Officials have contacted Beth Israel Deaconess Hospital where the person had been a patient and are dictating infection control measures that must be implemented at the facility, a DPH official said Friday.

Massachusetts health officials are investigating one case of health care-associated Legionnaires' disease involving a patient at a Boston-area hospital.

Legionnaires’ disease is a serious form of pneumonia that is caused by the Legionella bacteria, a water-borne organism found naturally in the environment and not transmitted person-to-person.