes 3 and 4 of hepatitis E virus (HEV), which is the major cause of acute hepatitis of viral origin in humans worldwide. An increasing number of autochthonous HEV infections have been observed in recent years in industrialized countries, most likely as a result of zoonotic transmission through the consumption of raw or undercooked meat products. Methods Two hundred and thirty-three blood and liver samples were collected at four different local slaughterhouses from domestic pigs bred in Abruzzo, a region of south-central Italy, where there is the highest human seroprevalence to HEV compared with the rest of Italy. An indirect enzyme-linked immunosorbent assay kit was used for detecting anti-HEV IgG in the sera, while the presence of HEV RNA was investigated by performing a real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Results Between 87.3% and 100% of swine serum samples collected in different slaughterhouses of Abruzzo were positive for anti-HEV antibodies. Conversely, none of the liver samples collected from the same animals were positive for HEV by real-time RT-PCR. Conclusions The hypothesis of foodborne zoonotic transmission from local pigs as responsible for the hyperendemic status of Abruzzo cannot be corroborated. However, the high seroprevalence observed in pigs indicates that HEV is highly circulating in these territories. We propose to further investigate the role of wild fauna and trade in carrier pigs, and the maintenance of HEV virulence in the environment and meat supply chain to shed light on the possible sources of human infection and the degree of occupational risk.

Cross-sectional study of hepatitis E virus (HEV) circulation in Italian pig farms

“…In the Abruzzo region, where 26 analyzed farms were located, small sized herds are present mainly for the Italian or local market. Abruzzo is an HEV genotype 3 hyperendemic area for humans (29) but this does not correspond either to a higher percentage of positive HEV herds (in this study) or to higher percentage of positive animals at slaughterhouse, as observed in a recent study conducted by HEV detection in liver on pigs at slaughter (40). The link between high seroprevalence in humans in Abruzzo and the consumption of raw pork liver (e.g., sausages) has been confirmed by epidemiological data (29).…”

Survey of Zoonotic Diarrheagenic Protist and Hepatitis E Virus in Wild Boar (Sus scrofa) of Portugal

“…Among them, the hepatitis E virus (HEV) is regarded as an emerging public health concern [60]. Hepatitis E virus belongs to the Hepeviridae family, genus Paslahepevirus [61][62][63], and causes hepatitis in humans by consumption of undercooked meat and meat products in industrialized countries [64].…”

Hepatitis E virus in pigs and the environment: An updated review of public health concerns

“…A recent study, anti-HEV IgG seroprevalence reached 66% in slaughterhouse staff, 51% in pig-farmers, and 38% in pork meat vendors [ 46 ] and those who had exposure to pigs or pork meat had high chances of HEV infection when compared with unexposed individuals [ 46 ]. A study from Abruzzo, Italy, a reportedly hyperendemic region having the highest HEV seroprevalence in humans, out of 233 blood samples collected from different local pig slaughterhouses between 87.3% and 100% of serum samples were found positive for anti-HEV antibodies (IgG), such high seroprevalence in pigs suggests the intense circulation of HEV in the region [ 82 ]. Previously published studies showed that pigs successively receive HEV infection on farms, where a higher prevalence was found among older pigs [ 26 , 83 , 84 ].…”