Clinical Screening and Diagnosis for Hepatitis C

Nearly half of people with hepatitis C are unaware of their infection status, and approximately 75%–85% of people with hepatitis C don’t have symptoms. 1234 Without testing, they can unknowingly transmit the virus to others.

There is no vaccine to prevent hepatitis C. Therefore, the best way to prevent infection is by avoiding behaviors that can transmit the virus.

For the public‎

How to make decisions on whether to test or screen

Clinicians should universally screen:

• All adults 18 and older at least once in their lifetime, except in settings where the prevalence of hepatitis C virus (HCV) infection (HCV RNA-positivity) is under 0.1%.
• All pregnant people during each pregnancy, except in settings where the prevalence of HCV infection (HCV RNA-positivity) is under 0.1%.

CDC recommends one-time hepatitis C testing for people with recognized risk factors or exposures, including:

• People who currently or have previously injected drugs and shared needles, syringes, or other drug preparation equipment.
• People with human immunodeficiency virus (HIV).
• People with selected medical conditions, including people who have ever received maintenance hemodialysis and persons with persistently abnormal alanine aminotransferase (ALT) levels.
• Prior recipients of transfusions or organ transplants, including:
  • People who received clotting factor concentrates produced before 1987.
  • People who received a transfusion of blood or blood components before July 1992.
  • People who received an organ transplant before July 1992.
  • People who were notified that they received blood from a donor who later tested positive for HCV infection.

  CDC also recommends routine periodic testing for patients with ongoing risk factors (regardless of setting prevalence), including:

  • People who currently inject drugs and share needles, syringes, or other drug preparation equipment.
  • People with selected medical conditions, including people who receive maintenance hemodialysis.

  Clinicians should test anyone who requests a hepatitis C test, regardless of stated risk factors, because patients may be hesitant to share stigmatizing risks.

  Screening and testing guidelines

  Clinicians should initiate hepatitis C testing with an HCV antibody test with reflex to NAT for HCV RNA if the antibody test is positive/reactive. See the complete testing sequence .

  If a patient’s antibody test is positive/reactive and they also have detectable HCV RNA, they have a current HCV infection and you should counsel the patient, evaluate for treatment, and initiate an appropriate direct-acting antiviral (DAA) regimen.

  Operational guidance for complete hepatitis C testing

  It is important to reduce time to diagnosis, evaluation, and treatment initiation. CDC recommends that clinicians collect all samples needed to diagnose hepatitis C in a single visit and order HCV RNA testing automatically when the HCV antibody is reactive. 5 When the HCV antibody test is reactive, the laboratories should automatically perform NAT testing for HCV RNA detection. This automatic testing streamlines the process because it occurs without any additional action on the part of the patient or the clinician. See complete recommendations.

  Possibility of false negatives

  During acute HCV infection, antibody becomes detectable at 8–11 weeks. Therefore, a patient who thinks they may have been recently exposed might not have antibody levels high enough for a positive HCV antibody test. In addition, some people might lack the immune response necessary to develop detectable antibodies within this time range. In cases like these, clinicians should consider virologic testing. 67

  HCV RNA testing for recent infection

  HCV RNA testing is recommended for the diagnosis of current HCV infection among people who might have been exposed to HCV within the past 6 months, regardless of HCV antibody result. 10 HCV RNA becomes detectable approximately 1 – 2 weeks after infection with HCV. Suspected exposure may be inferred from the patient's history or the context and setting of the patient encounter (e.g., inferred potential exposure among people who inject drugs presenting to a syringe service program).

  Recommended tests

  Clinicians should use an FDA-approved HCV antibody test followed by a NAT for HCV RNA test when antibody is positive/reactive. Tests include:

  • HCV antibody test (anti-HCV) (e.g., enzyme immunoassay [EIA]).
  • Nucleic acid test (NAT) to detect presence of HCV RNA (qualitative RNA test).
  • NAT to detect levels of HCV RNA (quantitative RNA test).

  A reactive HCV antibody test result indicates a history of past or current HCV infection. A detectable HCV RNA test result indicates current infection.

  NAT for detection of HCV RNA should be used among people with suspected HCV exposure within the past 6 months.

  Perinatally exposed infants

  Clinicians should test all perinatally exposed infants for HCV RNA using a NAT at 2–6 months. Care for infants with detectable HCV RNA should be coordinated in consultation with a provider who has expertise in pediatric hepatitis C management. Infants with undetectable HCV RNA do not require further follow-up unless clinically warranted.

  How to interpret screening results

  Interpretation of Results of Tests for HCV Infection and Further Actions

  Test Outcome