Classical swine fever virus (C strain) distribution in organ samples of inoculated piglets

Enzyme linked immunosorbent assays (ELISAs) and a nested polymerase chain reaction after reverse transcription (RT-PCR) were used for the detection of the Chinese strain (C strain) of classical swine fever virus (CSFV) in blood and tissue samples of experimentally inoculated piglets. One group of 10 piglets was inoculated with C strain material from rabbits and a second one with material from infected minipig kidney (MPK) cell culture. Tested blood samples were taken on the day of inoculation as well as on days 2, 4, 6, 8, 10, 13 and 16. Samples of spleen, tonsil and brain tissue were collected from piglets on days 6, 8, 10, 13 and 16 and tested for glycoprotein E RNS and protein NS2-3 using commercially available ELISA kits. E RNS and NS2-3 were detected earlier in blood samples of piglets inoculated with the C strain propagated in a cell culture. Regardless of propagation the presence of the viral E RNS and NS2-3 was detected in spleen and tonsil samples simultaneously. The C strain propagated in a cell culture was found in only one brain sample, whereas, the virus propagated in rabbits was detected in 70% of the brain samples. For the detection of the CSFV RNA in blood samples, a part within the 5′ non-coding region was amplified. The differences in the results gained by antigen detection in blood samples decreased when nested RT-PCR was used.