Mendocino County health officials are investigating three recent cases of Legionnaire’s disease, a potentially lethal bacterial infection contracted by breathing contaminated mist or vapor.

Two of the people have been released from the hospital. The third remains hospitalized, said Stacy Cryer, the county’s public health director.

She said investigators are checking for places the afflicted three may have visited before becoming ill. So far, they’ve found all three had stayed at the Discovery Inn, located in north Ukiah.

Cryer would not reveal when they were at the motel.

Legionnaire’s disease can result in pneumonia-like symptoms. They include cough, shortness of breath, high fever, muscle aches and headaches. The symptoms usually begin two- to 14 days after exposure to the bacteria.

The Legionella bacteria that cause the disease are naturally found in the environment, usually in water, health officials said. People can get sick when they breathe in the mist or vapor from contaminated water, such as in hot tubs that are not adequately disinfected.