CHICAGO (CBS) — An inmate at an Illinois prison was being treated for Legionnaires’ disease on Wednesday.

The Illinois Department of Corrections said an inmate at Stateville Correctional Center, located in Crest Hill, has been transferred to an outside hospital for treatment.

No other inmates have shown any symptoms of the disease, according to an IDOC spokesperson.

The infected inmate’s cell tested negative for the disease.

“We are working to identify the source, and have already begun sanitizing potential areas of concern,” IDOC spokeswoman Nicole Wilson said in an email.

The Legionella bacterium is found in water or water systems, especially in warm water, such as hot tubs that have not been properly cleaned and disinfected. A person can become infected by breathing steam or mist from contaminated water.

The disease is not spread from person to person, and is treatable if caught early enough.