RESUMO
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, remains a public health issue in endemic regions of the Americas, and is becoming globalised due to migration. In the chronic phase, 2 accordant serological tests are required for diagnosis. In addition to "in-house" assays, commercial tests are available (principally ELISA and rapid diagnostic tests). Herein, we discuss the discovery era of defined T. cruzi serological antigens and their utilisation in commercialised tests. A striking feature is the re-discovery of the same antigens from independent studies, and their overlapping use among commonly reported commercial serological tests. We also consider reports of geographical variation in assay sensitivity and areas for refinement including applications to congenital diagnosis, treatment monitoring, and lineage-specific antigens.
Assuntos
Antígenos de Protozoários , Doença de Chagas , Trypanosoma cruzi , Doença de Chagas/diagnóstico , Doença de Chagas/imunologia , Humanos , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/genética , Antígenos de Protozoários/imunologia , Testes Sorológicos/métodos , Sensibilidade e EspecificidadeRESUMO
Chagas disease (CD), caused by Trypanosoma cruzi, is a life-threatening neglected anthropozoonosis primarily transmitted by triatomine bugs. Affecting an estimated 5.7 million people globally, CD has significant morbidity and mortality, particularly in Latin America. The Oxente Chagas Bahia Project aims to screen approximately 30,000 individuals, validate a rapid diagnostic test in a real-world setting, and provide crucial data on its diagnostic performance and cost-effectiveness. Additionally, a biobank will be established to support further research on disease biomarkers and treatment cure rates. By enhancing access to timely diagnosis and treatment, the project will evaluate a strategy to reduce the CD burden.
Assuntos
Doença de Chagas , Trypanosoma cruzi , Doença de Chagas/diagnóstico , Humanos , Análise Custo-Benefício , Tripanossomicidas/uso terapêutico , Sensibilidade e Especificidade , Testes Diagnósticos de Rotina , Brasil , Testes de Diagnóstico RápidoRESUMO
Several reptile species have been described as hosts of Trypanosoma cruzi, the causative agent of Chagas disease, and therefore, they have become vertebrates of epidemiological interest. In recent decades, there has been a growing interest in animal welfare, especially in populations with small numbers where lethal sampling could have catastrophic consequences, and non-lethal methodologies have been developed for detecting zoonotic parasites. In this study, we compared three non-lethal sampling methodologies for detecting T. cruzi DNA in 21 captured specimens of the native lizard Liolaemus monticola, collected from the semiarid Mediterranean ecosystem of Chile. Specimens were subjected to xenodiagnosis (XD), tail clipping, and living syringe sampling procedures to evaluate whether lizards could serve as sentinel species for T. cruzi in endemic regions. To detect the protozoan, real-time PCR (qPCR) was performed on the DNA extracted from the samples (intestinal contents, tail tissues, and blood from living syringes). Trypanosoma cruzi DNA was detected in 12 of 21 lizards, considering all three methodologies. By XD, 12 specimens showed infection (57.1 %), and both living syringe and tail sampling methodologies detected only one infected lizard (4.8 %). Therefore, T. cruzi can be detected in lizards by qPCR using the three methodologies but XD is by far the most effective non-lethal detection methodology. The use of tail and living syringe methodologies showed a large underestimation; however, they might be options for monitoring the presence of T. cruzi in lizard populations when large sample sizes are available.
Assuntos
Doença de Chagas , DNA de Protozoário , Reservatórios de Doenças , Lagartos , Trypanosoma cruzi , Animais , Lagartos/parasitologia , Trypanosoma cruzi/isolamento & purificação , Trypanosoma cruzi/genética , Chile/epidemiologia , DNA de Protozoário/análise , DNA de Protozoário/isolamento & purificação , Doença de Chagas/veterinária , Doença de Chagas/diagnóstico , Doença de Chagas/parasitologia , Doença de Chagas/epidemiologia , Reservatórios de Doenças/parasitologia , Reservatórios de Doenças/veterinária , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Zoonoses/parasitologiaRESUMO
Chagas disease (CD) is a zoonotic infection caused by the protozoan parasite Trypanosoma cruzi, affecting over seven million people worldwide. T. cruzi can infect more than 100 species of wild mammals, including opossums, armadillos, bats, carnivores, rodents, and primates, as well as domestic animals like dogs, cats, and exotic pets. This is the first report of T. cruzi infection in an "exotic pet" African hedgehog (Atelerix albiventris), in an endemic area for CD in Colombia. After the patient underwent euthanasia due to worsening clinical signs including diarrhea, thrombocytopenia, leukopenia, and hemiplegia, anatomopathological and histopathological examinations were conducted. Simultaneously, molecular diagnosis and genotyping of T. cruzi were performed using qPCR and Next Generation sequencing of the 18S rRNA gene, respectively. Anatomopathological examination revealed significant changes across various systems, including ulcerative hemorrhagic enteritis, left ventricular hypertrophy, lymphadenitis and diffuse meningeal edema. The main histopathological findings included mononuclear inflammatory reaction, congestion and hemorrhages in several organs, accompanied of amastigote cysts in cardiomyocytes. qPCR confirmed the presence of T. cruzi in heart, lymph node, brain, salivary gland, blood, and spleen. Regarding genotyping analyses, all organs were positive for TcI. This case confirms the susceptibility of A. albiventris to infection with T. cruzi and suggest a potential role for these pets as disseminators of T. cruzi infection in endemic areas. The ecological and epidemiological implications of these findings are discussed here.
Assuntos
Doença de Chagas , Ouriços , Trypanosoma cruzi , Animais , Ouriços/parasitologia , Colômbia/epidemiologia , Trypanosoma cruzi/isolamento & purificação , Doença de Chagas/veterinária , Doença de Chagas/parasitologia , Doença de Chagas/epidemiologia , Doença de Chagas/diagnóstico , Doença de Chagas/patologia , Masculino , GenótipoRESUMO
We developed a protein to rapidly and accurately diagnose Chagas disease, a life-threatening illness identified by the WHO as a critical worldwide public health risk. Limitations in present day serological tests are complicating the current health situation and contributing to most infected persons being unaware of their condition and therefore untreated. To improve diagnostic testing, we developed an immunological mimic of the etiological agent, Trypanosoma cruzi, by combining ten pathogen-specific epitopes within the beta-barrel protein structure of Thermal Green Protein. The resulting multi-epitope protein, DxCruziV3, displayed high specificity and sensitivity as the antibody capture reagent in an ELISA platform with an analytical sensitivity that exceeds WHO recommendations. Within an immunochromatographic platform, DxCruziV3 showed excellent performance for the point of application diagnosis in a region endemic for multiple diseases, the municipality of Barcelos in the state of Amazonas, Brazil. In total, 167 individuals were rapidly tested using whole blood from a finger stick. As recommended by the Brazilian Ministry of Health, venous blood samples were laboratory tested by conventional assays for comparison. Test results suggest utilizing DxCruziV3 in different assay platforms can confidently diagnose chronic infections by T. cruzi. Rapid and more accurate results will benefit everyone but will have the most noticeable impact in resource-limited rural areas where the disease is endemic.
Assuntos
Doença de Chagas , Ensaio de Imunoadsorção Enzimática , Epitopos , Testes Sorológicos , Trypanosoma cruzi , Doença de Chagas/diagnóstico , Doença de Chagas/sangue , Doença de Chagas/imunologia , Humanos , Ensaio de Imunoadsorção Enzimática/métodos , Trypanosoma cruzi/imunologia , Testes Sorológicos/métodos , Epitopos/imunologia , Doença Crônica , Masculino , Sensibilidade e Especificidade , Feminino , Adulto , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Pessoa de Meia-Idade , Antígenos de Protozoários/imunologia , Antígenos de Protozoários/sangue , Brasil/epidemiologiaRESUMO
The diagnosis of Chagas disease mostly relies on the use of multiple serologic tests that are often unavailable in many of the remote settings where the disease is highly prevalent. In the Teniente Irala Fernández Municipality, in central Paraguay, efforts have been made to increase the diagnostic capabilities of specific rural health centres, but no quality assurance of the results produced has been performed. We comparatively analysed the results obtained with 300 samples tested using a commercial rapid diagnostic test (RDT) and enzyme linked immunosorbent assays (ELISA) at the laboratory of the Teniente Irala Fernández Health Center (CSTIF) with those generated upon repeating the tests at an independent well-equipped research laboratory (CEDIC). A subgroup of 52 samples were further tested at Paraguay's Central Public Health Laboratory (LCSP) by means of a different technique to evaluate the diagnostic performance of the tests carried out at CSTIF. We observed an excellent agreement between the ELISA results obtained at CSTIF and CEDIC (kappa coefficients between 0.85 and 0.93 for every kit evaluated), and an overall good performance of the tests carried out at CSTIF. However, the sensitivity of one kit was lower at CSTIF (81.3 %) than at CEDIC (100 %). The individual use of an RDT to detect the infection at CSTIF showed a similar sensitivity to that obtained combining it to an ELISA test (92.3% vs 88.5, p = 1). Nonetheless, the generalizability of this result is yet limited and will require of further studies.
Assuntos
Doença de Chagas , Atenção Primária à Saúde , População Rural , Sensibilidade e Especificidade , Testes Sorológicos , Paraguai , Humanos , Doença de Chagas/diagnóstico , Testes Sorológicos/métodos , Testes Sorológicos/normas , Adulto , Masculino , Feminino , Garantia da Qualidade dos Cuidados de Saúde , Adolescente , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Pessoa de Meia-Idade , Criança , Adulto Jovem , Pré-Escolar , Idoso , Anticorpos Antiprotozoários/sangueRESUMO
BACKGROUND: Orally transmitted acute Chagas disease (ACD) primarily affects low-visibility and low-income individuals in tropical and subtropical zones. Managing ACD remains challenging even after more than 100 years of its discovery. Its spread to non-endemic areas has made it a global health issue. The aim of this work is to demonstrate the difficulties encountered in handling a real-life situation. METHODOLOGY AND FINDINGS: This report examines an outbreak of 39 cases of ACD due to oral transmission by bacaba juice ingestion that occurred in Pedro do Rosário, Maranhão, Brazil. A clinical and epidemiological investigation, including an entomological search, was conducted. Diagnosis criteria included positive peripheral blood smear (PBS), seroconversion of IgG, and a two-fold increase in IgG titer (laboratory criteria); and clinical findings, epidemiological exposure, and at least one positive IgG test (clinical-epidemiological criteria). In-house conventional polymerase chain reaction (PCR) was performed on 33 samples. All patients were treated with benznidazole. After 4.5 years, IgG levels were reassessed in 26 individuals. The mean age was 33.6 years, with no gender difference. The mean incubation period was 13.8 days, and the mean between symptom onset and treatment was 16.6 days. The most common symptoms were fever and lymphadenopathy (90%). Diagnostic success rates were 66.6% (laboratory criteria), 23% (clinical-epidemiological criteria), and 10.2% (high clinical suspicion despite negative tests). Test positivity rates were 69.7% (PBS), 91.4% (serology), and 100% (PCR). There were no deaths. Serological cure was achieved in 34.6% of cases, and IgG titers decreased in 15.3%. CONCLUSIONS AND SIGNIFICANCE: We encountered several barriers in managing ACD, including population vulnerability, reliance on outdated diagnostic techniques, lack of standardized molecular biology methods, and limited therapeutic options. This report underscores the importance of rapid surveillance and early treatment to prevent fatalities. We recommend the standardization of conventional PCR in diagnostic routines.
Assuntos
Doença de Chagas , Surtos de Doenças , Trypanosoma cruzi , Humanos , Doença de Chagas/epidemiologia , Doença de Chagas/tratamento farmacológico , Doença de Chagas/diagnóstico , Masculino , Adulto , Feminino , Brasil/epidemiologia , Trypanosoma cruzi/imunologia , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Imunoglobulina G/sangue , Sucos de Frutas e Vegetais , Tripanossomicidas/uso terapêutico , Nitroimidazóis/uso terapêutico , Animais , Criança , Anticorpos Antiprotozoários/sangue , IdosoRESUMO
PURPOSE OF REVIEW: This review seeks to describe the updates in the literature - particularly with regards to the epidemiology and diagnosis of Chagas disease. Additionally, this paper describes updates to the antiparasitic treatment for Chagas disease. RECENT FINDINGS: With regards to changing epidemiology, autochthonous cases are being found within the USA in addition to Latin America. Additionally, there appears to be more intermixing of discrete typing units-meaning, they are not confined to specific geographic regions. Screening for Chagas disease is recommended in persons who lived in areas with endemic Chagas, persons wtih family member diagnosed with Chagas Disease, persons who have lived in homes of natural material in Latin America, and persons with history of kissing bug bites. Treatment for the parasitic infection remains limited to benznidazole and nifurtimox, and the role of these treatments in Chagas cardiomyopathy has not yet been definitively defined. Finally, indications for and management of heart transplant in the setting of Chagas disease are discussed. FUTURE RESEARCH: Use of antiparasitics during chronic chagas disease should be further explored. Additionally, future research identifying other markers of infection would be valuable to defining cure from infection.
Assuntos
Doença de Chagas , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Humanos , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Doença de Chagas/terapia , Doença de Chagas/tratamento farmacológico , Trypanosoma cruzi/isolamento & purificação , Nitroimidazóis/uso terapêutico , Tripanossomicidas/uso terapêutico , Nifurtimox/uso terapêutico , Transplante de Coração , América Latina/epidemiologia , Cardiomiopatia Chagásica/epidemiologia , Cardiomiopatia Chagásica/diagnóstico , Cardiomiopatia Chagásica/terapia , AnimaisRESUMO
Parasitic diseases have a significant impact on human and animal health, representing a major hazard to the public and causing economic and health damage worldwide. Extracellular vesicles (EVs) have long been recognized as diagnostic and therapeutic tools but are now also known to be implicated in the natural history of parasitic diseases and host immune response modulation. Studies have shown that EVs play a role in parasitic disease development by interacting with parasites and communicating with other types of cells. This review highlights the most recent research on EVs and their role in several aspects of parasite-host interactions in five key parasitic diseases: Chagas disease, malaria, toxoplasmosis, leishmaniasis and helminthiases. We also discuss the potential use of EVs as diagnostic tools or treatment options for these infectious diseases.
Assuntos
Vesículas Extracelulares , Interações Hospedeiro-Parasita , Doenças Parasitárias , Humanos , Vesículas Extracelulares/metabolismo , Animais , Doenças Parasitárias/terapia , Doenças Parasitárias/diagnóstico , Doenças Parasitárias/imunologia , Doença de Chagas/terapia , Doença de Chagas/diagnóstico , Doença de Chagas/imunologiaRESUMO
Chagas disease, caused by Trypanosoma cruzi, affects millions of people globally and is associated with significant underdiagnosis and undertreatment. Current diagnostic algorithms face challenges in remote regions. We aimed to review the potential of rapid diagnostic tests (RDTs) for screening or diagnosing chronic Chagas disease in endemic areas. An expert panel representing scientific and academic institutions from the Americas convened with the aim of discussing the use of RDTs. The study employed the nominal group technique, gathering insights from diverse experts during a 3-day meeting. Panel discussions covered RDT application, research protocols, and regulatory mechanisms. The results indicate that RDTs play a crucial role in surveillance and screening, although limitations in sensitivity and specificity exist. The expert group recommends standardized protocols, emphasizes the importance of cost-effectiveness assessments, and highlights the need to consider geographic validation. Despite these challenges, RDTs present a promising avenue for improving Chagas disease diagnosis in resource-limited settings. Future research and a collaborative approach are deemed essential for effective implementation.
Assuntos
Doença de Chagas , Testes Diagnósticos de Rotina , Trypanosoma cruzi , Doença de Chagas/diagnóstico , Humanos , Testes Diagnósticos de Rotina/métodos , Trypanosoma cruzi/isolamento & purificação , Doença Crônica , Sensibilidade e Especificidade , Testes de Diagnóstico RápidoRESUMO
Chagas disease, caused by the parasite Trypanosoma cruzi, affects over 6 million people, mainly in Latin America. Two different clinical phases, acute and chronic, are recognised. Currently, 2 anti-parasitic drugs are available to treat the disease (nifurtimox and benznidazole), but diagnostic methods require of a relatively complex infrastructure and trained personnel, limiting its widespread use in endemic areas, and the access of patients to treatment. New diagnostic methods, such as rapid tests (RDTs) to diagnose chronic Chagas disease, or loop-mediated isothermal amplification (LAMP), to detect acute infections, represent valuable alternatives, but the parasite's remarkable genetic diversity might make its implementation difficult. Furthermore, determining the efficacy of Chagas disease treatment is complicated, given the slow reversion of serological anti-T. cruzi antibody reactivity, which may even take decades to occur. New biomarkers to evaluate early therapeutic efficacy, as well as diagnostic tests able to detect the wide variety of circulating genotypes, are therefore, urgently required. To carry out studies that address these needs, high-quality and traceable samples from T. cruzi-infected individuals with different geographical backgrounds, along with associated clinical and epidemiological data, are necessary. This work describes the framework for the creation of such repositories, following standardised and uniform protocols, and considering the ethical, technical, and logistic aspects of the process. The manual can be adapted according to the resources of each laboratory, to guarantee that samples are obtained in a reproducible way, favouring the exchange of data among different work groups, and their generalizable evaluation and analysis. The main objective of this is to accelerate the development of new diagnostic methods and the identification of biomarkers for Chagas disease.
Assuntos
Doença de Chagas , Trypanosoma cruzi , Doença de Chagas/diagnóstico , Humanos , Trypanosoma cruzi/genética , Bancos de Espécimes Biológicos , Técnicas de Amplificação de Ácido Nucleico/métodosRESUMO
Untargeted metabolomic analysis is a powerful tool used for the discovery of novel biomarkers. Chagas disease (CD), caused by Trypanosoma cruzi, is a neglected tropical disease that affects 6-7 million people with approximately 30% developing cardiac manifestations. The most significant clinical challenge lies in its long latency period after acute infection, and the lack of surrogate markers to predict disease progression or cure. In this cross-sectional study, we analyzed sera from 120 individuals divided into four groups: 31 indeterminate CD, 41 chronic chagasic cardiomyopathy (CCC), 18 Latin Americans with other cardiomyopathies and 30 healthy volunteers. Using a high-throughput panel of 986 metabolites, we identified three distinct profiles among individuals with cardiomyopathy, indeterminate CD and healthy volunteers. After a more stringent analysis, we identified some potential biomarkers. Among peptides, phenylacetylglutamine and fibrinopeptide B (1-13) exhibited an increasing trend from controls to ICD and CCC. Conversely, reduced levels of bilirubin and biliverdin alongside elevated urobilin correlated with disease progression. Finally, elevated levels of cystathionine, phenol glucuronide and vanillactate among amino acids distinguished CCC individuals from ICD and controls. Our novel exploratory study using metabolomics identified potential biomarker candidates, either alone or in combination that if confirmed, can be translated into clinical practice.
Assuntos
Biomarcadores , Doença de Chagas , Metabolômica , Humanos , Biomarcadores/sangue , Metabolômica/métodos , Masculino , Feminino , Doença de Chagas/sangue , Doença de Chagas/diagnóstico , Pessoa de Meia-Idade , Adulto , Estudos Transversais , Metaboloma , Cardiomiopatia Chagásica/sangue , Cardiomiopatia Chagásica/metabolismo , IdosoAssuntos
Doença de Chagas , Nifurtimox , Tripanossomicidas , Humanos , Nifurtimox/uso terapêutico , Nifurtimox/efeitos adversos , Nifurtimox/administração & dosagem , Doença de Chagas/tratamento farmacológico , Doença de Chagas/diagnóstico , Tripanossomicidas/uso terapêutico , Tripanossomicidas/efeitos adversos , Trypanosoma cruzi/efeitos dos fármacos , Animais , Resultado do TratamentoRESUMO
We present a case of acute phase Chagas disease in a 40-year-old male patient from Vereda Buenos Aires, Municipality of Miraflores, Department of Guaviare. The patient attended the emergency department with fever, headache, asthenia, adynamia and dysuria. The blood smear and urinalysis were positive for symptomatic urinary tract infection, but negative for malaria. Five days later the diagnosis of acute phase Chagas disease was confirmed after a positive result for Trypanosoma cruzi. The patient was treated with nifurtimox and benznidazole, his contacts and risk areas were investigated, an active entomological community and institutional search was carried out, as well as in the reservoirs, finally, laboratory surveillance for possible cases of infection in the community was conducted. Five cases with similar symptoms were identified, but parasitological tests were negative. Health education measures were implemented to prevent the spread of the disease.
Se presenta un caso de enfermedad de Chagas en fase aguda en un paciente masculino de 40 años, procedente de la Vereda Buenos Aires, Municipio de Miraflores, Departamento del Guaviare. El paciente acudió a urgencias con fiebre, cefalea, astenia, adinamia y disuria. Se realizó un frotis de sangre y un análisis de orina, con resultados positivos para infección urinaria sintomática, pero negativos para malaria. Cinco días más tarde se confirmó el diagnóstico de enfermedad de Chagas en fase aguda tras recibir un resultado positivo para Trypanosoma cruzi. El paciente recibió tratamiento con nifurtimox y benznidazol, y se llevó a cabo una investigación de contactos y zonas de riesgo, búsqueda activa comunitaria e institucional, entomológica y de reservorios, y una vigilancia de laboratorio para detectar posibles casos de infección en la comunidad. Se identificaron cinco casos con síntomas similares, pero las pruebas parasitológicas fueron negativas. Se aplicaron medidas de educación sanitaria para prevenir la propagación de la enfermedad.
Assuntos
Doença de Chagas , Humanos , Masculino , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Adulto , Colômbia , Doença Aguda , Saúde da População UrbanaRESUMO
Chagas disease is a chronic, systemic parasitic infection caused by the protozoan Trypanosoma cruzi. The primary mode of transmission to humans is by the Reduviid insect, endemic to South America. Recent migration of the vector has led to increased cases in the southern United States and has prompted increased surveillance and blood donation screening. It is unusual to diagnose and treat individuals with Chagas disease in the northern United States. This case describes an immigrant female from El Salvador that was informed she had Chagas disease from a blood bank screening. Confirmation and treatment of the disease were performed by her South Dakota primary care provider thus demonstrating the importance of identifying Chagas disease in the immigrant population in regions where Chagas disease infection is uncommon.
Assuntos
Doença de Chagas , Humanos , Feminino , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Doença de Chagas/terapia , Doença de Chagas/tratamento farmacológico , South Dakota , Tripanossomicidas/uso terapêutico , El Salvador , Adulto , Emigrantes e Imigrantes , Nifurtimox/uso terapêuticoRESUMO
BACKGROUND: Vertical transmission of Trypanosoma cruzi represents approximately 20% of new Chagas disease cases. Early detection and treatment for women of childbearing age and newborns is a public health priority, but the lack of a simple and reliable diagnostic test remains a major barrier. We aimed to evaluate the performance of a point-of-care loop-mediated isothermal amplification (LAMP) assay for the detection of T cruzi. METHODS: In this proof-of-concept study, we coupled a low-cost 3D printer repurposed for sample preparation and amplification (PrintrLab) to the Eiken T cruzi-LAMP prototype to detect vertically transmitted T cruzi, which we compared with standardised PCR and with the gold-standard algorithm (microscopy at birth and 2 months and serological study several months later). We screened pregnant women from two hospitals in the Bolivian Gran Chaco province, and those who were seropositive for T cruzi were offered the opportunity for their newborns to be enrolled in the study. Newborns were tested by microscopy, LAMP, and PCR at birth and 2 months, and by serology at 8 months. FINDINGS: Between April 23 and Nov 17, 2018, 986 mothers were screened, among whom 276 were seropositive for T cruzi (28·0% prevalence, 95% CI 25·6-31·2). In total, 224 infants born to 221 seropositive mothers completed 8 months of follow-up. Congenital transmission was detected in nine of the 224 newborns (4·0% prevalence, 1·9-7·5) by direct microscopy observation, and 14 more cases were diagnosed serologically (6·3%, 3·6-10·3), accounting for an overall vertical transmission rate of 10·3% (6·6-15·0; 23 of 224). All microscopy-positive newborns were positive by PrintrLab-LAMP and by PCR, while these techniques respectively detected four and five extra positive cases among the remaining 215 microscopy-negative newborns. INTERPRETATION: The PrintrLab-LAMP yielded a higher sensitivity than microscopy-based analysis. Considering the simpler use and expected lower cost of LAMP compared with PCR, our findings encourage its evaluation in a larger study over a wider geographical area. FUNDING: Inter-American Development Bank.
Assuntos
Doença de Chagas , Transmissão Vertical de Doenças Infecciosas , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Trypanosoma cruzi , Humanos , Doença de Chagas/diagnóstico , Doença de Chagas/transmissão , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Trypanosoma cruzi/genética , Trypanosoma cruzi/isolamento & purificação , Recém-Nascido , Bolívia/epidemiologia , Feminino , Gravidez , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , Estudo de Prova de Conceito , Sensibilidade e Especificidade , AdultoRESUMO
INTRODUCTION: Chagas disease caused by Trypanosoma cruzi (T cruzi) found in the Americas is often missed during the early stage of infection due to lack of sensitive diagnostic tests. The classic immunological and parasitological tests often fail in the acute phase due to the nonspecific and low antibody level nature of the infection and in the chronic phase due to low levels of trypanosomes in the blood. For successful control strategies, there must be a sensitive and specific diagnostic test. OBJECTIVE/METHODS: We have demonstrated the possibility (proof of concept) of detecting T cruzi-specific repeat DNA via polymerase chain reaction (PCR) by (1) spiking 15 urine samples collected from volunteers free of prior infection with 3 different concentrations of T cruzi (3 strains), Trypanosoma brucei, and Trypanosoma rhodesiense (African strain) genomic DNA and (2) from filtered collected clinical samples from Argentina. Three sets of primers were used. RESULTS: Our approach detected repeat DNA specific for T cruzi strains from 1 clinical sample by 2 sets of primer and from spiked urine by all 3 sets of primer but not the African species. A serial dilution (spiking) also was performed on T cruzi strains to detect sensitivities of the assay. One set of primers constantly detected satellite DNA for all T cruzi strains from 70 pg/µl to 175 fg/µl. CONCLUSIONS: We were able to demonstrate the feasibility of detecting T cruzi-specific DNA from filtered urine samples by sensitive and specific PCR assay. Besides the evident increased sensitivity and specificity of primers, our approach can be used to explore Chagas prevalence in endemic areas - especially in congenital Chagas newborn screening - and in the acute phase.
Assuntos
Doença de Chagas , DNA de Protozoário , Reação em Cadeia da Polimerase , Trypanosoma cruzi , Humanos , Doença de Chagas/diagnóstico , Doença de Chagas/urina , DNA de Protozoário/urina , Trypanosoma cruzi/genética , Trypanosoma cruzi/isolamento & purificação , Sensibilidade e Especificidade , Argentina/epidemiologia , Especificidade da EspécieRESUMO
BACKGROUND: Chagas disease (CD), a neglected parasitic disease caused by Trypanosoma cruzi, poses a significant health threat in Latin America and has emerged globally because of human migration. Trypanosoma cruzi infects humans and over 100 other mammalian species, including dogs, which are important sentinels for assessing the risk of human infection. Nonetheless, the serodiagnosis of T. cruzi in dogs is still impaired by the absence of commercial tests. In this study, we investigated the diagnostic accuracy of four chimeric recombinant T. cruzi IBMP antigens (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) for detecting anti-T. cruzi antibodies in dogs, using latent class analysis (LCA). METHODS: We examined 663 canine serum samples, employing indirect ELISA with the chimeric antigens. LCA was utilized to establish a latent variable as a gold standard for T. cruzi infection, revealing distinct response patterns for each antigen. RESULTS: The IBMP (Portuguese acronym for the Molecular Biology Institute of Paraná) antigens achieved area under the ROC curve (AUC) values ranging from 90.9% to 97.3%. The highest sensitivity was attributed to IBMP-8.2 (89.8%), while IBMP-8.1, IBMP-8.3, and IBMP-8.4 achieved 73.5%, 79.6%, and 85.7%, respectively. The highest specificity was observed for IBMP-8.4 (98.6%), followed by IBMP-8.2, IBMP-8.3, and IBMP-8.1 with specificities of 98.3%, 94.4%, and 92.7%, respectively. Predictive values varied according to prevalence, indicating higher effectiveness in endemic settings. CONCLUSIONS: Our findings underscore the remarkable diagnostic performance of IBMP-8.2 and IBMP-8.4 for the serodiagnosis of Trypanosoma cruzi in dogs, representing a promising tool for the diagnosis of CD in dogs. These chimeric recombinant antigens may not only enhance CD surveillance strategies but also hold broader implications for public health, contributing to the global fight against this neglected tropical disease.
Assuntos
Anticorpos Antiprotozoários , Antígenos de Protozoários , Doença de Chagas , Doenças do Cão , Ensaio de Imunoadsorção Enzimática , Sensibilidade e Especificidade , Testes Sorológicos , Trypanosoma cruzi , Animais , Cães , Doença de Chagas/diagnóstico , Doença de Chagas/veterinária , Doença de Chagas/parasitologia , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/genética , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Antígenos de Protozoários/imunologia , Antígenos de Protozoários/genética , Testes Sorológicos/métodos , Testes Sorológicos/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Anticorpos Antiprotozoários/sangue , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genéticaRESUMO
Triatomine bugs are vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease in the American continent. Here, we have tested a loop-mediated isothermal amplification (LAMP) test for a direct detection of T. cruzi in feces of Triatoma infestans, the main vector of this parasite in the Southern Cone of America. The analytical evaluation showed positive results with samples of triatomine feces artificially inoculated with DNA from strains of T. cruzi corresponding to each Discrete Typing Units (I-VI), with a sensitivity of up to one parasite per reaction. Conversely, the reaction yielded negative results when tested with DNA from Trypanosoma rangeli and other phylogenetically related and unrelated organisms. In triatomines captured under real field conditions (from urban households), and defined as positive or negative for T. cruzi using the reference microscopy technique, the LAMP test achieved a concordance of 100 %. Our results demonstrate that this LAMP reaction exhibits excellent analytical specificity and sensitivity without interference from the fecal matrix, since all the reactions were conducted without purification steps. This simple molecular diagnostic technique can be easily used by vector control agencies under field conditions.
Assuntos
Doença de Chagas , Fezes , Insetos Vetores , Técnicas de Amplificação de Ácido Nucleico , Triatoma , Trypanosoma cruzi , Animais , Fezes/parasitologia , Trypanosoma cruzi/isolamento & purificação , Doença de Chagas/parasitologia , Doença de Chagas/diagnóstico , Triatoma/parasitologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Insetos Vetores/parasitologia , Sensibilidade e Especificidade , Técnicas de Diagnóstico MolecularRESUMO
Chagas disease is an underrecognized, chronic, and potentially life-threatening disease caused by the parasite Trypanosoma cruzi. We aimed to improve awareness and screening for Chagas disease among patients from endemic areas using a large safety-net academic hospital system in the United States. We developed an educational intervention consisting of a case-based didactic session presented to physicians, trainees, and other healthcare providers at conferences across different departments. Performance on a knowledge assessment administered before and after the presentation was analyzed with paired Student's t-test for within-subject difference testing. Institutional testing rates for T. cruzi were evaluated for an equal time period (29 months) before and after the start of the intervention. Testing rates were compared by a Welch's unequal variances t-test and by interrupted time series based on multivariate linear regression. Eleven educational sessions were held over the intervention period, and 103 participants completed the pre- and post-presentation surveys. The mean survey scores were 59.2% before the presentation and 96.6% after presentation (P <0.001). Trypanosoma cruzi testing during the postintervention period was significantly higher than testing during the pre-intervention period (171 patients pre-intervention versus 378 patients postintervention [P = 0.015]). Notable increases in testing from the pre-intervention to postintervention periods occurred among midwives (1-68 patients tested) and trainees (57-133 patients tested). Overall, 56/537 (10.4%) nonduplicate T. cruzi commercial screening tests were positive. Testing increased over time, both at an institutional level and within targeted departments. In addition to the educational program, other factors likely influenced expanded testing.