CDC Urges Second Test to Catch Hepatitis C Infection

( UPDATED May 8, 2013 ) — Patients who test positive for hepatitis C virus (HCV) antibodies need a follow-up blood test to determine whether they are still infected with the leading cause of liver cancer, the Centers for Disease Control and Prevention (CDC) announced today.

The lack of this complete testing regimen, said the agency, helps explain why up to 3 in 4 individuals who are infected with HCV do not know it — and do not receive the curative antiviral therapy they need.

The antibody test shows whether someone has ever been infected with HCV but does not indicate whether they have cleared the virus, as 20% do, or still harbor it. Clinicians can find that out by ordering an HCV RNA test.

In a news conference today, CDC Director Thomas Frieden, MD, MPH, said that a study published online May 7 in the Morbidity and Mortality Weekly Report illustrates the need for the HCV RNA test. The study analyzed HCV infections reported to the CDC by 2 cities and 6 states between 2005 and 2011. Only about half of the people who tested positive for HCV antibodies received the follow-up RNA test confirming that they were still infected, said Dr. Frieden. The other half were in the dark about their current HCV status.

The study also reinforced the importance of the CDC's recommendation, made last August, that clinicians test all Americans born between 1945 and 1965 — the baby boom generation — for HCV. Of all those found to be currently infected with HCV in the 8 sites studied by the CDC, 67.2% were baby boomers. In addition, this age group accounted for almost 72% of the deaths among those with HCV infection.

The CDC estimates that roughly 3 million adults, most of them baby boomers, are infected with HCV. An untreated infection can lead to serious liver damage and liver cancer, which is the fastest-growing cause of cancer-related deaths in the nation. HCV causes 15,000 deaths each year, which is double the figure 10 years ago.

"If you were born between [1945 and 1965], get tested, and if you're positive, get follow-up tested," said Dr. Frieden. "You may not remember everything that happened in the '60s and '70s, but your liver does.

"For healthcare providers, it's important to put in automatic systems to make sure that if someone has a positive antibody test that they go on to have follow-up testing and then get into care so they avoid further liver damage and, if appropriate, get treated. Right now, there are better hepatitis C treatments than ever, and more treatments coming, so confirming that someone is infected is more important than ever."

The CDC today also issued updated guidance for clinicians and laboratories on testing for HCV infection. The revisions reflect the need for follow-up RNA testing as well as the wider availability of rapid HCV antibody tests — suitable for physician offices — that rival the sensitivity and specificity of laboratory-conducted assays.

Morb Mortal Wkly Rep. Published online May 7, 2013. Full text