Legionellosis associated with artesian well excavation.

In October 1990 pneumonia due to Legionella pneumophila was diagnosed in two employees working in the area of Apulia, southern Italy, where artesian wells were in construction. Although the exposure to excavation has been associated with Legionnaires' disease, in our investigation the illness occurred only in those employees who were present when the water emerged from the ground under high pressure. On the basis of this report, water appears as the most likely reservoir of the organism and the main route of infection.