Abstract and Introduction
Current hepatitis C virus (HCV) testing guidance recommends a two-step testing sequence for diagnosis of HCV infection. Performing an HCV RNA test whenever an HCV antibody test is reactive (complete testing) is critical to achieve national HCV elimination goals. When an HCV antibody test is reactive and no HCV RNA test is performed, testing is considered incomplete. Historically, approximately one third of patients have incomplete testing. This update clarifies that all sites performing HCV screening should ensure single-visit sample collection. This approach allows for automatic HCV RNA testing when an HCV antibody test is reactive to avoid incomplete testing. Use of strategies that require multiple visits to collect HCV testing samples should be discontinued. Automatic HCV RNA testing on all HCV antibody reactive samples will increase the percentage of patients with current HCV infection who are linked to care and receive curative antiviral therapy.
Examination of the hepatitis C care cascade in the United States reveals a substantial gap between the number of persons who have a reactive hepatitis C virus (HCV) antibody test and those who undergo nucleic acid testing (NAT) for detection of HCV RNA. Performing an HCV RNA test whenever an HCV antibody test is reactive (complete testing) is critical to increase the percentage of patients diagnosed with current HCV infection who are linked to care and receive curative antiviral therapy. To address the challenge of incomplete hepatitis C testing, many laboratories have implemented automatic HCV RNA testing whenever an HCV antibody test result is reactive.[2–4] "Automatic" testing refers to laboratory testing that occurs without additional action on the part of the patient or the health care provider.
Testing for Hepatitis C Virus
Persons with a reactive HCV antibody test result and detectable HCV RNA are determined to have current HCV infection and should be linked to care. Persons who received a reactive HCV antibody test result and undetectable HCV RNA likely have a resolved HCV infection, although falsely reactive HCV antibody tests can occur. The 2013 CDC testing guidance* describes four possible operational strategies to diagnose current HCV infection:
Blood from a subsequent venipuncture is submitted for HCV RNA testing if the blood sample collected is reactive for HCV antibody during initial testing;
From a single venipuncture, two specimens are collected in separate tubes, one tube for initial HCV antibody testing, and a second tube for HCV RNA testing if the HCV antibody test is reactive;
The same sample of venipuncture blood used for initial HCV antibody testing, if reactive, is reflexed for HCV RNA testing without another blood draw; and
A separate blood sample is submitted for HCV RNA testing if the initial testing of HCV antibody has used finger-stick blood.
Operational strategies 2–4 allow for single-visit sample collection, which ensures that HCV RNA testing is performed automatically without requiring a separate health care visit. Operational strategy 1, however, requires two visits to a health care facility, and therefore leads to missed opportunities for HCV diagnosis and linkage to curative HCV treatment.
Morbidity and Mortality Weekly Report. 2023;72(28):766-768. © 2023 Centers for Disease Control and Prevention (CDC)