Estimation of hepatitis E virus transmission among pigs due to contact-exposure Martijn Bouwknegt, Klaas Frankena, Saskia A. Rutjes, Gerard J. Wellenberg, Ana Maria de Roda Husman, Wim H.M. van der Poel and Mart C.M. de Jong Vet. Res., 39 5 (2008) 40 Published online: 27 March 2008 DOI: 10.1051/vetres:2008017