Millions of people throughout the world are infected with hepatitis C virus (HCV). Left untreated, infection results in serious complications such as cirrhosis of the liver and cancer. Many HCV-infected patients respond well to anti-viral therapy and remain virus free. However, trace amounts of HCV RNA are sporadically detected in patients thought to have successfully responded to HCV treatment.
A recent study in the Journal of Clinical Investigation tested if this reappearing HCV RNA is infectious. Using an animal model, Barbara Rehermann and colleagues at the NIH found that blood from patients with trace amounts of HCV RNA is able to cause HCV infection, though the animals did not immediately show signs of HCV infection.
This study demonstrates that small amounts of HCV RNA in successfully treated patients can be infectious, but these transmission events may be hard to detect due to delayed onset of disease.