infectious diseases
Legionella Infections
Diagnosis ofLegionellaInfections
Direct fluorescent antibody staining Sputum culture using specific growth media Rapid urinary antigen test (forL. pneumophilaserogroup 1 only) (serogroup 1; Diagnosis references ), which accounts for 65% to 90% of cases ( Diagnosis of legionnaires' disease is by culture of sputum or bronchoalveolar lavage fluid; blood cultures are unreliable. Specific growth media are required. Slow growth on laboratory media may delay identification for 3 to 5 days. Chest x-ray should be done; it usually shows patchy and rapidly asymmetrically progressive infiltrates (even when effective antibiotic therapy is used), with or without small pleural effusions. Laboratory abnormalities often include hyponatremia, hypophosphatemia, and elevated aminotransferase levels and C-reactive protein. 1.Gassiep I, Armstrong M, Heather CS, Norton RE: Utility of theLegionellaurinary antigen.Intern Med J49(8):1050–1051, 2019. doi: 10.1111/imj.14381 2.Yu VL, Plouffe JF, Castellani Pastoris M, et al: Distribution ofLegionellaspecies and serogroups isolated by culture in patients with sporadic community-acquired legionellosis: An international collaborative survey.J Infect Dis186(1):127–128, 2002. doi: 10.1086/341087 3.Avni T, Bieber A, Green H, et al: Diagnostic accuracy of PCR alone and compared to urinary antigen testing for detection ofLegionellaspp.: A systematic review.J Clin Microbiol54(2):401–411, 2016. doi: 10.1128/JCM.02675-15 