Evaluation of Urinary Antigen Detection Methods for Rapid Diagnosis of Legionella pneumonia

Abstract

We have evaluated urine specimens of presumptive cases of legionnaires' disease (110 cases, 173 sample), collected in the past eight years (April, 1990-August, 1998) with the Binax EIA kit which detects the soluble antigen of Legionella pneumophila serogroup (SG) 1, and the Biotest EIA kit which detects Legionella species. Seven cases (19 specimens) were positive for the Binax EIA kit, and nine cases (22 specimens) were positive for the Biotest EIA kit. The sensitivity for culture, PCR, IFA method were 100%, 100%, and 50%, the specificity for these method were 93%, 97.1%, and 90% respectively. Overall agreements for these method were 93.5%, 97.4%, 86.8%, these results suggested that the urinary antigen detection test had high sensitivity and specificity. Our study indicated that concentrated urine samples increase sensitivity. We also evaluated the capabilities of both EIAs to detect soluble antigens were extracted from bacterial suspension of 18 strains of 5 Legionella species by heating. Both assays detected L. pneumophila serogroups 1 to 14, L. bozemanii. The Binax EIA proved to be useful as the Biotest EIA for diagnosis of legionellosis caused by Legionella species and serogroups other than L. pneumophila serogroup 1. Some cases have been shown to excrete antigen for prolonged period of times despite recovery from infection, so that the patient's history should be sought. The urine antigen detection EIA methods proved to be rapid and easy to use, detect antigen in the early stage of the disease with high sensitivity and specificity. Its use for the definition of legionellosis should be considered in Japan.

The JRS Guidelines for the Management of Community-acquired Pneumonia in Adults:An Update and New Recommendations

“…available from 2003) and the Binax NOW Legionella urinary antigen immunochromatographic test (Binax, Portland, ME, USA. available from 2004), for the detection of the L. pneumophila antigen in urine (83)(84)(85)(86)(87)(88). This assay is now an established and valuable tool for the diagnosis of Legionnaires' disease, particularly in regions where L. pneumophila serogroup 1 is the most common cause of the disease.…”

Clinical Utility of a Legionella pneumophila Urinary Antigen Test in a Large University Teaching Hospital

“…L pneumophila by urinary antigen testing (LPUAT) is a rapid tool for early diagnosis of Legionella infection (6)(7)(8)(9)(10)(11)(12)(13)(14). An enzyme immunoassay (EIA) for detecting L pneumophila serogroup 1, which accounts for between 50% and 70% of cases of Legionella pneumonia (15,16), has been shown to be both sensitive and specific.…”

Severe <i>Legionella</i> Pneumonia in Which Serial Testing by Ribotest^® <i>Legionella</i> was Useful for the Diagnosis

“…In the previous reports, three patients were negative on the urinary antigen test of the first specimen and turned positive on the second test (first specimen was from day 4, day 3, and day 6 after symptoms began, and the second was from 6 days later, 9 days later, and 6 days later, respectively). Urine specimens were examined by a solid-phase radio-immunoassay or enzyme-linked immunoassay (EIA; Biotest Legionella urinary antigen EIA Ⓡ or Binax Legionella Urine Antigen EIA Ⓡ ) ( 13 , 14 ). However, there have been few reports regarding the sequential detection of Legionella urinary antigen.…”