Torque teno sus virus (TTV) detection in aborted and slaughterhouse collected foetuses

The aim of this study was to estimate the presence of Torque teno sus virus (TTV) species in pig foetuses in order to assess the possible relationship between swine TTV infection and abortion in swine. A total of 98 abortion cases and foetuses collected from 55 pregnant sows at slaughterhouse were analysed by PCR for the presence of Torque teno sus virus 1 (TTV1) and Torque teno sus virus 2 (TTV2). All foetuses were necropsied and relevant tissues were collected, pooled, and submitted to DNA extraction. The overall prevalence of swine TTV1 and TTV2 in aborted foetuses (n = 98) was 17.0% and 29.6%, respectively. For slaughterhouse collected foetuses (n = 55), 10.9% were TTV1 PCR positive and 40.0% were positive for TTV2. There were no statistically significant differences when comparing prevalence of swine TTVs by type of sample (aborted versus slaughterhouse collected foetuses) or by gestation stage. The present work represents the first description of swine TTV infection in pig foetuses at different stages of gestation. Results obtained confirm that vertical transmission is an important route of TTVs dissemination. In addition, data obtained suggest that swine TTVs should not be considered as infectious agents responsible for abortion occurrence.