Five years after a deadly Legionnaire’s Disease outbreak began at the Illinois Veterans Home in Quincy, a group that is trying to reduce the number of cases says there is still more work to do.

The total number of cases of the waterborne respiratory illness has been steadily climbing in Illinois since 2015. The Alliance to Prevent Legionnaire’s Disease says many policies are driven in response to outbreaks… but notes that 96% of cases in the state are identified as “individual and sporadic,” and not part of an outbreak.

The group says more work is needed on public water supplies to ensure the quality of water going into homes and businesses.