2021 Volume 43 Issue 2 Pages 150-155
Background. Legionella pneumonia-when not properly treated-is associated with a high rate of mortality; thus, an early diagnosis and treatment are critical. In some cases, however, an early diagnosis may be difficult to make. Case. A 53-year-old Japanese man who visited a local hospital with a chief complaint of fever, was diagnosed with bacterial pneumonia and was given ceftriaxone; however, his condition did not improve. He was therefore transferred to our hospital for treatment. The initial antibiotic treatment failure and chest CT imaging suggested organizing pneumonia as a probable diagnosis. In order to distinguish between bacterial infection and organizing pneumonia, we performed bronchoalveolar lavage (BAL) soon after his arrival at our hospital. We could not perform a Legionella urinary antigen test because we could not obtain a urine sample. Thus, we performed the Legionella antigen test using bronchoalveolar lavage fluid (BALF) as a substitute for urine on a trial basis. Based on the positive test result, we suspected legionella pneumonia. The diagnosis of legionella pneumonia was subsequently confirmed by the analysis of a urine sample using a Legionella urinary antigen test. We immediately started treatment with levofloxacin and azithromycin. He made a good recovery and was discharged on the ninth hospital day. Conclusion. When a urine sample cannot be obtained in a case of suspected legionella pneumonia, BALF can be substituted for urine for the Legionella urinary antigen test.
