Assessment of prevalence and load of torquetenovirus viraemia in a large cohort of healthy blood donors

Clin Microbiol Infect. 2020 Oct;26(10):1406-1410. doi: 10.1016/j.cmi.2020.01.011. Epub 2020 Jan 20.


Objectives: Torquetenovirus (TTV) is an emerging marker of functional immune competence with the potential to predict transplant-related adverse events. A large-scale epidemiological study was performed to understand how basal values vary in healthy individuals according to age and gender.

Methods: We tested plasma from 1017 healthy blood donors aged 18-69 years. The presence and load of TTV were determined by a real-time PCR assay. A sub-cohort of 384 donors was tested for anti-cytomegalovirus IgG antibodies, and 100 participants were also tested for TTV viraemia on a paired whole blood sample.

Results: The overall prevalence of TTV was 65% (657/1017) with a mean (±SD) growth of 5 ± 4% every 10 years of age increase, but stably higher in males (465/690, 67%) than in females (192/327, 59%). Mean (±SD) TTV load was 2.3 ± 0.7 Log copies/mL with no sex difference. TTV viraemia showed modest increases along 10-year age intervals (mean ± SD: 0.3 ± 0.1). TTV viraemia in donors sampled 2 years later remained stable (mean ± SD: 2.3 ± 0.8 versus 2.2 ± 0.7 Log copies between samples). Twenty-six per cent (9/34) of blood donors with TTV-negative plasma scored positive when whole blood was tested, and the donors with positive plasma showed a mean (±SD) 1.4 ± 0.5 Log increase in copy numbers when whole blood was tested.

Conclusions: This study establishes the mean value of TTV viraemia in plasma in healthy blood donors and suggests that ageing causes only minimal increases in TTV viraemia.

Keywords: Anelloviridae; Blood donors; Healthy controls; Prevalence; Torquetenovirus; Viraemia.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging
  • Blood Donors / statistics & numerical data*
  • Blood Transfusion
  • DNA Virus Infections / epidemiology*
  • DNA, Viral / blood*
  • Female
  • Healthy Volunteers / statistics & numerical data
  • Humans
  • Male
  • Middle Aged
  • Plasma / virology
  • Real-Time Polymerase Chain Reaction
  • Torque teno virus / isolation & purification*
  • Viral Load
  • Viremia / epidemiology*
  • Young Adult


  • DNA, Viral