Relationship of TT virus infection with prevalence of hepatitis C virus infection and elevated alanine aminotransferase levels.
A novel DNA virus, TT virus (TTV), was identified in a Japanese patient with posttransfusion hepatitis. The epidemiology and etiological role of this virus have not been elucidated. We investigated the epidemiology of TTV infection in hepatitis C virus (HCV) high endemic and low endemic areas, R town and M town, respectively. The seroprevalence, potential risk factors, and laboratory features of TTV in relation to those of HCV were analyzed. TTV DNA was detected using a seminested polymerase chain reaction and the TTV genotypes were determined by a direct sequencing method. TTV DNA was detected in 16.1% of the subjects in R town and 17.5% of those in M town. The TTV DNA positivity rates of the 2 areas did not differ significantly. A history of blood transfusion was not a specific risk factor for TTV infection. The mean serum alanine aminotransferase (ALT) level of the anti-HCV-positive subjects was significantly higher than that of the TTV DNA-positive subjects, most of whom had normal ALT levels. The TTV genotype distributions of these 2 distinct areas differed. These results suggest that TTV infection is widespread with a geographical genotypic distribution independent of HCV infection and that the ALT abnormalities are not attributable to TTV but to HCV infection in the general population.
Watanabe
H
H
Second Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Shinzawa
H
H
Shao
L
L
Saito
T
T
Takahashi
T
T
D000368:Aged; D000410:Alanine Transaminase / Q000097:blood*; D001803:Blood Transfusion; D004266:DNA Virus Infections / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D004267:DNA Viruses / Q000235:genetics; D004279:DNA, Viral / Q000097:blood; D019353:Endemic Diseases; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006526:Hepatitis C / Q000097:blood* / Q000150:complications / Q000453:epidemiology; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence
D004279:DNA, Viral; D018937:Hepatitis C Antibodies; D000410:Alanine Transaminase