A case of severe Legionella pneumonia following alemtuzumab infusion for multiple sclerosis

Abstract

Abstract Legionella pneumophila is a gram-negative intracellular organism which can cause a severe pneumonia known as Legionnaires' disease, typically occurring after exposure to contaminated aqueous environments. We report the first case of a severe Legionella pneumophila pneumonia in a 35-year-old male with multiple sclerosis. The infection occurred after his second cycle of alemtuzumab. In hindsight, the patient had an incidental exposure to a hot tub and air conditioning equipment during the infusion. This case raises awareness about the risk of acquiring opportunistic infections, especially around the time of the alemtuzumab infusions, and the need to diligently monitor for severe respiratory infections in this vulnerable population.