Tests to diagnose hepatitis C
HCV testing if you are HIV positive
If you are HIV positive, annual HCV testing is recommended in the UK as part of your routine care.
But HCV testing is also based on your risks. For example, if you are sexually active and/or if you have another STI and/or if you shared anything when injecting drugs then HCV tests are more important.
HCV testing is also recommended if your liver enzymes become raised.
Tests to diagnose HCV
HCV testing has two stages, but depends on your HCV history, see Table 1.
1. The first test is usually an HCV antibody test.
A positive antibody result means that you have either had HCV and cleared it or that you still have HCV.
A negative result means that you might not have HCV. This test doesn’t detect recent HCV because it can take 6 to 24 weeks for HCV antibodies to develop.
Also, if your CD4 count is less than 200 your immune system may not make HCV antibodies.
If you have already had HCV and cleared it or been cured, routine testing (for reinfection) needs to be with an HCV viral load or HCV core antigen test.
2. An HCV viral load (RNA) or HCV core antigen test will confirm or rule out current infection.
These tests looks for direct evidence of the virus or viral replication.
If the results are positive it means that you have current HCV infection.
If the results are undetectable/negative, you might have spontaneously cleared HCV – but a second test six months later will confirm this.
The HCV core antigen test is a cheaper and quicker alternative to HCV viral load but that gives similar information. It looks for a protein produced by ongoing HCV, but is not always accurate if HCV viral load is very low.
Table 1: HCV tests and what the results mean for HCV infection
|Type of test|
|Diagnosis||Antibody test result||HCV RNA (viral load) or HCV core antigen||ALT: liver enzyme|
|Prior HCV but cleared.||Positive.||Undetectable or negative on two tests, at least 6 months apart.||Return to normal.|
|Acute HCV.||Negative; but positive within 6 to 24 weeks.||Detectable within 1 to 2 weeks, usually very high.||May be up to 7 to 10 times above normal.|
|Chronic HCV.||Positive.||Detectable.||May be persistently normal, fluctuate, or persistently raised.|
Last updated: 17 August 2017.