The most appropriate management is to initiate treatment for hepatitis C virus (HCV) infection. Testing for HCV consists of detecting antibody to HCV and has a very high positive predictive value in patients with elevated liver test results and risk factors for HCV infection. HCV RNA by polymerase chain reaction confirms HCV infection. HCV genotyping should be performed at the time of diagnosis to help choose a treatment regimen. This patient has HCV genotype 2 with significant fibrosis on liver biopsy. Effective antiviral treatment of HCV infection can prevent or delay the development of cirrhosis and hepatocellular carcinoma. Patients with HCV genotype 2 have a very high likelihood of sustained virologic response with sofosbuvir and ribavirin, and therefore treatment should be initiated with these agents.

This patient's positive IgG antibody to hepatitis A virus test is a marker of previous infection; therefore, hepatitis A vaccination will not be useful or necessary.

Likewise, this patient has immunity to hepatitis B based on her positive hepatitis B surface antibody test, and therefore hepatitis B vaccination is not necessary.

Although this patient has a normal alanine aminotransferase level, she has evidence of active inflammation with fibrosis on liver biopsy, and antiviral treatment is indicated despite her normal aminotransferase level. The need for treatment in individuals with HCV infection and normal liver enzyme levels is generally assessed similarly to those with abnormal liver enzyme levels.

Testing for IgM antibody to hepatitis A virus is helpful in the diagnosis of acute hepatitis A; however, this patient has no clinical features of acute hepatitis.