scholarly journals Potential of Direct Agglutination Test Based on Promastigote and Amastigote Antigens for Serodiagnosis of Post-Kala-Azar Dermal Leishmaniasis

2005 ◽  
Vol 12 (10) ◽  
pp. 1191-1194 ◽  
Author(s):  
Ruchi Singh ◽  
B. V. Subba Raju ◽  
R. K. Jain ◽  
Poonam Salotra
Keyword(s):  
Sensitivity And Specificity ◽  
Leishmania Donovani ◽  
Parasite Burden ◽  
Agglutination Test ◽  
Field Conditions ◽  
Antibody Detection ◽  
Direct Agglutination Test ◽  
Kala Azar ◽  
Potential Applicability ◽  
Strip Test

ABSTRACT Post-kala-azar dermal leishmaniasis (PKDL) is a dermal complication, a sequel to kala-azar. Diagnosis of PKDL presents a challenge due to the low parasite burden in the lesions. The direct agglutination test (DAT) based on promastigote and amastigote antigens of Leishmania donovani of indigenous isolates was developed to diagnose PKDL, and the results were compared with those of the rk39 strip test. The sensitivities of DAT for antileishmanial antibody detection, based on promastigote and amastigote antigens at a cutoff titer of 1:800 were 98.5% and 100%, respectively, with corresponding specificities of 96.5% and 100%. DAT could correctly detect 100% polymorphic cases and 95.4% macular PKDL cases. In comparison, the rk39 strip test was able to correctly diagnose 95.6% of polymorphic and 86.0% macular PKDL cases. DAT based on axenic amastigote antigen provided 100% sensitivity and specificity, making it particularly useful for macular PKDL cases, which are often missed by the rk39 strip test. Thus, DAT provides a simple, reliable, and inexpensive test for PKDL diagnosis with potential applicability in field conditions.

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 Use of a Newly Developed β-Mercaptoethanol Enzyme-Linked Immunosorbent Assay To Diagnose Visceral Leishmaniasis in Patients in Eastern Sudan

2007 ◽  
Vol 14 (12) ◽  
pp. 1592-1595 ◽  
Author(s):  
Durria Mansour ◽  
Elfadil M. Abass ◽  
Mohamed el Mutasim ◽  
Abdelhafeiz Mahamoud ◽  
Abdallah el Harith
Keyword(s):  
Visceral Leishmaniasis ◽  
Immunosorbent Assay ◽  
Leishmania Donovani ◽  
Clinical Evidence ◽  
High Reliability ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Agglutination Test ◽  
Symptomatic Group ◽  
Eastern Sudan

ABSTRACT Corroboration of serology results is essential for restricting the risk of inappropriate antileishmanial prescription. A direct agglutination test (DAT) and a recently developed β-mercaptoethanol-modified enzyme-linked immunosorbent assay (β-ME ELISA) based on the use of antigen prepared as described for the DAT were applied to 416 sera from two Sudanese populations with and without clinical evidence of visceral leishmaniasis (VL). Of 285 sera with the lowest antileishmanial DAT titers (≤1:100 to 1:1,600), 270 (94.7%) scored comparable minimum β-ME ELISA absorbance values (≤0.1 to 0.26). In 117 sera that demonstrated the highest DAT titers (1:12,800 to ≥1:25,600), 86 (73.5%) scored maximum (0.81 to ≥1.35) and 30 (25.6%) medium (0.27 to 0.80) β-ME ELISA absorbance values. VL diagnosis was established for 142 (44.1%) patients in the VL-symptomatic group (n = 322), based on positive microscopy for Leishmania donovani in lymph node aspirates or positive DAT (titer, ≥1:3,200). Of the 125 sera from the symptomatic patients for whom microscopy was positive for VL, 111 (88.8%) had comparable positive DAT and β-ME ELISA readings. In all 17 sera from the symptomatic DAT-positive patients for whom leishmaniasis was not established by microscopy but who responded favorably to antileishmanial therapy, absorbance values (≥0.27) indicative of VL were obtained by β-ME ELISA. Of 197 symptomatic patients for whom microscopy was negative for VL, 172 (87.3%) tested negative in β-ME ELISA and 180 (91.4%) in DAT. Based on the high reliability demonstrated here for VL detection, β-ME ELISA fulfills the requirement of confirming DAT results in patients manifesting suspected VL.

scholarly journals Increased natural killer activity does not prevent progression of experimental Kala-azar

1999 ◽  
Vol 41 (4) ◽  
pp. 215-219 ◽  
Author(s):  
Alexandrina SARTORI ◽  
Ramon KANENO ◽  
Nelson BARUZZI ◽  
Maria Terezinha Serrão PERAÇOLI
Keyword(s):  
Natural Killer ◽  
Experimental Model ◽  
Leishmania Donovani ◽  
Parasite Burden ◽  
Cell Number ◽  
Intravenous Route ◽  
Spleen Weight ◽  
Nk Activity ◽  
Killer Activity ◽  
Kala Azar

Kala-azar is the visceral form of leishmaniasis and it is caused by intracellular parasites from the complex Leishmania donovani. Golden hamster (Mesocricetus auratus) infected with Leishmania donovani develop a disease very similar to human Kala-azar. There is conspicuous hipergammaglobulinaemia and their T cells do not respond to stimulation with parasite antigens. We used this experimental model to evaluate the natural killer (NK) activity during the initial phase of the disease. Outbred hamsters infected by intravenous route with 5.106 amastigotes of L. donovani 1S showed a concurrent increase in the spleen weight and in the spleen cell number. Using the single cell assay we detected a significant increase in the percentage of NK effector cells on the 4th day of infection. Imprints from spleen and liver showed at days 14 and 28 a significant increase in the parasite burden . These results show that the increased NK activity in the beginning of the infection was not able to restrain the progression of the disease in this experimental model.

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 Detection of Leishmania DNA in saliva among patients with HIV/AIDS in Trang Province, southern Thailand

2018 ◽  
Author(s):  
Netranapha Pandey ◽  
Suradej Siripattanapipong ◽  
Saovanee Leelayoova ◽  
Jipada Manomat ◽  
Mathirut Mungthin ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Nested Pcr ◽  
Buffy Coat ◽  
Agglutination Test ◽  
Nucleotide Sequencing ◽  
Direct Agglutination Test ◽  
Southern Thailand ◽  
Fatal Form ◽  
Positive Agreement ◽  
Hiv Aids

ABSTRACTLeishmaniasis is a neglected tropical disease causing opportunistic infection among patients with HIV/AIDS. The fatal form of this disease is visceral leishmaniasis (VL). DNA of Leishmania can be detected in saliva, for which the collection is noninvasive and requires little expertise. This study aimed to evaluate the sensitivity and specificity of a nested-PCR to amplify the Internal Transcribed Spacer 1 (ITS1) to detect Leishmania DNA in paired saliva and buffy coat samples of 305 Thai patients with HIV/AIDS in Trang Hospital, Trang Province, southern Thailand. For asymptomatic Leishmania infection among Thai patients with HIV/AIDS, the sensitivity and specificity of the nested-PCR-ITS1 in buffy coat were 73.9 and 100%, respectively. However, the sensitivity in saliva was 26.1% and specificity was 100%. Using the nested-PCR-ITS1, saliva and buffy coat samples showed positive agreement in only 52.0% of patients. Saliva tested results with the nested-PCR-ITS1 showed positive agreement with the Direct Agglutination Test (DAT) in 46.5% of patients. Only 12.1% of the samples showed positive agreement for Leishmania infection among all the three tests: saliva, buffy coat and DAT results. Using nucleotide sequencing, at least three species of Leishmania infection were identified in saliva, i.e., L. siamensis (n=28), L. martiniquensis (n=9), and L. donovani complex (n=1). As a result, buffy coat still appears to be a better specimen to diagnose asymptomatic VL infection among individuals with HIV. However, the use of both buffy coat and saliva together as clinical specimens would increase the sensitivity of Leishmania detection.

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