Illinois state officials have confirmed a third new case of Legionnaires’ disease at a western Illinois veterans’ home since an outbreak there last year killed 12 people and sickened 54.

The directors of the Illinois departments of veterans’ affairs and public health said in a statement Thursday that three residents have tested positive for the disease at the Illinois Veterans Home in Quincy, Ill.

The new cases come less than a month after a nearly $5 million water treatment plant and delivery system was unveiled at the Illinois Veterans Home.