Genotyping of Paslahepevirus balayani Hepatitis E virus spread in wild boars in the Emilia Romagna region, Italy

Paslahepevirus balayani , previously named Orthohepevirus A or Hepatitis E v irus , belongs to the Orthohepevirus genu s in the family Hepeviridae . It infects several mammal animals and humans, in which causes hepatitis E. Eight distinct genotypes (Gs) have been identified so far. G1 and G2 have been detected only in humans, are main ly spread in developing countries and ca uses mainly water borne diseases. G3 and G4 are found mainly in domestic pigs and wild boars in many countries, are zoonotic and cause sporadic or claster cases of hepatitis in humans. Pregnant women and immunocompr omised humans can develop severe disease s or die. G5 G8 have been found in wild boars and camels and unlikely infect humans [ 1 ]. In Europe, the number of autochthonous cases in humans is increasing due to infections by G3 [2], which is most frequently dete cted in Italy in raw and dry pork liver sausages [3]. The aim of this study was to investigate and genotype P. blayani in wild boars in Emilia Romagna region, Italy. Forty four liver samples were collected from wild boars shot during the hunting seasons 20 22 2023 in five different municipalities in Emilia Romagna region, in Northern Italy. RNA was extracted from liver tissues by Trizol. A nested PCR protocol was used to amplify a specific part of the ORF2 [4]. PCR products of the expected size (348 bp) were sequenced by Sanger. The sequences were edited, analysed by nBLAST and used for phylogenetic analysis. Two samples (4.5%) gave a PCR product of the expected size. The analysis of the sequences obtained from the two samples identified genotype 3e and 3f, respectively. The nucleotide sequence of the 3f str ain showed the highest identity with sequences found recently in humans in Italy (98.68%) and in other countries (99.34%) The results show a low prevalence of P. balayani infection in the liver of wild boars hunted in the areas of study in comparison with other areas of Italy. The two positive samples were collected in the same municipality, while none positive samples were detected in the other areas investigated. The high genetic identity of the strains detected in the wild boars with strains previously identified in humans in Italy suggests their zoonotic potential. Particular attention should be taken during manipulation of organs from infected wild boars. Further studies are required for monitoring the spread of zoonotic strains in wild animals in the s e areas.