Tests to diagnose hepatitis C

HCV testing is recommended annually for HIV-positive people especially if diagnosed with another STI and/or are sexually active. It is also recommended after confirmed abnormal liver enzymes.

Although you may have already been diagnosed with HIV and HCV, information on how HCV is diagnosed is important.

HCV testing is a two-stage process. The first test is usually an HCV antibody test. If it is positive, it means that you have been infected with hepatitis C in the past, and that you may still be infected.People who have spontaneously cleared hepatitis C without treatment remain antibody-positive for years afterwards. On the other hand, antibody test results may be negative even when someone does have chronic hepatitis C. This may occur when:

• CD4 cell count is low (less than 200), because the immune system may not be producing antibodies
• In acute (early) HCV infection, since antibodies take six to twenty-four weeks after infection before they develop.

An HCV viral load test (RNA) will confirm or rule out chronic infection. The viral load test looks for genetic material of HCV in the same way as an HIV viral load test detects HIV. If you have detectable HCV viral load, it means that you are currently infected with HCV. If your hepatitis C viral load is undetectable, a second test should be done six months later. If two successive test results are undetectable, you have cleared HCV.

Table: HCV tests and what the results mean for HCV infection