Legionella pneumonia associated with adult respiratory distress syndrome caused by Legionella pneumophila serogroup 3.

A 68-year-old man developed pneumonia 2 days after nearly drowning in a bathtub of a hot spring spa. Chest radiography revealed bilateral consolidation shadows associated with adult respiratory distress syndrome. Initial treatment with antibiotics and pulse therapy with methylprednisolone was not effective. The patient died on the 4th hospital day. A urinary antigen test for Legionella was positive. Legionella pneumophila serogroup 3 was recovered from an intratracheal specimen. The same serotype of Legionella was isolated from the hot spring water. Restriction enzyme analysis by pulse-field gel electrophoresis revealed identical restriction fragments. We conclude that the water at the hot spring spa could have been the source of infection.