A Case of Septicemia due to Capnocytophaga ochracea Beginning Post Radiation Therapy for Lung Cancer

A 46-year-old man was admitted to our hospital on Mar. 16, 1988 with the chief complaint of productive cough. The chest roentgenogram and tomogram showed a tumorous shadow in the right upper lobe, accompanied with stenosis of the trachea and the right main bronchus. Bronchofiberscopic examination confirmed a nodular tumor protruding into the lower part of the trachea from the right lateral wall and nearly complete obstruction of the right main bronchus. Pathological specimen obtained by transbronchial biopsy revealed "low differentiated adenocarcinoma". It was highly suspected that the primary lung cancer had directly invaded the trachea and the right main bronchus. His symptoms and roentgenological findings remarkably improved after radiation therapy. He was discharged on May 12. On Sep. 14, he was admitted to our hospital again because of hoarseness, general fatigue and increasing dyspnea. The chest CT demonstrated severe stenosis of the trachea, which was treated with another radiation therapy. Although his symptoms diminished, he had a sudden onset of high fever on Oct. 15. Immediately a blood culture and transtracheal aspiration (TTA) were performed. Gram-negative bacilli were isolated from the blood culture four days later. The administration of fosfomycin and tobramycin was started. However he died because of massive hemoptysis on Oct. 23. Several days after the death, an isolated strain was identified as Capnocytophaga ochracea by the biochemical characteristics. Culture of sputum obtained by TTA was negative for Capnocytophaga ochracea. Septicemia due to Capnocytophaga spp. is very rare and only one case (due to Capnocytophaga sputigena) has been reported until now in Japan. Our patient is thought to be the first case of septicemia due to Capnocytophaga ochracea in Japan.