Hepatitis C virus testing in primary care

Testing for hepatitis C in primary care:

• the primary screening test is a blood test for antibodies to the virus (anti-HCV), which indicates if a person has ever been infected with HCV
• a positive test should be confirmed by testing a second sample
  • can take three months for antibodies to become detectable
  • a negative test should be repeated if the exposure was within three months of the test
  • about 20-40% of people will clear the virus naturally, so a test to detect HCV RNA is required to establish if the patient is still infected

Pre-test discussion about the HCV test:

• this should include (1):
  • hepatitis C, its natural history and the benefits offered by treatment
  • what the test involves, testing timescale and confidentiality of results
  • assessment of exposure risks and establishing when the last risk activity took place
  • implications of both a positive result and negative result for the individual and his/her family or close contacts (2)
  • importance of giving informed consent to the process (2)
  • what personal support network the individual may have; information about national/local organisations that provide support
• testing for hepatitis C may also offer the opportunity to advise injecting drug users about harm minimisation and to offer them the hepatitis A and hepatitis B vaccine

Post-test discussion about the HCV test:

• discussion will vary with respec to result of the HCV test (1)
  • negative antibody result
    • further testing will be required if the last exposure risk occurred in the preceding three month ?window period?
    • there should be a discussion concerning ways of avoiding infection in the future
  • positive antibody result
    • positive antibody results should be confirmed on a second blood sample, when tests for HCV RNA can also be performed if the positive antibody results are confirmed
    • the patient should be advised not to donate blood or carry an organ donor card
  • positive HCV RNA result
    • patients should be referred to a specialist for further assessment
    • the patient should be advised to stop or reduce alcohol consumption (associated with more rapid progression of liver disease)
    • there should be discussion concerning ways of avoiding infecting others
    • consider the need to test other family members or close contacts
  • negative HCV RNA result
    • a positive antibody and negative HCV RNA test indicates a previously resolved infection, but not immunity to further infection
    • patients who are antibody positive but HCV RNA negative should have a second HCV RNA test after 4?6 weeks to confirm their negative status

Reference:

• (1) Hepatitis C - Quick reference guide for primary care. Face it - Hepatitis C awareness campaign (2007). www.hepc.nhs.uk
• (2) Royal College of General Practitioners (RCGP) 2007. Guidance for the prevention, testing, treatment and management of hepatitis C in primary care