Distribution dynamics of PRV in the GI tract of challenged fish. Viral loads (Ct values) in four segments of the gastrointestinal tract from 0.25 to 10 dpc by i.p. (red), oral (orange), anal (green) administration routes. Markers indicate individual fish, horizontal bars group means and vertical bars the range. Graph for control group and parts of graph for oral group has been slightly parallel offset from x = 45 for improved intelligibility.