"Most people don't have any signs or symptoms," of hepatitis C, says Dr. Thomas Shehab, a fellow in the university's gastroenterology division.

"Given that people are asymptomatic and the disease is potentially affecting their liver without them knowing about it, we have to go looking for it," Shehab says.

It's estimated about 4.5 million Americans are infected with hepatitis C, yet few know they have the blood-borne virus. It can go undetected for years and cause cirrhosis, liver failure and liver cancer.

Shehab and two colleagues used a special mathematical model to estimate the impact of hepatitis C screening on life expectancy and associated medical costs in a population of 45-year-old Americans.

They found that such a screening program, which involves a simple blood test, would cost about $11,000 per life year saved, assuming that a response to therapy led to long-term medical care. They say that's well below the $50,000 per life year saving that's considered acceptable in the United States, Shehab says.

The findings were presented at a recent meeting of the American College of Gastroenterology.

Currently, most doctors just test for hepatitis C when someone shows symptoms of liver disease, Shehab says.

"Our research has suggested that we're missing the boat, that there are a ton of people out there walking, talking and feeling well who have the disease who aren't being diagnosed, either because they're not being asked about their risk factors or because nobody thinks to test them for the disease," Shehab says.

There are a number of factors that put you at risk for hepatitis C. They include receiving a blood transfusion or organ transplant before 1992, sexual promiscuity, being born to a mother with hepatitis C, or using intravenous drugs.

As for that last risk factor, Shehab notes you don't have to be a hard-core drug user to be at risk.

"They can be somebody who at one time in their 20s or 30s experimented with intravenous drugs, and shared a needle," he says.

The need for a widespread screening program for hepatitis C was made apparent by the terrorist attacks of Sept. 11, Shehab adds.

More than 10,000 people who donated blood in the aftermath of those attacks will be notified they have hepatitis C, says the American Liver Foundation (ALF).

But while hepatitis C is a serious public health issue, a universal screening program for hepatitis C isn't a priority for the foundation.

"I don't think anybody's ever brought this up before," says Dr. Caroline Riely, the associate medical director of ALF.

She says ALF does advocate screening for those at special risk, including people who use drugs, who received blood transfusions before 1992, or who engage in risky sexual behavior.

One major problem with universal hepatitis C screening is privacy, she adds.

"There's a lot of concern about screening large populations in terms of what it does to your employability, insurance and that kind of thing. So there would be some potential downsides," Riely says.

What To Do

Riely says hepatitis C kills 8,000 to 10,000 Americans each year. That number is expected to increase to 20,000 to 30,000 a year within a decade.

There is no vaccine to prevent hepatitis C infection. Antiviral medicines are effective in only about 2 to 3 of every 10 hepatitis C patients, says the Centers for Disease Control and Prevention (CDC). If you do have hepatitis C, you need to determine if you have liver disease and, if so, what treatments may be required.

You also need to learn how to protect your liver from more harm and how to prevent spreading hepatitis C to other people, the CDC says.

Protecting your liver includes: not drinking alcohol; visiting your doctor regularly; and not taking any medications -- including over-the-counter or herbal products -- without consulting your doctor.

Hepatitis C patients shouldn't donate blood, organs, other tissues or sperm. They shouldn't share a toothbrush, razor or other personal care items that may have blood on them. Any cuts or sores on the skin should be covered.