title: A Public Health initiative on hepatitis E virus epidemiology, safety and control in Portugal--study protocol.
abstract: BACKGROUND
  The discovery of autochthonous hepatitis E in industrialized countries has changed the understanding of hepatitis E virus (HEV) infection in these regions, now known to be mainly due to zoonotic transmission of genotype 3. The foodborne route of transmission via consumption of contaminated meat from HEV infected pigs is well documented as well as the direct occupational exposure to animal reservoirs. Accumulating evidence also points to an emerging potential threat to blood safety after the identification of viremic blood donors and the documentation of HEV-contaminated blood or blood products. Moreover, the origin of several iatrogenic cases remains unclear and porcine-derived pharmaceutic products have been suspected as a cause. Severe morbidity following HEV infection in patients receiving immunosuppressive therapy and in those with severe immunodeficiency from other causes has been recently recognized as a serious consequence of this infection in industrialized countries. In Portugal no large-scale HEV seroprevalence study has been undertaken, no professional risk groups have been identified, and the risk of blood donation from HEV silent infected donors is unknown. The present paper describes seroepidemiological and molecular approaches to answer these questions.
  
  
  METHODS
  To address these issues a study protocol was designed that will approach: i) the seroprevalence of HEV among the Portuguese general population; ii) HEV infection among butchers and slaughterhouse workers (occupational risk); iii) the silent HEV infection in Portuguese blood donors (HEV transfusion-associated risk); iv) the potential HEV contamination of porcine-derived pharmaceutical products. Commercial enzyme immunoassays and real-time/conventional RT-PCR assays will be used.
  
  
  CONCLUSIONS
  This study is the first evaluation of the seroepidemiological status to HEV infection of the Portuguese population, the first to potentially identify professional risk groups, and to evaluate the safety of blood and blood products and porcine-derived pharmaceutics in Portugal. It will generate valuable data applicable for preventive and control measures against HEV infection (e.g., introduction of systematic screening of blood donors, control of blood products or porcine derived pharmaceutical products), thus helping to manage the burden of this viral disease.
authors.affiliation: Escola Superior Agrária de Viseu, Instituto Politécnico de Viseu, Viseu, Portugal. jmesquita@esav.ipv.pt.
authors.forename: João R
authors.initials: JR
authors.lastname: Mesquita
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway. mette.myrmel@nmbu.no.
authors.forename: Mette
authors.initials: M
authors.lastname: Myrmel
authors.affiliation: Department of Virology, Norwegian Institute of Public Health, Oslo, Norway. Kathrine.Stene-Johansen@fhi.no.
authors.forename: Kathrine
authors.initials: K
authors.lastname: Stene-Johansen
authors.affiliation: Department of Virology, Norwegian Institute of Public Health, Oslo, Norway. Joakim.Overbo@fhi.no.
authors.forename: Joakim
authors.initials: J
authors.lastname: Øverbø
authors.affiliation: Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia da Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 228, 4050-313, Porto, Portugal. saojose@ff.up.pt.
authors.forename: Maria S J
authors.initials: MS
authors.lastname: Nascimento
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001782:Blood Donors; D058731:Blood Safety; D002985:Clinical Protocols; D005838:Genotype; D016751:Hepatitis E / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D016752:Hepatitis E virus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D009784:Occupational Diseases / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D011174:Portugal / Q000453:epidemiology; D011634:Public Health; D060888:Real-Time Polymerase Chain Reaction; D016036:Seroepidemiologic Studies; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000821:virology; D065227:Transfusion Reaction; D014766:Viremia / Q000209:etiology
chemical_list: D000914:Antibodies, Viral