(Seattle, WA)  --  Northwest Hospital & Medical Center in Seattle is warning that a former employee may have exposed patients to hepatitis B, hepatitis C, and HIV.  The hospital says the surgical technologist was employed there from December 30th, 2011 to March 9th, 2012.  Northwest Hospital officials say they believe the level of risk is very low, but more than 13-hundred patients who had surgery at the hospital during the period have been notified and have been asked to be tested.  More information is available at 800-695-0654.