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Torque Teno Virus (TTV) is a ubiquitous component of the human virome, not associated with any disease. As its load increases when the immune system is compromised, such as in kidney transplant (KT) recipients, TTV load monitoring has been proposed as a method to assess immunosuppression. In this prospective study, TTV load was measured in plasma and urine samples from 42 KT recipients, immediately before KT and in the first 150 days after it. Data obtained suggest that TTV could be a relevant marker for evaluating immune status and could be used as a guide to predict the onset of infectious complications in the follow-up of KT recipients. Since we observed no differences considering distance from transplantation, while we found a changing trend in days before viral infections, we suggest to consider changes over time in the same subjects, irrespective of time distance from transplantation.

Optimization of individual immunosuppression, which reduces the risks of both graft loss and patients' death, is considered the best approach to improve long-term outcomes of renal transplantation. Torque Teno Virus (TTV) DNAemia has emerged as a potential biomarker reflecting the depth of therapeutic immunosuppression during the initial year post-transplantation. However, its efficacy in long-term monitoring remains uncertain. In a cohort study involving 34 stable kidney transplant recipients and 124 healthy volunteers, we established lower and upper TTV DNAemia thresholds (3.75-5.1 log10 cp/mL) correlating with T-cell activatability, antibody response against flu vaccine, and risk for subsequent serious infections or cancer over 50 months. Validation in an independent cohort of 92 recipients confirmed that maintaining TTV DNAemia within this range in >50% of follow-up time points was associated with reduced risks of complications due to inadequate immunosuppression, including de novo DSA, biopsy-proven antibody-mediated rejection, graft loss, infections, or cancer. Multivariate analysis highlighted "in-target" TTV DNAemia as the sole independent variable significantly linked to decreased risk for long-term complications due to inadequate immunosuppression (odds ratio [OR]: 0.27 [0.09-0.77]; p = 0.019). Our data suggest that the longitudinal monitoring of TTV DNAemia in kidney transplant recipients could help preventing the long-term complications due to inadequate immunosuppression., (© 2024 Wiley Periodicals LLC.)

Ranaviruses are pathogens of ectothermic vertebrates (fish, amphibians, and reptiles). Turtles are the most common group of reptiles reported with ranaviral infections. However, there have been no surveys for wild ranaviral infection in any turtles from the suborder Pleurodira, despite ranaviral distributions and experimentally susceptible pleurodiran turtle populations overlapping in several areas, including Australia. We assayed 397 pooled blood samples from six Australian freshwater turtle species collected from five different sites in northern Australia between 2014 and 2019. Historical serologic surveys in the area had found antiranaviral antibodies; however, we did not detect any ranaviral DNA in our samples. Discrepancies between historical serologic and our molecular results may be explained by low viral prevalence during the years that these samples were collected, survivorship bias, or possibly an age class bias in sampling., (© Wildlife Disease Association 2024.)

Novel biomarkers reflecting the degree of immunosuppression in transplant patients are required to ensure eventual personalized equilibrium between rejection and infection risks. With the above aim, Torque Teno Virus (TTV) viremia was precisely examined in a large cohort of transplanted immunocompromised patients (192 hematological and 60 solid organ transplant recipients) being monitored for Cytomegalovirus reactivation. TTV load was measured in 2612 plasma samples from 448 patients. The results revealed a significant increase in TTV viral load approximately 14 days following CMV reactivation/infection in solid organ transplant (SOT) patients. No recognizable difference in TTV load was noted among hematological patients during the entire timeframe analyzed. Furthermore, a temporal gap of approximately 30 days was noted between the viral load peaks reached by the two viruses, with Cytomegalovirus (CMV) preceding TTV. It was not possible to establish a correlation between CMV reactivation/infection and TTV viremia in hematological patients. On the other hand, the SOT patient cohort allowed us to analyze viral kinetics and draw intriguing conclusions. Taken together, the data suggest, to our knowledge for the first time, that CMV infection itself could potentially cause an increase in TTV load in the peripheral blood of patients undergoing immunosuppressive therapy., (© 2024 The Author(s). Journal of Medical Virology published by Wiley Periodicals LLC.)

Background: Long-term allograft and patient survival after kidney transplantation (KTX) depends on the balance between over- and under-immunosuppression (IS). High levels of IS predispose to opportunistic infections. Plasma load of Torque Teno Virus (TTV), a non-pathogenic highly prevalent Annellovirus, is associated with its hosts immune status, especially after solid organ transplantation., Objectives: To investigate the association of plasma TTV load and opportunistic viral infections after pediatric KTX., Study Design: This retrospective study includes all pediatric KTX patients followed at the Medical University of Vienna 2014-2020. PCR for Cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), and TTV was performed every 4-8 weeks at routine follow-up visits., Results: 71 pediatric KTX patients were followed with TTV measurements for a median of 2.7 years. TTV plasma load was associated with CMV DNAemia at the next visit with an OR of 2.37 (95 % CI 1.15-4.87; p = 0.03) after adjustment for time after KTX and recipient age. For a cut-off of 7.68 log10 c/mL TTV a sensitivity of 100 %, a specificity of 61 %, a NPV 100 %, and a PPV of 46 % to detect CMV DNAemia at the next visit was calculated. TTV plasma loads were also associated with BKV DNAuria and BKV DNAemia at the next visit, but not with EBV DNAemia., Conclusions: This is the first study to analyse associations between TTV plasma loads and opportunistic viral infections in pediatric KTX. We were able to present a TTV cut-off for the prediction of clinically relevant CMV DNAemia that might be useful in clinical care., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Gregor Bond is coordinator of the TTVguideTX project (European Union's Horizon 2020 research and innovation programme, grant agreement number 896,932); bioMérieux is project partner and provider of TTV R-Gene(R). All the other authors have no disclosures in relation to products in the study., (Copyright © 2024. Published by Elsevier B.V.)

Background: Torquetenovirus (TTV) viremia is emerging as a promising tool to assess functional immune competence, to predict posttransplant immune-related complications, and eventually to customize immunosuppression., Methods: In this study, 327 blood samples were tested using two real-time PCR (rtPCR) assays both targeted to the untranslated region of the TTV genome. The first assay was an in-house rtPCR developed by our group, the second one was the recently marketed TTV R-GENE assay., Results: In the validation study, the TTV R-GENE showed good performances in precision and reproducibility, and sensitivity as low as 12 TTV DNA copies/mL, like previously reported for the in-house rtPCR. The Bland-Altman analysis showed that the mean difference between the two methods was -0.3 log copies/mL. In the comparison study, 69% and 72% of samples were detected positive by rtPCR and TTV R-GENE, respectively (94% concordance, κ = 0.88). Performances did not differ between the two rtPCRs by type of TTV group examined. When a newly-developed in-house digital droplet PCR was applied for TTV quantification and used as an alternative method of comparison on 94 samples, the results strongly correlated with those obtained by the two rtPCR methods (99% concordance)., Conclusion: In summary, all the molecular methods assayed are highly sensitive and accurate in quantitation of TTV DNA in blood samples., (© 2019 Wiley Periodicals, Inc.)

Exosomes are associated with cancer progression, pregnancy, cardiovascular diseases, central nervous system-related diseases, immune responses and viral pathogenicity. However, study on the role of exosomes in the immune response of teleost fish, especially antiviral immunity, is limited. Herein, serum-derived exosomes from mandarin fish were used to investigate the antiviral effect on the exosomes of teleost fish. Exosomes isolated from mandarin fish serum by ultra-centrifugation were internalized by mandarin fish fry cells and were able to inhibit Infectious spleen and kidney necrosis virus (ISKNV) infection. To further investigate the underlying mechanisms of exosomes in inhibiting ISKNV infection, the protein composition of serum-derived exosomes was analyzed by mass spectrometry. It was found that myxovirus resistance 1 (Mx1) was incorporated by exosomes. Furthermore, the mandarin fish Mx1 protein was proven to be transferred into the recipient cells though exosomes. Our results showed that the serum-derived exosomes from mandarin fish could inhibit ISKNV replication, which suggested an underlying mechanism of the exosome antivirus in that it incorporates Mx1 protein and delivery into recipient cells. This study provided evidence for the important antiviral role of exosomes in the immune system of teleost fish.

Monitoring of alphatorquevirus (torque teno virus [TTV]) DNA in plasma may prove to be useful to assess the net state of immune competence following allogeneic hematopoietic stem cell transplantation (allo-HSCT). There are scarce data published on the prevalence of beta (torque teno mini virus [TTMV]) and gammatorqueviruses (torque teno midi virus [TTMDV]) and, in particular, on the dynamics of anelloviruses in allo-HSCT patients. Twenty-five allo-HSCT recipients with available plasma specimens obtained before conditioning and after engraftment were included. Degenerated primers targeting a highly conserved genomic sequence across all anelloviruses were designed for genomic amplification and high-throughput sequencing. Co-detection of TTV, TTMV, and TTMDV both in pre-transplant and post-engraftment plasma specimens was documented in more than two-thirds of patients. The use of quantitative real-time polymerase chain reaction (PCR) assays targeting TTMV and TTMDV in addition to TTV may add value to TTV-specific PCR assays in the inference of the net state of immunosuppresion or immune competence in this clinical setting., (© 2020 Wiley Periodicals LLC.)

Torque teno virus (TTV) is a commensal human virus observed as a circular single-negative-strand DNA molecule in various tissues and biological samples, notably in blood serum and lymphocytes. TTV has no apparent clinical significance, although it might be very useful as a prospective tool for gene delivery or as an epidemiological marker. Human populations are ubiquitously infected with TTV; the prevalence may reach 100%. The majority of babies become spontaneously infected with TTV, so that by the end of the first year of life, the prevalence reaches 'adult' values. TTV positivity in healthy early infancy and the presence of TTV in umbilical cord blood samples have been reported. The mechanism of infection and the dynamics of TTV prevalence in infants with age remain understudied. Meanwhile, the potential diagnostic and prognostic value of TTV as a marker deserves special attention and study, along with the possibility, causes and consequences of placental transmission of TTV under normal or pathological conditions.

Torque teno virus (TTV) has been proposed as a surrogate biomarker of T-cell function in allogeneic-haematopoietic-stem-cell transplantation (allo-HSCT). Conflicting data exists regarding the value of TTV to assess the degree of immunosuppression. The aim of the present study was to investigate the correlation between TTV viral load and immune function. Using samples from a prospective cohort composed of healthy-volunteers (HV) and allo-HSCT recipients at 6 months post-transplantation, we assessed the correlation between TTV viraemia and immune cell counts or T-cell proliferation capacity post-phytohaemagglutinin stimulation. TTV viraemia was detected in 68% of HV ( n = 80) and 100% of allo-HSCT recipients ( n = 41; p < 0.001); it was significantly higher in allo-HSCT recipients (3.9 vs. 2.1 Log copies/mL, p < 0.001). There was no correlation between T-cell function and CD3 + T-cell count (rho: 0.002) suggesting that T-cell count can normalise without full functional recovery. Furthermore, no significant correlation was observed between TTV viraemia and absolute total/subset lymphocyte counts (rho: <0.13). The highest correlation was observed between TTV viral load and T-cell proliferation capacity (rho: -0.39). We therefore report an inverse correlation between T-cell function and TTV viraemia that is independent of T-cell count. Monitoring of TTV viraemia could be a fast suitable option to objectively assess the competence of immune function in at-risk populations.

Introduction: Torque teno virus (TTV) is a non-pathogenic anellovirus commonly found in the blood of human beings. Emerging data suggest that TTV viral load is proportional to the degree of immunosuppression, but its seroprevalence is unknown in Australia. We aimed to determine the seroprevalence of TTV in an Australian population of renal patients., Methods: We developed a real-time PCR to measure TTV viral load, using the TaqMan platform and previously published primers and probes. Following ethics approval and informed consent, we collected blood from hemodialysis patients not receiving immunosuppression, and renal transplant patients. All patients were recruited from a single teaching hospital in New South Wales., Results: We enrolled 50 hemodialysis and 30 renal transplant patients. 56 (70%) were males, and the mean (sd) age was 61 (16) years. TTV was detectable in plasma of 40/50 (80%) of hemodialysis patients and 28/30 (93%) of transplant patients. The mean TTV viral load was higher in transplant patients than in dialysis patients (6.3 log versus 5.0 log copies/ml, P = .001)., Conclusions: Torque teno virus is prevalent in Australian renal patients and thus may be a useful novel marker to help tailor immunosuppressive therapy in renal transplant patients. Further work is needed to establish TTV seroprevalence in other regions and patient groups, and to investigate whether there is correlation with clinically important events (infection and rejection episodes) in longitudinal studies., (© 2020 Wiley Periodicals LLC.)

Impaired immune reconstitution after allogeneic hematopoietic stem cell transplantation (HSCT) contributes to increased risk of cancer relapse and infection resulting in significant morbidity and mortality. Unfortunately, effective strategies to functionally assess the quality of immune reconstitution are still missing. Quantification of in vivo replication of the ubiquitous, non-pathogenic virus Torque Teno Virus (TTV) has been reported in small series as a test to functionally evaluate the quality of post-transplant immune reconstitution. In the present study, we analyzed by quantitative PCR TTV titers in plasma samples from a large cohort of 168 allogeneic HSCT recipients. Our analysis confirms that TTV titers peaked at 100 days post-transplant, followed by progressive normalization thereafter. Negative correlation of TTV titers with T cell absolute numbers during the first year post-transplant points to the restoration of an active anti-TTV immunity. Univariable and multivariable linear regression analysis demonstrated that donor CMV positive serostatus, donor type and immune suppression resulting from GVHD treatment affected the restoration of anti-TTV immunity. Importantly, higher TTV titers at 100 days after transplantation were associated with worse overall survival and higher risk of acute GVHD and infections. Our results provide new insights into the factors affecting the dynamics of TTV replication and indicate that TTV is a potentially useful biomarker to assess immune reconstitution and to predict complications and outcomes of allogeneic HSCT., (Copyright © 2020 Pradier, Masouridi-Levrat, Bosshard, Dantin, Vu, Zanella, Boely, Tapparel, Kaiser, Chalandon, Simonetta and Roosnek.)

The review presents the data accumulated for more than 20 years of research of torque teno virus (TTV). Its molecular genetic structure, immunobiology, epidemiology, diagnostic methods, possible replication sites, and pathogenicity factors are described. TTV is a virus that is frequently detectable in patients with different viral hepatitides, in cases of hepatitis without an obvious viral agent, as well as in a healthy population. There is evidence suggesting that biochemical and histological changes occur in liver tissue and bile duct epithelium in TTV monoinfection. There are sufficient histological signs of liver damage, which confirm that the virus can undergo a replicative cycle in hepatocytes. Along with this, cytological hybridization in TTV-infected cells has shown no substantial cytopathic (cell-damaging) effects that are characteristic of pathogenic hepatotropic viruses. Studying TTV has led to the evolution of views on its role in the development of human pathology. The first ideas about the hepatotropism of the virus were gradually reformed as new data became available on the prevalence of the virus and its co-infection with other viruses, including the viruses of the known types of hepatitides. The high prevalence of TTV in the human population indicates its persistence in the body as a virome and a non-pathogenic virus. It has recently been proposed that the level of TTV DNA in the blood of patients undergoing organ transplantation should be used as an endogenous marker of the body's immune status. The available data show the polytropism of the virus and deny the fact that TTV can be assigned exclusively to hepatitis viruses. Fortunately, the rare detection of the damaging effect of TTV on hepatic and bile duct epithelial cells may be indirect evidence of its conditionally pathogenic properties. The ubiquity of the virus and the variability of its existence in humans cannot put an end to its study., Competing Interests: Conflict-of-interest statement: The authors declare that they have no conflict of interest., (©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.)

The purpose of this study was to determine whether timing of the initiating event of spontaneous labor (either uterine contractions with intact fetal membranes or rupture of membranes prior to labor (PROM)) is associated with maternal viral infection. It was a prospective case control study of women with either spontaneous labor or PROM occurring < 37 weeks' gestation ("cases") or at term ("controls"). An initial unbiased screen for viruses was performed with next-generation sequencing (NGS) in serum pooled from eight cases delivered by C/S and represents a range of gestational ages, membrane rupture status, and presence or absence of chorioamnionitis. Custom PCR was used to query individual patient samples from the original cohort. The NGS screen generated 15 million reads. Seven unique viral sequences were detected in two cases, all identified as torque teno virus (TTV), an ubiquitous DNA anellovirus of no known pathogenicity. Using nested and semi-nested PCR, sera from 72 patients (47 cases and 25 matched controls, stratified by ROM status) were screened for the 3 subtypes of anelloviruses (TTV, TTMDV, or TTMV). These were found in 43/47 cases (91%) and 16/25 controls (64%) (p = 0.012, OR = 5.9 (95% CI = 1.4-29.9)). In logistic regression, pregnant women with at least one type of anellovirus were more likely to experience preterm labor than those with no anellovirus (p = 0.03, aOR = 4.6, CI = 1.2-18.7). Among women experiencing a spontaneous initiating event of labor, TTV virus was more likely to be present in the serum of preterm than term patients. TTV may have a role in determining the timing of parturition.

Background: Drug-induced immunosuppression following kidney transplantation is crucial to prevent allograft rejection, but increases risk for infectious disease. Tailoring of drug dosing to prevent both rejection and infection is greatly desirable. The apathogenic and ubiquitous torque teno virus (TTV) reflects immunocompetence of the host and might be a potential candidate for immunologic monitoring., Methods: To assess TTV as an infection biomarker, virus load was prospectively quantified in peripheral blood of 169 consecutive renal allograft recipients at the Medical University Vienna., Results: Patients with infection showed higher TTV levels compared to patients without infection (4.2 × 108 copies/mL [interquartile range, IQR, 2.7 × 107-1.9 × 109] vs 2.9 × 107 [IQR 1.0 × 106-7.2 × 108]; P = .006). Differences in TTV load became evident almost 3 months before infection (median 77 days, IQR 19-98). Each log level of TTV copies/mL increased the odds ratio for infection by 23% (95% confidence interval 1.04-1.45; P = .014). TTV >3.1 × 109 copies/mL corresponded to 90% sensitivity to predict infections. Logistic regression demonstrated independent association between TTV levels and infection., Conclusions: TTV quantification predicts infection after kidney transplantation and might be a potential tool to tailor immunosuppressive drug therapy.

Background: Torque teno virus is a small chronically persisting circular negative ssDNA virus reaching near 100% prevalence. It is reported to be a marker for immune function in immunocompromised patients. The possibility of vertical maternal-fetal transmission remains controversial but incidence rate of TTV DNA in children increased with age. TTV dynamics well studied for allogeneic hematopoietic stem cell transplantation as a predictor of post-transplant complications but there is no viral proliferation kinetics data for other patient groups or healthy individuals. The aim of this study was to determine TTV dynamics during the first year of life of healthy infants., Methods: Ninety eight clinically healthy breastfeeding infants (1-12 months of age) were analyzed by quantitative PCR for the whole blood TTV load with the test sensitivity of about 1000 viral copies per milliliter of blood (total number of samples including repeatedly tested infants was 109)., Results: 67% of all analyzed samples were TTV-positive demonstrating significant positive correlation between age and TTV load (r = 0.81, p < 0.01)., Conclusions: This is the first study to suggest that viral load increases during the first year of life reaching a plateau after 6 months with strong proliferation for the first 60 days. Our data well correlates with TTV dynamics in patients following allogeneic hematopoietic stem cell transplantation.

Torquetenovirus (TTV) has been proposed as a marker of immune function in patients receiving immunosuppression after solid organ transplantation. This study aimed to define TTV plasma dynamics and investigate clinical associations in patients following allogeneic hematopoietic stem cell transplantation (HSCT). This was a single-center prospective longitudinal study involving 50 consecutive patients treated with HSCT between March 2015 and April 2016. TTV plasma DNA levels were measured with quantitative PCR at 12 consecutive time points during the first year after HSCT. Forty of the 50 patients (80%) had detectable TTV viremia before HSCT (median level, 5.37 log10 copies/mL; interquartile range [IQR], 3.51-6.44 log10 copies/mL). All patients subsequently developed TTV viremia during the follow-up period. Plasma viral loads evolved dynamically over time, with a peak of 8.32 log10 copies/mL (IQR, 7.33-9.35 log10 copies/mL) occurring at 79 days (IQR, 50-117 days) following HSCT and a stable plateau toward the end of the follow-up period. The type of malignancy, the use of antithymocyte globulin during conditioning, and the occurrence of acute graft-versus-host disease requiring systemic therapy had temporary effects on TTV dynamics. TTV levels showed a significant correlation with absolute lymphocyte counts following engraftment (r s = -.27; P < .01) and with cytomegalovirus (CMV; r s =.39; P < .01) and Epstein-Barr virus (EBV; r s =.45; P = .02) viral loads during phases of viremia. Immune-related clinical events were not predicted by TTV levels. TTV viremia occurred universally and was sustained throughout the first year after HSCT. Several variables and events before and after HSCT were correlated with TTV levels and hint toward immune marker properties of TTV, but their complex interactions might perturb the capability of TTV to predict immune-related complications in this population., (Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: While viral surveillance of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus using PCR is routine in patients undergoing hematopoetic stem cell transplant and solid organ transplant, the utility in the nontransplant pediatric leukemia population is unknown. Our institution screens patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) for viral DNAemia by PCR as part of clinical care., Procedure: This retrospective chart review included patients treated for newly diagnosed or relapsed AML or ALL between April 2010 and September 2014. We retrieved data for viral PCR screening, detection and quantification, duration of positivity, and prophylaxis or treatment., Results: One hundred eleven patients were included in analyses. Forty (36.0%) had at least one blood PCR positive for EBV, CMV, or adenovirus. Patients with ALL had significantly higher rates of persistent viral detection and treatment than those with AML (P < 0.02, P < 0.01, respectively). International patients had significantly higher rates of viral detection (P < 0.01), persistence (P < 0.01), any treatment (P < 0.03), and antiviral treatment (P < 0.01); 16.9% of patients who received intravenous immunoglobulin (IVIG) prophylactically had viral detection compared to 63% of patients who did not receive prophylactic IVIG (P = 0.0008)., Conclusions: Patients with ALL were more susceptible than those with AML to viral reactivation that was persistent or resulted in treatment. Patients with relapsed ALL, refractory ALL, or infantile ALL are most likely to benefit from asymptomatic screening for CMV and adenovirus. International patients are at higher risk for reactivation and may merit screening. EBV reactivation was not significant and does not warrant screening., (© 2017 Wiley Periodicals, Inc.)

Background: Torque Teno virus (TTV) plasma DNA load directly correlate with the level of immunosuppresion in different clinical settings. It is uncertain whether this may be the case in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT)., Objectives: We characterized the dynamics of TTV DNAemia in patients undergoing T-cell replete allo-SCT., Study Design: Retrospective single-center observational study including 72 allo-HSCT patients. Plasma TTV DNA loads were quantified before initiating the conditioning regimen and at different time-points after transplant by real-time PCR. White blood cells (WBC) and absolute lymphocyte counts (ALC) were measured by flow cytometry., Results: A dramatic drop in plasma TTV DNA load was observed shortly after conditioning. The TTV DNA load increased steadily after engraftment reaching its peak at day +90 after transplant. The increase in TTV DNA load paralleled that of ALC, and was of greater magnitude in patients who developed severe (grades II-IV) acute graft vs. host disease., Conclusion: Repopulation of lymphocytes early after allo-HSCT correlates with an increase of plasma TTV DNA load. Prospective studies are nevertheless needed to determine whether the kinetics of TTV DNAemia may allow inference of the degree of overall immunocompetence in these patients., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The Torque teno canis virus (TTCaV) is a small virus with circular single-stranded DNA that has been reported to cause infections in dogs. The present study aimed to identify the presence of TTCaV in blood samples obtained from domestic dogs, and examine its diversity and evolution of the genomes. Five strains of TTCaV were detected, and the overall prevalence was found to be 7% (28/400). Phylogenetic analysis showed that the five genomes were closely clustered with the previously known Cf-TTV10 and LDL strains and formed a Thetatorque virus. Homology analysis of the whole genome showed a sequence identity of 94.6%-96.8% among the five genomes. The percent sequence similarity among the five complete genomes ranged from 95.3% to 97.4% and from 95.1% to 97% compared to the Cf-TTV10 and LDL strains respectively. The ORF1-encoded amino acid sequences showed 94.4%-97.2% identity among the five isolates. Our findings suggest that the TTCaV has a large genetic diversity and showed that TTCaV and canine parvovirus (CPV) co-infection exists in China. Further studies on the pathogenicity of TTCaV are required., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: TTV has been detected in almost every human tissue type or body fluid reaching near 100% prevalence. Several studies report mother-to-child postnatal transmission of TTV in infancy but the risk of transplacental transmission of TTV is still unclear., Methods: The blood and plasma collected postpartum from 100 mother-child pairs were analyzed using TTV-specific qPCR. Samples were collected from the peripheral vein of the mother and the umbilical cord., Results: Eighty four percent of pregnant women were TTV positive (median titers: 8 × 10 4 copies/mL; range: 10 3 - 3 × 10 7 ). The TTV load in plasma was approximately 100 times lower than in whole blood. TTV was not detected in any of cord blood samples., Conclusions: Our data demonstrate the lack of transplacental transmission of TTV (or effective prenatal inhibition of viral proliferation). The presence of the virus in infants may be associated with mother-to-child transmission through breast feeding or other routes of transmission.

Background: Although the Wood Frog, Rana sylvatica, is used in research on infectious diseases of amphibians, hematologic RIs or response to infection have not been established., Objectives: The purpose of the study was to determine hematologic RIs for adult Wood Frogs and alterations associated with infection with Frog Virus 3 (FV3, Ranavirus sp.)., Methods: Blood was collected from 40 wild-caught adult Wood Frogs that had been in captivity for 6 months. Complete (Natt-Herrick solution hemocytometry) and differential (Wright-Giemsa-stained smears) WBC, RBC, and thrombocyte cell counts, PCV, and automated total cell counts (WBC+RBC+thrombocytes, Sysmex particle counting) were determined. Concordance correlation coefficients determined agreement between hemocytometric and automated total cell counts. Thirteen frogs were orally infected with a lethal dose of 10(4.43) plaque-forming units of FV3 and terminally sampled 4, 9, or 14 days postinfection (dpi). Pre- and postinfection variables for each frog were compared., Results: Leukocyte morphology was similar to that of other amphibians and mammals. Lymphocytes were the most numerous WBC. PCV and RBC counts were similar to other frogs in the same family. Agreement was good between hemocytometry and automated total cell counts. Infection with FV3 caused neutrophilia, increase in undifferentiated blast-like cells, and reduction in the percentage of basophils. Lymphocytes decreased at 4 and 9 dpi but increased at 14 dpi. From 9 dpi onwards, nuclear deterioration and mild toxic change were present in neutrophils; viral cytoplasmic inclusion bodies were observed in lymphocytes, monocytes, neutrophils, and eosinophils., Conclusion: We provide hematology RIs for Rana sylvatica, and report hematologic changes associated with a lethal FV3 infection., (© 2016 American Society for Veterinary Clinical Pathology.)

Since the emergence of cyprinid herpesvirus 3 (CyHV-3), outbreaks have been devastating to Common Carp Cyprinus carpio and koi (a variant of Common Carp), leading to high economic losses. Current diagnostics for detecting CyHV-3 are limited in sensitivity and are further complicated by latency. Here we describe the detection of CyHV-3 by recombinase polymerase amplification (RPA). The RPA assay can detect as low as 10 copies of the CyHV-3 genome by an isothermal reaction and yields results in approximately 20 min. Using the RPA assay, the CyHV-3 genome can be detected in the total DNA of white blood cells isolated from koi latently infected with CyHV-3, while less than 10% of the latently infected koi can be detected by a real-time PCR assay in the total DNA of white blood cells. In addition, RPA products can be detected in a lateral flow device that is cheap and fast and can be used outside of the diagnostic lab. The RPA assay and lateral flow device provide for the rapid, sensitive, and specific amplification of CyHV-3 that with future modifications for field use and validation could lead to enhanced surveillance and early diagnosis of CyHV-3 in the laboratory and field. Received September 14, 2015; accepted April 9, 2016.

Outbreaks of cyprinid herpesvirus 2 (CyHV-2) disease, also known as herpesviral hematopoietic necrosis, among cultured Prussian Carp Carassius gibelio has occurred each year in Jiangsu province, China, since 2009. In autumn 2014, hematological, blood biochemical, and histological changes in naturally infected moribund Prussian Carp were investigated after CyHV-2 was confirmed as the sole etiologic agent by etiological analyses. Total erythrocyte count, total leukocyte count, hemoglobin concentration, and thrombocyte count were significantly reduced (P < 0.01), whereas erythrocyte osmotic brittleness was significantly increased (P < 0.01) in infected fish compared with control fish. In addition, monocyte count was higher (P < 0.01) and lymphocyte count was lower (P < 0.01) in diseased fish than in control fish. The blood biochemical analyses indicated significant increases (P < 0.01) in the activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase as well as in the levels of total protein, globulin, total bilirubin, creatinine, and urea along with significant decreases (P < 0.01) in glucose and albumin in the diseased group. Histopathological examinations indicated that the kidneys and spleens of moribund Prussian Carp were the most severely lesioned organs, followed by the gills and hearts. Hypertrophied nuclei with marginated chromatin also appeared in the hearts and renal tubular epithelia from diseased fish. Pathological analysis of blood cells showed that approximately 78% of erythrocytes and 94% of leukocytes were lesioned with different levels of degeneration and necrosis in the diseased group. These previously unreported observations may be useful in the diagnosis of CyHV-2 disease. Received May 11, 2015; accepted March 24, 2016.

Torque Teno Viruses (TTVs) are ubiquitous viruses which are highly prevalent in several mammalian species. Human TTV's are epidemiologically associated with several human disease conditions such as respiratory illnesses, auto-immune disorders and hepatitis. Recently it was found that swine TTV's (TTSuVs) can act as primary pathogens. The common occurrence of TTVs as environmental contaminants and the increasing interest in the use of swine organs for xenotransplantation lend importance to the question of whether TTV's can cross-infect across species. In this study, we examined human and swine sera by swine or human TTV-specific PCRs, to determine whether swine TTVs (TTSuV) DNA can be detected in humans and vice versa. Surprisingly, both human and TTSuV DNA were present in a majority of the samples tested. Transfection of human PBMC's with TTSuV1 genomic DNA resulted in productive viral infection which was sustained for the three serial passages tested. Lymphoproliferative responses in infected human PBMCs were diminished when compared to the controls. Furthermore, mild to moderate antibody responses against the TTSuV1 ORF2 protein was detected in 16 of the 40 human sera by ELISA. Therefore, these study findings provide initial and fundamental evidence for possible cross-species transmission of TTVs.

Background: A new Marseilleviridae virus family member, giant blood Marseille-like (GBM) virus, was recently reported in persons from France in the serum of an infant with adenitis, in the blood of 4% of healthy blood donors, and in 9% of multiply transfused thalassemia patients. These results suggested the presence of a nucleocytoplasmic large DNA virus potentially transmissible by blood product transfusion., Study Design and Methods: To investigate this possibility we tested the plasma from 113 US blood donors and 74 multiply transfused Cameroon patients for GBM viral DNA using highly sensitive polymerase chain reaction (PCR) assays., Results: GBM DNA was not detected by nested PCR in any of these 187 human specimens., Conclusions: Further testing is required to confirm the occurrence of human GBM virus infections., (© 2015 AABB.)

New diseases in marine animals are emerging at an increasing rate, yet methodological limitations hinder characterization of viral infections. Viral metagenomics is an effective method for identifying novel viruses in diseased animals; however, determining virus pathogenesis remains a challenge. A novel anellovirus (Zalophus californianus anellovirus, ZcAV) was recently reported in the lungs of captive California sea lions involved in a mortality event. ZcAV was not detected by PCR in the blood of these animals, creating the inability to assess the prevalence of ZcAV in live sea lions. This study developed an enzyme-linked immunosorbent assay (ELISA) to detect antibodies to ZcAV in sea lion serum. To assess ZcAV prevalence, paired serum and lung samples (n = 96) from wild sea lions that stranded along the California coast were tested through ELISA and PCR, respectively. Over 50% of the samples tested positive for ZcAV by ELISA (34%), PCR (29%), or both (11%) assays. ZcAV is prevalent in stranded wild sea lion populations and results suggest that PCR assays alone may grossly underestimate ZcAV exposure. This ELISA provides a tool for testing live sea lions for ZcAV exposure and is valuable for subsequent studies evaluating the potential pathogenicity of this anellovirus.

Objective: To critically evaluate plasma fibrinogen concentration as a diagnostic indicator of inflammation in red-eared sliders (Trachemys scripta elegans)., Design: Prospective induced-disease model and prospective cross-sectional study., Sample: Plasma samples from 12 purpose-bred red-eared sliders and 153 farm-raised red-eared sliders., Procedures: A modification of the Jacobsson method was developed to measure fibrinogen concentration in platelet-poor plasma from red-eared sliders. Purpose-bred turtles had been inoculated with a ranavirus (n = 4) or sterile PBS solution (8) as part of another study. Farm-raised red-eared sliders were categorized as healthy (n = 138) or overtly ill (15) on the basis of physical examination findings at the time of blood sample collection. Samples from 124 of the 138 healthy red-eared sliders were used to establish a fibrinogen concentration reference interval as measured by the modified Jacobsson method. Fibrinogen concentrations in ranavirus-infected and physically ill turtles were compared with those of healthy turtles to determine whether fibrinogen concentration would be a useful diagnostic indicator of inflammation in red-eared sliders., Results: The modified Jacobsson method was reliably used to measure fibrinogen concentration. The fibrinogen concentration reference interval from healthy reproductively active female red-eared sliders was right skewed. Fibrinogen concentration did not differ significantly between healthy red-eared sliders and ranavirus-infected or overtly ill red-eared sliders., Conclusions and Clinical Relevance: A reference interval for red-eared slider plasma fibrinogen concentration was established and partitioned by sex to account for considerable right skewing observed for females. Fibrinogen concentration was not a useful indicator of inflammation in red-eared sliders with ranavirus infection or other overt illnesses.

Aim: Viruses from genus Anelloviridae (TTV, TTMDV and TTMV) are small DNA viruses that are widespread in human popu- lation. Data on tissue tropism, cell localization and morphometry of anelloviruses are scarce. The purpose of this study was to determine the prevalence of TTV, TTMDV and TTMV in persons with liver disease and in healthy individuals, as well as electron-microscopic verification of Anelloviridae species., Methods: Detection of anelloviral DNA was performed in serum samples from 203 patients with liver diseases of various etiology and 115 voluntary blood donors using PCR with primers allowing to differentiate TTV, TTMDV TTMV based on the length of amplified fragment. Histopathological and electron microscopic studies were performed for liver biopsy specimens from 203 patients with liver disease., Results: High prevalence (70-90%) of all three anelloviruses in healthy individuals and patients with liver disease was demonstrated, with high frequency of triple TTV, TTMDV and TTMV infection (52.2-55.7%). Electron-microscopic study of liver biopsy specimens from TTMDV monoinfected patients gave a submicroscopic image of TTMDV virions with diameter 35.86 ± 2.04 nm. Electron microscopic studies confirmed the nature of liver damage in TTMDV monoinfection: accumulation of virus in the hepatocytes, significant cyropathy with enlightenment matrix of the cytoplasm and reduction of intracellula organelles involved in protein synthesis, portal and perivascular perisinusoidal fibrosis. TTV, TTMDV and TTMV virions were dentified in hepatocytes, confirming these viruses to be hepatotropic., Conclusion: Our results demonstrate that anelloviruses are lymphotropic viruses, individual genotypes of those might be hepatotropic and pathogenic to liver.

Ranavirus is an emerging disease that infects fish, amphibians, and reptiles. Ranavirus induces an inflammatory response leading to death in many susceptible species. Red-eared sliders (RES; Trachemys scripta elegans) are vulnerable to ranavirus infection and are economically significant chelonians kept in the pet trade and utilized in research. Early identification of RES with inflammatory diseases would allow for isolation of affected individuals and subsequent disease investigation, including molecular testing for ranavirus. Validation of an inexpensive, clinically relevant, and reproducible diagnostic test that detects inflammation in turtles is needed. Although commonly used, plasma protein electrophoresis to detect an inflammatory acute-phase protein response has not been evaluated in a controlled environment in turtles with experimentally induced inflammatory disease. The objective of this study was to measure plasma protein fractions by electrophoresis to determine if an acute-phase protein response occurs in RES during infection with a frog virus 3-like ranavirus (FV3-like virus) isolated from a chelonian. A Bradford assay and agarose gel electrophoresis (AGE) were performed using plasma collected during a study of the effect of temperature on the pathogenesis of ranavirus in RES. In RES at the time of viremia, total albumin (ALB(mg/ml)) and albumin to globulin ratio were significantly lower and beta-globulin percentage was significantly higher in RES exposed to ranavirus (n = 4) as compared to matched, uninfected RES (n = 8). In the last sample collected prior to death, total protein (TP(mg/ml)), ALB(mg/ml), alpha-globulin percentage, and total alpha-globulin (alpha(mg/ml)) were significantly lower in RES exposed to ranavirus (n = 4) than control individuals (n = 8). In summary, FV3-like virus induces a decrease in plasma albumin concentration at the onset ofviremia and decreases in TP(mg/ml, ALB(mg/ml), and alpha(mg/ml) concentrations prior to death in RES as measured by AGE.

Background: Emerging viral infections in humans are appearing at an increasing rate. Recently, we identified a new Marseillevirus, named Giant Blood Marseillevirus (GBM), by performing viral metagenomics on asymptomatic blood donors., Objectives: To study and compare the prevalence of Marseillevirus between asymptomatic blood donors and thalassemia patients., Design: Here, we present a combined molecular and serological study on 174 asymptomatic blood donors and 22 patients with thalassemia who receive repeated blood transfusions to estimate the prevalence of Marseillevirus in these two populations., Results: We identified Marseillevirus genomic DNA in 4% of donors, whereas 9.1% of the thalassemia patients were positive for this virus. Moreover, IgG seropositivity was detected in 22.7% of patients in the thalassemia group, whereas this seropositivity was observed in 12.6% of the blood donor population., Conclusion: These results suggest that Marseillevirus infection is not rare in healthy persons and may be transmitted by transfusion, thus raising speculation regarding the long-term consequences of this viral infection, particularly in patients requiring repeated blood transfusions., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Torque Teno Sus Virus (TTSuV) viral load in accordance with the Porcine Circovirus Type 2 (PCV2) infection and age of two pig herds was determined. A total of 100 and 155 piglets from two farms were divided into two groups. Half of the piglets from each farm were given a commercial vaccine against PCV2 (vaccinated group), and the remaining piglets were used as a control group (non-vaccinated group). An early onset and a chronic viremic state of TTSuV genogroups were present regardless of the PCV2 infection, and there were no significant differences in the dynamics of TTSuV genogroups., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The family Anelloviridae includes human and animal torque teno viruses (TTVs) with extensive genetic diversity. The antigenic diversity among anelloviruses has never been assessed. Using torque teno sus virus (TTSuV) as a model, we describe here the first investigation of the antigenic relationships among different anelloviruses. Using a TTSuV genotype 1a (TTSuV1a) or TTSuV1b enzyme-linked immunosorbent assay (ELISA) based on the respective putative ORF1 capsid antigen and TTSuV1-specific real-time PCR, the combined serological and virological profile of TTSuV1 infection in pigs was determined and compared with that of TTSuV2. TTSuV1 is likely not associated with porcine circovirus-associated disease (PCVAD), because both the viral loads and antibody levels were not different between affected and unaffected pigs and because there was no synergistic effect of concurrent PCV2/TTSuV1 infections. We did observe a higher correlation of IgG antibody levels between anti-TTSuV1a and -TTSuV1b than between anti-TTSuV1a or -1b and anti-TTSuV2 antibodies in these sera, implying potential antigenic cross-reactivity. To confirm this, rabbit antisera against the putative capsid proteins of TTSuV1a, TTSuV1b, or TTSuV2 were generated, and the antigenic relationships among these TTSuVs were analyzed by an ELISA and by an immunofluorescence assay (IFA) using PK-15 cells transfected with one of the three TTSuV ORF1 constructs. The results demonstrate antigenic cross-reactivity between the two genotypes TTSuV1a and TTSuV1b but not between the two species TTSuV1a or -1b and TTSuV2. Furthermore, an anti-genogroup 1 human TTV antiserum did not react with any of the three TTSuV antigens. These results have important implications for an understanding of the diversity of anelloviruses as well as for the classification and vaccine development of TTSuVs.

This study investigates the frequency of Torque teno virus (TTV) infection in 150 blood donors and 77 patients requiring haemodialysis in southern Brazil. Plasma samples were screened for TTV DNA using polymerase chain reaction (PCR). The prevalences of TTV among blood donors and patients requiring haemodialysis were 73.3% and 68.8%, respectively. The presence of TTV was correlated with age in the blood donors (p = 0.024). In haemodialysis patients, no association was found between TTV infection and the demographic parameters (age, sex and education), the duration of haemodialysis or a history of blood transfusion. This study is the first to evaluate the prevalence of TTV infection in Brazilian patients requiring haemodialysis.

Anelloviruses are small, non-enveloped viruses with circular single stranded DNA, which infect a number of animal species as well as humans. In pigs, two distinct Torque teno sus virus (TTSuV) species have been described so far, being one of them linked to disease occurrence. Specifically, TTSuV2 loads in serum have been found increased in pigs suffering from postweaning multisystemic wasting syndrome (PMWS). Since this pathological condition is able to be controlled by means of porcine circovirus type 2 (PCV2) vaccination, it was hypothesized the possibility that such vaccination would have an impact on TTSuV2 prevalence and loads. A total of 150 pigs were divided in two study groups. Half of them received a PCV2 commercial vaccine, while the other half remained as non-vaccinated controls. PCV2 infection was monitored at 3-4, 8, 12, 16 and 21 weeks of age by means of an standard PCR, while TTSuV2 loads were determined at 8, 16 and 21 weeks of age by a quantitative PCR. No obvious PMWS clinical signs were observed among studied animals, although PCV2 infection was confirmed in both groups of pigs. Almost all pigs got TTSuV2 infection throughout the study period, independently of the PCV2 vaccination status of animals. Moreover, TTSuV2 load did not show significant differences between different pig groups at each sampling time, but mean viral load increased with age. Taking into account that previous results suggest that TTSuV2 load in serum is increased in the background of PMWS, the present study suggests that this is not the case in a PCV2 subclinical infection scenario. Therefore, vaccination of PCV2 subclinically infected pigs did not modify the outcome of TTSuV2 infection., (Copyright © 2011 Elsevier B.V. All rights reserved.)

This study was carried out to investigate the presence of Torque teno sus virus types 1 (TTSuV1) and 2 (TTSuV2) in a longitudinally (14 to 150 days of age) collected paired pooled sera (pSE) and peripheral blood mononuclear cells (pPBMCs) using nested polymerase chain reaction. The detection rate of TTSuV1 in pSE increased from 14 to 90 days of age, but a progressive decline was observed from 120 to 150 days of age, while in pPBMC, a high value was maintained till the end of growing-finishing period. On the contrary, except in PBMCs at 30 days of age, high detection rates of TTSuV2 were found in both pSE and pPBMCs in all sampling ages. The detection rate of TTSuVs between pSE and pPBMCs was positively correlated at all sampling ages except for TTSuV1 at 150 days of age. This is the first study showing the presence of TTSuVs in PBMCs from pigs and describing the in vivo infection dynamics of TTSuV in paired sera and PBMCs during the entire growing and finishing periods of pigs reared in conventional farms.

Background: Rapid, high throughput extraction systems are needed to monitor viral infections in immunosuppressed patients., Objectives: Evaluate the performance of the MagNA Pure 96™ extraction system, and compare it to the COBAS Ampliprep™ for quantitative real-time PCR from whole blood samples., Study Design: Compare the MagNA Pure LC™, COBAS Ampliprep™ and MagNA Pure 96™ using ten-fold dilutions of blood samples containing cytomegalovirus. Evaluate analytical performances of the MagNA Pure 96™ from test samples containing cytomegalovirus. Evaluate clinical performances from 209 blood samples collected prospectively, extracted with the COBAS Ampliprep™ and the MagNA Pure 96™ systems and tested for cytomegalovirus, Epstein-Barr, BK and JC viruses., Results: All three extraction systems gave similar results with dilutions of a cytomegalovirus-positive sample. Analytical tests showed that the limit of detection was 500 copies/ml, specificity was 100%, with no cross-contamination. Quantification was linear from 3.0 to 6.0 log(10)copies/ml. Intra-assay variation was 8.3-0.9% and inter-assay variation 8.8-5.2%. Clinical specimens extracted with the MagNA Pure 96™ and COBAS Ampliprep™ instruments agreed well for cytomegalovirus (r=0.54; p=0.07), Epstein-Barr virus (0.69; p=0.0005) and BK virus (0.85; p=0.01). All 55 samples were negative for JC virus. Mean loads were similar for cytomegalovirus (0.17 log(10)copies/ml) and BK virus (-0.24 log(10)copies/ml) while that of Epstein-Barr virus was slightly lower (1.02 log(10)copies/ml)., Conclusions: The MagNA Pure 96™ instrument is an easy-to-use, reliable high throughput platform for extracting nucleic acid from clinical whole blood specimens., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Unlabelled: Recent studies on the torque teno virus (TTV), genus Anellovirus, have allowed formulating the hypothesis that TTV may trigger autoimmune rheumatic diseases or have some pathogenic role in them., Objectives: To determine the frequency of TTV infection in patients with systemic lupus erythematosus (SLE), the genetic diversity of TTV, the correlation between TTV infection and SLE clinical manifestations, and SLE clinical course and serological profile., Patients and Methods: Serum samples were obtained from 46 SLE patients treated at the University-Affiliated Hospital of Campo Grande (NHU/FAMED/UFMS), Brazil. For controls, serum samples were obtained from 46 healthy volunteer blood donors. Viral DNA was extracted from samples using the QIAamp DNA Blood Mini Kit (QIAGEN, Hilden, Germany) and amplified using nested PCR., Results: Positivity for TTV was found in 17 (37%) of SLE patients and in only seven (15.2%) of the controls (z test, P = 0.03). There was no correlation between TTV infection, SLE clinical manifestations, SLE clinical course, and the serological profile of the patients evaluated., Conclusion: Further studies on the presence of TTV in SLE patients are required.

An infectious etiology has been proposed for many human cancers, but rarely have specific agents been identified. One difficulty has been the need to propagate cancer cells in vitro to produce the infectious agent in detectable quantity. We hypothesized that genome amplification from small numbers of cells could be adapted to circumvent this difficulty. A patient with concomitant chronic lymphocytic leukemia (CLL) and polycythemia vera (PV) requiring therapeutic phlebotomy donated a large amount of phlebotomized blood to test this possibility. Using genome amplification methods, we identified a new isolate (BIS8-17) of torque teno virus (TTV) 10. The presence of blood isolate sequence 8-17 (BIS8-17) in the original plasma was confirmed by polymerase chain reaction (PCR), validating the approach, since TTV is a known plasma virus. Subsequent PCR testing of plasmas from additional patients showed that BIS8-17 had a similar incidence (~20%) in CLL (n = 48) or PV (n = 10) compared with healthy controls (n = 52). CLL cells do not harbor BIS8-17; PCR did not detect it in CLL peripheral blood genomic deoxyribonucleic acid (DNA) (n = 20). CLL patient clinical outcome or prognostic markers (immunoglobulin heavy chain variable region [IGHV ] mutation, CD38 or zeta-chain associated protein kinase 70 kDa [ZAP-70]) did not correlate with BIS8-17 infection. Although not causative to our knowledge, this is the first reported isolation and detection of TTV in either CLL or PV. TTV could serve as a covirus with another infectious agent or TTV variant with rearranged genetic components that contribute to disease pathogenesis. These results prove that this method identifies infectious agents and provides an experimental methodology to test correlation with disease.

Background: Anellovirus species Torque teno virus (TTV), Torque teno mini virus (TTMV), and Torque teno midi virus (TTMDV) and flavivirus GBV-C are highly prevalent and genetically diverse chronic human viral infections that have not yet been associated with disease., Study Design and Methods: To determine if these commensal viruses are transmitted by blood transfusions, we genetically analyzed viral species in cryopreserved samples from blood donors and corresponding pre- and posttransfusion samples from recipients enrolled in the Transfusion-Transmitted Viruses Study cohort., Results: All 24 individuals in 12 donor-recipient pairs were infected with TTV, while 16 were infected with TTMV, 15 with TTMDV, and four with GBV-C. None of the 12 informative cases of TTV transfusion or eight cases of TTMV transfusion, where the donor and recipient viruses could be genetically differentiated, resulted in detectable transmissions in which the donor viruses were detected in the recipient by direct sequencing of the polymerase chain reaction products. Of the five informative cases of TTMDV transfusion, including two cases of transfusion into TTMDV-negative recipients, one case of superinfection was seen with both the recipient and the donor viral variants detected in the transfusion recipient for at least 11 days posttransfusion. Three donor-recipient pairs were informative for GBV-C transmission with only one transfusion into a GBV-C-negative recipient resulting in a transiently detected infection., Conclusions: Transmission of the common commensal anelloviruses and GBV-C during transfusion was detected in 2 of 12 already infected or uninfected recipients. Underestimation of the true rate of viral transmission may be due to limitations in detecting donor viral variants present as minority variants in the already infected transfusion recipients., (© 2010 American Association of Blood Banks.)

Torque teno virus (TTV) is a recently identified virus that has a wide range of host tropisms from humans to shrews. Human TTV and Torque teno mini virus are distributed worldwide, and their high prevalence in human populations has been reported. Pigs have their own species-specific TTV, and like human TTV, a high prevalence of porcine TTV also has been reported. Despite its high prevalence, the role of TTV-related disease or syndrome in humans and pigs has not been determined. In the swine industry, TTV is thought to be one of the agents that aggravate clinical manifestation of Porcine circovirus-associated disease (PCVAD), a newly emerging, economically devastating disease. The purpose of the current study was to quantify TTV viral load in serum obtained from Porcine circovirus-2-negative pigs and PCVAD-affected pigs with real-time quantitative polymerase chain reaction assays and to compare TTV viral load between these groups. Results of this study indicate that there are no statically remarkable differences in TTV viral load between the 2 groups, which indicates that TTV might not be an agent of aggravation in PCVAD.

Forty-four raw milk and 15 serum samples from 44 healthy water buffaloes reared in Caserta, southern Italy, the most important region in Europe for buffalo breeding, were examined to evaluate the presence of Torque teno viruses (TTV) using molecular tools. Furthermore, 8 pooled pasteurized milk samples (from dairy factories having excellent sanitary conditions) and 6 Mozzarella cheese samples were also tested. Four of the cheese samples were commercial Mozzarella cheese; the remaining 2 were prepared with TTV-containing milk. Human TTV were detected and confirmed by sequencing in 7 samples of milk (approximately 16%). No TTV were found in serum, pooled pasteurized milk, or Mozzarella cheese samples. The samples of Mozzarella cheese prepared with TTV-containing milk did not show any presence of TTV, which provides evidence that standard methodological procedures to prepare Mozzarella cheese seem to affect viral structure, making this food fit for human consumption. The 7 TTV species from water buffaloes were identified as genotypes corresponding to the tth31 (3 cases), sle 1981, sle 2031, and NLC030 (2 cases each) human isolates. Although cross-species infection may occur, detection of TTV DNA in milk but not in serum led us to believe that its presence could be due to human contamination rather than a true infection. Finally, the mode of transmission of TTV has not been determined. Contaminated of the food chain with TTV may be a potential risk for human health, representing one of the multiple routes of infection.

Humans are frequently infected with three anelloviruses which have circular DNA genomes of 3.6-3.9 kb [Torque teno virus (TTV)], 2.8-2.9 kb [Torque teno mini virus (TTMV)] and 3.2 kb [a recently discovered anellovirus named Torque teno midi virus (TTMDV)]. Unexpectedly, human TTMDV DNA was not detectable in any of 74 chimpanzees tested, although all but one tested positive for both human TTV and TTMV DNA. Using universal primers for anelloviruses, novel variants of TTMDV that are phylogenetically clearly separate from human TTMDV were identified from chimpanzees, and over the entire genome, three chimpanzee TTMDV variants differed by 17.9-20.3 % from each other and by 40.4-43.6 % from all 18 reported human TTMDVs. A newly developed PCR assay that uses chimpanzee TTMDV-specific primers revealed the high prevalence of chimpanzee TTMDV in chimpanzees (63/74, 85 %) but low prevalence in humans (1/100). While variants of TTV and TTMV from chimpanzees and humans were phylogenetically interspersed, those of TTMDV were monophyletic for each species, with sequence diversity of <33 and <20 % within the 18 human and three chimpanzee TTMDV variants, respectively. Maximum within-group divergence values for TTV and TTMV were 51 and 57 %, respectively; both of these values were substantially greater than the maximum divergence among TTMDV variants (44 %), consistent with a later evolutionary emergence of TTMDV. However, substantiation of this hypothesis will require further analysis of genetic diversity using an expanded dataset of TTMDV variants in humans and chimpanzees. Similarly, the underlying mechanism of observed infrequent cross-species infection of TTMDV between humans and chimpanzees deserves further analysis.

Sera from 15 patients coinfected with TTV and HIV-1, collected before and at two times after introduction of highly active anti-retroviral therapy (HAART), were tested for TTV load and the presence of the five highly divergent TTV phylogenetic groups. Seven patients showed a 1-5 log TTV load decrease during HAART, while the others did not show significant variations. A decrease in the number of coinfecting TTV genogroups was detected in 12 of 15 patients, with the mean number of TTV genogroups/patient decreasing from 2.33 before HAART to 1.47 at the last collect. All five genogroups were less frequently found after introduction of HAART. Three hundred sixty-seven TTV clones from four different genogroups, derived from two patients, were sequenced. Noticeable fluctuations in TTV subpopulation frequencies were observed in both patients analyzed. In conclusion, HAART tends to reduce the number of TTV genotypes/genogroups and may affect the balance between different TTV isolates coinfecting single individuals.

Aim: TT virus (TTV) is genetically variable and widespread without apparent pathogenicity; however, its epidemiological features in children were not fully understood, partly because blood sampling is often unacceptable for healthy children. We therefore used saliva specimens to investigate epidemiology of TTV infection in early childhood., Methods: Saliva samples were collected from 83 1-month-old, 110 4-month-old and 49 42-month-old children. Peripheral blood mononuclear cells (PBMC) and saliva samples were obtained in pairs from 19 healthy adults aged 40 +/- 7 years. TTV DNA was detected and quantified by real-time PCR and classified into five genogroups (G1-G5) by a series of PCRs using genogroup-specific primer pairs., Results: TTV DNA was detected in 6, 34 and 90% of children aged 1, 4 and 42 months, respectively, and in 84% of adults. Comparable levels of TTV DNA were detected in pairs of saliva and PBMC. TTV loads in saliva were much higher in children than in adults. G3 was the most common genogroup in all age groups. The second most prevalent was G4 at 1-4 months of age and G1 thereafter., Conclusion: The prevalence of TTV infection reached a plateau at or before 42 months; however, somehow different epidemiologic features were observed among genogroups.

Background: To commence proper antiviral treatment, timely knowledge of whether the infection is caused by DNA or RNA virus would be beneficial for the clinician., Objectives: Our objective was to develop a method for distinguishing between DNA and RNA virus infections., Study Design: In this prospective study, total and differential count of leukocytes, serum C-reactive protein level, erythrocyte sedimentation rate, and quantitative flow cytometric analysis of FcgammaRI (CD64) on neutrophils and monocytes were obtained from 289 hospitalized febrile patients. After microbiological confirmation, 89 patients (31%) were found to have either bacterial (n=46) or viral (n=43) infection. The patient data was compared to 60 healthy controls., Results: For the first time ever, it was noticed that in dsDNA virus infections (n=21) the average amount of CD64 on neutrophils was over five-fold compared to ssRNA virus infections (n=22)., Conclusions: DNA virus score (DNAVS) point, which incorporates quantitative analysis of CD64 on neutrophils and total and differential count of leukocytes, varied between 0 and 8, and displayed 95% sensitivity and 100% specificity in distinguishing between dsDNA and ssRNA virus infections [average (S.D.); DNAVS points: 5.4 (2.5) vs. 0.3 (0.4); p<0.001].

Background: SEN virus is a blood-borne, single-stranded, nonenveloped DNA virus. Two of its strains (D and H), appear to be associated with non-A-to-E hepatitis more frequently than the others, although it is not clear whether this observation has any significance. The prevalence of SEN virus in otherwise healthy individuals, including blood donors, differs markedly by geographic region. In this study, an investigation to evaluate the prevalence of SEN virus strains among blood donors in Tehran was carried out., Methods: Sera of 260 blood donors who were negative for hepatitis B surface antigen (HBsAg) and third-generation hepatitis C virus antibody (anti-HCV) were tested for SEN virus-D and -H DNA. DNA was extracted from plasma of 260 blood donors and amplified by semi- nested polymerase chain reaction., Results: SEN virus-D viremia was detected in four (1.5%) of the 260 blood donors (95% confidence interval (CI), 0.0 - 3%). SEN virus-H viremia was detected in 47 (18.08%) of the 260 blood donors (95% CI, 13.4 - 22.8%). Both SEN virus-D and SEN virus-H viremia were detected in nine (3.4%) of the 260 blood donors (95% CI, 1.2 - 5.7%). SEN virus-D or SEN virus-H viremia was identified in 60 (23.08%) of the 260 blood donors (95% CI, 18.08 - 28.08%)., Conclusion: Out of the 260 blood donors, 60 (23%) were infected by SEN virus-D/H. The prevalence of SEN virus-H is more than SEN virus-D. Our results also showed that the high prevalence of SEN virus in healthy blood donors with no history of blood transfusion may attribute to the transmission modes other than parenteral transmission.