WASHINGTON (AFP) - US authorities on Tuesday urged all adults born between 1945 and 1965 to get tested for hepatitis C, saying millions of Americans are unaware that they are infected with the liver disease.

The so-called baby boom generation accounts for three out of four people with hepatitis C, according to Albert Siu, co-chair of the US Preventive Services Task Force.

"Many people in this age group contracted hepatitis C from a blood transfusion or unknown or unreported high-risk behaviours," he said.

"Even though they may have no symptoms yet, the evidence is convincing that one-time screening will help find millions of Americans with the infection before they develop a serious liver disease."

The US task force also recommends hepatitis C screening for adults at risk of infection, including people who currently use injection drugs or have in the past, as well as people who received a blood transfusion before 1992.

About 1.5 per cent of the US population is infected with hepatitis C, making it one of the most common causes of chronic liver disease in the United States today, according to the US National Library of Medicine.

The disease can cause cirrhosis of the liver and liver cancer.

Last year, the Centers for Disease Control and Prevention reported that more Americans died in 2007 from hepatitis C than from the virus that causes Aids.

More than 15,000 people died of hepatitis C infections in 2007, compared to 12,734 who died from HIV-related causes, said the data published in the Annals of Internal Medicine.