Urine antigen tests for the diagnosis of respiratory infections: legionellosis, histoplasmosis, pneumococcal pneumonia.

[legionellosis]

Urinary antigen testing has grown in popularity for several significant respiratory infections , particularly Legionella pneumophila , Streptococcus pneumoniae , and Histoplasma capsulatum . By capitalizing on the concentration of shed antigen from a variety of pathogens in the kidneys for excretion in the urine , urinary antigen testing can be used to obtain rapid test results related to respiratory infection , independent of an invasive collection such as a bronchoalveolar lavage . This article describes the 3 aforementioned organisms , their role in respiratory disease , and the current status of urinary antigen testing in their respective diagnosis .