Screening inmates in U.S. jails and prisons for the hepatitis C virus (HCV) could strike a major blow against the nation’s hepatitis C epidemic, according to an editorial published in The Journal of the American Medical Association.

Most people with hepatitis C—65 to 75 percent—don’t know they’re infected. Centers for Disease Control and Prevention (CDC) data from the late 1990s and early 2000s indicate that 12 to 35 percent of U.S. inmates have chronic hepatitis C. Assuming a conservative 12 percent chronic infection rate, the editorial’s authors estimate that of the roughly 9 million people jailed or incarcerated through the U.S. correctional system each year, as many as 1 million have undiagnosed hepatitis C.

Previously, it wasn’t considered cost-effective to provide routine HCV testing in jails or prisons because the high turnover rate in the penal system—especially in short-term holding facilities where the average stay is 48 hours—meant that only 1 percent of inmates would be expected to remain available for the 48 week course of treatment. But improvements in testing and treatment are changing how officials look at the problem.

In November 2011, the U.S. Food and Drug Administration (FDA) approved the use of a rapid HCV fingerstick test that produces results in 20 minutes. This can be used as part of an opt-out testing strategy that’s been proved successful in screening inmates for HIV, according to research published in the Journal of Acquired Immune Deficiency Syndromes.

In addition, hep C treatment is more effective and accessible than ever before. The new antivirals Victrelis (boceprevir) and Incivek (telaprevir) improve cure rates by 20 to 30 percent, with 40 to 60 percent of patients clearing the virus in less than the 48 week baseline using response-guided therapy. Pilot programs like the University of New Mexico’s Project ECHO (Extension for Community Healthcare Outcomes) provide treatment in community health centers for those who pass through the correctional system too quickly to receive treatment therein. And the Affordable Care Act will eventually finance post-release care for people who receive an HCV diagnosis while they’re in prison.

Performing such screenings will be challenging. The medical needs of inmates aren’t a primary focus for jail administration, and the high throughput of inmates through the system will make it hard to provide counseling and confirmatory tests for those who test positive—especially given a lack of funding for prison health care.

Assuming that 70 percent of inmates infected with HCV get the opportunity to be tested, and that 70 percent of those inmates take the test, the authors speculate that testing could reveal half a million cases of HCV in a hypothetical program’s first year. Backing up this testing with treatment and follow-up programs would put a serious dent in the U.S. hepatitis C epidemic.