title: Transfusion transmission of highly prevalent commensal human viruses.
abstract: 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.
  
  
  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.
authors.affiliation: Blood Systems Research Institute and the Department of Medicine, University of California, San Francisco, California 94118, USA.
authors.forename: Flavien
authors.initials: F
authors.lastname: Bernardin
authors.forename: Eva
authors.initials: E
authors.lastname: Operskalski
authors.forename: Mike
authors.initials: M
authors.lastname: Busch
authors.forename: Eric
authors.initials: E
authors.lastname: Delwart
mesh_terms: D000328:Adult; D001782:Blood Donors / Q000706:statistics & numerical data; D001793:Blood Preservation; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D015925:Cryopreservation; D004266:DNA Virus Infections / Q000097:blood / Q000453:epidemiology / Q000635:transmission; D004279:DNA, Viral / Q000097:blood; D005260:Female; D018178:Flaviviridae Infections / Q000097:blood / Q000453:epidemiology / Q000635:transmission; D029407:GB virus C / Q000235:genetics / Q000302:isolation & purification*; D014644:Genetic Variation; D006525:Hepatitis, Viral, Human / Q000097:blood / Q000453:epidemiology / Q000635:transmission; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D022783:Torque teno virus / Q000235:genetics / Q000302:isolation & purification*; D065227:Transfusion Reaction
chemical_list: D004279:DNA, Viral