Hepatitis C, a common blood-born illness that affects the liver, will be the subject of a class on Vashon next week.

Islander Steve Graham, the board chair of the Hepatitis Education Project in Seattle, will offer the class to provide information about the virus, including how the disease is spread, symptoms and treatments, and encourage people to get tested.

The most recent figures about the disease, which made health news headlines earlier this month, show that most of the roughly 3 million people affected in this country are the baby boomer set — men and women born between 1945 and 1965.

“This is a huge problem, and it’s not going away,” Graham said.

This information is particularly important on Vashon, Graham noted, because the island has a high number of people in this age group. While he does not have solid data about the prevalence of the disease on the island, he said state Department of Health records indicate there were 13 hepatitis C-related deaths on Vashon between 1991 and 2010, a higher number than anticipated for a community of this size.

“We have every reason to believe there is a hidden hepatitis C problem on the island,” he said.

The good news, Graham said, is that there has been considerable progress recently in treating hepatitis C.

Two new medications — sofosbuvir and simeprevir —  were recently approved for treatment, and more are expected to be approved next year.

Currently, public health officials say, more people die from Hepatitis C than from AIDS, even though hepatitis C is not always fatal.

Frequently, people who have the illness have no symptoms, and most do not know they have been infected with it, Graham said. While a small percentage of people are able to get rid of the virus, most go on to develop a chronic hepatitis C infection. Those with the illness have a much higher risk of developing liver disease, liver cancer and other chronic health issues, Graham said.

Hepatitis C is blood-born virus that can be spread through sharing needles with an infected person, from needle stick injuries among health care personnel in the workplace and previously was spread from blood transfusions and organ transplants. Since 1992, however, blood has been tested for the virus, eliminating this route of transmission.

The Centers for Disease Control recommends that all people born between 1945 and 1965 get tested for the virus.

The class, which is free, will meet from 7 to 9 p.m. Wednesday, March 19, at the Ober Park performance room.