Patients who are undiagnosed
Your approach to testing for hepatitis C will depend on your practice profile. One approach is to test everyone. Universal testing (or screening) is recommended as part of antenatal screening in Australia.11 GPs working in high-prevalence practices, such as in homeless health or opioid substitution therapy, might consider offering testing to all patients.
Otherwise, testing for hepatitis C is generally based on risk, as discussed in Part 1 of this series.4 Sometimes, risk factors for hepatitis C may be difficult to identify during a busy GP consultation. In addition, for many patients, risk factors may have occurred in the distant past, such as a period of injecting drug use in their youth.
Most GPs take a social history from new patients, and this is an opportunity to enquire sensitively about risk factors such as current or past injecting drug use, along with recording demographic variables such as country of birth and sexual behaviour. This information is also crucial for establishing whether there is a need to test for bloodborne viruses such as hepatitis B virus and HIV along with hepatitis C, which can all be performed as part of ‘a new patient screen’. Tests included in bloodborne virus screening are shown in Figure 1.9
Existing patients also need to be tested for hepatitis C. There are many opportunities for testing as part of general health checks, sexual health screens, pre-travel check-ups and antenatal screening.
Patients with hepatitis C can also be found by searching the practice management system. Third-party tools such as POLAR (https://outcomehealth.org.au/polar.aspx) and PenCat (https://help.pencs.com.au/dashboard.action) can help find patients with potential risk factors (e.g. abnormal liver function test results) for testing. Advice on using these tools can be obtained from your local Primary Health Network.
Patients who are diagnosed but not treated
Most people living with hepatitis C have been previously diagnosed. This group of patients includes those who have declined treatment and others who are not engaged in regular medical care. Many people living with hepatitis C belong to marginalised populations and may have limited contact with the healthcare system. They are also an important group to engage and to support into treatment. A GP outreach project, the Kombi Clinic, that aims to engage and support people with hepatitis C, especially marginalised populations, into treatment is described in Box 3.
Assessment of patients was covered in Part 2 of this series.5 The initial test to diagnose hepatitis C is a hepatitis C antibody test. If the result is positive then current infection needs to be confirmed with a qualitative hepatitis C virus (HCV) RNA PCR test. If this result is positive then it is followed by HCV genotyping.
Other recommended blood tests after diagnosis of chronic hepatitis C are shown in Figure 1. They include tests:
- to detect hepatitis A, hepatitis B and HIV infection (if not already performed)
- to assess renal and liver function
- to exclude pregnancy.