A birth cohort approach was more effective than the elevated alanine aminotransferase levels strategy among testing methods for hepatitis C antibody, according to new research.
With estimates of undiagnosed hepatitis C virus (HCV) infection ranging from 40% to 85%, and because of the limitations of risk-based testing, Bryce D. Smith, PhD, health scientist in CDC’s division of viral hepatitis, and colleagues compared two HCV antibody (anti-HCV) testing strategies for their sensitivity, number of cases identified and size of tested population. The first is based on elevated levels of alanine aminotransferase (ALT) that act as an indicator of liver injury, and the second is a birth cohort approach targeting baby boomers born from 1945 to 1965.
Bryce D. Smith
Both strategies were evaluated in 2013 using independent models based on ALT levels and birth year of 19,055 adults aged 20 to 70 years (mean age, 42.7 years) who participated in the National Health and Nutrition Examination Survey from 1999-2008. The investigators compared the number of individuals identified as anti-HCV-positive in each model, as well as the proportion of total cases identified and the projected number that would be tested using either strategy.
Approximately 46.8% of participants were in the birth cohort age-range, and 11.8% had elevated ALT levels. Anti-HCV prevalence estimates were 2% (95% CI; 1.8% to 2.3%) among the tested demographic, which represents an estimated 3.6 million individuals. The birth cohort strategy would test 85.4 million people and identify 2.8 million cases with 76.6% sensitivity. The ALT strategy would test 21.5 million cases and identify 1.8 million with 50% sensitivity. Co-implementation of both strategies would identify 87.3% of anti-HCV-positive adults.
“A combination of testing strategies is key to identifying more hepatitis C infections,” Smith told Healio.com/Gastroenterology. “Testing only those with elevated liver enzymes (ALT levels) is not enough – it misses far too many infections and it is not universally performed. In fact, our analysis found that following CDC’s recommendation to test all individuals born from 1945-1965 (i.e., baby boomers) would result in approximately one million more identified infections than ALT alone. Incorporating both CDC recommended strategies has the potential to identify 87% of all hepatitis C cases.”
Disclosure: The researchers report no relevant financial disclosures.