Open access peer-reviewed chapter

More than a Hundred Years in the Search for an Accurate Diagnosis for Chagas Disease: Current Panorama and Expectations

Written By

Aracely López-Monteon, Eric Dumonteil and Angel Ramos-Ligonio

Submitted: 19 February 2019 Reviewed: 28 April 2019 Published: 04 December 2019

DOI: 10.5772/intechopen.86567

From the Edited Volume

Current Topics in Neglected Tropical Diseases

Edited by Alfonso J. Rodriguez-Morales

Chapter metrics overview

1,814 Chapter Downloads

View Full Metrics

Abstract

Chagas disease, or American trypanosomiasis, is a parasitic disease of the Americas. In nature, Trypanosoma cruzi is transmitted through various species of triatomine bugs. However, non-vectorial transmission can also occur, such as transmission through blood products or by transplanting infected organs, by vertical transmission, and lately by oral route. Currently, Chagas disease affects approximately 6–7 million people worldwide, and the process of urbanization in Latin America and migratory movements from endemic countries have led to Chagas disease being diagnosed in areas where the infection is not endemic. There are several methods for diagnosing Chagas disease. Some of these are mostly used for research purposes, while others are used in routine diagnostic laboratories. According to the World Health Organization (WHO), chronic Chagas disease diagnosis is based on two serological techniques. To establish a definitive diagnosis, the results must be concordant. In the case of discordances, the WHO proposes repeating serology in a new sample, and if results remain inconclusive, a confirmatory test should be performed. This chapter shows aspects of the diagnosis of Chagas disease, which varies in its sensitivity and specificity, and its use depends on the geographical location, the available resources, and the purpose of the diagnosis.

Keywords

  • chagas disease
  • T. cruzi
  • diagnosis
  • serology
  • antigens

1. Introduction

The infection caused by the protozoan parasite Trypanosoma cruzi leads to Chagas disease, with an estimated 6–7 million infected people and nearly 60 million at risk of infection [1, 2]. Chagas disease ranks among the world’s most neglected diseases and is considered to be the parasitic infection with the greatest socioeconomic impact in Latin America, being responsible for an estimated US$ 1.2 billion in lost productivity annually [3]. It is a disease that a century after its discovery still requires appropriate control measures, effective treatment, and especially an accurate diagnosis. This disease is endemic to most countries in Latin America [4], but it has now become more important in other regions. The increasing presence of Chagas in non-endemic areas, as well as the resurgence of the disease in endemic countries, has been a major focus of attention in recent years [5] and, over the last 40 years, has become a global health concern due to the huge migration flows from Latin America to Europe, United States, Canada, and Japan. In Europe, most migrants from Chagas disease-endemic areas are concentrated in Spain, Italy, France, United Kingdom, and Switzerland (Figure 1) [6]. The flagellate protozoa T. cruzi is usually transmitted through infected feces and/or urine excreted by triatomines (Hemiptera: Reduviidae) during blood feeding. However, this is a nonlinear phenomenon, as mammals can be exposed to infection multiple times through distinct routes [7]; the main routes of transmission of the parasite are through the insect vector, blood transfusion, transplants of organs, congenital via, orally and it is now reported that the infection is capable of being transmitted sexually (Figure 2). In addition, the fact that Chagas disease can be transmitted sexually, along with the migration problems of individuals affected with Chagas disease to countries that were previously not endemic, and travel to endemic countries, has direct implications for public health for the spread of this disease [8], the transmission through vector only occurs in endemic areas for this disease. In non-endemic countries, the main routes of transmission are blood and congenital transmission [9, 10, 11]. T. cruzi has a high genetic diversity, which is why it has been classified into discrete typing units (DTU): TCI-TcVI, in addition, of a genotype associated with bats (TcBat); this classification was made based on different characteristics such as geographical distribution and clinical manifestations of the disease, among others. As TcI is the most widely distributed DTU and with a wide genetic diversity, it has been divided into domestic and sylvatic genotypes (TcIDom and TcISyl) [12].

Figure 1.

Distribution of Chagas Disease (WHO: Estimated data 2010).

Figure 2.

Main routes of transmission of the Trypanosoma cruzi.

The disease presents two phases. In the acute phase, ranging from the time of infection until about 6 weeks after this, patients present a high parasitemia and may show nonspecific symptoms, such as fever and headache. During the chronic phase, which can last up to 30 years, approximately 30% of patients develop cardiac complications such as arrhythmias and cardiomyopathy, and 10% of patients may present intestinal complications, especially constipation, or neurological complications. However, the chronic phase is characterized by the absence of symptoms in most patients (Figure 3) [1, 13]. The latter, coupled with the fact that patients can be found in non-endemic areas where the disease is unknown, represents an added difficulty for the diagnosis of infection [14]. The effectiveness of methods for diagnosing infectious diseases depends on their sensitivity and specificity for the unambiguous detection of the presence of the pathogen or the specific host response in response to infection. New technologies based on molecular biology have enabled the identification of biomarkers exclusive of infectious agents, molecules involved in interactions with their hosts, and of the host molecules which mediate response to infection [15]. Infectious diseases remain a major public health problem worldwide. In this scenario, the immunodiagnostic method has been and will remain an essential tool to demonstrate the presence of infection in patients, for disease prognosis, for monitoring clinical studies, and, also, as tools to monitor the success of strategies for control and epidemiological monitoring [16]. Finally, this chapter was conceived to the current need for an accurate diagnosis for Chagas disease, since the correct diagnosis is a priority not only to identify the people who should receive the appropriate treatment but also to reduce and prevent the risk of transmission through a blood transfusion or an organ transplant.

Figure 3.

Chagas disease has two stages or clinical phases: an acute phase and a chronic phase. People (from 70 to 80% of those infected) are asymptomatic throughout their lives, but from 20 to 30% of those affected, this disease progresses to chronic symptoms.

Advertisement

2. Why the need for an accurate diagnosis for Chagas disease

One of the limitations for the prevention and control of neglected tropical diseases is that the sociocultural aspects associated with diseases are ignored. Cases of Chagas disease in endemic areas occur in specific contexts marked by sociocultural, political, and economic circumstances. In addition, in the case of Chagas disease, the absence of symptoms in most cases, the lack of ability to detect and/or identify the disease, the lack of information on services and immigration policies, affect. It is very important to be able to obtain prevention and control measures for the disease, even in non-endemic countries [17]. Understanding this behavior can allow to guide health policies to combat these types of diseases, where indigenous groups and children are considered especially vulnerable groups.

2.1 The current status of the diagnosis of Chagas disease

Diagnostic methods for T. cruzi can be included in three main groups: parasitological, serological, and molecular (Figure 4). Parasitological methods aim to visualize the presence of parasites, and their sensitivity varies depending on the stage of infection [18]. For diagnosis of the disease in the phase where the parasitemia is very low, immunological methods (serological) are based primarily on the search for G antibodies (IgG) anti-T. cruzi in the blood of patients and their colorimetric reaction visible in the case that the blood of the patients contains the antibodies. [19]. The most commonly used methods are ELISA test (sensitivity = 94–100%, specificity = 96–100%), indirect hemagglutination (HAI, sensitivity = 88–99%, specificity = 96–100%), and indirect immunofluorescence (IFI, sensitivity = 98%, specificity = 98%). Despite being highly sensitive and specific, serological tests can have some cross-reactivity.

Figure 4.

Diagnostic methods for T. cruzi.

Another technique based on the search for anti-T. cruzi antibodies is the Western blot, which has been used in the diagnosis of Chagas disease using mainly excretion-secretion antigens and in some cases recombinant proteins. In the reported works, the Western blot has been used mainly to confirm the serological results obtained when other serological techniques are discordant or when there are cases of cross-reaction with Leishmania, and it has been observed that the technique possesses a high sensitivity and specificity. Although this test is not used routinely, and it is not considered as a substitute for conventional serological tests, it may be useful as an additional diagnostic test or for field studies [20, 21, 22]. Detection of parasite DNA using molecular diagnostic tools could be an alternative or complement to current diagnostic methods, but its implementation in endemic regions remains limited, due to lack of standardization, complexity, lack of clinical evidence, and the cost of implementation [23].

The application of molecular biological techniques has allowed the production of specific antigens in large quantities for use in immunologic techniques, including recombinant antigens and synthetic peptides [24]. Molecular biology methods are characterized by a high specificity and sensitivity, particularly during the acute phase, and hybridization techniques have been used for the detection of specific DNA fragments of the parasite genome by polymerase chain reaction (PCR) [25, 26, 27]. One of the major limitations of the PCR technique in the diagnosis of Chagas disease is its low sensitivity in the chronic phase due to the very low level of circulating parasites, since these are confined to tissues [28, 29]. However, it is important to note that the sensitivity of PCR is also influenced by the method of DNA extraction and the volume of blood that is used for DNA extraction [30]. Parasite detection from organ biopsies is indeed more successful during chronic infection when parasites sequester within organs; however, this technique is impractical because biopsies are not easily collected [31, 32]. Some authors proposed that circulating parasite antigens could be used as highly specific biomarkers of infection by T. cruzi as observed in mouse models [33]. Serum proteins have also been proposed as markers of Chagasic patients [34]. However, diagnosis remains mostly focused on the identification of antibodies against the parasite (Table 1) [35]. The nature of the antigens used in anti-T. cruzi assays is critical for the specificity of the assay, particularly in the case of individuals infected with related protozoan parasites such as Leishmania, as epitopes may cross-react with crude T. cruzi antigens [36]. Various types of serologic tests are currently used to establish the diagnosis of Chagas disease (Table 2), based on total parasite extracts and/or recombinant antigens [37, 38]. These serological assays for detecting antibodies to T. cruzi are generally classified as screening or confirmatory assays (Table 2). First-line screening assays provide the presumptive identification of antibody-reactive specimens, and supplemental assays are used to confirm whether samples found reactive with a particular screening assay do indeed contain antibodies specific to T. cruzi. When a single screening assay is used for testing in a population with a very low prevalence of Chagas disease, the probability that an individual is infected when a reactive test result is obtained (i.e., the positive predictive value) is very low, since the majority of individuals with reactive results are not infected. This problem occurs even when an assay with high specificity is used. Accuracy can be improved if a second supplemental assay is used to retest all those specimens found reactive by the first assay. Those found non-reactive by the assay are considered negative for antibodies to T. cruzi. Serum/plasma samples with low antibody titer are frequently found in individuals from endemic regions. In general, those samples are difficult to confirm and give a definitive final status. The clinical significance of these samples and associated potential risk of transmission by an individual presenting with low antibody titer is also little understood. These could represent individuals spontaneous cure or treated by current antiparasitic medication [39] or have cross-reactivity with other agents such as Leishmania [40]. To date, and according to the WHO, an individual is diagnosed as infected with T. cruzi in the chronic phase of the disease when the results of two serological tests are positive, due to the different immunogenicity of different strains of the parasite, different immune responses between patients, and the existence of cross-reactions with other trypanosomatids coexisting in endemic areas when using crude parasite antigens [16, 38]. When inconclusive or discordant results appear, a third technique [38] or additional samples are required [41]. However, during the diagnosis of the disease, we must take into account certain conditions and/or variables that are not directly dependent on the design and development of the test; as in the case of the host response, this depends partly on the strain of parasite and secondly on the genetic background of the host [42]. Moreover, the existence of the “immunological memory” in models where there was a parasitological cure suggests that parasite antigens may persist in some organs, which could be inducing the production of antibodies, regardless of the presence of live parasite [43, 44]. In patients treated during the chronic phase, the objective is to analyze a tendency for negativization of the serological tests, which requires to monitor patients for many years following treatment. This has brought controversies regarding the criterion of a serologic cure [45, 46]. Some researchers believe that a reduction in antibody titers after a prolonged time can be considered as a criterion of cure, in contrast to others who recommend total negativization of serological tests [47]. In areas where Chagas disease is endemic, the choice among ELISA, IIF, or IHA for serological testing is based on availability [31, 32, 38, 48]. However, these techniques may be unspecific as they can cross-react with other parasites [49]. Because of this cross-reaction, the use of antigen secretion/excretion of parasite in diagnostic tests has been proposed. It has been shown that proteins from trypomastigotes are better antigens to detect antibodies against the parasite; however, most antigens used for immunological tests are total protein extracts derived from epimastigotes, because of the ease of obtaining them, at lower cost and the presence of common antigens with trypomastigotes [50]. Nevertheless, these tests also show cases of false negatives and cross-reactivity [51, 52, 53, 54, 55, 56]. Due to the complexity of the interaction of T. cruzi with its host, a single recombinant antigen has not reached the efficacy shown by the total extracts of the parasite. Thus, the antigenic composition of the tests based on recombinant antigens includes a combination of several epitopes [57]. Flow cytometry has mainly been used for differential diagnosis between Chagas disease and leishmaniasis owing to cross-reactivity. Even with optimized serological assays that use parasite-specific recombinant antigens, inconclusive test results continue to be a problem [58]. However, this technique is utilized for monitoring treatments rather than for diagnosis [59]. In the past decade, several technologies have emerged as diagnostic tools capable of improving diagnosis by using several antigens. The diagnostic process becomes faster and less expensive, and the hands-on time in laboratories decreases substantially since these platforms can be fully automated. A multiplex assay platform was evaluated to detect T. cruzi infection using the recombinant antigens CRA, FRA, CRA-FRA fusion and parasite lysate; these antigens presented different sensitivity and specificity by themselves; however, when mixed they increased its sensitivity and specificity, suggesting that they could be an alternative to single-test detection for Chagas disease [60]. Moreover, the immunochromatography represents a promising method which can be performed with whole blood, and it has many advantages over most existing diagnostic methods, requires little time, and does not require trained personnel; its main advantage is that it can be used in field work [61], but there are cases of discordance [62]. However, despite that, there are reports where it manifests that it no longer needed investing so much in research and development for the diagnosis of Chagas disease, because that rapid tests on the market are sufficiently valid both in America and in Europe and Asia-Pacific [63]; however, this is not entirely true, since several studies have shown discordance between the various commercial techniques. As mentioned, the diagnosis of Chagas disease is based mainly on serological tests because parasitemia is generally low or cannot be detected during the chronic phase of the infection. Finally, low reaction samples may not be detectable by all serological assays; besides, the presence of the so-called “serosilent” infections [64], in which parasitemia is detectable in seronegative individuals, represents a potential risk to acquire the parasite.

Diagnostic methods in the acute phase
Direct methods without concentration
Direct methods of concentration
  • Microhematocrit

  • Strout test

Diagnostic methods in the chronic phase
Serology
  • ELISA

  • Indirect immunofluorescence

  • Indirect hemagglutination

Other parasitological and molecular biology methods*
  • Xenodiagnostic

  • In vitro culture

  • PCR

Table 1.

Diagnoses for chagas disease.

Can be used in any phase, with low parasitemia, and is not detected by other methods.


Test Antigen Manufacturer Country
Immunoenzymatic assay
AccuDiag™ Chagas ELISA Kit NI Diagnostic Automation/Cortez Diagnostics, Inc. USA
ImmunoComb® II Chagas Ab Kit RA Alere Inc. Germany
Anti-Chagas IgG ELISA Kit NI Abcam United Kingdom
Abbott ESA Chagas Purified antigens Abbott Laboratories USA
Abbott PRISM Chagas Purified antigens Abbott Laboratories USA
T. cruzi Ab (Chagas) Bioars Argentina
EIAgen Trypanosoma cruzi Ab Total extract Adaltis Italy
Chagas screen ELISA Cytoplasmic membrane antigen Wiener lab Argentina
Chagas ELISA IgG + IgM RA Vircell Spain
Pathozyme Chagas RA Omega Diagnostics Limited Scotland
Chagas Rec ELISA RA Human Diagnostics Worldwide Germany
Chagas ELISA Total extract Ebram Produtos Laboratoriais Ltda Brazil
Chagatek ELISA Purified antigens Laboratório Lemos SRL Argentina
NovaLisa Chagas (Trypanosoma cruzi) NI NovaTec Immundiagnostica Germany
Premier Chagas IgG ELISA test Purified antigens Meridian Diagnostics USA
Test ELISA para Chagas Total extract strain (Tulahuén and Mn) BIOSChile Chile
Bio-Manguinhos EIA Total extract/RP Bio-Manguinhos Brazil
IVD ELISA NI IVD Research Inc. USA
DRG®Trypanosoma cruzi IgG NI DRG International Inc. USA
Chagas IgG ELISA RA Gull Laboratories Inc./Meridian Bioscience Inc. USA
Cellabs T. cruzi IgG CELISA NI Cellabs Pty Ltd. Australia
BIOELISACRUZI Total extract Biolab-Mérieux Brazil
Dia Kit Bio-Chagas RA Gador SA Argentina
BIOZIMA Chagas kit Purified antigens Laboratório Lemos SRL Argentina
Abbott Chagas Anticorpos EIA RA Abbott Laboratories USA
Cruzi TEST ELISA NI GenCell Biosystems Ireland
Chagas test IICS, ELISA Total extract (Y strain) IICS Univ de Asunción Paraguay
HBK 401 Hemobio Chagas Total extract Embrabio Brazil
Chagatest ELISA Total extract/RP Wiener lab Argentina
Bioelisa Chagas Synthetic peptides Biokit Spain
Chagas Hemagen Purified antigens Hemagen Diagnósticos USA
BioMérieux Total extract/RP BioMérieux France
BLK Total extract BLK diagnostics Spain
Siemens IMMULITE Chagas IgG RA Siemens Healthcare USA
Anti-Chagas Symbiosis NI Symbiosys Brazil
ORTHO T. cruzi ELISA Test System Total extract Jhonson and Jhonson USA
Certest (Strain Tulahuen and Mn) Abbott Laboratories Spain
ImmunoComb II Chagas Ab RA/peptides Orgenics Israel
Elecsys Chagas assay Recombinant antigens Roche Diagnostic
Gold ELISA Chagas Recombinant proteins and purified lysates Brazil
ELISA Chagas III Total extract Grupo Bios Chile
Imuno-ELISA Chagas Recombinant antigens Wama Diagnóstica Brazil
T. cruzi Ab, DIAPRO Recombinant antigens Diagnostic BioProbes Italy
Trypanosoma cruzi IgG ELISA Kit Total extract MyBiosource USA
Chagas (Trypanosoma cruzi) IgG assay NI DEMEDITEC Diagnostics GmbH Germany
Chagas (Trypanosoma cruzi) IgG ELISA NI GenWay Biotech, Inc. USA
Chagas (Trypanosoma cruzi) IgG ELISA NI IBL International GmbH Germany
CELQUEST CHAGAS ELISA Recombinant antigens ATGen Diagnostica Italy
Immunochromatographic assay
OnSite Chagas Ab Rapid test RA CTK Biotech USA
Chagas AB Rapid RA Standard Diagnostics Korea
WL Check Chagas RA Wiener Lab Argentina
Chagas Instantest Antigens attached to colloidal gold Silanes Mexico
Prueba rápida Chagas Antigens attached to colloidal gold Amunet Labarotarios Mexico
Chagas Detect™ Plus Multi-epitope
recombinant antigen
InBios, Inc. USA
Chagas-certum Antigens attached to colloidal gold Certum® Diagnostics Mexico
Chagas Quick Test Multi-epitope
recombinant antigen
Cypress Diagnostic Belgium
Chagas Stat-Pak assay RA Chembio Diagnostic Systems USA
PATH-Lemos rapid test RA Laboratório Lemos SRL Argentina
Immu-Sure Chagas (T. cruzi) Millennium Biotech USA
SD Chagas Ab Rapid RA Standard Diagnostic Korea
ICT Operon Purified antigens Operon Spain
Hemagglutination assays
Chagas HAI Imunoserum Sheep red blood cells are sensitized by binding
T. cruzi antigen
Laboratório Lemos SRL Argentina
ID-PaGIA, version 2 Ag/version 3 Ag RA/purified antigens DiaMed Switzerland
Chagatest IHA Erythrocytes sensitized with parasite lysate Wiener Argentina
Chagas HAI Bird red blood cells are sensitized by binding purified
T. cruzi (Y strain)
Ebram Brazil
Imuno-HAI Chagas Bird red blood cells are sensitized by binding purified
T. cruzi (Y strain)
WAMA Brazil
Chagas Hemagen HA Human red blood cells are sensitized by binding
epimastigote and amastigote forms of T. cruzi
(Y and CL strain)
Hemagen Diagnosticos USA
Hemacruzi Erythrocytes sensitized with parasite lysate Biolab-Mérieux Brazil
ID-Chagas antibody test Gel particles coated with peptides DiaMed-ID Switzerland
Serodia Chagas Gelatin particles coated with inactivated Trypanosoma cruzi antigens Fujirebio, Inc. Japan
Immunofluorescence assays
Chagas IFA NI Vircell Spain
Inmunofluor Chagas kit Epimastigotes Biocientífica S.A Argentina
Kit Trypanosomiasis IFI Epimastigotes Tryniti-Mardx (Inverness Medical) USA
Inmunofluor Chagas IFI Parasites NI Biocientífica S.A. (Inverness Medical) Argentina
MarDx IFA MarDx Diagnostics, Inc. USA
IFA Kit Trypanosomiasis Innogenetics Ibérica Spain
Chemiluminescent immunoassay
Architect Chagas assay (prototype) immunoparticles RA Abbott Laboratories Spain
CHAGAS VIRCLIA NI Vircell Spain
PCR assays
T. cruzi OligoC-TesT NA Coris BioConcept Belgium
AMPLIRUN® TRYPANOSOMA DNA CONTROL NA Vircell Spain
Loop-mediated isothermal amplification (LAMP) assay NA Eiken Chemical Company China
RealCycler CHAG NA Progenie Molecular Spain
TCRUZIDNA.CE NA Diagnostic Bioprobes Srl Italy
RealStar® Chagas PCR Kit RUO NA altona Diagnostics GmbH Germany
VIASURE Trypanosoma cruzi Real Time PCR Detection Kit NA Certets Biotec Spain
Confirmatory assays
Radioimmunoprecipitation analysis [RIPA] Radiolabeled T. cruzi
surface antigens
University of Iowa USA
INNO-LIA Chagas assay Recombinant and synthetic
T. cruzi antigens
Innogenetics Belgium
IF Imunocruzi Epimastigotes Biolab Mérieux Brazil
TESA-blot Excreted-secreted antigens Biolab Mérieux Brazil
Multiplex Immunoassay Multi-cruzi (prototype) Protein array NA NA

Table 2.

List of commercial diagnostic tests for the serological detection of T. cruzi (Chagas disease).

RA, recombinant antigen; NI, not indicated; NA, not applicable.

2.2 The world of diagnosis for Chagas disease: a discordant paradise

The accurate diagnosis of T. cruzi infection is pivotal to the clinical management of Chagas disease. T. cruzi has a complex life cycle, and its ability to infect any nucleated cell complicates diagnosis [65]. Additionally, the absence of a “gold standard” test that reliably and consistently detects the presence of a T. cruzi infection makes the evaluation of current methods difficult [28, 66]. Serodiscordance in Chagas disease remains a challenge since individuals with inconclusive results are clinically complicated to manage [67]; this problem usually arises in the diagnosis during the chronic phase. Performing two or more serological testing does not guarantee that the result shall be univocal. It is called serodiscordance when in the same patient two tests give different results (frequent situation during treatment, in pregnant patients or patient in acute cases), because the main criterion for “cure” has been the conversion to negative serology on all tests performed. However, this result is often not observed until 8–10 years posttreatment and then only in approximately 15% of treated adult subjects [68]. Experts recommend that the IFI which has a sensitivity of 95% and a specificity of 100% is used. However, it is often not the most advisable since reading can be subjective, depending on the experience of the technician. Another situation that often occurs in reading spectrophotometric tests, such as ELISA, is that the values of optical density (OD) are very close to the cutoff value (±10%), in which case the result should not be considered positive or negative but rather indeterminate. Alternatives have been proposed as IFI, antigens’ parasite excretion-secretion (TESA) used in ELISA or immunoblot assays or by radioimmunoassay (RIPA), or various recombinant antigens used in immunoblot [14]. To date no test alone can establish the diagnosis or confirmation of infection by T. cruzi nor rule out the problem of cross-reactivity; the combination of tests usually generates discrepant results, often in a limited number of cases. Some commercial tests have very limited ability to detect T. cruzi infection in populations of particular study; internal tests based on crude parasite antigens showed a higher sensitivity but were still unable to detect all cases of T. cruzi infection [69], for example, the University of Sao Paulo conducted tests to detect T. cruzi antibodies using the three methods IH, IIF, and ELISA; 4000 serum samples were analyzed, of which only 1901 (48%) were positive for all three tests, 718 (18%) were negative, and 1381 (35%) had a questionable or inconclusive results. The discrepancies were attributable to the type of parasite antigen; IIF detects a specific antibody that reacts with a parasite membrane antigen, whereas HI detects an antibody that reacts with a subcellular antigen. Each of these serological reactions operates in different specificity systems [70]. Another study in Spain was found to have a higher sensitivity (97–100%), and for serological screening of T. cruzi infection, a combination of tests is needed [71]. Finally, in a study conducted in a rural community in Veracruz, Mexico, using a combination of five ELISA tests based on different antigenic preparations (two in-house enzyme-linked immunosorbent assay based on crude extract, Chagatest ELISA recombinant v3.0, Chagatek ELISA, and NovaLisa Chagas), a very high level of discordance (32%) was also found among the ELISA tests used, with very poor agreement among them. This showed that the commercial tests had a very limited ability to detect T. cruzi infection, and the in-house tests based on crude parasite antigens showed a greater sensitivity but were still unable to detect all cases of T. cruzi infection, even when based on a local parasite strain [69].

To date, T. cruzi diagnostic present problems of sensitivity, making the diagnosis confusing and often requiring additional testing [40, 70, 71]. In congenital cases, it has been observed that discordance between the samples analyzed also occurs, and discordant results were confirmed by a third diagnostic test [72]. Although numerous assays are available for diagnosing Chagas disease, no single test is considered the reference standard to confirm the diagnosis of infection by the parasite [73, 74, 75, 76]. Serology is a useful tool in the diagnosis of Chagas disease, but in certain circumstances, none of the techniques described above serves as a marker of cure or progression of infection. Some authors mention that the Western blot is suitable for confirmation of infection by T. cruzi, so it is strongly recommended for confirmation and discrimination of discordant cases [22, 77], because this technique has a sensitivity of 86.6% [20, 78], 99% [79], and 100% [80, 81] and a specificity of 100%, making it more effective than techniques such as ELISA, HAI, and IIF. The adequate choice of T. cruzi strains as antigen source for the diagnosis of Chagas disease is still controversial due to differences in terms of accuracy reported between different diagnostic tests. The results of this study showed that the sensitivity index did not vary, with percentages of 100% for all strains in both tests. However, the specificity index for the ELISA tests showed differences between 92 and 98% but was reduced to 78–89% when the Leishmania-positive sera were included [82].

2.3 Looking for the correct diagnosis

After more than a century of the discovery of Chagas disease, there is no consensus on the choice of a reference technique. Studies in South America reported a high efficiency of commercial kits manufactured in this region [40, 83]. However, work carried out in Central America shows that the use of antigens prepared from T. cruzi strains that are isolated in these areas increases the sensitivity of antibody detection assays [69, 84, 85]. This could be due to the predominance of the lineage TcI in the region [86] and the wide expansion of genotypes TcII–TcVI reported in the Southern Cone countries [87]; but lately, the presence of additional DTUs has been demonstrated in countries such as Mexico and the United States [88, 89]. The development of new diagnostics is partially limited by the availability of well-characterized antigens, in addition to the great variability among strains and DTUs in terms of virulence, infectivity, tissue tropism, progression of disease, drug susceptibility, and geographical distribution [31, 90, 91, 92]. However, there is as yet no clear association between genetic variants of the parasite and these life history or epidemiological characteristics. Several recombinant antigens that have serologic utility have been identified. However, the most effective antigens have been those with immunodominant, repeating B-cell epitopes [93]. The use of recombinant antigens and/or synthetic peptides has been proposed [94] to improve specificity and sensitivity, which is essential if false-positive or false-negative results are to be avoided. Peptide analysis is a technique widely used for mapping of linear epitopes in proteins from pathogens [95, 96].

The recent availability of peptide microarrays allows rapid and inexpensive serological diagnosis with high performance [97, 98]. The availability of complete pathogen genomes has renewed interest in the development of diagnostics for infectious diseases. Synthetic peptide microarrays provide a rapid, high-throughput platform for immunological testing of potential B-cell epitopes. Therefore, computational approaches for prediction and/or prioritization of diagnostically relevant peptides are required [99]. Currently, high-density peptide chips for the discovery of linear B-cell epitopes’ specific pathogens from clinical samples provide the basis for the detection of biomarkers and proteome-scale studies of the immune response against pathogens [100].

The challenge for this process is to identify, by bioinformatics within a given proteome, peptides that could be good targets for a B-cell response. A number of algorithms have been developed for computational prediction of B-cell epitopes [101]. Computational prediction of B-cell epitopes is still an active research field, and a number of state-of-the-art predictors show improved performance [102, 103, 104, 105]. As a consequence, predicting diagnostic epitopes in the context of a particular disease or infection is a complex problem, where many additional limitations are not taken into account, such as the mechanism of invasion of infectious agents, the expression pattern of parasite proteins. All these additional variables affect the outcome of the immune response and may explain the observed variability in responses [99]. In recent years, microarray technology has been of great interest, offering valuable opportunities to study the function of genes and the development of diagnostics. The main advantage of a microarray assay is to determine different analytes simultaneously, and it is more sensitive and faster than the conventional ELISA system. Peptide microarrays combined with a bioinformatics peptide selection strategy constitute a powerful and cost-effective platform for serodiagnostic biomarker screening of infectious diseases just as Chagas disease [100]. The development of efficient methods for the detection of microspots with high sensitivity and specificity will enable new applications in future studies applied to protein microarrays [106, 107].

New-generation tests with potentially improved accuracy have been developed recently. The use of a large mixture of recombinant antigens and the incorporation of different detection systems, such as chemiluminescence, increase the sensitivity and specificity of the techniques. Other advantages of new-generation tests are automation, rapidity, and high performance, such as the Architect Chagas or Bio-Flash Chagas (Biokit, Lliçà d’Amunt, Spain), which have improved the diagnosis of Chagas disease with innovative new tools (large mixture of recombinant antigens and chemiluminescence as detection system). Previous studies have also proposed a chemiluminescent ELISA (CL-ELISA) with purified trypomastigote glycoproteins for the detection of lytic protective antibodies against T. cruzi in human serum [35, 108, 109, 110]. Detection systems, such as chemiluminescence, increase light amplification and signal duration in comparison with traditional ELISAs, which may be a point in favor of these new methodologies, leading to higher accuracy in the diagnosis of Chagas disease. Further studies with other new-generation techniques with similar characteristics (recombinant antigens and chemiluminescence) are necessary [35]. The use of a single technique would reduce diagnosis costs and therefore allow the application of screening and control programs in countries where such systems have not yet been implemented. Previous studies on the cost-effectiveness of Chagas disease management have been undertaken, but the costs of different diagnostic methods have not been compared [111, 112, 113, 114]. Thus, several groups have implemented the usage of PCR to the identification of the genetic material from the parasite, in blood and serum samples as well as tissue samples. Several types of the PCR techniques are available to detect T. cruzi DNA in serum and blood samples; among them we find conventional PCR, hot-start PCR, and nested PCR. Several tools that use probes to verify the presence/absence of specific DNA are also used; such as: Southern Blot or PCR and hybridization and real-time PCR. An important advantage that the use of PCR offers as a diagnosis tool is that it allows the characterization of the circulating strains in an endemic area for Chagas disease [115]. Finally, there is a need to develop new non-serological non-PCR-based assays to address the limitations of the current methods available for T. cruzi detection. For this purpose, assays that detect biomarkers of Chagas disease need to be developed. Biomarker discovery studies reported for Chagas disease lead to the identification of characteristics of host origin, such as host proteins or immune markers, which were elevated in Chagas disease [116, 117]. However, one cannot exclude the possibility that these host markers could also be modulated in conditions unrelated to T. cruzi infection, and thus these biomarkers have limited specificity [118]. In order to overcome the issues of specificity, the detection of pathogen-specific factors would be ideal biomarkers of T. cruzi infection [33].

Advertisement

3. Conclusions

Chagas disease causes 12,000 deaths each year, and it is estimated that between 7 and 8 million people suffer. This is one of the major public health problems in Latin America. In recent decades, cases have also been detected in North America, Europe, and Asia-Pacific, mainly as a result of migration. An ideal serological test should be easy to perform in a single step, be fast, and be cheap, require no special equipment or refrigeration of reagents, and have 100% sensitivity and specificity; unfortunately, no such test exists for Chagas disease. The lack of a reference standard serological assay for the diagnosis of T. cruzi infection has prompted the development of new tests, which require further evaluation, so that the development of diagnostic methods for detecting T. cruzi infections, after more than a hundred years of its discovery, remains a challenge which depends mainly on the availability of specific high-affinity antigens. The diagnosis of Chagas disease has limitations, mainly due to the great complexity of the factors that involve it, as well as to the low sensitivity of the parasitological techniques and the low specificity of the immunological tests. Finally, the application of immunomics, which combines serology with proteomics, would help to discover genes and molecules related to the susceptibility and immunity of T. cruzi infection, allowing the creation of an adequate diagnosis for the disease, elucidating new therapeutic targets, and, why not, allowing the creation of a vaccine against Chagas disease.

Advertisement

Acknowledgments

This work was supported by grant CONACyT-DCPN-247505-2014.

Advertisement

Conflict of interest

The authors declare no conflict of interest.

References

  1. 1. WHO. Chagas Disease (American trypanosomiasis) [Internet]. WHO; 2016. Available from: http://www.who.int/entity/mediacentre/factsheets/fs340/en/index.html
  2. 2. WHO. Reporte del grupo de trabajo científico sobre la enfermedad de Chagas. Geneva: 2017. Available from: http://whqlibdoc.who.int/hq/2007/tDR_SWG_09_spa.pdf
  3. 3. WHO—World Health Organization. Research priorities for Chagas disease, human African trypanosomiasis and leishmaniasis. 2012. Available from: apps.who.int/iris/bitstream/10665/77472/1/WHO_TRS_975_eng.pdf
  4. 4. WHO. Tropical Disease Research. Program for Research and Training Tropical Disease (TDR). Fact Sheet Nu340. Geneva: World Health Organization; 2013
  5. 5. Andrade DV, Gollob KJ, Dutra WO. Acute chagas disease: New global challenges for an old neglected disease. PLoS Neglected Tropical Diseases. 2014;8(7):e3010. DOI: 10.1371/journal.pntd.0003010
  6. 6. Antinori S, Galimberti L, Bianco R, Grande R, Galli M, Corbellino M. Chagas disease in Europe: A review for the internist in the globalized world. European Journal of Internal Medicine. 2017;43:6-15. DOI: 10.1016/j.ejim.2017.05.001
  7. 7. Jansen AM, Xavier SC, Roque AL. The multiple and complex and changeable scenarios of the Trypanosoma cruzi transmission cycle in the sylvatic environment. Acta Tropica. 2015;151:1-15
  8. 8. Gomes C, Almeida AB, Rosa AC, Araujo PF, Teixeira ARL. American trypanosomiasis and Chagas disease: Sexual transmission. International Journal of Infectious Diseases. 2019;81:81-84. DOI: 10.1016/j.ijid.2019.01.021. Epub 2019 Jan 18
  9. 9. Jackson Y, Pinto A, Pett S. Chagas disease in Australia and New Zealand: Risks and needs for public health interventions. Tropical Medicine & International Health. 2014;19:212-218
  10. 10. Norman FF, Lopez-Velez R. Mother-to-child transmission of trypanosoma cruzi infection (chagas disease): A neglected problem. Transactions of the Royal Society of Tropical Medicine and Hygiene. 2014;108:388-390
  11. 11. Requena-Mendez A, Albajar-Vinas P, Angheben A, Chiodini P, Gascon J, Munoz J, et al. Health policies to control chagas disease transmission in european countries. PLoS Neglected Tropical Diseases. 2014;8:e3245
  12. 12. Velásquez-Ortiz N, Hernández C, Herrera G, Cruz-Saavedra L, Higuera A, Arias-Giraldo LM, et al. Trypanosoma cruzi infection, discrete typing units and feeding sources among Psammolestes arthuri (reduviidae: Triatominae) collected in eastern Colombia. Parasites & Vectors. 2019;12:157
  13. 13. Roca Saumell C, Soriano-Arandes A, Solsona Díaz L, Gascón Brustenga J. Consensus document for the detection and management of chagas disease in primary health care in a non-endemic areas. Grupo de consenso chagas-APS. Atencion Primaria. 2015;47(5):308-317
  14. 14. Moure Z, Angheben A, Molina I, Gobbi F, Espasa M, Anselmi M, et al. Serodiscordance in chronic chagas disease diagnosis: A real problem in non-endemic countries. Clinical Microbiology and Infection. 2016;22(9):788-792. DOI: 10.1016/j.cmi.2016.06.001. pii: S1198-743X(16)30186-0
  15. 15. Hernández-Hernández FC, Rodríguez MH. Biotechnological advances in infectious diseases diagnosis. Salud Pública de México. 2009;51(suppl 3):S424-S438
  16. 16. Peeling RW, Nwaka S. Drugs and diagnostic innovations to improve global health. Infectious Disease Clinics of North America. 2011;25:693-705
  17. 17. Romay-Barja M, Boquete T, Martinez O, González M, Álvarez-Del Arco D, Benito A, et al. Chagas screening and treatment among Bolivians living in Madrid, Spain: The need for an official protocol. PLoS One. 2019;14(3):e0213577. DOI: 10.1371/journal.pone.0213577
  18. 18. Becerril M. Parasitología Médica. Tercera edición ed. México DF, México: McGraw Hill Interamericana Editores; 2011. pp. 81-93
  19. 19. Guhl F, Vallejo AG. Trypanosoma (herpetosoma) rangeli tejera, 1920—An updated review. Memórias do Instituto Oswaldo Cruz. 2003;98:435-442
  20. 20. Reiche EM, Cavazzana M Jr, Okamura H, Tagata EC, Jankevicius SI, Jankevicius JV. Evaluation of the western blot in the confirmatory serologic diagnosis of chagas’ disease. The American Journal of Tropical Medicine and Hygiene. 1998;59(5):750-756
  21. 21. Escalante H, Jara C, Davelois K, Iglesias M, Benites A, Espinoza R. Western blot technique standardization for specific diagnosis of Chagas disease using excretory-secretory antigens of Trypanosoma cruzi epimastigotes. Revista Peruana de Medicina Experimental y Salud Pública. 2014;31(4):644-651
  22. 22. Ramos-Ligonio A, Ramírez-Sánchez ME, González-Hernández JC, Rosales-Encina JL, López-Monteon A. Prevalence of antibodies against Trypanosoma cruzi in blood bank donors from the IMSS general Hospital in Orizaba, Veracruz, Mexico. Salud Pública de México. 2006;48:13-21
  23. 23. Picado A, Cruz I, Redard-Jacot M, et al. The burden of congenital chagas disease and implementation of molecular diagnostic tools in Latin America. BMJ Global Health. 2018;3:e001069. DOI: 10.1136/bmjgh-2018-001069
  24. 24. Umezawa ES, Luquetti AO, Levitus G, Ponce C, Ponce E, Henriquez D, et al. Serodiagnosis of chronic and acute Chagas’ disease with Trypanosoma cruzi recombinant proteins: Results of a collaborative study in six latin american countries. Journal of Clinical Microbiology. 2004;42(1):449-452
  25. 25. De Winne K, Büscher P, Luquetti AO, Tavares SB, Oliveira RA, Solari A, et al. The Trypanosoma cruzi satellite DNA oligoC-test and Trypanosoma cruzi kinetoplast DNA oligoC-test for diagnosis of chagas disease: A multi-cohort comparative evaluation study. PLoS Neglected Tropical Diseases. 2014;8:e2633
  26. 26. Portela-Lindoso AA, Shikanai-Yasuda MA. Chronic Chagas’ disease: From xenodiagnosis and hemoculture to polymerase chain reaction. Revista de Saúde Pública. 2003;37(1):107-115
  27. 27. Schijman AG, Bisio M, Orellana L, Sued M, Duffy T, Mejia Jaramillo AM, et al. International study to evaluate PCR methods for detection of Trypanosoma cruzi DNA in blood samples from chagas disease patients. PLoS Neglected Tropical Diseases. 2011;5:e931
  28. 28. Ávila H, Pereira J, Thiemmano DE, Paiva E, Degrave W, Morel C, et al. Detection of trypanosoma cruzi in blood specimens of chronic chagasic patients by polymerase chain reaction amplification of kinetoplast minicircle DNA: Comparison with serology and xenodiagnosis. Journal of Clinical Microbiology. 1993;31:2421-2426
  29. 29. Wincker P, Bosseno MF, Britto C, Yaksic N, Cardoso MA, Morel CM, et al. High correlation between chagas disease serology and PCR-based detection of Trypanosoma cruzi kinetoplast DNA in bolivian children living in an endemic area. FEMS Microbiology Letters. 1994;124(3):419-424
  30. 30. Ferrer E, Da CF, Campioli P, Lares M, López M, Rivera MG, et al. Validación de protocolos de PCR para el diagnóstico molecular de la enfermedad de Chagas. Salus. 2009;12(S1):163-174
  31. 31. Perez CJ, Lymbery AJ, Thompson RC. Chagas disease: The challenge of polyparasitism? Trends in Parasitology. 2014;30(4):176-182
  32. 32. Ramirez JD, Guhl F, Umezawa ES, Morillo CA, Rosas F, Marin-Neto JA, et al. Evaluation of adult chronic chagas heart disease diagnosis by molecular and serological methods. Journal of Clinical Microbiology. 2009;47:3945-3951
  33. 33. Nagarkatti R, de Araujo FF, Gupta C, Debrabant A. Aptamer based, non-PCR, non-serological detection of chagas disease biomarkers in trypanosoma cruzi infected mice. PLoS Neglected Tropical Diseases. 2014;8(1):e2650. DOI: 10.1371/journal.pntd.0002650
  34. 34. Wen JJ, Zago MP, Nunez S, Gupta S, Burgos FN, Garg NJ. Serum proteomic signature of human chagasic patients for the identification of novel potential protein biomarkers of disease. Molecular & Cellular Proteomics. 2012;11:435-452
  35. 35. Abras A, Gállego M, Llovet T, Tebar S, Herrero M, Berenguer P, et al. Serological diagnosis of chronic chagas disease: Is it time for a change? Journal of Clinical Microbiology. 2016;54:1566-1572
  36. 36. Gorlin J, Rossmann S, Robertson G, Stallone F, Hirschler N, Nguyen KA, et al. Evaluation of a new Trypanosoma cruzi antibody assay for blood donor screening. Transfusion. 2008;48:531-540
  37. 37. Longhi SA, Brandariz SB, Lafon SO, Niborski LL, Luquetti AO, Schijman AG, et al. Evaluation of in-house ELISA using Trypanosoma cruzi lysate and recombinant antigens for diagnosis of chagas disease and discrimination of its clinical forms. The American Journal of Tropical Medicine and Hygiene. 2012;87:267-271
  38. 38. WHOControl of chagas disease: Second report of the WHO expert committee. World Health Organization Technical Report Series. 2002;905:1-109
  39. 39. Viotti R, Vigliano C, Lococo B, Bertocchi G, Petti M, Alvarez MG, et al. Long-term cardiac outcomes of treating chronic chagas disease with benznidazole versus no treatment: A nonrandomized trial. Annals of Internal Medicine. 2006;144(10):724-734
  40. 40. Caballero ZC, Sousa OE, Marques WP, Saez-Alquezar A, Umezawa ES. Evaluation of serological tests to identify Trypanosoma cruzi infection in humans and determine cross-reactivity with trypanosoma rangeli and leishmania spp. Clinical and Vaccine Immunology. 2007;14:1045-1049
  41. 41. Lapa JS, Saraiva RM, Hasslocher-Moreno AM, Georg I, Souza AS, Xavier SS, et al. Dealing with initial inconclusive serological results for chronic chagas disease in clinical practice. European Journal of Clinical Microbiology & Infectious Diseases. 2012;31:965-974
  42. 42. Reyes M, Luquetti A, Rassi A, Frasch A. Long lasting IgM and IgG reactivities against Trypanosoma cruziantigens in human cases of chagas disease. Anales de la Asociacion Quimica Argentina. 1993;81:101-110
  43. 43. Andrade S, Freitas L, Peyrol S, Pimentel A, Sadigursky M. Experimental chemotherapy of Trypanosoma cruzi infections persistence of parasite antigens and positive serology in parasitologically cured mice. Bulletin of the World Health Organization. 1991;69:191-199
  44. 44. Andrade S, Pimentel A, de Souza M, Andrade Z. Interstitial dendritic cells of the Herat harbor Trypanosoma cruzi antigens in experimentally infected dogs: Importance for the pathogenesis of chagasic myocarditis. The American Journal of Tropical Medicine and Hygiene. 2000;63:64-70
  45. 45. Sosa S, Segura E, Ruiz A, Velásquez E, Porcel B, Yampotis C. Efficacy of chemotherapy with benznidazole in children in the indeterminate phase of chagas´ disease. The American Journal of Tropical Medicine and Hygiene. 1998;59:526-529
  46. 46. Andrade A, Zicker F, Oliveira R, Almeida S, Luquetti A, Travassos L, et al. Randomized trial of efficacy of benznidazole in treatment of early Trypanosoma cruzi infection. Lancet. 1996;348:1407-1413
  47. 47. Cançado J. Criteria of chagas disease cure. Memórias do Instituto Oswaldo Cruz. 1999;94(suppl I):331-335
  48. 48. Sanchez Negrette O, Sánchez Valdéz FJ, Lacunza CD, García Bustos MF, Mora MC, Uncos AD, et al. Serological evaluation of specific-antibody levels in patients treated for chronic chagas disease. Clinical and Vaccine Immunology. 2008;15:297-302
  49. 49. Ferrer E. Técnicas moleculares para el diagnóstico de la enfermedad de Chagas. SABER. Revista Multidisciplinaria del Consejo de Investigación de la Universidad de Oriente. 2015;27:359-371
  50. 50. De Lima A, Arévalo P, Bastidas V, Bolívar M, Navarro M, Contreras V. Efecto de las condiciones de mantenimiento de Trypanosoma cruzi sobre la calidad de los antígenos para el diagnóstico serológico de la enfermedad de Chagas. Salus. 2007;11(suppl 1):20-26
  51. 51. Amato-Neto V, De Marchi CR, Ferreira CS, Ferreira AW. Observations on the use of TESA blot for the serological diagnosis of chagas’ disease. Revista da Sociedade Brasileira de Medicina Tropical. 2005;38:534-535
  52. 52. Chang K, Cheng Y, Jiang LX, Salbilla VA, Haller AS, Yem AW. Evaluation of a prototype Trypanosoma cruzi antibody assay with recombinant antigens on a fully automated chemiluminescence analyzer for blood donor screening. Transfusion. 2006;46:1737-1744
  53. 53. Flores-Chávez M, Cruz I, Rodríguez M, Nieto J, Franco E, Gárate T, et al. Comparación de técnicas serológicas convencionales y no convencionales para el diagnóstico de la enfermedad de Chagas importada en España. Enfermedades Infecciosas y Microbiología Clínica. 2010;28:284-293
  54. 54. Umezawa ES, Nascimento MS, Kesper N Jr, Coura JR, Borges-Pereira J, Junqueira AC. Immunoblot assay using excreted-secreted antigens of Trypanosoma cruzi in serodiagnosis of congenital, acute, and chronic chagas’ disease. Journal of Clinical Microbiology. 1996;34:2143-2147
  55. 55. Wendel S. Transfusion-transmitted american and african trypanosomiasis (chagas disease and sleeping sickness): Neglected or reality? ISBT Science Series. 2006;1:140-151
  56. 56. Winkler MA, Brashear RJ, Hall HJ, Schur JD, Pan AA. Detection of antibodies to trypanosoma cruzi among blood donors in the southwestern and western United States. II. Evaluation of a supplemental enzyme immunoassay and radioimmunoprecipitation assay for confirmation of seroreactivity. Transfusion. 1995;35:219-225
  57. 57. Da Silveira JF, Umezawa ES, Luquetti AO. Chagas disease: Recombinant Trypanosoma cruzi antigens for serological diagnosis. Trends in Parasitology. 2001;17:286-291
  58. 58. Teixeira-Carvalho A, Campos FM, Geiger SM, Rocha RD, de Araújo FF, Vitelli-Avelar DM, et al. FC-TRIPLEX Chagas/Leish IgG1: A multiplexed flow cytometry method for differential serological diagnosis of chagas disease and leishmaniasis. PLoS One. 2015;e0122938:10. DOI: 10.1371
  59. 59. Martins-Filho OA, Pereira ME, Carvalho JF, Cançado JR, Brener Z. Flow cytometry, a new approach to detect anti-live trypomastigote antibodies and monitor the efficacy of specific treatment in human Chagas’ disease. Clinical and Diagnostic Laboratory Immunology. 1995;2(5):569-573
  60. 60. Foti L, Fonseca B d P, Nascimento LD, Marques C d F, da Silva ED, Duarte CA, et al. Viability study of a multiplex diagnostic platform for chagas disease. Memórias do Instituto Oswaldo Cruz. 2009;104(Suppl 1):136-141
  61. 61. Luqueti A, Ponce C, Ponce E, Estefandiari J, Schijman A, Revollo S, et al. Chagas disease diagnosis: A multicentric evaluation of Chagas Stat-Pak, a rapid immunocrhromatographic assay with recombinant proteins of Trypanosoma cruzi. Diagnostic Microbiology and Infectious Disease. 2003;46:265-271
  62. 62. López-Chejade P, Roca C, Posada E, Pinazo MJ, Gascon J, Portús M. Utility of an immunochromatographic test for chagas disease screening in primary healthcare. Enfermedades Infecciosas y Microbiología Clínica. 2010;28:169-171
  63. 63. Sánchez-Camargo CL, Albajar-Viñas P, Wilkins PP, Nieto J, Leiby DA, Paris L, et al. Comparative evaluation of 11 commercialized rapid diagnostic tests for detecting Trypanosoma cruzi antibodies in serum banks in areas of endemicity and nonendemicity. Journal of Clinical Microbiology. 2014;54(7):2506-2512
  64. 64. Oliveira LC, Lee TH, Ferreira AM, Bierrenbach AL, Souza-Basqueira M, Oliveira CDL, et al. Lack of evidence of seronegative infection in an endemic area of chagas disease. Revista do Instituto de Medicina Tropical de São Paulo. 2019;61:e11. DOI: 10.1590/S1678-9946201961011
  65. 65. Morocoima A, Socorro G, Avila R, Hernández A, Merchán S, Ortiz D, et al. Trypanosoma cruzi: Experimental parasitism in the central nervous system of albino mice. Parasitology Research. 2012;111:2099-2107
  66. 66. Tarleton RL, Reithinger R, Urbina JA, Kitron U, Gürtler RE. The challenges of chagas disease—Grim outlook or glimmer of hope. PLoS Medicine. 2007;4:e332
  67. 67. Moure Z, Sulleiro E, Iniesta L, Guillen C, Molina I, Alcover MM, et al. The challenge of discordant serology in Chagas disease: The role of two confirmatory techniques in inconclusive cases. Acta Tropica. 2018;185:144-148. DOI: 10.1016/j.actatropica.2018.05.010. Epub 2018 May 15
  68. 68. Viotti R, Vigliano C, Alvarez MG, Lococo B, Petti M, Bertocchi G, et al. Impact of aetiological treatment on conventional and multiplex serology in chronic chagas disease. PLoS Neglected Tropical Diseases. 2011;5(9):e1314. DOI: 10.1371/journal.pntd.0001314
  69. 69. Guzmán-Gómez D, López-Monteon A, Lagunes-Castro S, Álvarez-Martínez C, Hernández-Lutzon MJ, Dumonteil E, et al. Highly discordant serology against Trypanosoma cruzi in Central Veracruz, Mexico: Role of the antigen used for diagnostic. Parasites & Vectors. 2015;17(8):466
  70. 70. De Souza RM, Amato V. Discrepancies and consequences of indirect hemagglutination, indirect immunofluorescence and elisa tests for the diagnosis of chagas disease. Revista do Instituto de Medicina Tropical de São Paulo. 2012;54:141-143
  71. 71. Santos FL, de Souza WV, Barros Mda S, Nakazawa M, Krieger MA, Gomes Y d M. Chronic chagas disease diagnosis: A comparative performance of commercial enzyme immunoassay tests. American Journal of Tropical Medicine and Hygiene. 2016;94(5):1034-1039. DOI: 10.4269/ajtmh.15-0820.
  72. 72. Langhi DM Jr, Bordin JO, Castelo A, Walter SD, Moraes-Souza H, Stumpf RJ. The application of latent class analysis for diagnostic test validation of chronic Trypanosoma cruzi infection in blood donors. The Brazilian Journal of Infectious Diseases. 2002;6:181-187
  73. 73. Leiby DA, Wendel S, Takaoka DT, Fachini RM, Oliveira LC, Tibbals MA. Serologic testing for Trypanosoma cruzi: Comparison of radioimmunoprecipitation assay with commercially available indirect immunofluorescence assay, indirect hemagglutination assay, and enzyme-linked immunosorbent assay kits. Journal of Clinical Microbiology. 2000;38:639-642
  74. 74. Otero S, Sulleiro E, Molina I, Espiau M, Suy A, Martín-Nalda A, et al. Congenital transmission of Trypanosoma cruzi in non-endemic areas: Evaluation of a screening program in a tertiary care hospital in Barcelona, Spain. The American Journal of Tropical Medicine and Hygiene. 2012;87(5):832-836
  75. 75. Carlier Y, Torrico F, Sosa-Estani S, Russomando G, Luquetti A, Freilij H, et al. Congenital chagas disease: Recommendations for diagnosis, treatment and control of newborns, siblings and pregnant women. PLoS Neglected Tropical Diseases. 2011;5(10):e1250
  76. 76. Riera C, Verges M, Iniesta L, Fisa R, Gállego M, Tebar S, et al. Identification of a Western blot pattern for the specific diagnosis of Trypanosoma cruzi infection in human sera. The American Journal of Tropical Medicine and Hygiene. 2012;86:412-416
  77. 77. Torres-Gutiérrez E, Barrios-Palacios D, Ruiz-Hernández AL, Cabrera-Bravo M, Guevara-Gómez Y, Rojas-Wastavino G, et al. Identification of immunodominant components of an isolate of Trypanosoma cruzi by immunoblot and its standardization for diagnostic purposes. Gaceta Médica de México. 2015;151(1):6-13
  78. 78. Gil j CR, López I, Cajal S, Acosta N, Juarez M, Zacca R, et al. Reactividad del antígeno GST-SAPA de Trypanosoma cruzi frente a sueros de pacientes con enfermedad de Chagas y leishmaniasis. Medicina. 2011;71:113-119
  79. 79. Otani MM, Vinelli E, Kirchhoff LV, del Pozo A, Sands A, Vercauteren G, et al. WHO. Comparative evaluation of serologic assays for chagas disease. Transfusion. 2009;49(6):1076-1082
  80. 80. Silveira-Lacerda EP, Silva AG, Junior SF, Souza MA, Kesper N, Botelho-Filho A, et al. Chagas’ disease: Application of TESA-blot in inconclusive sera from a Brazilian blood bank. Vox Sanguinis. 2004;87(3):204-207
  81. 81. Umezawa ES, Souza AI, Pinedo-Cancino V, Marcondes M, Marcili A, Camargo LM, et al. TESA-blot for the diagnosis of chagas disease in dogs from co-endemic regions for Trypanosoma cruzi, Trypanosoma evansi and Leishmania chagasi. Acta Tropica. 2009;111(1):15-20
  82. 82. Caballero EZ, Correa R, Nascimento MS, Villarreal A, Llanes A, Kesper N Jr. High sensitivity and reproducibility of in‐house ELISAs using different genotypes of Trypanosoma cruzi. Parasite Immunology. 2019;e12627. https://doi.org/10.1111/pim.12627
  83. 83. Gomes YM, Pereira VR, Nakazawa M, Rosa DS, Barros MD, Ferreira AG. Serodiagnosis of chronic chagas infection by using EIE-recombinant-chagas-biomanguinhos kit. Memórias do Instituto Oswaldo Cruz. 2001;96:497-501
  84. 84. Enciso C, Montilla M, Santacruz MM, Nicholls RS, Rodríguez A, Mercado M. Comparison of the indirect immunofluorescent (IFAT), ELISA test and the commercial chagatek test for anti-Trypanosoma cruzi antibodies detection. Biomédica. 2004;24:104-108
  85. 85. Sánchez B, Monteon V, Reyes PA, Espinoza B. Standardization of micro-enzyme-linked immunosorbent assay (ELISA) and Western blot for detection of Trypanosoma cruzi antibodies using extracts from Mexican strains as antigens. Archives of Medical Research. 2001;32:382-388
  86. 86. Bosseno MF, Barnabe C, Magallon GE, Lozano KF, Ramsey J, Espinoza B. Predominance of Trypanosoma cruzi lineage I in Mexico. Journal of Clinical Microbiology. 2002;40:627-632
  87. 87. Miles MA, Feliciangeli MD, De Arias AR. American trypanosomiasis (chagas’ disease) and the role of molecular epidemiology in guiding control strategies. BMJ. 2003;326:1444-1448
  88. 88. Herrera CP, Licon MH, Nation CS, Jameson SB, Wesson DM. Genotype diversity of Trypanosoma cruzi in small rodents and Triatoma sanguisuga from a rural area in New Orleans, Louisiana. Parasites & Vectors. 2015;24, 8:123
  89. 89. Ramos-Ligonio A, Torres-Montero J, Lopez-Monteon A, Dumonteil E. Extensive diversity of Trypanosoma cruzi discrete typing units circulating in Triatoma dimidiata from Central Veracruz, Mexico. Infection, Genetics and Evolution. 2012;12(7):1341-1343
  90. 90. Andersson J, Orn A, Sunnemark D. Chronic murine chagas disease: The impact of host and parasite genotypes. Immunology Letters. 2003;86:207-212
  91. 91. Macedo AM, Pena SD. Genetic variability of Trypanosoma cruzi: Implications for the pathogenesis of chagas disease. Parasitology Today. 1998;14:119-124
  92. 92. Zingales B, Miles MA, Campbell DA, Tibayrenc M, Macedo AM, Teixeira MM, et al. The revised trypanosoma cruzi subspecific nomenclature: Rationale, epidemiological relevance and research applications. Infection, Genetics and Evolution. 2012;12:240-253
  93. 93. Houghton RL, Benson DR, Reynolds L, McNeill P, Sleath P, Lodes M, et al. Multiepitope synthetic peptide and recombinant protein for the detection of antibodies to Trypanosoma cruzi in patients with treated or untreated Chagas’ disease. The Journal of Infectious Diseases. 2000;181(1):325-330
  94. 94. Umezawa ES, Bastos SF, Coura JR, Levin MJ, Gonzalez A, Rangel-Aldao R, et al. An improved serodiagnostic test for chagas’ disease employing a mixture of Trypanosoma cruzi recombinant antigens. Transfusion. 2003;43:91-97
  95. 95. Alvarez P, Leguizamo’n MS, Buscaglia CA, Pitcovsky TA, Campetella O. Multiple overlapping epitopes in the repetitive unit of the shed acute-phase antigen from Trypanosoma cruzi enhance its immunogenic properties. Infection and Immunity. 2001;69:7946-7949
  96. 96. Vanniasinkam T, Barton MD, Heuzenroeder MW. B-cell epitope mapping of the VapA protein of Rhodococcus equi: Implications for early detection of R. equi disease in foals. Journal of Clinical Microbiology. 2001;39:1633-1637
  97. 97. Andresen H, Bier FF. Peptide microarrays for serum antibody diagnostics. Methods in Molecular Biology. 2009;509:123-134
  98. 98. Pellois JP, Zhou X, Srivannavit O, Zhou T, Gulari E, Gao X. Individually addressable parallel peptide synthesis on microchips. Nature Biotechnology. 2002;20:922-926
  99. 99. Carmona SJ, Sartor PA, MS L’n, Campetella OE, Agüero F. Diagnostic peptide discovery: Prioritization of pathogen diagnostic markers using multiple features. PLoS One. 2012;7(12):e50748
  100. 100. Carmona SJ, Nielsen M, Schafer-Nielsen C, Mucci J, Altcheh J, Balouz V, et al. Towards high-throughput immunomics for infectious diseases: Use of next-generation peptide microarrays for rapid discovery and mapping of antigenic determinants. Molecular & Cellular Proteomics. 2015;14:1871-1884
  101. 101. Larsen JEP, Lund O, Nielsen M. Improved method for predicting linear B-cell epitopes. Immunome Res. 2006;24:2-9
  102. 102. Liang S, Zheng D, Standley DM, Yao B, Zacharias M, Zhang C. EPSVR and EPMeta: Prediction of antigenic epitopes using support vector regression and multiple server results. BMC Bioinformatics. 2010;11:381
  103. 103. Ponomarenko J, Bui HH, Li W, Fusseder N, Bourne PE, Sette A, et al. ElliPro: A new structure-based tool for the prediction of antibody epitopes. BMC Bioinformatics. 2008;9:514
  104. 104. Sweredoski MJ, Baldi P. PEPITO: Improved discontinuous B-cell epitope prediction using multiple distance thresholds and half sphere exposure. Bioinformatics. 2008;24:1459-1460
  105. 105. Sweredoski MJ, Baldi P. COBEpro: A novel system for predicting continuous B-cell epitopes. Protein Engineering, Design & Selection. 2009;22:113-120
  106. 106. Ekins R, Chu FW. Microarrays: Their origins and applications. Trends in Biotechnology. 1999;17:217-218
  107. 107. Wilson DS, Nock S. Recent developments in protein microarray technology. Angewandte Chemie (International Ed. in English). 2003;42(5):494-500
  108. 108. Almeida IC, Covas DT, Soussumi LM, Travassos LR. A highly sensitive and specific chemiluminescent enzyme-linked immunosorbent assay for diagnosis of active Trypanosoma cruzi infection. Transfusion. 1997;37:850-857
  109. 109. De Marchi CR, Di Noia JM, Frasch ACC, Amato Neto V, Almeida IC, Buscaglia CA. Evaluation of a recombinant Trypanosoma cruzi mucin-like antigen for serodiagnosis of chagas’ disease. Clinical and Vaccine Immunology. 2011;18:1850-1855
  110. 110. Faraudo S, López N, Canela B, Guimarães A, Sáez-Alquezar A. Evaluation in Brazil of the new bio-flash chagas assay on Biokit’s bio-flash analyzer. Revista Española de Salud Pública. 2015:65-66
  111. 111. Imaz-Iglesia I, Miguel LGS, Ayala-Morillas LE, García-Pérez L, González-Enríquez J, Blasco-Hernández T, et al. Economic evaluation of chagas disease screening in Spain. Acta Tropica. 2015;148:77-88
  112. 112. Lee BY, Bacon KM, Bottazzi ME, Hotez PJ. Global economic burden of chagas disease: A computational simulation model. The Lancet Infectious Diseases. 2013;13:342-348
  113. 113. Ramsey JM, Elizondo-Cano M, Sanchez-González G, Peña-Nieves A, Figueroa-Lara A. Opportunity cost for early treatment of chagas disease in Mexico. PLoS Neglected Tropical Diseases. 2014;8:e2776
  114. 114. Sicuri E, Muñoz J, Pinazo MJ, Posada E, Sanchez J, Alonso PL, et al. Economic evaluation of Chagas disease screening of pregnant Latin American women and of their infants in a non-endemic area. Acta Tropica. 2011;118:110-117
  115. 115. Ballesteros GR, Cuevas TIM, Jiménez BR, et al. Chagas disease: An overview of diagnosis. Journal of Microbiology & Experimentation. 2018;6(3):151-157. DOI: 10.15406/jmen.2018.06.00207
  116. 116. Ndao M, Spithill TW, Caffrey R, Li H, Podust VN, Perichon R, et al. Identification of novel diagnostic serum biomarkers for Chagas’ disease in asymptomatic subjects by mass spectrometric profiling. Journal of Clinical Microbiology. 2010;48:1139-1149
  117. 117. De Araujo FF, Vitelli-Avelar DM, Teixeira-Carvalho A, Antas PR, Assis Silva Gomes J, Sathler-Avelar R, et al. Regulatory T cells phenotype in different clinical forms of Chagas’ disease. PLoS Neglected Tropical Diseases. 2011;5:e992
  118. 118. Adamczyk M, Brashear RJ, Mattingly PG. Circulating cardiac troponin-I autoantibodies in human plasma and serum. Annals of the New York Academy of Sciences. 2009;1173:67-74

Written By

Aracely López-Monteon, Eric Dumonteil and Angel Ramos-Ligonio

Submitted: 19 February 2019 Reviewed: 28 April 2019 Published: 04 December 2019