Legionnaires' disease in a transplant unit: isolation of the causative agent from shower baths

Legionnaires' disease was diagnosed in two patients in a transplant unit, both patients having occupied the same postoperative cubicle shortly before onset of their illnesses. Legionella pneumophila was found in water taken from the cubicle shower bath and from other showers in the unit. To eradicate the legionellae, the water supply was treated with chlorine, but this had only a temporary effect.