Multicentre evaluation of a direct agglutination test prototype kit (DAT-LPC) for diagnosis of visceral leishmaniasis

Parasitology ◽  
2017 ◽  
Vol 144 (14) ◽  
pp. 1964-1970 ◽  
Author(s):  
E. OLIVEIRA ◽  
D. OLIVEIRA ◽  
F. A. CARDOSO ◽  
J. R. BARBOSA ◽  
A. P. MARCELINO ◽  
...  
Keyword(s):  
Public Health ◽  
Visceral Leishmaniasis ◽  
Diagnostic Accuracy ◽  
Antibody Test ◽  
Agglutination Test ◽  
Parasitic Infections ◽  
Reference Laboratory ◽  
Direct Agglutination Test ◽  
Serum Samples ◽  
Freeze Dried

SUMMARYIn this study, we assessed the sensitivity, specificity, and diagnostic accuracy of a previously developed direct agglutination test (DAT) using a freeze-dried antigen derived fromLeishmania infantumpromastigotes and composed in a prototype kit for visceral leishmaniasis (VL) diagnosis, named DAT-LPC. To evaluate DAT-LPC reproducibility, the kit was used to analyse 207 serum samples from VL patients and 80 serum samples from patients with other parasitic infections or healthy subjects in four laboratories from different public health institutions in Brazil. DAT-LPC showed sensitivity between 96·2 and 99·5% (P= 0·14), specificity ranging from 96·2 to 97·5% (P= 0·95), and diagnostic accuracy ranging from 96·5 to 99% (P= 0·34). The inter-laboratory reproducibility of qualitative results was classified as excellent (κindex: 0·94–0·97). The reproducibility of the end-titre results in relation to the reference laboratory, ranged from 31 to 85%. These results demonstrate an excellent performance of the DAT-LPC, and validate it for the diagnosis of VL that could replace the immunofluorescent antibody test as the routine diagnostic test in the Brazilian public health system.

scholarly journals Performance of an indigenous β-mercaptoethanol-modified antigen in comparison with a commercial reference in direct agglutination test for detection of canine visceral leishmaniasis

2014 ◽  
Vol 63 (1) ◽  
pp. 106-110
Author(s):  
Saul José Semião-Santos ◽  
Laura Barral Veloso ◽  
Paulo Paes de Andrade ◽  
Marcia Almeida de Melo ◽  
Luis Miguel Lourenço Martins ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Leishmania Donovani ◽  
Agglutination Test ◽  
Canine Visceral Leishmaniasis ◽  
Direct Agglutination Test ◽  
Serum Samples

We compared the performance of a locally produced β-mercaptoethanol-modified promastigote antigen (β-ME-Ag) of an indigenous Leishmania infantum strain against that of a trypsinized Leishmania donovani reference (REF-Ag) in the direct agglutination test (DAT) for detection of canine visceral leishmaniasis (CVL). One hundred and fifty-one serum samples collected from dogs belonging to four groups with different conditions were included. At a DAT titre of 1 : 320, statistically determined as optimal cut-off value for β-ME-Ag, and 1 : 160 for REF-Ag, a sensitivity and a specificity of 100 % were estimated for β-ME-Ag in comparison with 96.6 % and 100 %, respectively, for REF-Ag. Overall, levels of agglutination titres recorded for the two antigens were highly concordant (Cohen’s κ = 0.879) in both the CVL and non-CVL groups. Based on current results, and ease experienced in processing the antigen and reading the test outcome, we recommend incorporation of β-ME-Ag in DAT for confirmation or exclusion of suspected CVL in dogs.

scholarly journals Dog-DAT: a direct agglutination test using stabilized, freeze-dried antigen for the serodiagnosis of canine visceral leishmaniasis

1996 ◽  
Vol 16 (3-4) ◽  
pp. 235-239 ◽  
Author(s):  
Linda Oskam ◽  
Rob J. Slappendel ◽  
Eef G.M. Beijer ◽  
Nel C.M. Kroon ◽  
Cor W. van Ingen ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Agglutination Test ◽  
Canine Visceral Leishmaniasis ◽  
Direct Agglutination Test ◽  
Freeze Dried

scholarly journals The Diagnostic Accuracy of Direct Agglutination Test for Serodiagnosis of Human Visceral Leishmaniasis: A Systematic Review with Meta-analysis

2020 ◽  
Author(s):  
Mehdi Mohebali ◽  
Hossein Keshavarz ◽  
Sedigheh Shirmohammad ◽  
Behnaz Akhoundi ◽  
Alireza Borjian ◽  
...  
Keyword(s):  
Systematic Review ◽  
Visceral Leishmaniasis ◽  
Diagnostic Accuracy ◽  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Meta Analysis ◽  
Agglutination Test ◽  
Direct Agglutination Test ◽  
Summary Receiver Operating Characteristic

Abstract Background: Direct agglutination test (DAT) as a simple, accurate and reliable method, has been widely used for serodiagnosis of visceral leishmaniasis (VL) during the last three decades. The present study is a systematic review and meta-analysis to evaluate the diagnostic accuracy of DAT for serodiagnosis of human VL.Methods: Electronic databases, including MEDLINE (via PubMed), SCOPUS, Web of Science, SID and Mag Iran (two Persian scientific search engines) were searched from December 2004 to April 2019. We determined the pooled sensitivity and specificity rates of DAT for the diagnosis of human VL, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic (ROC) curves parameters across the eligible studies.Results: Of the 2928 records identified in the mentioned electronic databases and after examining reference lists of articles, 24 articles met inclusion criteria and were enrolled in the systematic review and out of them 20 records qualified for meta-analysis. The pooled sensitivity and specificity rates of DAT was 96% [95% CI, 92–98] and 98% [95 % CI, 86–99], respectively. The likelihood ratio of a positive test (LR+) was found to be 21 [CI95%, 6.6–66.5] and the likelihood ratio of a negative test (LR−) was found to be 0.04 [(CI95%, 0.02–0.08]. The combined estimate of the diagnostic odds ratio for DAT was high [467 (CI95%, 114-1912]). We found that the summary receiver operating characteristic curve (SROC) is positioned near the upper left corner of the curve and the area under curve (AUC) was 0.98 (95% CI, 0.97 to 0.99).Conclusion: Referring to our analysis, we determined that DAT can be considered as a valuable tool for the serodiagnosis of human VL with high sensitivity and specificity. As DAT is a simple, accurate and efficient serological test, it can be recommended for serodiagnosis of human VL particularly in endemic areas.

scholarly journals The Diagnostic Accuracy of Direct Agglutination Test for Serodiagnosis of Human Visceral Leishmaniasis: A Systematic Review with Meta-analysis

2020 ◽  
Author(s):  
Mehdi Mohebali ◽  
Hossein Keshavarz ◽  
Sedigheh Shirmohammad ◽  
Behnaz Akhoundi ◽  
Alireza Borjian ◽  
...  
Keyword(s):  
Systematic Review ◽  
Visceral Leishmaniasis ◽  
Diagnostic Accuracy ◽  
Receiver Operating Characteristic ◽  
Likelihood Ratio ◽  
Operating Characteristic ◽  
Meta Analysis ◽  
Agglutination Test ◽  
Direct Agglutination Test ◽  
Summary Receiver Operating Characteristic

Abstract Background: Direct agglutination test (DAT) as simple, accurate and non-expensive tool that has been used widely for serodiagnosis of visceral leishmaniasis (VL) during the last three decades. We conducted a systematic review and meta-analysis to evaluate the diagnostic accuracy of DAT for serodiagnosis of human VL. Methods: Electronic databases, including MEDLINE (via PubMed), SCOPUS, Web of Science, SID and Mag Iran (two Persian scientific search engines) were searched from December 2004 to April 2019. The study quality was evaluated using the QUADAS checklist. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic(ROC) curves parameters. Results: Of the 2928 records identified in the mentioned electronic databases and through articles’ reference lists, 25 articles met inclusion criteria and enrolled into the systematic review and among them 22 records were qualified for meta-analysis. The pooled sensitivity and specificity of DAT was 96% [(95% CI, 93–98])and 95% [(95% CI, 88–98]), respectively. The likelihood ratio of a positive test (LR+) was found to be 19.8 [CI95%, 7.6–51.8] and the likelihood ratio of a negative test (LR−) was found to be 0.04 [CI95%, 0.02–0.08]. The combined estimate of the diagnostic odds ratio for DAT was high [454)136-1561]) ].We found that the summary receiver operating characteristic curve (SROC) is positioned near the upper left corner of the curve and the area under curve (AUC) was 0.98 (95% CI, 0.97 to 0.99). Conclusion: Based on our analysis, we find DAT can be considered as valuable tool for the serodiagnosis and seroprevalence of human VL with high sensitivity and specificityrates. As DAT is simple, accurate, non-invasive and efficient serological test, it can be used for serodiagnosis of human VL particularly in endemic areas of the disease.

scholarly journals Evaluation of a glycerol-preserved antigen in the direct agglutination test for diagnosis of visceral leishmaniasis at rural level in eastern Sudan

2006 ◽  
Vol 55 (10) ◽  
pp. 1343-1347 ◽  
Author(s):  
Mohamed el Mutasim ◽  
Durria Mansour ◽  
Elfadil M. Abass ◽  
Wisam M. Hassan ◽  
Abdallah el Harith
Keyword(s):  
Visceral Leishmaniasis ◽  
Freeze Drying ◽  
Weighted Kappa ◽  
Agglutination Test ◽  
Direct Agglutination Test ◽  
Ambient Conditions ◽  
Diagnostic Reliability ◽  
Peripheral Hospital ◽  
Freeze Dried ◽  
Eastern Sudan

Three-hundred and eight patients with suspected visceral leishmaniasis (VL) were received at Doka Hospital (eastern Sudan) during the period September 2004 to October 2005. The sensitivity and specificity of a glycerol-preserved (GP) antigen for VL diagnosis was assessed against the results of repeated lymph node aspiration and readings from a direct agglutination test (DAT) employing standard formaldehyde-fixed (FF) or freeze-dried (FD) antigen. Despite 13 months of storage at ambient temperature (28–47 °C), the GP antigen mean titres obtained from these 308 patients were no different from those that were FD (P=0.945) and stored under similar conditions, but were significantly different (P=0.019) from those that were FF and kept continuously at the optimum temperature for storage (4–8 °C). Taking the parasitological result as the gold standard and using a pre-established titre of 1 : 3200 as the DAT cut-off, the GP antigen revealed a sensitivity (91/105, 86.7 %) and specificity (187/203, 92.1 %) comparable to that of FD antigen (92/105, 87.6 %, and 188/203, 92.6 %, respectively) and FF antigen (94/105, 89.5 %, and 188/203, 92.6 %, respectively). At a titre range of 1 : 400–1 : 800, statistically determined as the optimum cut-off for the three antigens, sensitivities of 92.4, 90.5 and 96.2 % and specificities of 90.6, 90.1 and 88.7 % were achieved for the GP, FD and FF antigens, respectively, at a peripheral hospital. Regardless of the antigen preparation used, DAT results obtained in the peripheral hospital were highly reproducible in the central laboratory in Omdurman (weighted kappa: GP=0.957, FD=0.979 and FF=0.936). With a diagnostic reliability comparable to formaldehyde fixation and stability under ambient conditions similar to freeze drying, glycerol preservation, by virtue of its high potential for reproduction, meets the requirements for the management of VL in developing countries.

scholarly journals Leish-KIT, a stable direct agglutination test based on freeze-dried antigen for serodiagnosis of visceral leishmaniasis.

1995 ◽  
Vol 33 (7) ◽  
pp. 1742-1745 ◽  
Author(s):  
S E Meredith ◽  
N C Kroon ◽  
E Sondorp ◽  
J Seaman ◽  
M G Goris ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Agglutination Test ◽  
Direct Agglutination Test ◽  
Freeze Dried
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