Sensitivity and specificity of a latex agglutination test for detection of calf enterotoxigenic Escherichia coli isolates in comparison with PCR

Latex agglutination test (KAtex) has been used in the last two decades for the diagnosis of visceral leishmaniasis (VL) in different VL-endemic areas. Here, we present a meta-analysis of studies which evaluated the KAtex for the diagnosis of VL to find out its overall diagnostic performance. A database search was performed on PubMed, Scopus, ISI Web of Science, Iranmedex and Google Scholar. The search of databases found 57 papers, of which 17 articles fulfilled our eligibility criteria. Meta-analysis of diagnostic accuracy (MADA) and Hierarchical Summary Receiver Operating Curve (HSROC) packages were used to do the meta-analysis and to obtain pooled estimates of sensitivity and specificity. Fixed effect bivariate analysis was conducted, using Mantel-Haenszel estimator, to measure the performance and diagnosis odds ratio (DOR) of the test. Heterogeneity of the test results was assessed by Chi-squared test. The sensitivity of individual studies ranged from 39.8 to 100%, and the specificity ranged from 64 to100%. The combined sensitivity and specificity estimates of KAtex were 77% (95% CI, 70-83%), and 97% (95% CI, 93-97%), respectively. Comparing the performance of the test by region suggests a significant difference where the lowest and highest sensitivities are reported from Nepal/Tunisia and Europe/Middle East respectively (p < 0.05). On the other hand, the lowest and highest rates of specificity were reported from Sudan and America/Middle East respectively. The overall specificity of KAtex is satisfactory. However, KAtex suffers from low sensitivity and this shortcoming should be improved. The test provides a rapid and simple diagnosis of VL and improvement of its sensitivity deserve further studies.

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Effects of Pretreating Serum Samples on the Performance of a Latex Agglutination Test for Serodiagnosis of Paracoccidioidomycosis

Clinical and Vaccine Immunology ◽

10.1128/cvi.05274-11 ◽

2011 ◽

Vol 19 (3) ◽

pp. 386-390 ◽

Cited By ~ 5

Author(s):

Fabíola Silveira-Gomes ◽

Silvia Helena Marques-da-Silva

Keyword(s):

Sensitivity And Specificity ◽

Bacterial Infections ◽

Paracoccidioides Brasiliensis ◽

Latex Agglutination ◽

Agglutination Test ◽

Latex Agglutination Test ◽

Serum Samples ◽

Content Type ◽

Human Sera ◽

Normal Human

ABSTRACTParacoccidioidomycosis (PCM) is a fungal disease caused byParacoccidioides brasiliensis, and Brazil is one of the principal countries where it is endemic. Diagnosis is based on the observation of buddingP. brasiliensisyeast in clinical specimens from patients; however, the sensitivity of the visualization of fungi is low, indicating that serological tests are used for early diagnosis. The double-immunodiffusion test (ID) is the “gold standard” test for serology in PCM, although the execution of this test requires the availability of laboratorial infrastructure. We report the improved performance of a latex agglutination test (LAT) by pretreating 30 serum samples from PCM patients and 71 controls (histoplasmosis and aspergillosis patients, patients with bacterial infections, and normal human sera) with a dilution buffer incubated at 37°C for 30 min. The sensitivity and specificity of the LAT test in the nonpretreated samples were 73% and 79%, respectively. However, when samples were pretreated, the sensitivity and specificity of the test increased to 90%. In this study, we did not observe cross-reactivity with histoplasmosis patient sera, but some reactions to sera from patients with aspergillosis and bacterial infections were noted. Normal human sera were not reactive in our tests. These results indicate the need for the elimination of heterologous reactions so that we can adequately use this method for screening cases of PCM.

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Evaluation of a reversed passive latex agglutination test for the detection of Verocytotoxin (VT) expressed by strains of VT-producing Escherichia coli

Letters in Applied Microbiology ◽

10.1046/j.1472-765x.2001.00921.x ◽

2001 ◽

Vol 32 (6) ◽

pp. 370-374 ◽

Cited By ~ 9

Author(s):

H. Chart ◽

G.A. Willshaw ◽

T. Cheasty

Keyword(s):

Escherichia Coli ◽

Latex Agglutination ◽

Agglutination Test ◽

Latex Agglutination Test

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Efficacy of a Latex Agglutination Test for Rapid Identification of Staphylococcus aureus: Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/79.3.661 ◽

1996 ◽

Vol 79 (3) ◽

pp. 661-670 ◽

Cited By ~ 3

Author(s):

Tsung C Chang ◽

Su H Huang ◽

H Y Chao ◽

B L Chen ◽

C Chen ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Sensitivity And Specificity ◽

Collaborative Study ◽

False Negative ◽

Pairwise Comparison ◽

Latex Agglutination ◽

Agglutination Test ◽

Latex Agglutination Test ◽

Official Method ◽

Latex Test

Abstract Fifteen laboratories completed a collaborative study comparing the efficacy of a latex agglutination kit (Aureus Test) with that of AOAC Official Method 987.09 (coagulase test for identification of Staphylococcus aureus). Each laboratory analyzed 240 strains of bacteria, including 160 isolates of S. aureus and 80 isolates of other bacteria. Upon receipt of cultures, collaborators subcultured each isolate on both tryptic soy agar (TSA) and Baird-Parker agar medium (BPA) to determine whether the growth medium has any effect on either method. For cultures grown on TSA, the latex test had sensitivity and specificity rates of 99.2 and 97.1 %, respectively, whereas the coagulase test had respective rates of 98.4 and 92.5%. For cultures able to grow on BPA, the latex test had sensitivity and specificity rates of 99.2 and 96.6%, respectively, while the coagulase test had respective rates of 98.3 and 91.3%. By using the McNemar pairwise comparison test of the 2 methods, the falsepositive and false-negative rates of the latex test were significantly lower (p < 0.01) than those of the coagulase test for strains grown either on TSA or BPA. The latex agglutination test for identification of S. aureus isolated from foods has been adopted by AOAC INTERNATIONAL.

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