Torque teno sus virus in pigs: an emerging pathogen?

Area of Science:

• Veterinary Virology
• Molecular Biology
• Animal Health

Background:

• Anelloviridae family includes Torque teno viruses (TTVs) infecting various species.
• Torque teno sus viruses (TTSuV) are small, circular, single-stranded DNA viruses prevalent in domestic swine and wild boar.
• Two distinct TTSuV species infect swine, spreading efficiently via vertical and horizontal transmission, with increasing prevalence and viral load by age.

Purpose of the Study:

• To review the current understanding of Torque teno sus viruses (TTSuV) in swine.
• To highlight the increasing attention on TTSuV due to emerging disease associations.
• To discuss the potential impact of TTSuV on swine health and disease outcomes.

Main Methods:

• Literature review and synthesis of existing research on TTSuV.
• Analysis of prevalence, transmission routes, and immunological responses to TTSuV.
• Examination of evidence linking TTSuV to specific swine diseases.

Main Results:

• TTSuVs are highly prevalent in pigs, with infection and viral loads increasing with age.
• Efficient vertical and horizontal transmission of TTSuV occurs, including fetal infection.
• Limited immunological control of TTSuV viraemia is observed.
• Growing evidence suggests TTSuV influences the development or outcome of other swine diseases, particularly those caused by porcine circoviruses.

Conclusions:

• TTSuV, despite long-term circulation and prior non-pathogenic classification, is increasingly recognized for its role in swine disease.
• Further research is needed to elucidate the mechanisms by which TTSuV affects disease development and outcomes in pigs.
• Understanding TTSuV's impact is crucial for improving swine health management and disease control strategies.