Project description:Hepatitis E virus (HEV) is a zoonotic virus for which pigs are the primary animal reservoir. To investigate whether HEV occurs in mink in Denmark, we screened feces and tissues from domestic and wild mink. Our finding of a novel HEV variant supports previous findings of HEV variants in a variety of species.
Project description:Hepatitis E virus (HEV) is an emerging infectious agent in developed countries. HEV genotypes 1 (G1) and 3 (G3) have been identified in environmental and clinical samples in Europe. In Israel, the overall prevalence of anti-HEV IgG antibodies was found to be 10.6%; however, reports of HEV infection are scarce. In this study, the presence of HEV in Israel was investigated using 169 sewage samples from 32 treatment facilities and 49 samples from acute hepatitis patients, all collected between 2013 and 2015. Fourteen sewage samples, from Haifa (11/18 samples), Tel Aviv (2/29 samples), and Beer Sheva (1/17 samples), regions with good sanitary conditions and middle-high socioeconomic populations, were HEV positive. Among the patient samples, 6.1% (3/49) were HEV positive, all returning travelers from India. Genotype analysis revealed G1 HEV in patients and G3 HEV sequences in sewage. Evidence that HEV could be establishing itself in our region may justify more active surveillance to monitor its spread.
Project description:Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis globally. HEV comprises four genotypes with different geographic distributions and host ranges. We utilize this natural case-control study for investigating the evolution of zoonotic viruses compared to single-host viruses, using 244 near-full-length HEV genomes. Genome-wide estimates of the ratio of nonsynonymous to synonymous evolutionary changes (dN/dS ratio) located a region of overlapping reading frames, which is subject to positive selection in genotypes 3 and 4. The open reading frames (ORFs) involved have functions related to host-pathogen interaction, so genotype-specific evolution of these regions may reflect their fitness. Bayesian inference of evolutionary rates shows that genotypes 3 and 4 have significantly higher rates than genotype 1 across all ORFs. Reconstruction of the phylogenies of zoonotic genotypes demonstrates significant intermingling of isolates between hosts. We speculate that the genotype-specific differences may result from cyclical adaptation to different hosts in genotypes 3 and 4.IMPORTANCE Hepatitis E virus (HEV) is increasingly recognized as a pathogen that affects both the developing and the developed world. While most often clinically mild, HEV can be severe or fatal in certain demographics, such as expectant mothers. Like many other viral pathogens, HEV has been classified into several distinct genotypes. We show that most of the HEV genome is evolutionarily constrained. One locus of positive selection is unusual in that it encodes two distinct protein products. We are the first to detect positive selection in this overlap region. Genotype 1, which infects humans only, appears to be evolving differently from genotypes 3 and 4, which infect multiple species, possibly because genotypes 3 and 4 are unable to achieve the same fitness due to repeated host jumps.
Project description:We characterized 42 hepatitis E virus (HEV) genotype 3 strains from infected patients in France in 3 parts of the genome and sequenced the full-length HEV genotype 3f genome found in Europe. These strains are closely related to swine strains in Europe, which suggests zoonotic transmission of HEV in France.