المؤلفون: Lumbala C; Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo.; Global Health Institute, University of Antwerp, Antwerp, Belgium., Biéler S; Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland., Kayembe S; Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland., Makabuza J; Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo., Ongarello S; Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland., Ndung'u JM; Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland.

المصدر: PLoS neglected tropical diseases [PLoS Negl Trop Dis] 2018 Mar 28; Vol. 12 (3), pp. e0006386. Date of Electronic Publication: 2018 Mar 28 (Print Publication: 2018).

نوع المنشور: Comparative Study; Evaluation Study; Journal Article; Multicenter Study; Research Support, Non-U.S. Gov't

بيانات الدورية: Publisher: Public Library of Science Country of Publication: United States NLM ID: 101291488 Publication Model: eCollection Cited Medium: Internet ISSN: 1935-2735 (Electronic) Linking ISSN: 19352727 NLM ISO Abbreviation: PLoS Negl Trop Dis Subsets: MEDLINE

مواضيع طبية MeSH: Antibodies, Protozoan/*blood , Antigens, Protozoan/*genetics , Trypanosoma brucei gambiense/*immunology , Trypanosomiasis, African/*diagnosis, Algorithms ; Antigens, Protozoan/immunology ; Cost-Benefit Analysis ; Democratic Republic of the Congo ; Humans ; Prospective Studies ; Sensitivity and Specificity ; Trypanosoma brucei gambiense/chemistry ; Trypanosomiasis, African/immunology ; Trypanosomiasis, African/parasitology

مستخلص: Background: Diagnosis and treatment are central elements of strategies to control Trypanosoma brucei gambiense human African trypanosomiasis (HAT). Serological screening is a key entry point in diagnostic algorithms. The Card Agglutination Test for Trypanosomiasis (CATT) has been the most widely used screening test for decades, despite a number of practical limitations that were partially addressed by the introduction of rapid diagnostic tests (RDTs). However, current RDTs are manufactured using native antigens, which are challenging to produce.
Methodology/principal Findings: The objective of this study was to evaluate the accuracy of a new RDT developed using recombinant antigens (SD BIOLINE HAT 2.0), in comparison with an RDT produced using native antigens (SD BIOLINE HAT) and CATT. A total of 57,632 individuals were screened in the Democratic Republic of the Congo, either passively at 10 health centres, or actively by 5 mobile teams, and 260 HAT cases were confirmed by parasitology. The highest sensitivity was achieved with the SD BIOLINE HAT 2.0 (71.2%), followed by CATT (62.5%) and the SD BIOLINE HAT (59.0%). The most specific test was CATT (99.2%), while the specificity of the SD BIOLINE HAT and SD BIOLINE HAT 2.0 were 98.9% and 98.1%, respectively. Sensitivity of the tests was lower than previously reported, as they identified cases from partially overlapping sub-populations. All three tests were significantly more sensitive in passive than in active screening. Combining two or three tests resulted in a markedly increased sensitivity: When the SD BIOLINE HAT was combined with the SD BIOLINE HAT 2.0, sensitivity reached 98.4% in passive and 83.0% in active screening.
Conclusions/significance: The recombinant antigen-based RDT was more sensitive than, and as specific as, the SD BIOLINE HAT. It was as sensitive as, but slightly less specific than CATT. While the practicality and cost-effectiveness of algorithms including several screening tests would need to be investigated, using two or more tests appears to enhance sensitivity of diagnostic algorithms, although some decrease in specificity is observed as well.

المؤلفون: Matovu E; College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda. matovue@covab.mak.ac.ug., Kitibwa A; College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda., Picado A; Foundation for Innovative New Diagnostics (FIND), Campus Biotech, Chemin des Mines, Geneva, Switzerland., Biéler S; Foundation for Innovative New Diagnostics (FIND), Campus Biotech, Chemin des Mines, Geneva, Switzerland., Bessell PR; Epi Interventions Ltd., Edinburgh, EH3 5HT, UK., Ndung'u JM; Foundation for Innovative New Diagnostics (FIND), Campus Biotech, Chemin des Mines, Geneva, Switzerland.

المصدر: Parasites & vectors [Parasit Vectors] 2017 Nov 03; Vol. 10 (1), pp. 546. Date of Electronic Publication: 2017 Nov 03.

نوع المنشور: Evaluation Study; Journal Article

بيانات الدورية: Publisher: BioMed Central Country of Publication: England NLM ID: 101462774 Publication Model: Electronic Cited Medium: Internet ISSN: 1756-3305 (Electronic) Linking ISSN: 17563305 NLM ISO Abbreviation: Parasit Vectors Subsets: MEDLINE

مواضيع طبية MeSH: Serologic Tests*, Antibodies, Protozoan/*blood , Cattle Diseases/*diagnosis , Trypanosoma brucei gambiense/*immunology , Trypanosomiasis, African/*veterinary, Animals ; Antigens, Protozoan/immunology ; Cattle ; Cattle Diseases/epidemiology ; Cattle Diseases/immunology ; Cross Reactions ; Humans ; Polymerase Chain Reaction ; Sensitivity and Specificity ; Trypanosomiasis, African/diagnosis ; Trypanosomiasis, African/epidemiology ; Trypanosomiasis, African/immunology

مستخلص: Background: Serological tests for gambiense human African trypanosomiasis (gHAT) detect antibodies to antigens on the cell surface of bloodstream trypanosomes. As trypanosomes that cause animal African trypanosomiasis (AAT) also express related antigens, we have evaluated two rapid diagnostic tests (RDTs) on cattle in trypanosomiasis endemic and non-endemic regions, to determine whether gHAT serological tests could also be used to screen for AAT.
Methods: Two RDTs, 1G RDT, made with native antigens, and p2G RDT, made with recombinant antigens, were tested on 121 cattle in a trypanosomiasis-free region, and on 312 cattle from a rhodesiense HAT and AAT endemic region. A subset of samples from the endemic region were also tested with two immune trypanolysis (TL) tests. The sensitivity of the tests was estimated by evaluating the result of the RDT on samples that were positive by both microscopy and internal transcribed spacer (ITS) PCR, whilst specificity was the result of the RDT on samples that were negative by ITS PCR and microscopy, and others from the non-endemic region.
Results: The specificity of the p2G RDT on cattle from the non-endemic region was 97.5% (95% CI: 93.0-99.2%), compared to only 57.9% (95% CI: 48.9-66.3%) for 1G RDT. The specificities of 1G RDT, p2G RDT and TL on endemic control cattle were 14.6% (95% CI: 9.7-21.5%), 22.6% (95% CI: 16.4-30.3%) and 68.3% (95% CI: 59.6-75.9%), respectively. The sensitivities of the tests on trypanosome positive samples were 85.1% (95% CI: 79.1-89.7%), 89.1% (95% CI: 83.7-93.0%) and 59.3% (95% CI: 51.8-66.4%), respectively. Among the same samples, 51.7% were positive by both TL and the 1G RDT.
Conclusions: These serological tests detect cross-reacting antibodies in cattle. The p2G RDT based on recombinant antigens had a high specificity in a non-endemic region, while the 1G RDT had a lower specificity, suggesting cross-reactivity with other pathogens.