Seroprevalence of hepatitis E virus in Lithuanian domestic pigs and wildlife

Abstract

Hepatitis E is an important public health concern disease that causes acute hepatitis in humans with different hepatitis E virus strains reported among domestic and wild animals. In Lithuania, seroprevalence studies on animals considered to be possible virus reservoirs, particularly in wildlife species, had never been investigated before. In order to assess the actual distribution of the virus in the domestic pig and wildlife species, serum samples originating from different geographic areas of Lithuania were tested for the presence of antibodies to the virus using enzyme-linked immunosorbent assay. The study results proved that hepatitis E virus infection is prevalent among domestic pigs, wild boar, moose, and roe deer in Lithuania, with the overall prevalence of IgG antibodies against hepatitis E virus being 43.75%, 57.05%, 11.76%, and 1.20%, respectively. Significantly higher (P < 0.01) seroprevalence values of 53.66% and 80% were observed in weaned pigs and adult wild boar. Herds with 15 001-30 000 pigs were 2.4 times more likely (P < 0.01) to test positive for hepatitis E virus antibodies (70.18%), than herds with ≤ 500 pigs (21.11%). The differences in seroprevalence rates between domestic pigs (from 25 to 66.67%) and wild boar (from 42.86 to 73.33% ) in all 10 counties were not significant (P > 0.05). Estimated low seroprevalence rate in moose, roe deer and absence of antibodies in red deer suggest that such wildlife species are accidental hosts of hepatitis E virus or at least hepatitis E virus is not present in Lithuanian cervides. HEV, sow, wild boar, cervidae, serum, zoonosisAccording to data reported by the World Health Organization (2015), in humans there are estimated 20 million cases of hepatitis E infections, over 3 million symptomatic cases of hepatitis E, and 56 600 hepatitis E-related deaths every year. Therefore, hepatitis E is considered an emerging zoonotic disease in many developing and industrialized countries. The aetiological agent of the disease is hepatitis E virus (HEV) that affects multiple hosts. The HEV is unique among known hepatitis (A, B, C, D) viruses because domestic pigs, wild boar, deer, and other animal species are considered to be possible reservoirs of HEV. Up to date, at least seven genotypes of HEV have been reported, and five of them have been described in humans (HEV-1 and HEV-2 anthroponotic, HEV-3 and HEV-4 zoonotic, HEV-7 zoonotic potential is still being questioned) (Roth et al. 2016). In contrast to humans, pigs and wild boar infected by HEV do not show obvious clinical manifestations.The consumption of raw or undercooked contaminated meat of domestic pig, wild boar or deer and also seafood receiving sewage sludge or direct contact with infected animals have been identified as modes of transmission linked to autochthonous sporadic cases of acute hepatitis E in humans (Pavio et al. 2010;Kaba et al. 2013). Moreover, increased distribution and availability of game meat poses a major risk for foodborne transmission of HEV worldwide. In addition,

Wild Boar: A Reservoir of Foodborne Zoonoses

“…High seroprevalences of hepatitis E (>30%) in wild boars were reported in Japan and several European countries (Charrier et al, 2018, Hara et al, 2014, Kukielka et al, 2016, Larska et al, 2015, Mazzei et al, 2015, Motoya et al, 2016, Schielke et al, 2015, Spancerniene et al, 2016, Thiry et al, 2017, Weiner et al, 2016, Žele et al, 2016 (Tables 1 and 1S). In North-Central Italy, the seroprevalence of hepatitis E varied significantly between provinces: the lowest prevalence in wild boars was 4% and the highest 49% (Martinelli et al, 2015).…”

Public health risks associated with hepatitis E virus (HEV) as a food‐borne pathogen

“…It appears that the Swedish moose HEV strains are not closely related to those currently found in humans, unlike those occurring in wild boar, and are likely to be species‐specific (Meng, ; Roth et al., ). In Lithuania, 11.8% of 34 serum samples from moose were found positive for anti‐HEV antibodies during a study of domestic pigs and wild game mammals conducted between 2014 and 2015 (Spancerniene et al., ).…”

Foodborne Zoonoses Common in Hunted Wild Boars

“…Antibodies to HEV were detected in 18% of wild boars in our study. A seroprevalence of over 50% has quite recently been reported in Germany, Italy, Lithuania and Spain (Mazzei et al 2015;Kukielka et al 2016;Spancerniene et al 2016;Anheyer-Behmenburg et al 2017). Foodborne HEV transmission has been associated with the liver, meat and sausages of wild boar (Fredriksson-Ahomaa 2019).…”