Washington health officials are investigating a man charged with swapping syringes in Colorado who used to work in Seattle as a surgery technician.
They have also warned hundreds of patients to get tested for blood borne pathogens.
Rocky Allen, 28, is accused of stealing a syringe of a powerful pain-killer and replacing it with a syringe of an unidentified substance. He has pleaded not guilty in Colorado to federal charges.
Washington's Department of Health says Allen previously worked at Northwest Hospital in Seattle, Lakewood Surgery Center, and Naval Hospital Bremerton. DOH spokesperson Julie Graham said they're helping those facilities investigate.
She said their goal is to identify the activities that he was able to have access to and determine if there was a risk to patients and who those patients may be.
Naval Hospital Bremerton said Allen didn't have access to controlled substances when he was stationed there between 2008 and 2011.
But the other two facilities have arranged free tests for HIV and hepatitis as a precaution for patients who had surgery during his employment.
That includes 1,300 patients at Northwest Hospital, according to spokesperson Karen Peck. He worked there for about 10 weeks, ending in his termination in March 2012.
"While we understand the situation is very concerning to our patients, based on our preliminary investigation we believe that the risks to our patients are extremely low," Peck said.
Northwest Hospital has set up a hotline for people with additional concerns.
Allen recently applied to renew his Washington certifications, but was denied by the state.
At his preliminary hearing last month, a judge agreed that Allen suffered from a "considerable" drug problem.