既往からのリスク因子 : 高齢、慢性肝障害、喫煙、喘息
CHADS2-VASc : 5点
PSI : 120点
CURB65 : 3点
A-DROP : 3点
血液ガス分析 pO2 ：64
呼吸数 > 30
提案 : LVFX or AZM inj
期間 : 10-14日、反応が悪ければ21日
治療経過の想定 : レジオネラ肺炎の臨床反応はゆっくり
Up To Date より引用し復習
The newer macrolides (especially azithromycin) and the respiratory tract quinolones (especially levofloxacin) are effective for Legionella infection. In four studies that included a total of nearly 600 patients with Legionnaires' disease, outcomes were similar in patients who received quinolones (levofloxacin, ofloxacin,ciprofloxacin) compared with those who received macrolides (erythromycin, clarithromycin). However, more rapid defervescence, fewer complications, and/orshorter hospital stay were seen with the quinolones.
●Suspected or proven Legionella pneumonia should be treated in most patients with levofloxacin (750 mg once daily) or azithromycin (1 gram on day one, followed by 500 mg once daily). Patients from long-term care facilities, those with nosocomial infection, and those who have received transplants should be treated with a fluoroquinolone to provide better coverage of other gram-negative bacilli and, in the case of transplant recipients and HIV patients, to avoid interactions between macrolides and immunosuppressive drugs.
●We recommend parenteral treatment initially for all patients with suspected Legionella pneumonia, given gastrointestinal dysfunction in some patients. A switch to oral therapy can be made after the patient defervesces.
●The total duration of therapy for Legionella pneumonia is 7 to 10 days. A longer course of antibiotics of 21 days might be considered for immunosuppressed patients who are severely ill upon presentation.
●Combination antibiotic therapy of a quinolone plus azithromycin might be considered for severely ill patients with extrapulmonary legionellosis. We also userifampin as part of combination therapy with quinolones in selected patients, but drug interactions can be problematic.
●Legionnaires' disease is not transmitted from person-to-person; thus, isolation for hospitalized patients is unnecessary. Since the source of the organism is the hospital drinking water, prevention of nosocomial legionellosis is possible by routine culturing of the hospital drinking water. Monochloramine disinfection of municipal water supplies is associated with decreased risk of Legionella infection in the community.