PITTSBURGH — The inspector general’s office at the Department of Veterans Affairs says the Pittsburgh VA Healthcare System didn’t follow its own rules to combat the waterborne bacteria that causes Legionnaires’ disease.

Tuesday’s report was prompted by 21 veterans sickened by the bacteria at VA hospitals in Oakland and O’Hara Township since February 2011. Five died.

The hospital developed guidelines after an outbreak in 1982, but the inspector general found the hospitals didn’t maintain a copper silver ionization system used to track the bacteria, didn’t routinely flush hot water faucets, and didn’t properly test patients who developed pneumonia.