Anelloviruses

Torque teno sus viruses (TTSuVs) are the Torque teno virus (TTV) species infecting swine. The classification of TTSuVs is based on several tentative pairwise identity thresholds: variants, subtypes, types, species and genus. TTVs have been found in humans, nonhuman primates, livestock species, companion animals, wild boars, badgers, pine martens, tupaias, rodents, bats, sea turtles, and sea lions. TTSuVs can be detected in tissues, blood, semen, colostrum, nasal, and fecal samples. In fetuses, the highest concentration of TTSuV is found in the lung, heart, spleen, and kidney, suggesting that these tissues contain a significant number of cells supporting viral replication. Diagnosis of TTSuV infection is based on the detection of viral DNA and/or antibodies against the virus. The high percentage of viremic, but antibody-positive, pigs reflects an inefficient anti-TTSuV immune response. The immunopathogenesis of swine anelloviruses is unknown.