Clinical Presentation of Legionella pneumophila Serogroup 1-Associated Pneumonia and Diffuse Alveolar Hemorrhage: A Case Report and Literature Review

Kazuhiro Ishikawa, Tomoaki Nakamura, Takahiro Matsuo, Fujimi Kawai, Hinako Murakami, Kotaro Aoki, Tatsuya Nagasawa, Yuki Uehara, Nobuyoshi Mori

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Patient: Female, 44-year-old Final Diagnosis: Legionella pneumophila serogroup 1-associated pneumonia and diffuse alveolar hemorrhage Symptoms: Dyspnea Medication: — Clinical Procedure: Bronchoalveolar lavage Specialty: Infectious Diseases Objective: Background: Case Report: Conclusions: Rare disease We report a case of diffuse alveolar hemorrhage (DAH) caused by Legionella pneumophila serogroup (SG) 1 and review the existing literature to identify risk factors and determine the prognosis of patients with Legionella pneumonia-associated DAH. A 44-year-old woman was admitted to our hospital following the presentation of dyspnea for a few days. Chest computed tomography (CT) findings revealed “crazy-paving” pattern in the right upper lobe implicating DAH and consolidation in the lower lobe. Analysis of the bronchoalveolar lavage (BAL) fluid revealed DAH, with fur-ther analyses identifying L. pneumophila SG 1 as the causative agent. The patient was successfully treated with levofloxacin and a red blood cell transfusion and discharged on the 32nd day of hospitalization. A literature review of 6 reported cases (including our case) of Legionella pneumonia-associated DAH revealed that the medi-an age of patients with DAH was 59 years (range, 44-75 years), involving female patients in 4 cases (67%) and the use of immunosuppressive drugs in 2 cases (33%). Three cases were BAL Legionella polymerase chain re-action (PCR)-positive and 4 cases were diagnosed using a urinary Legionella antigen test (one case was simul-taneously PCR-positive). These infections were caused by L. pneumophila SG 1 in three cases and SG 3 in one case. Mechanical ventilation was used in 5 cases (83%) and one patient had an unfavorable prognosis. Steroids for DAH were used in 5 cases (83%), and 2 cases responded to this treatment. Our case highlights that clinicians should be aware of Legionella spp. as a cause of DAH in an immunocompe-tent host with “crazy-paving” pattern on chest CT, and perform a urinary antigen test and BAL PCR for diagnosis.

Original languageEnglish
Article numbere936309
JournalAmerican Journal of Case Reports
Publication statusPublished - 2022
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Medicine


Dive into the research topics of 'Clinical Presentation of Legionella pneumophila Serogroup 1-Associated Pneumonia and Diffuse Alveolar Hemorrhage: A Case Report and Literature Review'. Together they form a unique fingerprint.

Cite this