Comparison of conventional serology and PCR methods for the routine diagnosis of Trypanosoma cruzi infection

Accuracy of Diagnostic Tests for the Detection of Chagas Disease: A Systematic Review and Meta-Analysis

The present systematic review and meta-analysis about the accuracy of diagnostic tests aim to describe the findings of literature over the last thirty years for the diagnosis of Chagas disease (CD). This work aimed to determine the accuracy of diagnostic techniques for CD in the disease's acute and chronic phases. The PubMed database was searched for studies published between 1990 and 2021 on CD diagnostics. Fifty-six published studies that met the criteria were analyzed and included in the meta-analysis, evaluating diagnostic accuracy through sensitivity and specificity. For Enzyme-Linked Immunosorbent Assay (ELISA), Fluorescent Antibody Technique (IFAT), Hemagglutination Test (HmT), Polymerase Chain Reaction (PCR), and Real-Time Polymerase Chain Reaction (qPCR) diagnosis methods, the sensitivity had a median of 99.0%, 78.0%, 75.0%, 76.0%, and 94.0%, respectively; while specificity presented a median of 99.0%, 99.0%, 99.0%, 98.0%, and 98.0%, respectively. This meta-analysis showed that ELISA and qPCR techniques had a higher performance compared to other methods of diagnosing CD in the chronic and acute phases, respectively. It was concluded utilizing the Area Under the Curve restricted to the false positive rates (AUCFPR), that the ELISA diagnostic test presents the highest performance in diagnosing acute and chronic CD, compared to serological and molecular tests. Future studies focusing on new CD diagnostics approaches should be targeted.

Combined use of real-time PCR and serological techniques for improved surveillance of chronic and acute American trypanosomiasis in dogs and their owners from an endemic rural area of Neotropical Mexico

In this study, the prevalence of T. cruzi infection was estimated in dogs and their owners from a rural community in Mexico using serological techniques for chronic infection cases, qPCR for acute phase cases, and a combination of both techniques to detect chronic and acute infections. Eighty-nine blood samples were collected from owners and their dogs for obtaining serum and parasite DNA. Prevalence was calculated using (i) positive cases detected in a serological test (ELISA and Western blot), (ii) positive cases detected in a qPCR test, and (iii) positive cases detected by both techniques. Sensitivity, specificity, and predictive values were determined individually for serology, qPCR and for both techniques used simultaneously. The prevalence observed varied: for serology, 25.8% of the dogs and 7.9% of the owners were seropositive, while for qPCR 29.2% of the dogs and 10.1% of the owners were identified as positive. Combination of serological and molecular techniques resulted in a prevalence of 38.2% for dogs and 12.4% for their owners. The sensitivity, specificity and predictive values calculated for both techniques improved when both techniques were used simultaneously (sensitivity of 92.4% and specificity of 100% for infected dogs and sensitivity of 93.4% and specificity of 100% for infected owners). Combined use of serological tests and qPCR allowed identifying a greater number of positive cases in dogs and their owners. This strategy may help implement adequate and timely epidemiological surveillance of American trypanosomiasis in order to prevent the appearance of new cases of Trypanosoma cruzi infections in endemic zones.

Association Between Trypanosoma cruzi DNA in Peripheral Blood and Chronic Chagasic Cardiomyopathy: A Systematic Review

Chronic chagasic cardiomyopathy (CCC) is the most important complication of patients with Chagas disease (CD). The role of persistent detection of DNA in peripheral blood and its association to CCC is unknown. We performed a systematic review up to July 2021, including studies that reported ratios of CCC and PCR positivity among non-treated adult patients. We identified 749 records and selected 12 for inclusion corresponding to 1,686 patients. Eight studies were performed in endemic countries and 4 in non-endemic countries. Only two studies showed an association between CCC and Trypanosoma cruzi parasitemia by means of PCR detection. Six studies reported greater positive PCR ratios among patients with CCC than in the patients with indeterminate chagas disease (ICD) with no statistical significance. A significant risk of bias has been detected among most of the studies. Therefore, while we performed a meta-analysis, wide inter-study heterogeneity impeded its interpretation.

Conclusions

With the available information, we could not establish a correlation between PCR-detectable parasitemia and CCC.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020216072, identifier: CRD42020216072.

Presence of Acute Chagas Disease Among Febrile Patients in the Western Coast of Mexico

Chagas disease (ChD) is a parasitosis caused by the protozoan Trypanosoma cruzi (Tc). It is endemic to almost all Latin American countries, including the southern United States. The acute form of ChD and its actual incidence have rarely been described in Mexico, despite the extensive presence of favorable niches for its transmission. The objective of this study was to estimate the frequency of acute ChD in febrile patients at the central Pacific coast of Mexico. For this, we surveyed patients with persistent fever (5 to 10 days) in five hospitals at the Mexican states of Jalisco, Colima, and Nayarit in 2012. Samples were taken from a total of 485 patients to detect Tc in blood using the polymerase chain reaction (PCR) test and direct microscopic examination. Of these subjects, 10 were positive for PCR and none for microscopic examination (2% in 12 months). We adjusted this rate by the total people at risk in the area and obtained an incidence of 7.4/100,000 habs./year. The positive cases showed no association with sex, rural settlement, or pet ownership, only with the contact with Triatominae insects (odds ratio = 9.22 and confidence interval: 1.93-44.06). The clinical picture of positive patients showed an association with the diagnosis of lower respiratory tract infections. Meanwhile, only one fatal case showed the typical picture of acute fatal cardiomyopathy. The pulmonary manifestations of our patients suggest possible lung pathogenicity of Tc, which merits further investigation. Our findings differ markedly from the official reports for ChD. This difference suggests an underestimation of the disease. These findings urge the Mexican health authorities to implement more vigorous actions aimed at improving medical skills in the timely diagnosis of ChD, as well as to apply efficient preventive programs.

An observational longitudinal study to evaluate tools and strategies available for the diagnosis of Congenital Chagas Disease in a non-endemic country

OBJECTIVES

Congenital Chagas Disease (CCD) has become a global health problem. Early diagnosis and treatment is essential for the cure of the disease. Our aim was to evaluate techniques and samples used for the diagnosis of CCD in order to improve diagnostic strategies.

METHODS

A total of 181 children born in Spain from Latin American Chagas-infected mothers were consecutively enrolled and studied by microhematocrit, PCR and serology tests at 0-2, 6 and 9-12 months of age and followed up when it was required. Samples of cord blood and peripheral blood were collected for T. cruzi detection by PCR. Parasite culture was performed in patients with a positive PCR.

RESULTS

Of 181 children, 7 children (3.9%) were lost to follow-up. A total of 174 children completed follow-up, 12 were diagnosed with CCD (6.9%) and 162 (93.1%) as uninfected children (negative serology tests at the end of the follow-up). Traditional parasitological diagnosis by microhematocrit had a poor performance (sensitivity was 10%), while PCR in peripheral blood showed high sensitivity (90.9%) and specificity (100%), allowing the early diagnosis of 9 infected children during the first 6-months-old. In the other 3 congenital cases, diagnosis was only possible at 12 months by serological and molecular techniques. However, PCR in cord blood showed low sensitivity (33.3%) and less specificity (96.4%) for the diagnosis.

CONCLUSION

PCR in peripheral blood has proven to be the most adequate strategy for the diagnosis of CCD, allowing an early and reliable diagnosis.

Uncovering Trypanosoma spp. diversity of wild mammals by the use of DNA from blood clots

Trypanosoma spp. infection in wild mammals is detected mainly through parasitological tests that usually display low sensitivity. We propose the use of DNA extracted directly from blood clots (BC), which are neglected sources of DNA for diagnosis and identification of Trypanosoma spp. This approach followed by nested PCR targeting the 18S SSU rDNA demonstrated to be sensitive and suitable to evaluate the diversity of trypanosomes infecting sylvatic mammals, including subpatent and mixed infections. Infection was detected in 95/120 (79.2%) samples from bats, carnivores and marsupials that included negative serological and hemoculture testing mammals. Thirteen Trypanosoma spp. or Molecular Operational Taxonomic Units (MOTUs) were identified, including two new MOTUs. The high diversity of trypanosomes species and MOTUs infecting bats and marsupials showed that these hosts can be considered as bio-accumulators of Trypanosoma spp., with specimens of Didelphis spp. displaying the highest trypanosome diversity. The use of blood clots allowed direct access to non-culturable parasites, mixed infections, besides bypassing the selective pressure on the parasites inherent to cultivation procedures. Trypanosoma cruzi was the species found infecting the highest number of individuals, followed by T. lainsoni. Positive PCR for T. cruzi was observed in 16 seronegative individuals and 30 individuals with negative hemocultures. Also, T. lainsoni, previously found only in rodents, showed to be capable of infecting bats and marsupials. This finding makes it clear that some species of Trypanosoma are more generalist than previously thought. Molecular diagnosis using nested PCR from DNA extracted from BC allowed the increase of the knowledge about host-spectrum and distribution of Trypanosoma spp. and allowed the identification of new MOTUs.

Development of nested multiplex polymerase chain reaction (PCR) assay for the detection of Toxocara canis, Toxocara cati and Ascaris suum contamination in meat and organ meats

Ascarid Larva Migrans Syndrome (ascarid LMS) is a clinical syndrome in humans, caused by the migration of animal roundworm larvae such as Toxocara canis, Toxocara cati and Ascaris suum. Humans may acquire infection by ingesting embryonated eggs, or infective larvae of these parasites in contaminated meat and organ meats. To detect these pathogenic contaminations, a novel nested multiplex PCR system was developed. Our novel nested multiplex PCR assay showed specific amplification of T. canis, T. cati and Ascaris spp. Detection limit of the nested multiplex PCR was tested with serial dilution of T. canis, T. cati or A. suum genomic DNA (gDNA) from 100 pg to 100 ag and found to be 10 fg, 1 fg and 100 fg, respectively. When larvae were spiked into chicken liver tissue, DNA of T. canis and A. suum was detected from the liver spiked with a single larva, while the assay required at least 2 larvae of T. cati. Moreover, the ascarid DNA was detected from the liver of mice infected with 100 and 300 eggs of T. canis, T. cati or A. suum. This nested multiplex PCR assay could be useful for the detection of contamination with ascarid larvae in meat and organ meats.

qPCR for the detection of foodborne Trypanosoma cruzi

Here we presented a potential real-time PCR (qPCR) method with public health importance and relevance for detection of Trypanosoma cruzi in açai pulp. There is not a current process to identify T. cruzi in açai, that ensures innocuity of this food concerning oral transmission. First, six new primers were designed using the DNA sequences of T. cruzi y152 and Emerald strains obtained from GenBank. For primers evaluation and titration they were validated regarding the amplification and not with the fluorophore chosen 1ngμL^-1 of the T. cruzi DNA as target. For determination of the ideal concentration the titration of the primers drawn in this study showed T. cruzi DNA amplification in five primer pairs at concentrations 100, 200 and 300nM and DNA fixed concentrations at 1ngμL^-1. For standardization all reactions were performed in triplicate with 5.0μL and positives and negatives controls were included in every run. As positive control DNA from two genotypes TcI and TcII were used. As negative control the reaction product without DNA of the parasite was used. The best primer concentration, for the expected fragments, was 300nM. From six primers improved the Ep1F/Ep1R primer detected 1×10^-4ngμL^-1 for both genotype of the parasite. The Bp1F/Bp1R showed amplification for 1.70.10^-7ngμL^-1 for TcI and 4.31.10^-8ngμL^-1 for TcII, based on the standard curve. The last step we tested the selected primers in qPCR for monitoring T. cruzi in açai pulp experimentally contaminated. The recovery rate for the TcII was 71%, whereas in açai samples contaminated with TcI it was 76%.

Comparison of four PCR methods for efficient detection of Trypanosoma cruzi in routine diagnostics

Due to increased migration, Chagas disease has become an international health problem. Reliable diagnosis of chronically infected people is crucial for prevention of non-vectorial transmission as well as treatment. This study compared four distinct PCR methods for detection of Trypanosoma cruzi DNA for the use in well-equipped routine diagnostic laboratories. DNA was extracted of T. cruzi-positive and negative patients' blood samples and cultured T. cruzi, T. rangeli as well as Leishmania spp. One conventional and two real-time PCR methods targeting a repetitive Sat-DNA sequence as well as one conventional PCR method targeting the variable region of the kDNA minicircle were compared for sensitivity, intra- and interassay precision, limit of detection, specificity and cross-reactivity. Considering the performance, costs and ease of use, an algorithm for PCR-diagnosis of patients with a positive serology for T. cruzi antibodies was developed.

Screening of living organ donors for endemic infections: Understanding the challenges and benefits of enhanced screening

Living organ donor candidates are screened for medical and psychosocial contraindications to donation. One important goal of this process is to prevent donor-derived infectious diseases transmissions. These transmissions are exceptionally rare, but have the potential to cause significant morbidity and mortality. The Organ Procurement and Transplantation Network now requires each recovery hospital to develop a protocol for evaluating living donors for tuberculosis and other geographically-defined endemic pathogens, including Trypanosoma cruzi (the causative pathogen of Chagas' disease), Strongyloides stercoralis, and West Nile Virus (WNV), in addition to universal screening for blood-borne pathogens. Enhanced screening requirements were developed in response to the changing epidemiology and endemicity of these diseases, as well as recent case reports of donor-derived disease transmission. Living organ donor disease screening presents a number of unique challenges to clinicians and policy-makers, including deciding which donors to test, which testing modality to use, when to test, and appropriate interpretation of results. This review will analyze the epidemiology of T. cruzi, S. stercoralis, and WNV, the assays available for screening for these diseases, and the subsequent impact on the living organ donor process . This article is protected by copyright. All rights reserved.

Differential parasitological, molecular, and serological detection of Trypanosoma cruzi I, II, and IV in blood of experimentally infected mice

Trypanosoma cruzi is the etiological agent of American trypanosomiasis (Chagas' disease), which affects 6-7 million people worldwide, mainly in Latin America. It presents great genetic and biological variability that plays an important role in the clinical and epidemiological features of the disease. Our working hypothesis is that the genetic diversity of T. cruzi has an important impact on detection of the parasite using diagnostic techniques. The present study evaluated the diagnostic performance of parasitological, molecular, and serological techniques for detecting 27 strains of T. cruzi that belonged to discrete typing units (DTUs) TcI (11 strains), TcII (four strains), and TcIV (12 strains) that were obtained from different hosts in the states of Amazonas and Paraná, Brazil. Blood samples were taken from experimentally infected mice and analyzed by fresh blood examination, hemoculture in Liver Infusion Tryptose (LIT) medium, polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA). Polymerase chain reaction presented the best detection of TcI, with 80.4% positivity. For all of the detection methods, the animals that were inoculated with TcII presented the highest positivity rates (94.1-100%). ELISA that was performed 7 months after inoculation presented a higher detection ability (95.4%) for TcIV. Intra-DTU comparisons showed that the reproducibility of the majority of the results that were obtained with the different methods was weak for TcI and good for TcII and TcIV. Our data indicate that the detection capability of different techniques varies with the DTUs of the parasites in mammalian blood. The implications of these findings with regard to the diagnosis of human T. cruzi infection are discussed.

Commercial enzyme-linked immunosorbent assay versuspolymerase chain reaction for the diagnosis of chronic Chagas disease: a systematic review and meta-analysis

Chronic Chagas disease diagnosis relies on laboratory tests due to its clinical characteristics. The aim of this research was to review commercial enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) diagnostic test performance. Performance of commercial ELISA or PCR for the diagnosis of chronic Chagas disease were systematically searched in PubMed, Scopus, Embase, ISI Web, and LILACS through the bibliography from 1980-2014 and by contact with the manufacturers. The risk of bias was assessed with QUADAS-2. Heterogeneity was estimated with the I2 statistic. Accuracies provided by the manufacturers usually overestimate the accuracy provided by academia. The risk of bias is high in most tests and in most QUADAS dimensions. Heterogeneity is high in either sensitivity, specificity, or both. The evidence regarding commercial ELISA and ELISA-rec sensitivity and specificity indicates that there is overestimation. The current recommendation to use two simultaneous serological tests can be supported by the risk of bias analysis and the amount of heterogeneity but not by the observed accuracies. The usefulness of PCR tests are debatable and health care providers should not order them on a routine basis. PCR may be used in selected cases due to its potential to detect seronegative subjects.

Highly discordant serology against Trypanosoma cruzi in central Veracruz, Mexico: role of the antigen used for diagnostic

Background

Chagas disease is a parasitic disease caused by the protozoan parasite Trypanosoma cruzi. In Mexico, the burden of the disease is difficult to estimate and improving surveillance for Chagas disease is an important priority. We aimed here at determining the seroprevalence of T. cruzi infection in humans in a rural community in Veracruz.

Methods

Serum samples (196) were analyzed for T. cruzi infection using five enzyme-linked immunosorbent assay (ELISA) tests: two in-house tests based on crude parasite extract and three commercial ELISA kits. Because of highly discordant results, we further explored the importance of parasite antigens and strains by western-blot analysis.

Results

A total of 74 samples (37.7 %) were reactive with at least one ELISA, but discordance among tests was very high. The best agreement was between Chagatest recombinant and Chagatek ELISA (Kappa index = 0.798). The agreement between other combinations of tests ranged from 0.038 to 0.518. Discordant samples were confirmed by western-blot analysis using up to nine parasite strains, giving a seroprevalence of 33.7 %.

Conclusions

Commercial tests had a very limited ability to detect T. cruzi infection in the study population. 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. The high seroprevalence confirmed the hyper-endemicity of T. cruzi infection in the region. Reliable epidemiological surveillance of Chagas disease will require the development of improved diagnostic tests.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-1072-2) contains supplementary material, which is available to authorized users.

Trypanosoma cruzi burden, genotypes, and clinical evaluation of Chilean patients with chronic Chagas cardiopathy

There are currently no biomarkers to assess which patients with chronic indeterminate Chagas disease will develop heart disease and which will spend their entire life in this state. We hypothetize that the parasite burden and Trypanosoma cruzi genotypes are related to the presence of heart disease in patients with Chagas disease. This study is aimed to investigate the parasite burden and T. cruzi genotypes in chagasic cardiopaths versus chagasic individuals without cardiac involvement according to the New York Heart Association. Patients with chronic Chagas disease, 50 with and 50 without cardiopathy (controls), groups A and B, respectively, were submitted to anamnesis, physical examination, and electrocardiogram. Echo-Doppler was performed for group A; all important known causes of cardiopathy were discarded. Xenodiagnosis, conventional PCR, and quantitative PCR were performed on patients of both groups. T. cruzi genotyping was done for 25 patients of group A and 20 of group B. The 50 cardiopaths had 80 electrocardiographic alterations, most of them in grade II of the New York Heart Association classification; 49 were classified in grade I by Echo-Doppler, and only one patient was in grade III. The difference in average parasitemia in patients of groups A and B was not significant. The most frequent T. cruzi DTU found was TcV. The parasite burden and genotype of the groups with and without cardiopathy were similar.

Graphical abstract

Biomarkers of therapeutic responses in chronic Chagas disease: state of the art and future perspectives

The definition of a biomarker provided by the World Health Organization is any substance, structure, or process that can be measured in the body, or its products and influence, or predict the incidence or outcome of disease. Currently, the lack of prognosis and progression markers for chronic Chagas disease has posed limitations for testing new drugs to treat this neglected disease. Several molecules and techniques to detect biomarkers in Trypanosoma cruzi-infected patients have been proposed to assess whether specific treatment with benznidazole or nifurtimox is effective. Isolated proteins or protein groups from different T. cruzi stages and parasite-derived glycoproteins and synthetic neoglycoconjugates have been demonstrated to be useful for this purpose, as have nucleic acid amplification techniques. The amplification of T. cruzi DNA using the real-time polymerase chain reaction method is the leading test for assessing responses to treatment in a short period of time. Biochemical biomarkers have been tested early after specific treatment. Cytokines and surface markers represent promising molecules for the characterisation of host cellular responses, but need to be further assessed.

Usefulness of real time PCR to quantify parasite load in serum samples from chronic Chagas disease patients

Background

Inconclusive results of serological diagnosis in Chagas disease have an important impact on blood banks worldwide, reflecting in the high number of discarded bags or in an increased transmission by blood transfusion. Molecular techniques such as qPCR have been used for diagnosis and to monitor Trypanosoma cruzi load in peripheral blood samples. A promising perspective refers to the possibility of parasite DNA detection in serum, taking advantage in using the same samples collected for serological screening.

Methods

In order to evaluate the effectiveness of a qPCR strategy for detecting and quantifying T. cruzi DNA in serum, we selected 40 chronic Chagas disease patients presenting different clinical manifestations: Cardiac (23), Digestive (4), Mixed form [cardiodigestive] (7), and asymptomatic (6). Twenty seronegative individuals from non-endemic areas were included as controls. Samples were extracted using QIAamp DNA mini kit (QIAGEN) and qPCR was performed in a multiplex format with TaqMan probes for the nuclear satellite DNA of T. cruzi and for the human RNase P gene. In addition, DNA migration to serum during blood coagulation was assessed using a commercial exogenous control (Exo IPC, Applied Biosystems) in a separate qPCR reaction.

Results

The comparative duplex qPCR analysis revealed that, even with an increase in Ct values, it was possible to detect all DNA targets in serum. In addition, the same linearity range for T. cruzi quantification (from 10⁵ to 0.5 par. eq./mL) between serum, blood or culture samples (T. cruzi epimastigotes – Cl Brener strain) was found. When patient samples were evaluated, no significant differences in parasite load between the distinct clinical manifestations were found for both blood and serum samples. Moreover, median values of parasite burden were 1.125 and 1.230 par. eq./mL for serum and blood, respectively. Using serology as gold standard, we found 95% sensitivity for T. cruzi detection in serum and 97.5% for blood, and 100% specificity for both samples.

Conclusions

Taken together, our data indicate the potential of using serum samples for molecular diagnosis and parasite load quantification by qPCR, suggesting its use in reference laboratories for the diagnosis of Chagas disease patients.

Molecular diagnosis in clinical parasitology: When and why?

Microscopic detection and morphological identification of parasites from clinical specimens are the gold standards for the laboratory diagnosis of parasitic infections. The limitations of such diagnostic assays include insufficient sensitivity and operator dependence. Immunoassays for parasitic antigens are not available for most parasitic infections and have not significantly improved the sensitivity of laboratory detection. Advances in molecular detection by nucleic acid amplification may improve the detection in asymptomatic infections with low parasitic burden. Rapidly accumulating genomic data on parasites allow the design of polymerase chain reaction (PCR) primers directed towards multi-copy gene targets, such as the ribosomal and mitochondrial genes, which further improve the sensitivity. Parasitic cell or its free circulating parasitic DNA can be shed from parasites into blood and excreta which may allow its detection without the whole parasite being present within the portion of clinical sample used for DNA extraction. Multiplex nucleic acid amplification technology allows the simultaneous detection of many parasitic species within a single clinical specimen. In addition to improved sensitivity, nucleic acid amplification with sequencing can help to differentiate different parasitic species at different stages with similar morphology, detect and speciate parasites from fixed histopathological sections and identify anti-parasitic drug resistance. The use of consensus primer and PCR sequencing may even help to identify novel parasitic species. The key limitation of molecular detection is the technological expertise and expense which are usually lacking in the field setting at highly endemic areas. However, such tests can be useful for screening important parasitic infections in asymptomatic patients, donors or recipients coming from endemic areas in the settings of transfusion service or tertiary institutions with transplantation service. Such tests can also be used for monitoring these recipients or highly immunosuppressed patients, so that early preemptive treatment can be given for reactivated parasitic infections while the parasitic burden is still low.

Chagas disease in the 21st century: a public health success or an emerging threat?

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a major public health burden in Latin America and a potentially serious emerging threat to a number of countries throughout the world. Although public health programs have significantly reduced the prevalence of Chagas disease in Latin America in recent decades, the number of infections in the United States and non-endemic countries in Europe and the Western Pacific Region continues to rise. Moreover, there is still no vaccine or highly effective cure available for the approximately 10 million people currently infected with T. cruzi, a third of which will develop potentially fatal cardiomyopathy and/or severe digestive tract disorders. As Chagas disease becomes an increasingly globalized public health issue in the twenty-first century, continued attentiveness from governmental and health organizations as well as improved diagnostic tools, expanded surveillance and increased research funding will be required to maintain existing public health successes and stymie the spread of the disease to new areas and populations.

Challenges and perspectives of Chagas disease: a review

Chagas disease (CD), also known as American trypanosomiasis, is caused by the flagellated protozoan Trypanosoma cruzi, and affects an estimated 8 to 10 million people worldwide. In Latin America, 25 million people live in risk areas, while in 2008 alone, 10,000 CD-related deaths were reported. This review aimed to evaluate the challenges of CD control, future perspectives, and actions performed worldwide to control expansion of the disease and its impact on public health in Latin America.