scholarly journals Sensitivity and specificity of a rapid diagnostic test for chronic Chagas disease at a referral center in Brazil - can it be included as a standard serological diagnostic test in the clinical practice of a referral center?

2021 ◽  
Vol 1 ◽  
pp. e1236
Author(s):  
Alejandro M. Hasslocher-Moreno ◽  
Ingebourg Georg ◽  
Luiz H. C. Sangenis ◽  
Mauro F. F. Mediano
Keyword(s):  
Clinical Practice ◽  
Diagnostic Test ◽  
Chagas Disease ◽  
Sensitivity And Specificity ◽  
Diagnostic Testing ◽  
Chronic Phase ◽  
Neglected Tropical Disease ◽  
Rapid Diagnostic Testing ◽  
Referral Center ◽  
Chronic Chagas Disease

Introduction: Chagas disease (CD) is a neglected tropical disease. In the chronic phase of CD, the diagnosis is essentially serologic. Conventional reactions are currently in use. More recently, the use of rapid diagnostic testing (RDT) is indicated when conventional techniques are not available. Objective: To evaluate the sensitivity and specificity of RDTs for chronic CD diagnosis. Methodology: Individuals under suspicion of CD were evaluated using ELISA, Chemiluminescence (ChLIA) and RDT tests. Results: The RDT showed 95.1% sensitivity and 96.7% specificity, respectively. Conclusion: The findings of the present study showed that RDT used in the diagnosis of CD at a referral center in Brazil were not able to detect all CD cases when compared to Elisa and ChLIA.

scholarly journals Observed Differences in Diagnostic Test Accuracy between Patient Subgroups: Is It Real or Due to Reference Standard Misclassification?

2007 ◽  
Vol 53 (10) ◽  
pp. 1725-1729 ◽  
Author(s):  
Corné Biesheuvel ◽  
Les Irwig ◽  
Patrick Bossuyt
Keyword(s):  
Clinical Practice ◽  
Diagnostic Test ◽  
Sensitivity And Specificity ◽  
Diagnostic Test Accuracy ◽  
Test Accuracy ◽  
Reference Standard ◽  
Target Condition ◽  
Test Sensitivity ◽  
The Past ◽  
Patient Subgroups

Abstract Before a new test is introduced in clinical practice, its accuracy should be assessed. In the past decade, researchers have put an increased emphasis on exploring differences in test sensitivity and specificity between patient subgroups. If the reference standard is imperfect and the prevalence of the target condition differs among subgroups, apparent differences in test sensitivity and specificity between subgroups may be caused by reference standard misclassification. We provide guidance on how to determine whether observed differences may be explained by reference standard misclassification. Such misclassification may be ascertained by examining how the apparent sensitivity and specificity change with the prevalence of the target condition in the subgroups.

Chagas Disease Chemotherapy: What Do We Know So Far?

2021 ◽  
Vol 27 ◽  
Author(s):  
Aline Araujo Zuma ◽  
Wanderley de Souza
Keyword(s):  
Host Cell ◽  
Chagas Disease ◽  
Chronic Phase ◽  
Cell Types ◽  
Neglected Tropical Disease ◽  
Cell Type ◽  
Cure Rate ◽  
New Compounds

: Chagas disease is a Neglected Tropical Disease (NTD), and although endemic in Latin America, affects around 6-7 million people infected worldwide. The treatment of Chagas disease is based on benznidazole and nifurtimox, which are the only available drugs. However, they are not effective during the chronic phase and cause several side effects. Furthermore, BZ promotes cure in 80% of the patients in the acute phase, but the cure rate drops to 20% in adults in the chronic phase of the disease. In this review, we present several studies published in the last six years, which describes the antiparasitic potential of distinct drugs, from the synthesis of new compounds aiming to target the parasite, as well as the repositioning and the combination of drugs. We highlight several compounds for having shown results that are equivalent or superior to BZ, which means that they should be further studied, either in vitro or in vivo. Furthermore, we stand out the differences in the effects of BZ on the same strain of T. cruzi, which might be related to methodological differences such as parasite and cell ratios, host cell type and the time of adding the drug. In addition, we discuss the wide variety of strains and also the cell types used as a host cell, which makes it difficult to compare the trypanocidal effect of the compounds.

scholarly journals Analytical Evaluation of Dried Blood Spot and Rapid Diagnostic Test as a New Strategy for Serological Community Screening for Chronic Chagas Disease

2021 ◽  
Vol 11 ◽  
Author(s):  
Aroa Silgado ◽  
Lídia Gual-Gonzalez ◽  
Adrián Sánchez-Montalvá ◽  
Inés Oliveira-Souto ◽  
Lidia Goterris ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Chagas Disease ◽  
Latin American ◽  
Whole Blood ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lower Sensitivity ◽  
Blood Samples ◽  
Screening Programs ◽  
Chronic Chagas Disease

BackgroundChagas disease is a public health problem not only in Latin America, but also in other regions, including Spain, due to migration movements. Conventional serological diagnosis requires an invasive sample (plasma or serum) and a well-equipped laboratory. To circumvent those limitations, blood samples dried on filter paper (DBS) or Rapid Diagnostic Test (RDT) could be a practical alternative to reference protocol for serological screening in epidemiological studies. We evaluated the usefulness of dried blood sampling and a rapid diagnostic test (Trypanosoma Detect™) for the detection of antibodies against T. cruzi for their use in community-based screening.Methodology/Principal FindingsA total of 162 stored paired whole-blood and serum samples from Latin American migrants and 25 negative-control blood samples were included. Diagnosis of chronic Chagas disease was performed in serum according to WHO algorithms. Blood samples were retrospectively collected as dried spots and then analyzed using two different serological techniques, enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence immunoassay (E-CLIA). Whole-blood samples were also used to evaluate a rapid diagnostic test based on immunochromatography. A better correlation with conventional serum was observed in dried blood elutes using E-CLIA than ELISA (97% vs. 77% sensitivity, respectively). Both assays reported 100% specificity. The median cut-off index values of E-CLIA for dried blood were significantly lower than those for serum (138.1 vs. 243.3, P<0.05). The Trypanosoma Detect™ test presented a sensitivity and specificity of 89.6% and 100%, respectively.ConclusionsThe detection of antibodies against T. cruzi in dried blood samples shows a higher sensitivity when using E-CLIA compared with ELISA. Trypanosoma Detect™ is easier to use but has a lower sensitivity. Hence, we propose a sequential strategy based on performing the rapid test first, and a negative result will be confirmed by DBS-ECLIA for use in community Chagas disease screening programs.

scholarly journals Towards a Paradigm Shift in the Treatment of Chronic Chagas Disease

2013 ◽  
Vol 58 (2) ◽  
pp. 635-639 ◽  
Author(s):  
R. Viotti ◽  
B. Alarcón de Noya ◽  
T. Araujo-Jorge ◽  
M. J. Grijalva ◽  
F. Guhl ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Paradigm Shift ◽  
Chronic Phase ◽  
World Health ◽  
Chronic Patients ◽  
Content Type ◽  
Current Medical Practice ◽  
Health Organization ◽  
Criteria For Evaluation ◽  
Chronic Chagas Disease

ABSTRACTTreatment for Chagas disease with currently available medications is recommended universally only for acute cases (all ages) and for children up to 14 years old. The World Health Organization, however, also recommends specific antiparasite treatment for all chronic-phaseTrypanosoma cruzi-infected individuals, even though in current medical practice this remains controversial, and most physicians only prescribe palliative treatment for adult Chagas patients with dilated cardiomyopathy. The present opinion, prepared by members of the NHEPACHA network (Nuevas Herramientas para el Diagnóstico y la Evaluación del Paciente con Enfermedad de Chagas/New Tools for the Diagnosis and Evaluation of Chagas Disease Patients), reviews the paradigm shift based on clinical and immunological evidence and argues in favor of antiparasitic treatment for all chronic patients. We review the tools needed to monitor therapeutic efficacy and the potential criteria for evaluation of treatment efficacy beyond parasitological cure. Etiological treatment should now be mandatory for all adult chronic Chagas disease patients.

scholarly journals Evaluation of the rabbit as a model for chagas' disease: I. Parasitological studies

1987 ◽  
Vol 82 (4) ◽  
pp. 531-536 ◽  
Author(s):  
Luiz Eduardo Ramirez ◽  
Zigman Brener
Keyword(s):  
Tissue Culture ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Chronic Phase ◽  
Suitable Model ◽  
Parasite Strain ◽  
Fresh Blood ◽  
Blood Examination ◽  
Chronic Chagas Disease ◽  
Selective Interactions

In order to investigate the value of the rabbit as an experimental model for Chagas' disease, 72 animals have been inoculated by intraperitoneal and conjunctival route with bloodstream forms, vector-derived metacyclic trypomastigotes and tissue culture trypomastigotes of Trypanosoma cruzi strains Y, CL and Ernane. In 95.6% of the animals trypomastigotes had been detected at the early stages of infection by fresh blood examination. The course of parasitemia at the acute phase was strongly influenced by the parasite strain and route of inoculation. At the chronic phase parasites had been recovered by xenodiagnosis and/or hemoculture in 40% of the examined animals. The xenodiagnosis studies have shown selective interactions between the T. cruzi strains and the four species of vectors used, inducing significant variability in the results. The data herein present are consistent with the parasitological requirements established for a suitable model for chronic Chagas' disease.

scholarly journals Molecular Testing for Plasmodium falciparum by Use of Serum or Plasma and Comparison with Microscopy and Rapid Diagnostic Testing in Febrile Nigerian Patients

2015 ◽  
Vol 53 (11) ◽  
pp. 3596-3600 ◽  
Author(s):  
Jesse J. Waggoner ◽  
Chika Okangba ◽  
Alisha Mohamed-Hadley ◽  
Martina I. Lefterova ◽  
Niaz Banaei ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Sensitivity And Specificity ◽  
Diagnostic Testing ◽  
Rank Correlation ◽  
Sample Volume ◽  
Nucleic Acid Amplification ◽  
Published Data ◽  
Molecular Testing ◽  
Content Type

Plasmodiumnucleic acids have been detected in serum and plasma, but there is little published data describing the diagnostic performance of malaria nucleic acid amplification tests (NAATs) using these specimen types. Previously, our group described a multiplex NAAT for the detection of dengue virus,Leptospira, andPlasmodiumspecies with a callout forP. falciparum(the DLM assay) that demonstrated sensitive detection ofP. falciparumfrom plasma samples during initial evaluation. In this study, we evaluated the sensitivity and specificity ofP. falciparumdetection in febrile Nigerian patients using the DLM assay, microscopy, and a rapid diagnostic test (BinaxNOW Malaria). Assay performances were compared using a composite reference, which was considered positive if malaria was detected by two or more methods. Serum (n= 182) or plasma (n= 148) from 317 patients was tested; the average sample volume was 70 μl (range, 5 to 300 μl). The sensitivity and specificity of the DLM assay were 97.1% and 93.5%, respectively. The sensitivity of the malaria rapid diagnostic test (98.1%) was similar to that of the DLM assay, and both proved significantly more sensitive than microscopy (79%;P< 0.0001). When analysis was limited to samples with ≥75 μl of serum or plasma, the sensitivity of the DLM assay improved to 99% and specificity was 97.5%. ForP. falciparumcases, cycle threshold values in the DLM assay correlated with the parasite density detected by microscopy (Spearman's rank correlation coefficient,P< 0.0001). In conclusion, malaria detection using the DLM assay on serum or plasma is more sensitive than and equal in specificity to microscopy in patients withP. falciparummalaria.

scholarly journals Field-deployable, rapid diagnostic testing of saliva samples for SARS-CoV-2

2020 ◽  
Author(s):  
Shan Wei ◽  
Esther Kohl ◽  
Alexandre Djandji ◽  
Stephanie Morgan ◽  
Susan Whittier ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Diagnostic Testing ◽  
Open Economies ◽  
Rapid Diagnostic Testing ◽  
Microcentrifuge Tube ◽  
One Step

AbstractRapid, scalable, point-of-need, COVID-19 diagnostic testing is necessary to safely re-open economies and prevent future outbreaks. We developed an assay that detects single copies of SARS-CoV-2 virus directly from saliva and swab samples in 30 min using a simple, one-step protocol that utilizes only a heat block and microcentrifuge tube prefilled with a mixture containing the necessary reagents and has a sensitivity and specificity of 97% and 100%, respectively.

scholarly journals Excretory-Secretory Antigens of Trypanosoma cruzi Are Potentially Useful for Serodiagnosis of Chronic Chagas' Disease

2001 ◽  
Vol 8 (5) ◽  
pp. 1024-1027 ◽  
Author(s):  
Mineo Nakazawa ◽  
Daniela S. Rosa ◽  
Valéria R. A. Pereira ◽  
Milena O. Moura ◽  
Veridiana C. Furtado ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
High Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chronic Chagas Disease ◽  
Secreted Antigens

ABSTRACT The reactivities of sera from chronic chagasic patients against the trypomastigote excreted-secreted antigens (TESA) of Trypanosoma cruzi strains with different biodemes were analyzed by TESA-blot and TESA–enzyme-linked immunosorbent assay (ELISA). Although both tests presented high sensitivity and specificity, TESA-ELISA is more appropriate for screening a larger number of samples.

Use of clomipramine as chemotherapy of the chronic phase of Chagas disease

Parasitology ◽  
2013 ◽  
Vol 140 (7) ◽  
pp. 917-927 ◽  
Author(s):  
ROMINA FAURO ◽  
SILVINA LO PRESTI ◽  
CAROLINA BAZAN ◽  
ALEJANDRA BAEZ ◽  
MARIANA STRAUSS ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Latin American ◽  
Chronic Phase ◽  
Tricyclic Antidepressant ◽  
Trypanothione Reductase ◽  
Parasite Intensity ◽  
Collateral Effects ◽  
Inflammatory Infiltrates ◽  
Latin American Countries ◽  
Chronic Chagas Disease

SUMMARYChagas infection is a major endemic disease affecting Latin American countries. The persistence ofTrypanosoma cruzigenerates a chronic inflammatory reactivity that induces an immune response directed to the host's tissues. The effectiveness of the treatment in the chronic phase is still unsatisfactory due, amongst other reasons, to the collateral effects of the drugs used. We investigated the effect of clomipramine, a tricyclic antidepressant that, when used as a treatment ofT. cruzi-chronically infected mice, inhibits trypanothione reductase, an exclusive and vital enzyme ofT. cruzi. Clomipramine improved survival (P<0·05) by diminishing the parasite intensity as demonstrated by PCR studies in the heart and skeletal muscle, and significantly prevented the evolution to fibrosis of the inflammatory infiltrates. Clomipramine could be a good candidate for the treatment of chronic Chagas disease.

Sign in / Sign up

Export Citation Format

Share Document