scholarly journals Evaluation of Four Lateral Flow Assays for the Detection of Legionella Urinary Antigen

2021 ◽  
Vol 9 (3) ◽  
pp. 493
Author(s):  
Alicia Y. W. Wong ◽  
Alexander T. A. Johnsson ◽  
Aina Iversen ◽  
Simon Athlin ◽  
Volkan Özenci
Keyword(s):  
Sensitivity And Specificity ◽  
Lateral Flow ◽  
Urine Samples ◽  
Visual Interpretation ◽  
Urinary Antigen ◽  
Lateral Flow Assays ◽  
Legionnaires Disease ◽  
Antigen Tests ◽  
Weak Result ◽  
Visual Results

Urinary antigen tests (UATs) are often used to diagnose Legionnaires’ disease as they are rapid and easy to perform on readily obtainable urine samples without the need for specialized skills compared to conventional methods. Recently developed automated readers for UATs may provide objective results interpretation, especially in cases of weak result bands. Using 53 defined patient urine samples, we evaluated the performance of the BinaxNOW Legionella Antigen Card (Abbott), ImmuView S. pneumoniae and Legionella (SSI Diagnostica), STANDARD F Legionella Ag FIA (SD Biosensor), and Sofia Legionella FIA (Quidel) simultaneously with their respective automated readers. Automatic and visual interpretation of result bands were also compared for the immunochromatography-based BinaxNOW and ImmuView UATs. Overall sensitivity and specificity of Legionella UATs were 53.9–61.5% and 90.0–94.9%, respectively. All four UATs successfully detected all samples from L. pneumophila serogroup 1-positive patients, but most failed to detect samples for Legionella spp., or other serogroups. Automatic results interpretation of results was found to be mostly concordant with visual results reading. In conclusion, the performance of the four UATs were similar to each other in the detection of Legionella urinary antigen with no major difference between automated or visual results reading.

scholarly journals Method Comparison of the ImmuView L. pneumophila and L. longbeachae Urinary Antigen Test with the BinaxNOW Legionella Urinary Antigen Card for Detection of Legionella pneumophila Serogroup 1 Antigen in Urine

2019 ◽  
Vol 58 (3) ◽  
Author(s):  
Paul Badoux ◽  
Lianne Kracht-Kosten ◽  
Bjorn Herpers ◽  
Sjoerd Euser
Keyword(s):  
Sensitivity And Specificity ◽  
Legionella Pneumophila ◽  
Limit Of Detection ◽  
Method Comparison ◽  
Urine Samples ◽  
Analytical Sensitivity ◽  
Antigen Test ◽  
Urinary Antigen ◽  
Urinary Antigen Test ◽  
Content Type

ABSTRACT We compared the clinical performance of the ImmuView L. pneumophila and L. longbeachae urinary antigen test (SSI Diagnostica A/S, Hillerød, Denmark) to that of the BinaxNOW Legionella urinary antigen card (Binax; Abbott, Lake Buff, IL) using urine specimens from patients suspected of having pneumonia. In total, 100 frozen urine samples (derived from 50 Legionella cases and 50 noncases) were analyzed with both tests, as were 200 nonfrozen prospectively collected samples. For urine samples from five Legionella cases and two non-Legionella cases, analytical sensitivity (limit of detection) and repeatability were examined. The urine samples from the five Legionella cases were diluted with urine samples that tested Legionella urinary antigen negative with both tests. The analyses of the 100 frozen samples resulted in a sensitivity and specificity of both ImmuView and the BinaxNOW of 96.0% (48/50) and 100% (50/50), respectively. Of the 200 nonfrozen samples, there were three samples that showed a positive result for L. pneumophila by both tests. The analyses of reproducibility showed that for the 34 (diluted) samples that were tested at two consecutive times, 33 samples showed a consistent result for both the ImmuView and the BinaxNOW tests (Cohen’s kappa values of 0.916 and 0.928). In addition, the ImmuView test may have detected two L. longbeachae-positive urine samples, although other diagnostic tests could not confirm this. Both ImmuView and BinaxNOW showed high sensitivity and specificity for the detection of L. pneumophila serogroup 1 antigen in urine samples from clinical patients with a suspected lower respiratory tract infection.

scholarly journals Comparison of the Novel Immunocatch Legionella Test with Sofia Legionella FIA Assay and with BinaxNOW Legionella Card Assay for Detection ofLegionella pneumophila(Serogroup 1) Antigen in Urine Samples

2019 ◽  
Vol 57 (8) ◽  
Author(s):  
F. Congestrì ◽  
M. Morotti ◽  
R. Vicari ◽  
M. F. Pedna ◽  
M. Sparacino ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Signs And Symptoms ◽  
Laboratory Diagnosis ◽  
Antigen Detection ◽  
Urine Samples ◽  
Urinary Antigen ◽  
Content Type ◽  
High Clinical Suspicion ◽  
Legionnaires Disease ◽  
Urinary Antigen Detection

ABSTRACTLegionnaires’ disease (LD) refers to a serious form of acute pneumonia caused byLegionellaspecies. LD can be difficult to diagnose because the signs and symptoms are nonspecific, and therefore a rapid laboratory diagnosis is of paramount importance. In this study, a recently introduced immunochromatographic test (Immunocatch Legionella; Eiken Chemical Co., Ltd.) forLegionella pneumophila(serogroup 1) urinary antigen detection was compared with the Sofia Legionella fluorescent immunoassay (FIA) (Quidel) (routinely used in our laboratory) and with the widely used BinaxNOW Legionella assay (Alere). A total of 248 urine samples (60 frozen and 188 fresh) were evaluated. All of the samples were collected from patients with high clinical suspicion of Legionnaires’ disease. The three assays were performed simultaneously according to the manufacturers’ instructions. A total of 180 concordant negative and 66 concordant positive results were obtained. Only 2 discrepant results were registered. The sensitivity and specificity of Immunocatch compared with Sofia were, respectively, 98.5% and 99.4%. Cohen's kappa coefficient and overall percent agreement between Immunocatch and Sofia were also calculated and resulted in, respectively, 0.97 and 99.2%. These performances suggest that the Immunocatch test is a useful tool forLegionella pneumophila(serogroup 1) urinary antigen detection.

Hospital Characteristics Associated With Colonization of Water Systems byLegionellaand Risk of Nosocomial Legionnaires' Disease: A Cohort Study of 15 Hospitals

1999 ◽  
Vol 20 (12) ◽  
pp. 798-805 ◽  
Author(s):  
Jacob L. Kool ◽  
David Bergmire-Sweat ◽  
Jay C. Butler ◽  
Ellen W. Brown ◽  
Deborah J. Peabody ◽  
...  
Keyword(s):  
Drinking Water ◽  
San Antonio ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Control Measures ◽  
Chlorine Concentration ◽  
Urinary Antigen ◽  
Legionnaires Disease ◽  
Antigen Tests

AbstractObjective:To investigate an increase in reports of legionnaires' disease by multiple hospitals in San Antonio, Texas, and to study risk factors for nosocomial transmission of legionnaires' disease and determinants forLegionellacolonization of hospital hot-water systems.Setting:The 16 largest hospitals in the cities of San Antonio, Temple, and Austin, Texas.Design:Review of laboratory databases to identify patients with legionnaires' disease in the 3 years prior to the investigation and to determine the number of diagnostic tests forLegionellaperformed; measurement of hot-water temperature and chlorine concentration and culture of potable water forLegionella. Exact univariate calculations, Poisson regression, and linear regression were used to determine factors associated with water-system colonization and transmission ofLegionella.Results:Twelve cases of nosocomial legionnaires' disease were identified; eight of these occurred in 1996. The rise in cases occurred shortly after physicians started requestingLegionellaurinary antigen tests. Hospitals that frequently usedLegionellaurinary antigen tests tended to detect more cases of legionnaires' disease.Legionellawas isolated from the water systems of 11 of 12 hospitals in San Antonio; the 12th had just experienced an outbreak of legionnaires' disease and had implemented control measures. Nosocomial legionellosis cases probably occurred in 5 hospitals. The number of nosocomial legionnaires' disease cases in each hospital correlated better with the proportion of water-system sites that tested positive forLegionella (P=.07) than with the concentration ofLegionellabacteria in water samples (P=.23). Hospitals in municipalities where the water treatment plant used monochloramine as a residual disinfectant (n=4) and the hospital that had implemented control measures wereLegionella-free. The hot-water systems of all other hospitals (n=11) were colonized withLegionella. These were all supplied with municipal drinking water that contained free chlorine as a residual disinfectant. In these contaminated hospitals, the proportion of sites testing positive was inversely correlated with free residual chlorine concentration (P=.01). In all hospitals, hot-water temperatures were too low to inhibitLegionellagrowth.Conclusions:The increase in reporting of nosocomial legionnaires' disease was attributable to increased use of urinary antigen tests; prior cases may have gone unrecognized. Risk of legionnaires' disease in hospital patients was better predicted by the proportion of water-system sites testing positive forLegionellathan by the measured concentration ofLegionellabacteria. Use of monochloramine by municipalities for residual drinking water disinfection may help prevent legionnaires' disease.

scholarly journals Evaluation of Serological SARS-CoV-2 Lateral Flow Assays for Rapid Point of Care Testing

2020 ◽  
Author(s):  
Steven E Conklin ◽  
Kathryn Martin ◽  
Yukari C Manabe ◽  
Haley A Schmidt ◽  
Morgan Keruly ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Symptom Onset ◽  
Point Of Care ◽  
Negative Control ◽  
Lateral Flow ◽  
Point Of Care Testing ◽  
Specific Antibodies ◽  
Testing Performance ◽  
Lateral Flow Assays ◽  
Point Of Care Tests

Background. Rapid point-of-care tests (POCTs) for SARS-CoV-2-specific antibodies vary in performance. A critical need exists to perform head-to-head comparison of these assays. Methods. Performance of fifteen different lateral flow POCTs for the detection of SARS-CoV-2-specific antibodies was performed on a well characterized set of 100 samples. Of these, 40 samples from known SARS-CoV-2-infected, convalescent individuals (average of 45 days post symptom onset) were used to assess sensitivity. Sixty samples from the pre-pandemic era (negative control), that were known to have been infected with other respiratory viruses (rhinoviruses A, B, C and/or coronavirus 229E, HKU1, NL63 OC43) were used to assess specificity. The timing of seroconversion was assessed on five POCTs on a panel of 272 longitudinal samples from 47 patients of known time since symptom onset. Results. For the assays that were evaluated, the sensitivity and specificity for any reactive band ranged from 55%-97% and 78%-100%, respectively. When assessing the performance of the IgM and the IgG bands alone, sensitivity and specificity ranged from 0%-88% and 80%-100% for IgM and 25%-95% and 90%-100% for IgG. Longitudinal testing revealed that median time post symptom onset to a positive result was 7 days (IQR 5.4, 9.8) for IgM and 8.2 days (IQR 6.3 to 11.3). Conclusion. The testing performance varied widely among POCTs with most variation related to the sensitivity of the assays. The IgM band was most likely to misclassify pre-pandemic samples. The appearance of IgM and IgG bands occurred almost simultaneously.

scholarly journals Evaluation of the Binax and Biotest Urinary Antigen Kits for Detection of Legionnaires' Disease Due to Multiple Serogroups and Species of Legionella

2000 ◽  
Vol 38 (7) ◽  
pp. 2763-2765 ◽  
Author(s):  
Robert F. Benson ◽  
Patrick W. Tang ◽  
Barry S. Fields
Keyword(s):  
Immunosorbent Assay ◽  
Broad Spectrum ◽  
Legionella Pneumophila ◽  
Urine Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Urinary Antigen ◽  
Legionnaires Disease

The Binax and the Biotest urinary antigen kits for the detection of Legionnaires' disease caused by organisms other than Legionella pneumophila were compared by testing 45 urine samples from non-Legionella pneumophila serogroup 1 patients previously positive in a broad-spectrum enzyme-linked immunosorbent assay (ELISA). Eighteen were positive with the Binax kit, and 13 were positive with the Biotest. Although neither kit is as sensitive as ELISA, these results extend the number of serogroups and species ofLegionella that can be diagnosed with the Binax or Biotest kit.

scholarly journals Evaluation of Serological SARS-CoV-2 Lateral Flow Assays for Rapid Point of Care Testing

2020 ◽  
Author(s):  
Steven E. Conklin ◽  
Kathryn Martin ◽  
Yukari C Manabe ◽  
Haley A Schmidt ◽  
Jernelle Miller ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Symptom Onset ◽  
Point Of Care ◽  
Negative Control ◽  
Lateral Flow ◽  
Point Of Care Testing ◽  
Specific Antibodies ◽  
Testing Performance ◽  
Lateral Flow Assays ◽  
Point Of Care Tests

Background. Rapid point-of-care tests (POCTs) for SARS-CoV-2-specific antibodies vary in performance. A critical need exists to perform head-to-head comparison of these assays. Methods. Performance of fifteen different lateral flow POCTs for the detection of SARS-CoV-2-specific antibodies was performed on a well characterized set of 100 samples. Of these, 40 samples from known SARS-CoV-2-infected, convalescent individuals (average of 45 days post symptom onset) were used to assess sensitivity. Sixty samples from the pre-pandemic era (negative control), that were known to have been infected with other respiratory viruses (rhinoviruses A, B, C and/or coronavirus 229E, HKU1, NL63 OC43) were used to assess specificity. The timing of seroconversion was assessed on five LFAs on a panel of 272 longitudinal samples from 47 patients of known time since symptom onset. Results. For the assays that were evaluated, the sensitivity and specificity for any reactive band ranged from 55%-97% and 78%-100%, respectively. When assessing the performance of the IgM and the IgG bands alone, sensitivity and specificity ranged from 0%-88% and 80%-100% for IgM and 25%-95% and 90%-100% for IgG. Longitudinal testing revealed that median time post symptom onset to a positive result was 7 days (IQR 5.4, 9.8) for IgM and 8.2 days (IQR 6.3 to 11.3) for IgG. Conclusion. The testing performance varied widely among LFAs with most variation related to the sensitivity of the assays. The IgM band was most likely to misclassify pre-pandemic samples. The appearance of IgM and IgG bands occurred almost simultaneously.

scholarly journals Sensitivity of Three Urinary Antigen Tests Associated with Clinical Severity in a Large Outbreak of Legionnaires' Disease in The Netherlands

2002 ◽  
Vol 40 (9) ◽  
pp. 3232-3236 ◽  
Author(s):  
E. P. F. Yzerman ◽  
J. W. d. Boer ◽  
K. D. Lettinga ◽  
J. Schellekens ◽  
J. Dankert ◽  
...  
Keyword(s):  
The Netherlands ◽  
Clinical Severity ◽  
Urinary Antigen ◽  
Large Outbreak ◽  
Legionnaires Disease ◽  
Antigen Tests

scholarly journals Pneumococcal and Legionella Urinary Antigen Tests in Community-acquired Pneumonia: Prospective Evaluation of Indications for Testing

2018 ◽  
Vol 68 (12) ◽  
pp. 2026-2033 ◽  
Author(s):  
Shawna Bellew ◽  
Carlos G Grijalva ◽  
Derek J Williams ◽  
Evan J Anderson ◽  
Richard G Wunderink ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Legionella Pneumophila ◽  
Community Acquired Pneumonia ◽  
Urinary Antigen ◽  
Prospective Surveillance ◽  
Expert Opinions ◽  
Urinary Antigen Testing ◽  
Antigen Tests ◽  
Individual Criterion ◽  
Antigen Testing

Abstract Background Adult, community-acquired pneumonia (CAP) guidelines from the Infectious Diseases Society of America (IDSA) and American Thoracic Society (ATS) include indications for urinary antigen tests (UATs) for Streptococcus pneumoniae (SP) and Legionella pneumophila (LP). These recommendations were based on expert opinions and have not been rigorously evaluated. Methods We used data from a multicenter, prospective, surveillance study of adults hospitalized with CAP to evaluate the sensitivity and specificity of the IDSA/ATS UAT indications for identifying patients who test positive. SP and LP UATs were completed on all included patients. Separate analyses were completed for SP and LP, using 2-by-2 contingency tables, comparing the IDSA/ATS indications (UAT recommended vs not recommended) and UAT results (positive vs negative). Additionally, logistic regression was used to evaluate the association of each individual criterion in the IDSA/ATS indications with positive UAT results. Results Among 1941 patients, UATs were positive for SP in 81 (4.2%) and for LP in 32 (1.6%). IDSA/ATS indications had 61% sensitivity (95% confidence interval [CI] 49–71%) and 39% specificity (95% CI 37–41%) for SP, and 63% sensitivity (95% CI 44–79%) and 35% specificity (95% CI 33–37%) for LP. No clinical characteristics were strongly associated with positive SP UATs, while features associated with positive LP UATs were hyponatremia, fever, diarrhea, and recent travel. Conclusions Recommended indications for SP and LP urinary antigen testing in the IDSA/ATS CAP guidelines have poor sensitivity and specificity for identifying patients with positive tests; future CAP guidelines should consider other strategies for determining which patients should undergo urinary antigen testing.

scholarly journals When Legionnaires’ Disease Isn’t: Case Presentation and Implications of the Council of State and Territorial Epidemiologists (CSTE) Changes to Case Definitions

2020 ◽  
Vol 41 (S1) ◽  
pp. s512-s513
Author(s):  
Janet E. Stout ◽  
Anurag Malani
Keyword(s):  
Health Department ◽  
Health Departments ◽  
Urinary Antigen ◽  
Case Definitions ◽  
Case Presentation ◽  
New Information ◽  
Legionnaires Disease ◽  
Antigen Tests ◽  
Council Of State ◽  
Outbreak Case

Background: Most cases of Legionnaires’ disease are diagnosed by the urinary antigen test (UAT). Single cases of suspected healthcare-acquired Legionnaires’ disease are often investigated by local and state health departments. Such investigations can result in disruptive and expensive interventions. We report a case of a urine-antigen–positive patient whose clinical presentation was inconsistent with Legionnaires’ disease. Within the same year, an employee at this hospital was diagnosed with presumed community-acquired Legionnaires’ disease; however, the case was considered by the health department to be healthcare acquired. The occurrence of 2 cases, as determined by the health department, fulfilled the definition for an outbreak investigation and triggered water restrictions and extensive testing of the environment and patients for Legionella. The cases and the implications of these actions are reviewed in the context of new information about false-positive urinary-antigen tests and changes to the outbreak case definitions for Legionnaires’ disease by the Council of State and Territorial Epidemiologists (CTSE). This includes “probable” cases that have no positive diagnostic tests.Funding: NoneDisclosures: Janet E. Stout reports salary from the Special Pathogens Laboratory and is an owner.

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