The number of deaths from the hepatitis C virus is up while deaths related to HIV/AIDS are down, according to U.S. researchers. As a result, more Americans are now dying from hepatitis C than from HIV/AIDS.

Researchers at the U.S. Centers for Disease Control and Prevention (CDC) used death certificates to track fatal cases of three viral infections - hepatitis B, hepatitis C, and HIV/AIDS - over almost a decade, starting in 1999.

Over nine years, HIV deaths steadily decreased as prevention programs took effect and better treatment became available. At the same time, hepatitis C cases climbed, and by 2007, more Americans were dying from that virus than from the one that causes AIDS.

Hepatitis B deaths were relatively steady during the study period, and they accounted for a fraction of the deaths caused by the other two viruses.

Co-author John Ward, director of the CDC hepatitis division, says the uptick in hepatitis C deaths doesn't indicate more people are becoming infected.

"The number of deaths from hepatitis C [is] increasing," he says, "because the persons infected with this virus are aging into a period of their lives when they're becoming sick with liver cirrhosis or liver cancer caused by this viral infection."

Hepatitis C was discovered in 1989, and Ward says most of the three million Americans who are infected with it were exposed before then - for example through contaminated blood transfusions or by injecting illicit drugs.

A person can carry the virus for decades without any symptoms, until major, and often fatal, liver disease develops.

Ward says the successes of the fight against HIV/AIDS could serve as a roadmap for battling hepatitis C. That includes more testing of people at risk, especially those born between 1945 and 1965, and developing a robust treatment network to reach patients with the latest generation of effective medicines.  

"And when we say effective, we're really talking about eliminating the viral infection - essentially, a cure of the infection, not lifelong or ongoing chronic therapy, but a course of treatment that for 70 percent of persons can lead to elimination of the virus."

He says the effort could save 80-120,000 lives over the coming years.