First Self-Test for Hepatitis C Virus

WHO has prequalified the first self-test for hepatitis C virus (HCV), specifically designed for lay users.

The burden of HCV infections still poses a substantial global health challenge. Despite the development of direct-acting antiviral therapies with response rates of more than 95%, limited access to diagnostic tests and treatment has resulted in chronic infection and consequential serious illness and progressive liver damage for millions of individuals worldwide. WHO estimates that, globally, approximately 50 million people have chronic HCV infection, and around 242 000 individuals died in 2022 from causes resulting from ongoing HCV infection, mostly cirrhosis and hepatocellular carcinoma.

Because of the public health threat and burden of viral hepatitis, WHO have called for its elimination by 2030, setting targets of diagnosing 90% of people living with hepatitis C and starting treatment for 80% of those diagnosed. However, these targets are still a long way off, hampered by obstacles such as a lack of funding for hepatitis C elimination programmes in low-income and middle-income countries (LMICs), which bear the heaviest burden of hepatitis C disease—around 30 million people have chronic infection in the WHO Eastern Mediterranean, South-East Asian, and African Regions, with many of these countries experiencing extreme poverty, civil unrest, or war.

Other obstacles to hepatitis C elimination include delays to starting treatment while waiting for confirmation of current HCV infection by quantitative RNA laboratory testing, and delays to testing for anti-HCV antibodies. Early detection and treatment can prevent long-term liver damage and improve health outcomes; however, acute HCV infections are usually asymptomatic, so individuals might not be aware that they are infected and do not seek testing. Although 30% of acute infections resolve spontaneously within 6 months without treatment, around 70% of infected individuals develop chronic HCV infection. WHO recommends testing for individuals who might be at increased risk of infection, such as people who inject drugs, men who have sex with men, sex workers, those living with HIV and other individuals who may be exposed to blood. However, diagnosis of HCV infection can be a multi-step process requiring several health-care visits for testing, sending samples to a central laboratory for RNA confirmation, receiving the results, and potential additional tests, which might discourage many at-risk individuals from getting tested and receiving necessary treatment.

The first hepatitis C self-test, which uses a finger-prick blood sample and is designed to be used by individuals at home, is therefore, a welcome addition to the testing and diagnosis armamentarium. The self-test, manufactured by OraSure Technologies (Bethlehem, PA, USA), is a rapid test for anti-HCV antibodies and is specifically designed for lay users. Neil Gupta (Coalition for Global Hepatitis Elimination, The Task Force for Global Health, Decatur, GA, USA) commented “HCV self-testing provides an effective and empowering approach to improving awareness of [hepatitis C viral] status and community-based screening, and the Coalition for Global Hepatitis Elimination applauds the recent WHO pre-qualification for HCV self-testing”. However, noting the heavy burden of infection and disease in low-income countries, Gupta highlighted “The test will need to be affordable for national programmes in LMICs and stringent measures will be needed to avoid price mark-ups in private, retail, or other direct-to-consumer markets”.

Additionally, although the self-tests are an important step forward in accomplishing the goal of 90% diagnosis rates by 2030 and eventual elimination, they are antibody-based and do not distinguish between active and cleared infection. Raymond T Chung (Hepatology and Liver Center, Massachusetts General Hospital, Boston, MA, USA) commented “This would require an additional test for presence of viral nucleic acid (HCV RNA) or antigen. Thus, the uncovering of a positive self-test would still require additional testing and linkage to care to achieve clearance of infection, the ultimate goal of elimination efforts”. To accomplish this goal more swiftly and effectively than requiring samples to be sent off for RNA testing, Chung highlighted a strategy of deployment of rapid point-of-care testing for HCV RNA or antigen tied to immediate treatment with curative antiviral therapy, noting the recent US Food and Drug Administration’s authorisation of the first point-of-care hepatitis C virus RNA test. “This test-and-treat approach, particularly applied to high-prevalence settings such as substance use disorder facilities, could substantively contribute to HCV elimination. However, additional efforts will still be required to make antiviral therapy more readily available at the point of care”. Gupta added “Additionally, whereas affordable HCV self-testing can improve HCV screening, the price and availability of virologic testing, which is required to confirm HCV diagnosis prior to treatment, remains a major obstacle to HCV elimination in LMICs and must be urgently addressed”.

By Priya Venkatesan

Source: The Lancet Microbe