Onset and duration of urinary antigen excretion in Legionnaires disease

Abstract

The purposes of this study were to determine whether antigen is excreted by patients with Legionnaires disease early enough after the onset of symptoms to be useful for making therapeutic decisions and whether antigen excretion ends when successful treatment is concluded. Specific antigen was detected in the urine of 14 (88%) of 16 patients with Legionnaires disease during days 1 to 3 of symptoms, 33 (80%) of 41 patients during days 4 to 7, 25 (89%) of 28 patients during days 8 to 14, and 11 of 11 patients after day 14, by solid-phase immunoassays for serogroup 1 Legionella pneumophila antigen. Antigen excretion persisted for 42 days or longer after the onset of treatment in at least 15 patients. The longest documented duration of excretion was 326 days. We conclude that antigen can be detected approximately as often early after symptoms begin as later, allowing meaningful therapeutic decisions to be made, but that prolonged antigen excretion may negate the diagnostic value of urinary antigen detection for relapsing or recurrent L. pneumophila pneumonia.

Emerging respiratory infections: The infectious disease pathology of SARS, MERS, pandemic influenza, and Legionella

“…Additional caveats include a small percent of patients that do not excrete the antigen and frequently the antigen can be detected for several weeks after infection, which complicates interpretation of the time-course of infection. 69,83 Studies vary greatly in the local species and serogroup distributions; likely components of actual geographic distribution of the organism and reporting bias. In one study, half of all sporadic cases over a 15 year period were due to species other than L. pneumophila serogroup 1.…”

Detection of Legionella pneumophila serogroup 1 urinary antigen using an enhanced chemiluminescence ELISA

“…Urine is, with the exception of patients in oliguric renal failure, an easily and non-invasively collected specimen. In addition it has previously been reported that urinary antigen is detectable as early as 1-3 days after the onset of the illness (Kohler et al, 1984) thus allowing a rapid diagnosis to be established. This latter finding was confirmed by this study (data not shown) in the few instances where appropriately timed urine specimens were available for examination.…”

Microbiologic Diagnosis of Lung Infection

“…192 Urine antigen for L. pneumophila is detectable in 80% to 89% of patients with legionnaires' disease beginning with the first 3 days of symptoms and continuing for at least 14 days; the duration of antigenuria was reduced by antibiotic therapy and was detectable for up to 42 days, especially in immunocompromised patients. 193 The urinary antigen assays are limited to detection of infections due to L. pneumophila serogroup 1 and not other Legionella serogroups or species. 94 Detection of fungal antigen in serum, urine, and other body fluids is used as an aid in the diagnosis of infections due to Cryptococcus neoformans, Aspergillus, H. capsulatum, and P. jirovecii.…”