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 Persistence ofLeishmania donovaniAntibodies in Past Visceral Leishmaniasis Cases in India

2010 ◽  
Vol 18 (2) ◽  
pp. 346-348 ◽  
Author(s):  
Kamlesh Gidwani ◽  
Albert Picado ◽  
Bart Ostyn ◽  
Shri Prakash Singh ◽  
Rajiv Kumar ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Immunosorbent Assay ◽  
Leishmania Donovani ◽  
Extended Period ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Agglutination Test ◽  
History Of ◽  
Antibody Titers

ABSTRACTThe persistence of anti-Leishmania donovaniantibodies in past visceral leishmaniasis (VL) cases was retrospectively assessed by means of the direct agglutination test (DAT) and the rK39 enzyme-linked immunosorbent assay (ELISA). Antibody titers remained high for an extended period of time in past cases of VL. These results highlight the need to carefully elicit the history of patients with VL symptoms.

scholarly journals Comparison of Enzyme-Linked Immunosorbent Assay, Indirect Fluorescent Antibody Test, and Direct Agglutination Test for Detecting Toxoplasma Gondii Antibodies in Naturally Aborted Ovine Fetuses

1989 ◽  
Vol 1 (2) ◽  
pp. 124-127 ◽  
Author(s):  
Sheryl L. Seefeldt ◽  
Clyde A. Kirkbride ◽  
Jitender P. Dubey
Keyword(s):  
Toxoplasma Gondii ◽  
Immunosorbent Assay ◽  
Indirect Fluorescent Antibody Test ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Agglutination Test ◽  
Indirect Fluorescent Antibody ◽  
Special Equipment

Results obtained in an enzyme-linked immunosorbent assay (ELISA), an indirect fluorescent antibody test (IFA), and a modified direct agglutination test (MAT) for Toxoplasma gondii antibodies from examination of fetal fluids from 377 aborted ovine fetuses were compared. Sixty-seven samples were positive by MAT (titers 1:16 to > 1:65,536), 58 were positive by ELISA, and 62 were positive by immunoglobulin G-IFA. The MAT was preferred because it required less time, labor, and special equipment. It was simple to run, could be done on serum from any species without modification, and it was more effective than the IFA for detecting toxoplasma antibodies in severely autolyzed fetuses. No advantage was found in determining immunoglobulin M antibodies in ovine fetal sera.

scholarly journals Diagnosis of Visceral Leishmaniasis by Enzyme-Linked Immunosorbent Assay Using Urine Samples

2002 ◽  
Vol 9 (4) ◽  
pp. 789-794 ◽  
Author(s):  
Mohammad Zahidul Islam ◽  
Makoto Itoh ◽  
S. M. Shamsuzzaman ◽  
Rusella Mirza ◽  
Farzana Matin ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
Leishmania Donovani ◽  
Laboratory Diagnosis ◽  
Urine Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Controls ◽  
Serum Samples ◽  
Crude Antigen

ABSTRACT A diagnostic method has been developed to detect anti-Leishmania donovani immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-L. donovani IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using L. donovani promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated L. donovani promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of L. donovani crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-L. donovani IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-L. donovani IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.

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.

Successful substitution of fetal calf serum by human plasma for bulk cultivation of Leishmania donovani promastigotes

2013 ◽  
Vol 62 (8) ◽  
pp. 1165-1169 ◽  
Author(s):  
Abdelhafeiz Mahamoud ◽  
Hussam Ali Osman ◽  
Durria Mansour ◽  
Abdallah el Harith
Keyword(s):  
Visceral Leishmaniasis ◽  
Human Plasma ◽  
Leishmania Donovani ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Diagnostic Procedures ◽  
Agglutination Test ◽  
Direct Agglutination Test ◽  
Standard Medium ◽  
Liver Infusion Tryptose

The potential of human plasma (HP) or serum (HS) as a replacement for fetal calf serum (FCS) was evaluated in a liver infusion tryptose (LIT) medium for bulk cultivation of Leishmania donovani promastigotes. The promastigote yield with the LIT-FCS standard medium was 0.4–1.8×107 ml−1, and yields of 0.5–3.4×107 (P = 0.527) and 0.4–2.4×107 (P = 0.062) were recorded for two LIT medium variants containing HP or HS as supplement instead of FCS. Significantly, higher promastigote yields of 1.3–4.9×107 ml−1 were demonstrated when LIT medium was supplemented with HP of blood group O but not A, B, AB or equally pooled ABO (P = 0.007–0.020). Matching (P = 0.56) strong positive (1 : 10 2400 to ≥1 : 262 144 00) and weak negative (1 : 5–1 : 160) direct agglutination test (DAT) titres, respectively, were demonstrated in 24 visceral leishmaniasis (VL) and 45 non-VL sera for both standard LIT-FCS and alternative LIT-HP derived antigens. Our findings indicate strong potential for sustainable production of promastigotes for important diagnostic procedures such as DAT in the VL affected areas.

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 rK39 Enzyme-Linked Immunosorbent Assay for Diagnosis of Leishmania donovani Infection

1998 ◽  
Vol 5 (5) ◽  
pp. 717-720 ◽  
Author(s):  
E. E. Zijlstra ◽  
N. S. Daifalla ◽  
P. A. Kager ◽  
E. A. G. Khalil ◽  
A. M. El-Hassan ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Leishmania Donovani ◽  
Epidemiological Studies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Agglutination Test ◽  
Subclinical Infection ◽  
Kala Azar ◽  
Leishmanin Skin Test ◽  
Parasite Replication ◽  
Negative Controls

ABSTRACT The rK39 enzyme-linked immunosorbent assay (ELISA) was compared with the direct agglutination test (DAT) for Leishmania donovani infection in the Sudan. rK39 ELISA proved more sensitive than DAT in diagnosis of kala-azar (93 and 80%, respectively); both tests may remain positive up to 24 months after treatment. For patients with post-kala-azar dermal leishmaniasis and individuals with subclinical infection, rK39 ELISA performed as well as DAT but could detect infection 6 months earlier in ∼40% of patients. Conversion in DAT and rK39 ELISA also occurred in leishmanin skin test (LST)-positive individuals, suggesting active parasite replication (rK39 is an amastigote antigen) in these presumably immune individuals. In contrast to DAT, rK39 ELISA also detected infection in randomly selected LST-positive individuals (in four of six) and endemicity (LST-negative) controls (in one of five). rK39 ELISA appears more sensitive than DAT and may prove an important tool in epidemiological studies.

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