Seroprevalence of Torque teno sus virus types 1 and 2 in postweaning multisystemic wasting syndrome-suspected pigs and porcine circovirus type 2-vaccinated normal pigs in southern Japan

We investigated the seroprevalence rate of Torque teno sus virus types 1 (TTSuV1) and 2 (TTSuV2) in the sera of 38 post weaning multisystemic wasting syndrome (PMWS)-suspected pigs and 43 porcine circovirus type 2 (PCV2)-vaccinated normal pigs on 3 commercial pig farms in southern Japan by using nested polymerase chain reaction. High seroprevalence rate of TTSuVs was observed in both PMWS-suspected pigs (100%) and PCV2-vaccinated normal pigs (90.7%). The seroprevalence rate of TTSuV2 was significantly higher in the PMWS-suspected pigs than in PCV2-vaccinated normal pigs (97.4% versus 81.4%, P<0.05), whereas no such difference was observed for TTSuV1 between the 2 groups of pigs. In both pig groups, the seroprevalence rate of TTSuV2 was significantly higher than that of TTSuV1 (P<0.01-0.05). These results show that TTSuVs are highly seroprevalent in both PMWS-suspected pigs and PCV2-vaccinated normal pigs with TTSuV2 being more seroprevalent in the former than in the latter.