Quantitative and genotypic analysis of TT virus infection in Chinese blood donors.
Transfusion
; 41(8): 1001-7, 2001 Aug.
Article
in En
| MEDLINE
| ID: mdl-11493731
ABSTRACT
BACKGROUND:
The TT virus (TTV) is a member of a newly described family of human viruses related to the C ircoviridae viruses. Its association with specific diseases has not been established, and screening of blood donors has not been implemented. To date, 16 genotypes have been identified. STUDY DESIGN ANDMETHODS:
Sera from 471 healthy blood donors (aged 11-58 years) were randomly selected and tested for TTV by the use of two sets of primers NG59d/NG61d/NG63d primers and T801/T935 primers. Quantitative competitive PCR (QC-PCR) was developed to measure the TTV DNA concentration among the blood donors. Sequencing of a part of the genome was performed to identify the various genotypes. Several samples showed a mixed genotype infection.RESULTS:
TTV was detected in 251 (53.3%) of 471 healthy Hong Kong blood donors by the use of NG59d/NG61d/NG63d primers. The prevalence of the virus increased steadily with age (p = 0.03). TTV DNA was detected in 90 percent (90 of a randomly selected 100) of samples by the use of T801/T935 primers. TTV DNA concentration was also measured by QC-PCR in the blood donors who were positive for TTV DNA in the first round of the heminested PCR. TTV titers ranged from 4.8 x 10(2) copies per mL to 6 x 10(4) copies per mL, with a median value of 1.2 x 10(4) copies per mL. Sequencing and phylogenetic analysis of a 223-bp fragment from open reading frame 1 showed three main genotypes (G1 [60.7%], G2 [24.3%], and G3 [14%]) and a new genotype 17 (G17), with the latter bearing 60-percent nucleotide homology with other genotypes deposited at GenBank. In addition, a new TTV subtype, G2f, was found.CONCLUSION:
The prevalence of TTV is high in healthy Chinese blood donors. Three main genotypes (G1, G2, and G3) were detected. In addition, a new TTV genotype, tentatively designated as G17, and a new subtype, G2f, were identified.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Blood Donors
/
Viral Load
/
Torque teno virus
/
DNA Virus Infections
/
Genotype
Type of study:
Risk_factors_studies
Limits:
Adolescent
/
Adult
/
Child
/
Female
/
Humans
/
Male
/
Middle aged
Country/Region as subject:
Asia
Language:
En
Journal:
Transfusion
Year:
2001
Document type:
Article
Affiliation country:
China