State prisons across the country are failing to provide hepatitis C virus (HCV) treatment to at least 144,000 inmates living with the virus — roughly 97 percent of the total HCV-positive prison population — says a recent study of state corrections departments in the United States, Kaiser Health News reports.

Conducted for a master’s project at Columbia University’s Graduate School of Journalism, the survey asked corrections departments in all 50 states about their hepatitis C treatment policies. State prisons were also asked how many patients were living with the virus and which drugs were typically used for treatment. Almost all states responded to the information request, excluding Washington, DC, South Carolina and North Carolina.

State prisons house nearly 1.3 million inmates — the largest group of incarcerated people in the country. It is also estimated that one in seven state inmates is living with hepatitis C. This latest study shows just 3 percent have been given access to treatment.

Many of the states that responded to the survey cited high drug prices as their primary reason for denying treatment. Without discounts, the drugs can cost up to $90,000 per patient for a full course of treatment (although many state prison systems are negotiating lower prices for the cures).

Meanwhile, advocates say denying hepatitis C treatment ignores a 1976 Supreme Court ruling that determined that inmates have a constitutional right to medical care. They also argue that treating people in state prison systems, which release more than 75,000 people with HCV into the general population every year, is one of the best places to concentrate efforts to end the epidemic.

In response to the vast undertreatment of the prison population, class-action lawsuits currently under way — in Minnesota, Virginia, Alabama, California, Colorado, Florida, Missouri, South Carolina and Tennessee — are challenging prisons to provide hepatitis C medications to their HCV-positive inmates.

In the meantime, thousands of prisoners fear they will get sick and die behind bars — from a preventable and curable disease.