What test is typically performed to check for chronic hepatitis C?

To determine the presence of chronic hepatitis C, the most definitive test performed is HCV RNA testing. This test directly measures the amount of hepatitis C virus (HCV) in the blood and is crucial for confirming an active infection. While the presence of HCV RNA indicates active viral replication, it is critical to assess for chronic infection rather than just initial exposure.

Anti-HCV testing is commonly used for screening and indicates whether an individual has been exposed to the virus at any point. However, it does not differentiate between acute and chronic infection, as antibodies may take weeks to develop after infection.

Liver biopsy is not routinely performed to check for chronic hepatitis C unless assessing the extent of liver damage or fibrosis in diagnosed cases. It's a more invasive procedure with associated risks and is usually reserved for treatment planning rather than initial diagnosis.

Serum AFP (alpha-fetoprotein) is a tumor marker often associated with liver cancer. Although it can be elevated in liver disease, it is not a specific test for hepatitis C infection or for determining its chronicity.

Thus, HCV RNA testing is the primary tool utilized to establish the presence of chronic hepatitis C infection, making it the correct choice in this context.