Fitness doesn't faze hepatitis C, a potentially fatal disease you may not even know you have. Shockingly, four million Americans, largely between the ages of 20 and 39 and more often male than female, are infected with HCV, a malady that was unknown a decade ago and even today is unfamiliar to many. According to the Centers for Disease Control and Prevention, about 30,000 new infections occurred in the United States last year, and the HCV-related annual death rate, currently about 9,000, is expected to triple by 2008.

Hepatitis C is particularly dangerous because it can linger in the body for 10 to 30 years before symptoms appear. As a result, 90 percent of HCV carriers don't even know they're infected. Meanwhile, the virus attacks the liver, inflicting damage that can lead to cancer or cirrhosis.

"When people first get the infection, the majority may not have discernible symptoms," says CDC epidemiologist Scott Kellerman, MD. Some experience mild flulike symptoms or a yellowing of the eyes and skin known as jaundice. Later symptoms include loss of appetite, fatigue, nausea, vomiting, dull pain in the upper right torso and dark urine.

How To, How Not To
The main cause of hepatitis C infection is blood-to-blood contact. If you had a transfusion before 1993, when routine HCV screening in American blood banks began, it's possible you may have been exposed. Intravenous drug use is another major risk factor, as is steroid use.

Other means of infection aren't clear; unnervingly, some people with hepatitis C have no idea how they got it. Possible transmission routes are work-related needle sticks; getting acupuncture; getting a tattoo or body piercing with unsterile equipment; and sharing razors, toothbrushes or nail clippers with an infected person.

What about sex? "No one knows for sure," says hepatologist Willis Maddrey, MD. "In monogamous relationships, it's unusual for the uninfected partner to become infected. It has occurred in only 5 percent of those situations." On the other hand, the CDC recently estimated that up to 20 percent of cases may have been sexually transmitted. Bottom line: Use a condom, especially when anal sex or menstrual blood is involved.

You can't get hepatitis C by shaking hands, hugging, kissing or sitting next to an infected person. That goes for most sports as well; sweat has not been shown to pass the virus, so unless there's exposure to blood, there's almost no risk from working out in a gym. If you think you might have been exposed to HCV, don't ignore the possibility -- see your doctor for a test. If you do have hepatitis C, the sooner you get help, the better.

A little good news
About 15 percent of people who contract HCV will naturally clear the virus from their bodies. And the FDA has approved a combination therapy of interferon, a virus-blocking protein, with the antiviral drug Rebetron (ribavirin). This pharmaceutical cocktail has increased cure rates for HCV by tenfold, working in about half of the patients who try it. There are side effects, however; ask your doctor about them.

A substance that makes things worse is alcohol, so if you have HCV, stop drinking. Furthermore, be wary of taking too much aspirin or other pain-killers. In the end, this is a chronic disease, one that many patients simply learn to live with. "Hepatitis C is not a death sentence," says Kellerman. "People who test positive for hepatitis C should absolutely continue to work out. They should continue to lead a normal life."

For more information, contact the American Liver Foundation at 800-465-4837