bytemarks/Flickr An odd cluster of 5 bloodstream infections occurred in the same hospital in a 5-week period. An investigation was launched, and syringes around the hospital were discovered emptied out and refilled with salt water. A nurse had apparently entered her password to remove medications just before four of the patients who contracted infections received their medicine. The nurse, who reported struggling with opioid addiction, was swiftly fired for stealing the drugs. The string of infections stopped, but one infected person died. As an infectious disease doctor, Nasia Safdar is a detective of sorts at the University of Wisconsin Hospital in Madison.