A novel avian-like hepatitis E virus in wild aquatic bird, little egret (Egretta garzetta), in Hungary.

Hepatitis E virus (HEV), family Hepeviridae, has public health concerns because of its zoonotic potential; however, the host species spectrum, animal to animal transmissions, the natural chain of hepevirus infections and the genetic diversity of HEV in wildlife especially in birds are less known. Using random amplification and next generation sequencing technology a genetically divergent avian HEV was serendipitously identified in wild bird in Hungary. HEV RNA was detected with high faecal viral load (1.33×108genomiccopies/ml) measured by real-time PCR in faecal sample from a little egret (Egretta garzetta). The complete genome of HEV strain little egret/kocsag02/2014/HUN (KX589065) is 6660-nt long including a 18-nt 5' end and a 103-nt 3' end (excluding the poly(A)-tail). Sequence analyses indicated that the ORF1 (4554nt/1517aa), ORF2 (1728nt/593aa) and ORF3 (339nt/112aa) encoded proteins of little egret/kocsag02/2014/HUN shared the highest identity (62.8%, 71% and 61.5%) to the corresponding proteins of genotype 1 avian (chicken) HEV in species Orthohepevirus B, respectively. This study reports the identification and complete genome characterization of a novel orthohepevirus distantly related to avian (chicken) HEVs at the first time in wild bird. It is important to recognize all potential hosts, reservoirs and spreaders in nature and to reconstruct the phylogenetic history of hepeviruses. Birds could be an important reservoir of HEV generally and could be infected with genetically highly divergent strains of HEV.