Watch CBSN Live

Half of Hepatitis C patients face major health risks because of incomplete testing

Half of Americans with hepatitis C may not be getting sufficient care, putting their health at risk.

A new report from the Centers for Disease Control and Prevention (CDC) shows that half of U.S. adults who were diagnosed with the disease at one point skipped follow-up testing health officials deem necessary to stay ahead of serious complications that can destroy the liver.

"Many people who test positive on an initial hepatitis C test are not receiving the necessary follow-up test to know if their body has cleared the virus or if they are still infected," CDC Director Dr. Tom Frieden said in an agency news release. "Complete testing is critical to ensure that those who are infected receive the care and treatment for hepatitis C that they need in order to prevent liver cancer and other serious and potentially deadly health consequences."

The hepatitis C blood test is comprised of a test for antibodies, immune system responses that show up when a person is infected. The follow-up test, called an RNA test, determines whether a patient is infected and requires medical treatment. About 20 percent of people with antibody-positive tests clear the virus on their own, but most remain infected and go on to have health problems, the CDC said.

The CDC is updating its treatment guidelines to reinforce the importance of properly testing and identifying people with hepatitis C.

About 3 million Americans are infected with hepatitis C, according to CDC statistics, and up to 75 percent of them have no idea. The infection is caused by a virus that attacks the liver and causes inflammation, according to the Mayo Clinic. Most people infected do not show any symptoms, or even realize they have the disease until decades pass and liver damage shows up on routine medical tests.

Left untreated, hepatitis C can cause scarring of the liver -- called cirrhosis -- 20-30 years after getting infected. Liver cancer and liver failure are also potential complications, according to the Clinic.

Deaths from hepatitis C have nearly doubled in the U.S. over the past decade, making up more than 15,000 deaths each year.

The CDC points out that baby boomers, who were born between 1945 and 1965, make up about two-thirds of the hepatitis C cases and deaths in the country. Last August, the agency told all boomers to get a one-time blood test to see if they have the disease, given the lengthy time lapse before symptoms may appear.

The FDA re-emphasized that advice Tuesday.

"Hepatitis C has few noticeable symptoms, and left undiagnosed it threatens the health of far too many Americans -- especially baby boomers," Dr. John Ward, director of CDC's Division of Viral Hepatitis, said in the news release. "Identifying those who are currently infected is important because new effective treatments can cure the infection better than ever before, as well as eliminate the risk of transmission to others."

Baby boomers, in fact, are five times more likely to have hepatitis C, according to the CDC. The disease is spread mostly through contact with infected blood, and some adults may have gotten infected before widespread blood screening was enforced in 1992. Other high-risk groups that should get tested include people who received blood products with clotting factor prior to 1987, people with HIV, people who have been on kidney dialysis for several years, health and public safety workers who have been struck with a needle or people who have injected drugs -- even if it was only once a long time ago.

The CDC's new guidance on hepatitis C was published May 7 in a Vital Signs report.