Prevalence and implication of a newly identified infectious agent (SEN virus) in Taiwan.

To investigate the prevalence and clinical relevance of a recently identified SEN virus (SENV) in Taiwan, 2 SENV variants (SENV-D and SENV-H) were studied in high-risk persons, patients with liver disease, and healthy adults. SENV-D and/or SENV-H (SENV-D/H) infections were more frequent in high-risk groups (54%-90%) and in patients with chronic hepatitis B (41%), hepatitis B-related hepatocellular carcinoma (HCC) (54%), chronic hepatitis C (67%), and hepatitis C-related HCC (76%) than in healthy adults (15%). The prevalence of SENV-D/H infection was comparable between patients with non-A to E fulminant hepatitis (30%) and healthy adults. Most subjects with SENV-D/H infection alone had no or mild hepatitis, and coinfection of SENV-D/H with chronic hepatitis B or C was not associated with increased evidence of liver disease and the risk of HCC. These results suggest that SENV-D/H infection is common in high-risk groups in Taiwan but that SENV-D/H infection is not associated with hepatitis.