[Legionnaires' disease with acute renal failure caused by Legionella pneumophilla serogroup 4].

A 77-year-old man who had fever and chest pain was admitted to a neighboring hospital on a diagnosis of pneumonia. Chest X-ray film finding deteriorated despite treatment with 2 g cefotaxime per day. Because of accompanying acute renal failure, he was transferred to our hospital. Hemodialysis with intravenous administration of erythromycin and meropenem resulted in recovery from acute renal failure, and his general condition improved. Because of liver dysfunction, erythromycin was changed to pazufloxacin. Although he was negative for Legionella urinary antigen determined with a rapid assay kit, Binax NOW, his serum titer for Legionella pneumophila serogroup 4 was elevated. Finally, a diagnosis of Legionnaires' disease caused by Legionella pneumophila serogroup 4 was established.