Legionnaires’ disease is caused by Legionella pneumophila and is an acute respiratory disease. It can take the course of a mild influenza-like illness (so called Pontiac fever) or can cause pneumonia which, if left untreated, can show a relatively high lethality rate. The mortality rate, which in the case of immunocompetent subjects can reach 20% without adequate treatment, can be reduced if appropriate antimicrobial therapy is commenced at an early stage as a result of rapid diagnosis. With regard to infections in humans, the species Legionella pneumophila is detected most frequently (80-85%) and although rarer, 18 further Legionella species occur as infectious agents of pneumonia. Strains of Legionella species isolated from patients belonged mainly to the serogroup 1, however 14 other serogroups exist. Since 1979, the detection of specific antigen in urine has on many occasions been described as a reliable and simple test, but until now this has been limited to the detection of serogroup 1.
The Legionella Urine Antigen EIA detects specific Legionella antigen and recognizes all L. pneumophila serogroups with a relatively wide spectrum of cross-reactivity as well as other Legionella species.