Association between SEN virus infection and hepatitis C in Japan.

There is a strong association between 2 SEN virus (SENV) variants (SENV-D and SENV-H) and transfusion-associated non-A-E hepatitis. In total, 200 subjects from a Japanese region where hepatitis C virus (HCV) is highly endemic and 194 persons from a contiguous area where HCV is not endemic were tested for SENV-D and SENV-H DNA by polymerase chain reaction. SENV DNA was detected equally in subjects from each area (56% prevalence in the area of high endemicity vs. 61% in the nonendemic area). Age-specific prevalence of SENV was similar to that of TT virus, with equal distribution at all ages in both areas; HCV was predominant in the elderly population. Alanine aminotransferase levels were significantly associated with HCV viremia but not with SENV viremia. SENV is a common infection that appears to have transmission routes and age-related prevalence that are distinct from those of HCV. No evidence was found that SENV caused hepatitis or worsened the course of hepatitis C.