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Viruses
Published in Loretta A. Cormier, Pauline E. Jolly, The Primate Zoonoses, 2017
Loretta A. Cormier, Pauline E. Jolly
Few studies have been conducted to identify the presence of TTV-like viruses in wild primates. However, one study has found an Alphatorquevirus in wild chimpanzees (Calvignac-Spencer et al. 2012). Due to the ability of TTVSuV to be transmitted zoonotically from swine to humans, it is possible that the Alphatorquevirus in chimpanzees may represent a pathogen that could be passed to humans through bushmeat consumption or other environmental contamination. In addition, in a study of captive chimpanzees in a zoological park, both human TTV and TTMV DNA were identified, which suggests the potential for anthroponotic transfer to wild primates (Ninomiya et al. 2009). Alternatively, the viruses designated as human TTVs may not be unique to humans and may have broader diversity within wild primate populations.
Predictive tools to determine risk of infection in kidney transplant recipients
Published in Expert Review of Anti-infective Therapy, 2020
Mario Fernández-Ruiz, Francisco López-Medrano, José María Aguado
First isolated in 1997, torque teno virus (TTV) belongs to the genus Alphatorquevirus within the Anelloviridae family. Anelloviruses are small, non-enveloped, single-stranded DNA viruses which account for about 70% of human blood virome. TTV prevalence exceeds 70–80% in the general population of most developed and developing countries. Anelloviruses exhibit a high degree of genetic heterogeneity, similar to that observed among RNA viruses. Originally thought to cause hepatitis, TTV is currently considered an orphan virus [97]. Although TTV replication has been associated with various pro-inflammatory conditions, such as sepsis [98], cancer [99] or chronic pulmonary diseases [100], higher viremia levels are found in immunocompromised populations such as allogeneic hematopoietic stem-cell transplant recipients [101], HIV patients (with an inverse correlation with CD4+ T-cell counts) [102], or those with primary immunodeficiencies [103] or receiving biological therapies [104]. The plausibility and feasibility of monitoring TTV DNAemia to assess post-transplant immunocompetence are supported by the fact that viral replication is not influenced by the administration of valganciclovir prophylaxis and by the recent introduction of commercial real-time PCR assays targeting a highly conserved segment of the 5ʹ untranslated region of the viral genome [105].
Quantification of torque teno virus (TTV) DNA in saliva and plasma samples in patients at short time before and after kidney transplantation
Published in Journal of Oral Microbiology, 2022
Alexandre Mendes Batista, Matheus W. Caetano, Maria A. Stincarelli, Ana C. Mamana, Rodrigo Melim Zerbinati, Dmitry J. S. Sarmento, Marina Gallottini, Rafael A. V. Caixeta, José Medina-Pestana, Bengt Hasséus, Louise Zanella, Tania R. Tozetto-Mendoza, Simone Giannecchini, Paulo H. Braz-Silva
TTV is a naked, small virus with circular single-strand DNA genome, discovered in 1997 [5,6], comprising to date at least 29 genetically different species included in the genus Alphatorquevirus within the Anelloviridae family [7–9]. TTV possesses several characteristics, such as its presence as a main virus of the human virome, high viral load in immunosuppressed patients compared to healthy ones, considerable genetic diversity and lack of association with any human illness [8–11].