Evaluation of an EDTA version of CATT/Trypanosoma brucei gambiense for serological screening of human blood samples.

CATT/Trypanosoma brucei gambiense, a direct card agglutination test designed for field surveys on human African trypanosomosis, is currently used with freshly collected heparinized blood samples. When testing serum samples, it has been observed earlier that, at lower sample dilutions, a complement-mediated inhibition phenomenon may cause false negative test results. This can be avoided by adding an anticomplementary agent such as di-sodium ethylenediaminetetraacetate dihydrate (EDTA) to the reaction.

Follow-up of Card Agglutination Trypanosomiasis Test (CATT) positive but apparently aparasitaemic individuals in Côte d'Ivoire: evidence for a complex and heterogeneous population.

The aetiological diagnosis of human African trypanosomiasis (HAT) is based on the detection of the parasite, but currently available parasitological tests have low sensitivity and are hampered by fluctuating parasitaemia. The identification of seropositive individuals on whom to focus parasitological examination is based on antibody detection by means of the Card Agglutination Trypanosomiasis Test (CATT/T.b.

Comparative in vitro isolation of Trypanosoma theileri from cattle in Belgium.

Ten blood samples randomly collected from cows on a farm nearby Antwerp, Belgium, were inoculated into KIVI culture medium (Kit for In Vitro Isolation of trypanosomes) and RPMI 10%+feeder medium. Within 3 weeks of incubation all KIVI cultures and four RPMI 10%+feeder revealed presence of Trypanosoma theileri. Some practical implications regarding the use of KIVI for isolation of pathogenic African trypanosomes from cattle and other Bovidae are discussed.

Improved latex agglutination test for detection of antibodies in serum and cerebrospinal fluid of Trypanosoma brucei gambiense infected patients.

A rapid latex agglutination test (LATEX/T. b. gambiense) for detection of antibodies in patients infected with Trypanosoma brucei gambiense is presented.

Human African trypanosomiasis: a latex agglutination field test for quantifying IgM in cerebrospinal fluid.

LATEX/IgM, a rapid agglutination test for the semi-quantitative detection of IgM in cerebrospinal fluid of patients with African trypanosomiasis, is described in this article. The lyophilized reagent has been designed for field use and remains stable at 45 degrees C for one year. The test has been evaluated on cerebrospinal fluid samples from trypanosome-infected and non-infected patients, by comparison with commercial latex agglutination, radial immunodiffusion, and nephelometry.

A VSG expression site-associated gene confers resistance to human serum in Trypanosoma rhodesiense.

Infectivity of Trypanosoma brucei rhodesiense to humans is due to its resistance to a lytic factor present in human serum. In the ETat 1 strain this character was associated with antigenic variation, since expression of the ETat 1.10 variant surface glycoprotein was required to generate resistant (R) clones.

Increased sensitivity of the card agglutination test CATT/Trypanosoma brucei gambiense by inhibition of complement.

CATT/Trypanosoma brucei (T.b.) gambiense is an antibody detection test currently used in field surveys on Gambian sleeping sickness.

Diagnostic evaluation of PCR on dried blood samples from goats experimentally infected with Trypanosoma brucei brucei.

In seven goats experimentally infected with a pleomorphic clone of Trypanosoma brucei brucei, parasitaemia was monitored weekly for 6 weeks by wet blood film and microhaematocrit buffy coat examination. Dried blood samples on filter paper were concomitantly collected and tested by PCR using three different primer sets, putatively specific for Trypanozoon, T. vivax and T.

A semi-quantitative ELISA for detection of Trypanosoma brucei gambiense specific antibodies in serum and cerebrospinal fluid of sleeping sickness patients.

A semi-quantitative ELISA, using variable surface glycoprotein of T.b. gambiense as antigen, was developed for the detection of antibodies of different immunoglobulin isotypes in serum and cerebrospinal fluid of sleeping sickness patients.

Detection and characterization of autoantibodies directed against neurofilament proteins in human African trypanosomiasis.

In serum and in cerebrospinal fluid (CSF) from patients with human African trypanosomiasis (HAT) with central nervous system involvement, we detected autoantibodies directed to some proteins from these tissues. The characterization of antigenic proteins by Western blotting showed that the antibodies recognized the 200-kD and 160-kD proteins of neurofilament (NF). Serum anti-NF antibodies were more frequent in HAT patients than in control subjects (86% versus 24%; P < 10[-9]) and they belonged predominantly to the IgM class (anti-NF IgM = 86% versus anti-NF IgG = 4%; P < 10[-9]) in the patients with stage II (central nervous system involvement) HAT.

Diagnostic evaluation of PCR in goats experimentally infected with Trypanosoma vivax.

Six goats were experimentally infected with a stock of Trypanosoma vivax. Parasitaemia was weekly monitored by buffy coat and wet blood film examination during a period of 15 weeks and another 3 weeks following drug-treatment. Dried blood samples were tested by the polymerase chain reaction (PCR), using an extraction method with Chelex 100 (BioRad).

Evaluation of various diagnostic techniques for Trypanosoma evansi infections in naturally infected camels.

One hundred and eight camels (Camelus dromedarius) from Trypanosoma evansi endemic areas of the Thar Desert of Rajasthan State, India, were evaluated by various diagnostic tests including parasitological tests (wet blood film-WBF, stained thick blood film), chemical test (mercuric chloride), biological test (mouse subinoculation-MSI), and immunodiagnostic tests based on antibody detection (double immunodiffusion test-DID, card agglutination test-CATT), antigen detection (double antibody sandwich enzyme linked immunosorbent assay-Ag-ELISA). Of the tested camels 49 were found infected using the WBF of which nine gave false negative results with the mercuric chloride test. The efficacy of MSI was 87.

Evaluation of variant specific trypanolysis tests for serodiagnosis of human infections with Trypanosoma brucei gambiense.

Twelve T.b. gambiense clone populations of distinct Variable Antigen Type (VAT) were combined in immune lysis tests with 340 sera of trypanosome infected patients from 8 different African countries and 267 non trypanosomiasis control sera.

[Evaluation of a direct serologic card agglutination test for the diagnosis of camel trypanosomiasis caused by Trypanosoma evansi].

The results of a novel direct serological card agglutination test for the diagnosis of camel trypanosomosis due to Trypanosoma evansi (CATT/T. evansi) were compared with those obtained by direct detection of parasites in a study using 1,093 sera from camels raised in northern Mali. A good correlation was revealed between the percentage of positive results obtained by CATT and the presence of trypanosomes (89%), as well as a good coincidence between the percentage of positive results obtained by CATT and low haematocrit values (packed cell volume).

[Serological evidence of the existence of a wild reservoir of Trypanosoma brucei gambiense in the Pendjari biosphere reservation in the Republic of Benin].

In the national park of Pendjari, situated in the North-West of Benin, 91 wild animals, belonging to seven species, were darted. Thick and thin blood smears were examined for trypanosomes and plasma for trypanolytic antibodies against 6 antigenic variants of Trypanosoma brucei gambiense. Parasites were found in 13.

An experimental latex agglutination test for antibody detection in human African trypanosomiasis.

A latex card agglutination test for detection of antibodies in human African trypanosomiasis is presented. The latex was covalently coated with semipurified surface glycoprotein of Variable Antigen Type LiTat 1.6 of Trypanosoma brucei gambiense.

Variant-specific trypanolytic antibodies in sera from patients infected with Trypanosoma brucei rhodesiense.

Infections with salivarian trypanosomes are characterized by the successive development of parasite populations of distinct variable antigen types (VATs), the corresponding antibodies accumulating in the blood of the host. Sixty VATs had been cloned during previous studies on variable antigen repertoires of Trypanosoma brucei rhodesiense; 12 of these were selected for immunolysis tests against 85 sera from T.b.

A gene expressed only in serum-resistant variants of Trypanosoma brucei rhodesiense.

The human infective African trypanosomes are host range variants of Trypanosoma brucei which are resistant to a lytic component in primate serum. T. b.

Spread of Trypanosoma brucei to the nervous system: early attack on circumventricular organs and sensory ganglia.

The distribution of Trypanosoma brucei brucei in the nervous system of experimentally infected Sprague-Dawley rats and BALB/c and deer mice was examined with immunohistochemical techniques. The trypanosomes showed an early invasion in areas lacking a so-called blood-brain or blood-nerve barrier, i.e.

Evidence for genetic diversity in Trypanosoma (Nannomonas) congolense.

Genetic proximity between two karyotypic groups of Trypanosoma congolense was investigated using as hybridization probes: total genomic DNA, a 35 nucleotide long synthetic oligonucleotide, and non-variant antigen type (non-VAT) specific complementary DNAs. The phylogenetic relationship between Trypanosoma brucei and T. evansi, both of which are accepted species in the subgenus Trypanozoon, was used as a reference to assess the phylogenetic proximity of the two groups of T.

Telomeric reciprocal recombination as a possible mechanism for antigenic variation in trypanosomes.

In African trypanosomes, antigenic variation is achieved through differential gene activation, with one antigen gene being expressed at a time among a large collection of antigen-specific sequences. Transcription of the antigen gene always takes place in a telomere, but different telomeres can alternatively act as the expression site. Telomeric antigen genes can be expressed without apparent DNA rearrangement, but they can also, like non-telomeric genes, have access to the telomeric expression site through a duplicative transposition mechanism resembling gene conversion.