Quantitative detection of porcine Torque teno virus in Porcine circovirus-2-negative and Porcine circovirus-associated disease-affected pigs.

Torque teno virus (TTV) is a recently identified virus that has a wide range of host tropisms from humans to shrews. Human TTV and Torque teno mini virus are distributed worldwide, and their high prevalence in human populations has been reported. Pigs have their own species-specific TTV, and like human TTV, a high prevalence of porcine TTV also has been reported. Despite its high prevalence, the role of TTV-related disease or syndrome in humans and pigs has not been determined. In the swine industry, TTV is thought to be one of the agents that aggravate clinical manifestation of Porcine circovirus-associated disease (PCVAD), a newly emerging, economically devastating disease. The purpose of the current study was to quantify TTV viral load in serum obtained from Porcine circovirus-2-negative pigs and PCVAD-affected pigs with real-time quantitative polymerase chain reaction assays and to compare TTV viral load between these groups. Results of this study indicate that there are no statically remarkable differences in TTV viral load between the 2 groups, which indicates that TTV might not be an agent of aggravation in PCVAD.