Z-008. Study of Torque Teno Virus Natural Dissemination in a Swine Herd

M-J. Gagné, D. Leblanc, A. Houde, J. Brassard;
Agriculture and Agri-Food Canada, Saint-Hyacinthe, QC, CANADA.

The presence of Torque Teno virus (TTV) has been reported in different regions around the world. TTV pathogenicity and transmission in animals and humans are poorly understood. Although the fecal-oral route is suspected to be the primary transmission mode, no supporting data are yet available. In the province of Quebec (Canada), TTV was detected in 60 % of the feces and 80-90 % of the plasma samples within a selected pig population. Human and swine TTV (swTTV) shared the same genomic organization and swTTV could be used as a model to increase our knowledge concerning this virus. This work presents data on the detection of TTV in blood and feces samples using PCR into a selected pig population (n = 40) housed on a simulated commercial farm setting at four times (2, 8, 18 weeks and between 22-29 weeks of age) from nursery to slaughter. Results showed that swTTV was detected in 3 animals (7.5 %) in the first sampling and was then disseminated very quickly within the herd. TTV DNA was detected in 97.5 % and 87.5 % of the plasma and feces samples at the third sampling period, respectively. Nucleotide sequence analysis revealed a high genetic diversity of swTTV strains within the population. At slaughter, TTV DNA was still detected in plasma (97.5 %) and feces (65 %) samples. The high proportion of positive plasma samples compared to feces at slaughter suggests the persistence of TTV in animals after the shedding period is over and these latter may become chronic carriers of this virus in their blood after the excretion period as demonstrated in human. These results also support the natural dissemination of swTTV through the fecal-oral route. It is unknown if swTTV could be transmitted to humans as a foodborne pathogen, however, it is clear that swTTV can be found at the slaughterhouse, in the agro-environment and that further studies would be useful.