China
Africa
Explore chapters and articles related to this topic
Toxoplasma
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Fernanda Silva de Souza, Renato Augusto DaMatta
Fulton proposed a direct agglutination test to serologically diagnose toxoplasmosis. In this test a suspension of the parasites preserved in formalin was used as antigen.148 In 1980, Desmonts and Remington149 improved this method by standardizing the obtained antigens, their concentration, and time incubated with formalin, as well as using an alkaline buffer in the resuspension to avoid spontaneous agglutination.149 This test detects IgG antibodies in serum, but false-negative results may occur, because in early stages, IgG titer is low.138
Case 16: Hepatosplenomegaly
Published in Layne Kerry, Janice Rymer, 100 Diagnostic Dilemmas in Clinical Medicine, 2017
An inguinal lymph node was biopsied. Rather than showing malignancy, this showed large numbers of what appeared to be Leishman–Donovan bodies, consistent with a diagnosis of leishmaniasis. Histoplasmosis could not be excluded as the parasites have a similar appearance and the infectious diseases team therefore advised sending blood tests for leishmania serology and histoplasmosis antigen and commencing a course of amphotericin B, which would treat both conditions. The leishmania direct agglutination test (DAT) test was positive (titre 1:102,400).
Leishmania spp.
Published in Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward, Case Studies in Infectious Disease, 2010
Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward
Serological immunological tests are unable to distinguish current from past infection. A commonly used test for anti-leishmanial antibody is the direct agglutination test (DAT). Promastigotes are formalin-fixed onto slides and serum is placed on top. Agglutination is observed after 24 hours. DAT has a sensitivity of about 95% and its specificity is about 86%. A dip-stick test has been developed with the K39 antigen impregnated on a reagent strip. Blood is added to the strip and a reaction noted after 20 minutes. The K39 dipstick has a sensitivity of about 94% and specificity of about 90%.
An immunoproteomic approach to identifying immunoreactive proteins in Leishmania infantum amastigotes using sera of dogs infected with canine visceral leishmaniasis
Published in Pathogens and Global Health, 2019
Sajad Rashidi, Zahra Mojtahedi, Bahador Shahriari, Kurosh Kalantar, Ghasem Ghalamfarsa, Mehdi Mohebali, Gholamreza Hatam
Approximately, 40 µg of the obtained proteins were electrophoresed using SDS-PAGE that was performed on 4% stacking gels over 12% separating gels (Roche Applied Science). Sample lysates were boiled at 100°C for 5 min in 6X SDS gel-loading buffer consisting of 375 mM Tris-HCl (pH 6.8), 60% glycerol, 12% SDS, 30% 2-mercaptoethanol, and 0.6% bromophenol blue. After running, using an electroblotting system (Bio-Rad, Hercules, California, USA), the gel was transferred (20 V, 1 h) to a polyvinylidene difluoride (PVDF) membrane (Bio-Rad, Hercules, CA, USA). The non-specific binding sites on the membranes were then blocked by BSA [21], and CVL-infected dogs’ pooled sera (n = 5) (asymptomatic and symptomatic) and non-infected dogs’ pooled sera (n = 5) were used to probe the membranes. Symptomatic and asymptomatic sera of the infected dogs with CVL were achieved from Meshginshahr city, Ardabil province, Iran. All sera were checked for CVL with direct agglutination test (DAT). The extracted proteins from non-infected J774 macrophages were used as a negative control. Antibody binding proceeding was performed with 1:1000 dilutions of primary anti-sera in skim milk (2 h at RT). After three washes, 15 min each, with PBS containing 0.5% Tween-20, HRP rabbit anti-dog (IgG) (1:4000 dilutions, Abcam, USA) was allowed to react (1.5 h at RT) with proteins. After washing, the immunoreactive bands were developed using diaminobenzidine tetrahydrochloride (DAB) substrate (Sigma, Germany). For scanning the obtained bands, the ChemiDoc MP Imaging System (Bio-Rad, USA) was used. The experiment was repeated three times with different CVL-infected and non-infected dogs’ pooled sera to confirm the results.
Loop-mediated isothermal amplification methods for diagnosis of visceral leishmaniasis (kala-azar) – a systematic review
Published in Expert Review of Molecular Diagnostics, 2020
Gilberto Silva Nunes Bezerra, Walter Lins Barbosa Júnior, Amanda Virgínia Batista Vieira, Amanda Tavares Xavier, Manoel Sebastião Da Costa Lima Júnior, Edeneide Maria Xavier, Elis Dionísio Da Silva, Nilma Cintra Leal, Zulma Maria De Medeiros
Several antibody-based tests for Leishmania detection have been used in clinical practice to be sensitive, simple, and affordable such as direct agglutination test (DAT) and rK39, but they have major limitations: (i) they are not able to detect relapses since antibody levels remain detectable for years after cure, (ii) they have demonstrated cross-reaction with closely related species, (iii) people from endemic areas may have antibody titers related to exposure or asymptomatic infection and (iv) they loss accuracy in immunocompromised patients, including those infected with human immunodeficiency virus (HIV) [7].
Toxoplasma Screening Results of 84587 Pregnant Women in a Tertiary Referral Center in Turkey
Published in Fetal and Pediatric Pathology, 2019
Umit Yasemin Sert, A. Seval Ozgu-Erdinc, Sibel Gokay, Yaprak Engin-Ustun
There are several maternal serum tests available to women when toxoplasmosis is suspected. These tests include the latex agglutination test or direct agglutination test, dye test, indirect hemagglutination test, ELISA for IgG and IgM, immunosorbent agglutination assay (ISAGA) for IgM and IgA, enzyme-linked immunofiltration assay (ELIFA) or immunoblotting (IB). A positive result should be repeated with another maternal serum sample for confirmation [37]. Serological diagnosis is the other step that should be obtained as a primary step to determine maternal infection and risk of fetal transmission [37].