CASPER, Wyo. (AP) — The state health department says SageWest hospital in Lander should inform patients who had surgery between December 2013 and October 2016 that they could have been exposed to non-sterile surgical instruments.

Officials with the Wyoming Department of Health say surgeons on several occasions found dried blood and "bone-like fragments" on instruments that were supposed to be sterile.

Health Department spokeswoman Kim Deti says that while the risk of infection is low, patients should still be informed they may have been placed at risk for hepatitis B, hepatitis C or human immunodeficiency virus. The state says the hospital should offer free blood tests.

SageWest spokeswoman Lindsey Anderson said the hospital's sterilization equipment and procedures have been improved. She says there is no evidence any surgical patients contracted any infectious diseases.