The number of programs that provide clean needles to people who inject drugs increased from one to about 50 in Kentucky, North Carolina and West Virginia between 2013 and 2017, HealthDay reports.

The findings come from a new study by the Centers for Disease Control and Prevention

These programs, also known as syringe services programs (SSPs), were legal in West Virginia in 2013, but were banned in Kentucky until 2015 and in North Carolina until 2016. The study found that visits to SSPs by clients who inject drugs increased during this period. The researchers conclude, “The increase in client visits to SSPs by persons who inject drugs represents an unprecedented opportunity to improve access to care for this highly stigmatized population.”