Torque Teno Virus Primary Infection Kinetics in Early Childhood

Abstract

Human torque teno viruses (TTVs) are a diverse group of small nonenveloped viruses with circular, single-stranded DNA genomes. These elusive anelloviruses are harbored in the blood stream of most humans and have thus been considered part of the normal flora. Whether the primary infection as a rule take(s) place before or after birth has been debated. The aim of our study was to determine the time of TTV primary infection and the viral load and strain variations during infancy and follow-up for up to 7 years. TTV DNAs were quantified in serial serum samples from 102 children by a pan-TTV quantitative PCR, and the amplicons from representative time points were cloned and sequenced to disclose the TTV strain diversity. We detected an unequivocal rise in TTV-DNA prevalence, from 39% at 4 months of age to 93% at 2 years; all children but one, 99%, became TTV-DNA positive before age 4 years. The TTV-DNA quantities ranged from 5 × 101 to 4 × 107 copies/mL, both within and between the children. In conclusion, TTV primary infections occur mainly after birth, and increase during the first two years with high intra- and interindividual variation in both DNA quantities and virus strains.

Immune monitoring in pediatric kidney transplant

“…In children, TTV is present in 39% of children by age 4 months and 93% by 2 years of age with levels varying significantly between children and in serial samples from individual children 102 . Similar to adults, TTV levels increase sharply post‐transplant, peaking at approximately 3 months before declining to a steady state 103 .…”

TTV and other anelloviruses: The astonishingly wide spread of a viral infection

“…The astonishingly widespread infection in the general community and around the world is a well-documented aspect of AV epidemiology. Nearly two-thirds of the general population are infected with TTV ( Spezia et al., 2022 ; Shulman and Davidson, 2017 ; Väisänen et al., 2022 ; Spandole et al., 2015 ). However, AV could be even more prevalent, reaching 100%, when subjects without viremia but harbouring the viruses in other body tissues are considered.…”

Herpesviruses, polyomaviruses, parvoviruses, papillomaviruses, and anelloviruses in vestibular schwannoma

“…CuV, BuV, and TuV were detected and quantified by a multiplex qPCR (Väisänen et al 2019) targeting the NS1 region of BuV and VP2 regions of TuV and CuV. For TTV detection, the conserved untranslated region (UTR) was targeted by a multiplex qPCR, which detects most TTV types (Toppinen et al 2020;Väisänen et al 2022). All real-time qPCR assays were performed with AriaMx Realtime PCR System (Agilent Technologies, Santa Clara, CA).…”