Half of Reported HCV Cases Not Tested for Infection, Prompting Changes to CDC Testing Recommendations
Only half of patients reported to have hepatitis C virus (HCV) infection undergo HCV RNA testing to identify current infection, according to a Vital Signs report published in the May 10 issue of Morbidity and Mortality Weekly Report. This current lack of identification of patients who could benefit from treatment is prompting the U.S. Centers […]
Only half of patients reported to have hepatitis C virus (HCV) infection undergo HCV RNA testing to identify current infection, according to a Vital Signs report published in the May 10 issue of Morbidity and Mortality Weekly Report. This current lack of identification of patients who could benefit from treatment is prompting the U.S. Centers for Disease Control and Prevention (CDC) to update its testing guidelines to include HCV RNA reflex testing in patients with a reactive HCV antibody test. Previous CDC guidelines for HCV laboratory testing and reporting (2003) focused on identifying HCV antibody-positive persons and, therefore, reports to state and local surveillance programs have included persons with a past HCV infection that has resolved. Only HCV RNA testing can identify patients with current infection who could benefit from treatment. But according to the latest CDC data, only half of patients reported for reactive HCV antibody tests receive HCV RNA testing. Researchers analyzed surveillance data from eight U.S. reporting sites (2005 to 2011). For the sake of analysis a positive HCV RNA result could be determined from either HCV nucleic acid testing or HCV genotyping. The researchers found that of 217,755 persons with newly reported positive test results, 49.2 percent were HCV antibody-positive only and 50.8 percent were reported with a positive HCV RNA result, indicating current HCV infection. The percentage reporting positive HCV antibody results varied only by reporting site, ranging from 76 percent in New Mexico to 23 percent in Minnesota. As is consistent with the heavy burden of HCV infection among persons born from 1945 to 1965, the majority of patients reported in both groups were born in this range—58.5 percent of the HCV antibody-positive-only and 67.2 percent of the HCV RNA-positive. The CDC had amended testing recommendations in 2012 to include one-time HCV testing for all persons born between 1945 and 1965, regardless of other risk factors, because of the high prevalence of HCV infection in this group. Acknowledging that testing strategies must ensure the identification of those persons with current HCV infection, in May, the CDC issued an update to its HCV testing recommendations. For primary care and public health providers, initial HCV testing begins with either a rapid or a laboratory-conducted assay for HCV antibody in blood and for reactive results HCV RNA testing using either serum- or plasma-reactive result should follow. “CDC is issuing this update in guidance because of 1) changes in the availability of certain commercial HCV antibody tests, 2) evidence that many persons who are identified as reactive by an HCV antibody test might not subsequently be evaluated to determine if they have current HCV infection, and 3) significant advances in the development of antiviral agents with improved efficacy against HCV,” wrote the CDC Association of Public Health Laboratories workgroup responsible for the amendment. Among the changes in the commercial HCV testing market since 2003 are the availability of OraSure Technologies’ rapid HCV antibody test and the discontinuation of previously recommended RIBA HCV test (Novartis Vaccines and Diagnostics).