Characterization of ORF2 of swine strains of Hepatits E virus in Italy

Hepatitis E virus (HEV) is the causative agent of hepatitis E, and is an unenveloped positive sense single-stranded RNA virus. The genome of HEV is approximately 7.2 kb and contains three open reading frames. ORF1 encodes non structural proteins, and ORF2 and 3 code for the capsid protein and a small protein of unknown function, respectively. HEV is an emerging public health concern in many developing countries, where it can cause large epidemics mainly via contaminated water. Swine HEV strains are genetically close to human strains from the same area, suggesting the occurrence of zoonotic transmission. This route might play an important role in spreading infection also in Europe and other industrialized areas. Recently, hepatitis E cases have been linked to eating raw or undercooked meat from deer, wild boars or pigs. Detection of virus in stools or bile relies onto nested-RT-PCR protocols targeting the ORF2 region, and is particularly troublesome in swines due to the occurrence of asymptomatic infections. A pilot investigation was performed to identify the presence of HEV swine infection within farm in Northern Italy. Results of molecular diagnostic assays indicate the presence of genotype 3 HEV strains in Northern Italy. Viral genomic RNAs from positive samples were used to obtain a full length fragment of ORF2. Improved quantitative PCR technology and development of immunological reagents maybe useful for improving surveillance and control of hepatitis E infection.