Norton Healthcare, Louisville, Ky., has become the latest system to require its employees to get flu vaccines.

The five-hospital system said in a news release (PDF) that more than 12,000 employees who work in its clinical facilities, including independent physicians, would be to receive an influenza vaccination by Dec. 10 unless they have a medical condition that prohibits it.

The Kentucky system becomes one of a small but growing number of healthcare organizations to take the step. Last month Phoenix-based Banner Health said it would do so for its 36,000 employees.

Norton's announcement comes a week after the state of Rhode Island began requiring flu vaccines for healthcare workers. The CDC reported recently that about two-thirds of healthcare workers received a flu vaccination in the 2011-2012 season, an increase of 3.4 percentage points over the previous season.

“It is important that our employees know the impact they have on patient care and community health,” Norton's Dr. Paul Schultz, medical director, infection control and employee health, said in the release. “Early adoption of this policy proves our leadership in the healthcare community.”