Vergis E N, Akbas E, Yu V L
VA Medical Center and University of Pittsburgh, Pittsburgh, Pennsylvania 15240, USA.
Semin Respir Crit Care Med. 2000;21(4):295-304. doi: 10.1055/s-2000-9862.
Legionella pneumophila has been found to be a common cause of community-acquired pneumonia in patients who required intensive care unit (ICU) admission. In many studies, the clinical manifestations for Legionnaires' disease were more severe and the mortality was higher when compared with pneumonias of other etiology. However, this may be due to delay in diagnosis and suboptimal antibiotic therapy, rather than enhanced virulence of L. pneumophila. A syndromic approach using high fever, diarrhea, mental status changes, hyponatremia, etc., may be useful in suggesting the correct diagnosis in patients with severe pneumonia, but this remains to be validated. The availability of Legionella diagnostic microbiology testing in-house (rather than being sent to an outside reference laboratory) maximizes the ability to correctly diagnose Legionnaires' disease. All patients with community-acquired pneumonia admitted to an ICU should undergo Legionella testing using the urinary antigen and culture on selective media. Moreover, we recommend routine cultures of the hospital water supply once a year (regardless of whether a case of nosocomial Legionnaires' disease has ever been diagnosed). If Legionella is found in the water supply, all patients with nosocomial pneumonia should undergo diagnostic tests for Legionella; empiric anti-Legionella antibiotics should be administered pending definitive diagnosis.
嗜肺军团菌已被发现是需要入住重症监护病房（ICU）的社区获得性肺炎的常见病因。在许多研究中，与其他病因引起的肺炎相比，军团病的临床表现更为严重，死亡率更高。然而，这可能是由于诊断延迟和抗生素治疗欠佳，而非嗜肺军团菌的毒力增强。采用高热、腹泻、精神状态改变、低钠血症等症状导向的方法，可能有助于对重症肺炎患者做出正确诊断，但这仍有待验证。在医院内部进行嗜肺军团菌诊断微生物检测（而非送至外部参考实验室）可最大程度地提高正确诊断军团病的能力。所有入住ICU的社区获得性肺炎患者均应使用尿抗原检测及在选择性培养基上进行培养来检测嗜肺军团菌。此外，我们建议每年对医院供水系统进行常规培养（无论是否曾诊断出医院内军团病病例）。如果在供水系统中发现嗜肺军团菌，所有医院内肺炎患者均应接受嗜肺军团菌诊断检测；在明确诊断之前应给予经验性抗军团菌抗生素治疗。
