Distribution and Molecular Characterization of Hepatitis E virus in Domestic Animals and Wildlife in Croatia

Abstract

Hepatitis E is becoming a growing health concern in European countries as an increase of sporadic human cases of unknown origin has been recorded lately. Its causative agent, Hepatitis E virus (HEV), is known to have zoonotic potential and thus the role of domestic and wild animals in the chain of viral spread should be considered when investigating risk factors and the epidemiology of the disease. A comprehensive survey based on viral RNA detection was carried out in Croatia including blood, spleen and liver samples originating from 1816 different domestic and wild animals and digestive gland samples from 538 molluscs. A high HEV prevalence was detected in domestic pigs (24.5%) and wild boars (12.3%), whereas cattle, molluscs, ruminant and carnivore wildlife samples tested negative. Molecular characterization of both ORF1 and ORF2 genomic regions confirmed the phylogenetic clustering of the obtained sequences into genotype 3, previously reported in Europe. Furthermore, our results proved the presence of identical sequence variants in different samples, regardless of their origin, age or habitat of the host, suggesting transmission events between domestic swine, as well as between domestic swine and wild boars in the country. Moreover, a close genetic relationship of Croatian animal strains and known human HEV strains from GenBank opens the question of possible cross-species HEV transmission in Croatia, especially in the areas with an intensive swine production.

Differences in hepatitis E virus (HEV) presence in naturally infected seropositive domestic pigs and wild boars - an indication of wild boars having an important role in HEV epidemiology

“…Both results correspond to results previously reported in European countries (BURRI et al, 2014;ANITA et al, 2014;MONTAGNARO et al, 2015;THIRY et al, 2015;MAZZEI et al, 2015). The majority of samples tested within our study were collected from the northern regions of Croatia, where heV rNa prevalence in pigs and wild boars L. Jemeršić et al: Hepatitis E virus persistence in pigs and wild boars in Croatia was previously detected (PRPIĆ et al, 2015). Our study reveals a statistically significant (P<0.0001) higher seroprevalence detected in domestic pigs and wild boars from OsijekBaranja and Vukovar-Srijem Counties than from all other counties included in the study.…”

“…all isolates belonged to genotype heV-3 (PRPIĆ et al, 2015). In our present study we supplemented the epidemiological data with the first results of HEV seroprevalence in domestic pigs and wild boars from 14 and 16 counties in Croatia (table 1), respectively.…”

“…to gain a better understanding of the farm-to-table risk in Croatia, a survey of heV RNA presence in domestic pigs and wild boars was carried out from 2009 and revealed a prevalence of 24.50% and 12.30%, respectively (JEMERŠIĆ et al, 2010;PRPIĆ et al, 2015). all isolates belonged to genotype heV-3 (PRPIĆ et al, 2015).…”

Seroprevalence of hepatitis E virus in Lithuanian domestic pigs and wildlife

“…The highest seroprevalence of 70.6% and the lowest seroprevalence of 12.1% were noted in Italy, in sows and weaners, respectively (Mazzei et al 2015b). In contrast, a study in Croatia reported the highest prevalence of HEV in the age class of 1-4 week suckling piglets (Prpic et al 2015). Our study results support the notion by Pavio et al (2010) that wide variations in within-herd seroprevalence would appear to be the norm in HEV-infected herds.…”

“…A Polish study determined 44.4% of HEV antibodies in the serum of wild boar from 11 different Polish provinces (Larska et al 2015), while a Spanish study found an overall seroprevalence of 42.7% in wild boar population from South Central Spain, whereas IgG seroprevalence ranged from 0% to 63.3% depending on geographical region. On the other hand, overall seroprevalence in wild boar population in Switzerland and Croatia was reported to be 12.5% (Burri et al 2014) and 12.3% (Prpic et al 2015) of all tested samples, respectively.…”