Development of body temperature and viremia following experimental infection of pigs with JEV. 12 piglets were infected with 107 TCID50 JEV Nakayama strain. Pigs were killed in groups of three on days 3, 5, 7, and 11 pi. From three pigs daily serum samples were obtained, and from nine pigs blood samples were collected at necropsy (days 3, 5, 7 and 11 pi). A Daily body temperature of all animals. Each colour represents an individual animal. B Viral RNA loads in the serum. Relative JEV RNA quantities were determined using real-time RT-PCR. Quantification employed a standard curve created using a viral preparation with a known infectious titre. One U was defined as the viral RNA quantity corresponding to 1 TCID50 of the virus preparation used as standard. C Viral titres in the serum of individual bled daily. The detection limit of the assay was 5 TCID50/mL (dotted line). D Viral RNA loads in the oro-nasal swabs collected daily from three different animals. The red symbols represent samples from which live virus isolation succeeded.