Hepatitis C virus (HCV) testing should shift from the current two-step process to one that requires just a single blood draw, making it quicker and easier to identify people who could benefit from treatment, according to updated guidance from the Centers for Disease Control and Prevention (CDC).
Estimates suggest that more than 2 million people in the United States have hepatitis C. Modern direct-acting antiviral therapy is highly effective, and starting treatment promptly can prevent progression to advanced liver disease, including cirrhosis and liver cancer. However, only a third of people living with HCV have been successfully treated, the CDC recently reported.
Guidelines recommend that all adults should be screened for HCV at least once, regardless of risk factors. One barrier to timely treatment is a cumbersome testing process in which a person first undergoes blood collection for HCV antibody screening and then, if they test positive, must return for a second blood draw to test for HCV RNA, or viral load. People who have ever been infected with HCV—even if they have successfully cleared the virus—will test positive for antibodies. Detectable HCV RNA shows that a person has current active infection and could benefit from treatment.
When an HCV antibody test is positive and no follow-up HCV RNA test is performed, testing is considered incomplete. Historically, about one third of people screened for antibodies have incomplete testing.
According to the updated guidance, all sites that perform HCV screening should collect blood samples at a single visit. Samples that test positive for antibodies should then be tested for HCV RNA, a process known as reflex testing, or automatic testing, because it does not require additional action on the part of patients or health care providers.
Automatic testing can be done using either the same sample of blood drawn from a vein or a second sample collected at the same time. If screening is done using blood from a finger stick, a venous blood sample should also be collected at the same time for HCV RNA testing.
As described in Morbidity and Mortality Weekly Report, Emily Cartwright, MD, of the CDC’s National Center for HIV, Viral Hepatitis, STD, and TB Prevention, and colleagues reviewed data comparing outcomes of traditional two-step testing and automatic HCV RNA testing. A Veterans Health Administration (VA) study found that automatic testing increased the rate of complete testing from 64% to 98%; the VA has required this approach since 2018. Similarly, the Cherokee Nation Health Services found that complete testing rose from 68% to 85% after automatic testing was implemented.
“Use of strategies that require multiple visits to collect HCV testing samples should be discontinued,” the CDC authors wrote. “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.”