[Show abstract][Hide abstract] ABSTRACT: Using the indirect hemagglutination (IH), indirect immunofluorescence (IIF) and enzyme linked immunosorbent assay (ELISA) tests for the diagnosis of Chagas disease, 4000 serum samples were examined. This study was conducted with different purposes: clinical interest, research support and parasitological monitoring of those patients with Chagas disease who were treated with heart transplantations. The tests occurred without patient selection and in accordance with the medical requests. The results showed discrepancies and brought about several questions, considering the different results that all three methods showed when considered together. What was found brought about concerns and we suggest the adoption of different measures, aiming to avoid these mismatches in the context of this disease.
Revista do Instituto de Medicina Tropical de São Paulo 06/2012; 54(3):141-3. · 0.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and is one of the most important endemic problems in Latin America. Lately, it has also become a health concern in the United States and Europe. Currently, a diagnosis of Chagas' disease and the screening of blood supplies for antiparasite antibodies are achieved by conventional serological tests that show substantial variation in the reproducibility and reliability of their results. In addition, the specificity of these assays is curtailed by antigenic cross-reactivity with sera from patients affected by other endemic diseases, such as leishmaniasis. Here we used a highly sensitive chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) to evaluate a recombinant protein core of a mucin-like molecule (termed trypomastigote small surface antigen [TSSA]) for the detection of specific serum antibodies in a broad panel of human sera. The same samples were evaluated by CL-ELISA using as the antigen either a mixture of native T. cruzi trypomastigote mucins or an epimastigote extract and, for further comparison, by conventional serologic tests, such as an indirect hemagglutination assay and indirect immunofluorescence assay. TSSA showed ∼87% sensitivity among the seropositive Chagasic panel, a value which was increased up to >98% when only parasitologically positive samples were considered. More importantly, TSSA showed a significant increase in specificity (97.4%) compared to those of currently used assays, which averaged 80 to 90%. Overall, our data demonstrate that recombinant TSSA may be a useful antigen for the immunodiagnosis of Chagas' disease.
[Show abstract][Hide abstract] ABSTRACT: Following advances in the control of vector and blood transfusion transmission of Chagas disease, alternative mechanisms of transmission have become more relevant. This article discusses the importance of each one of these alternative mechanisms and the measures to prevent them.
A review was conducted of the scientific literature concerning alternative transmission mechanisms of Trypanosoma cruzi occurring in Brazil and the measures to prevent them. PubMed and BVS databases were consulted.
Twenty-five publications describing alternative mechanisms of transmission of Chagas disease were identified.
Oral transmission, through ingestion of contaminated food items has been the most frequent mode of transmission in Brazil in recent years. Other alternative mechanisms of transmission occur less frequently. It is important to understand these occurrences, especially now that vector transmission of the parasite is under control. Preventive measures have been presented, according to each of the situations considered, in line with current knowledge.
Revista da Sociedade Brasileira de Medicina Tropical 05/2011; 44(3):375-9. · 0.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vectorial, transfusion and congenital are considered the main transmission mechanisms in human Chagas disease. Alternative mechanisms are accidental, oral and by organ transplantation. Other hypothetic mechanisms could be by other vectors, sexual, criminal and by means of marsupial anal secretions. The present accorded strategies for prevention are: CONGENITAL: early case detection and immediate treatment. If possible, start during the pre natal period, throughout mothers serology, performing parasitological tests in the new born from positive women. For positive cases, immediate treatment; for those negative babies, conventional serology at the 8th month, treating specifically those with positive results. ACCIDENTAL TRANSMISSION: Rigorous training and utilization of protection equipments. IF accident occurs, immediate disinfection, conventional serology and beginning of specific treatment by ten days. Revision of the serology after 30 days: if positive, extend the treatment until the total dose (60 days or more). ORGAN TRANSPLANTATION: previous serology for donor and receptor. When the former is infected and the last negative, cancel the surgery or install the specific treatment by ten days before the surgery for the donor, followed by the receptor during ten days after the transplantation. ORAL TRANSMISSION: Specific measures are not available, food hygiene is recommended, including the cooking of meats delivered from possible reservoirs. Nowadays, the detection and immediate treatment of the case is recommended, followed by active research of new cases around the detected one.
Revista da Sociedade Brasileira de Medicina Tropical 01/2011; 44 Suppl 2:68-72. · 0.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recently, there has been an increase in the incidence of cutaneous leishmaniasis (CL), which represents an important health problem. This increase may be related to the epidemiologic expansion of the infective agent and the increase in tourism in tropical areas. The difficulty in clinical diagnosis, mainly in areas in which CL is not the first consideration of local physicians, has intensified efforts to describe diagnostic tests, which should be specific, sensitive, and practical. Amongst the new tests described are those including nucleic acid amplification (polymerase chain reaction, PCR) and immunohistochemistry (IHC).
In this study, we evaluated the sensitivity of a PCR based on small subunit (SSU) ribosomal DNA, in comparison with IHC using Leishmania spp. antibodies, in biopsies embedded in paraffin.
The results indicated a total sensitivity of 96% (90.9% with PCR and 68.8% with IHC), showing the possibility of using paraffin-embedded biopsies to diagnose CL.
We propose the use of the two tests together as a routine protocol for diagnosis. This would require the provision of local medical services to perform molecular biology techniques and adequate Leishmania antibodies.
International journal of dermatology 10/2009; 48(10):1091-5. · 1.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mucosal leishmaniasis is caused mainly by Leishmania braziliensis and it occurs months or years after cutaneous lesions. This progressive disease destroys cartilages and osseous structures from face, pharynx and larynx.
The aim of this study was to analyse the significance of clinical and epidemiological findings, diagnosis and treatment with the outcome and recurrence of mucosal leishmaniasis through binary logistic regression model from 140 patients with mucosal leishmaniasis from a Brazilian centre.
The median age of patients was 57.5 and systemic arterial hypertension was the most prevalent secondary disease found in patients with mucosal leishmaniasis (43%). Diabetes, chronic nephropathy and viral hepatitis, allergy and coagulopathy were found in less than 10% of patients. Human immunodeficiency virus (HIV) infection was found in 7 of 140 patients (5%). Rhinorrhea (47%) and epistaxis (75%) were the most common symptoms. N-methyl-glucamine showed a cure rate of 91% and recurrence of 22%. Pentamidine showed a similar rate of cure (91%) and recurrence (25%). Fifteen patients received itraconazole with a cure rate of 73% and recurrence of 18%. Amphotericin B was the drug used in 30 patients with 82% of response with a recurrence rate of 7%. The binary logistic regression analysis demonstrated that systemic arterial hypertension and HIV infection were associated with failure of the treatment (P < 0.05).
The current first-line mucosal leishmaniasis therapy shows an adequate cure but later recurrence. HIV infection and systemic arterial hypertension should be investigated before start the treatment of mucosal leishmaniasis. Conflicts of interest The authors are not part of any associations or commercial relationships that might represent conflicts of interest in the writing of this study (e.g. pharmaceutical stock ownership, consultancy, advisory board membership, relevant patents, or research funding).
Journal of the European Academy of Dermatology and Venereology 05/2009; 23(9):1026-34. · 2.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This brief review discusses the history of leishmaniasis, considering its origin from the Paleoartic, Neoartic or Neotropic. We reassess some of the theories of the likely origin of this protozoan since the beginning of life on Earth, passing through the Mesozoic and continuing to the appearance of humans. The relationship between this parasite or its ancestors, possible vectors and hosts with regard to ecological modifications is discussed. Recent molecular techniques have helped to elucidate some of the evolutionary questions regarding Leishmania, but have also brought doubts about the origin and evolution of this human parasite. PCR has been used for studies in the new discipline of paleoparasitology, helping to elucidate some of the remaining evolutionary questions. Understanding of this global condition is fundamental in determining the best approach to use against the parasite, specifically for the development of an efficient vaccine.
[Show abstract][Hide abstract] ABSTRACT: The definitive diagnosis of visceral leishmaniasis (VL) requires invasive procedures with demonstration of amastigotes in tissue or promastigotes in culture. Unfortunately, these approaches require laboratory materials not available in poor countries where the disease is endemic. The correct diagnosis of VL is important, and made more difficult by the fact that several common tropical diseases such as malaria, disseminated tuberculosis, and enteric fever share the same clinical presentation. Serological tests have been developed to replace parasitological diagnosis in the field. A commercially available K39-based strip test for VL has been developed for this purpose. The endemic area of leishmaniasis in Brazil overlaps the endemic area of Chagas disease, a disease that can cause false-positive serological test results. The aim of this study was to evaluate the incidence of false-positive exams using a rapid test for VL in patients with Chagas disease.
A rapid test based on the recombinant K39 antigen of Leishmania was used in: (1) 30 patients with confirmed Chagas disease, (2) 30 patients with a serological diagnosis of Chagas disease by ELISA, indirect immunofluorescence, indirect hemagglutination, and chemiluminescence, (3) 30 healthy patients from a non-endemic area as the control group, (4) 30 patients with confirmed VL, and (5) 20 patients with proved cutaneous leishmaniasis.
The sensitivity and specificity of the rapid strip test were 100% when compared with healthy volunteers and those with confirmed Chagas disease. One false-positive result occurred in the group with Chagas disease diagnosed by serological tests (specificity of 96%).
The rapid test based on recombinant K39 is a useful diagnostic assay, and a false-positive result rarely occurs in patients with a serological diagnosis of Chagas disease.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 10/2008; 13(2):182-5. · 2.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chagas' disease is the illness caused by the protozoan Trypanosoma cruzi and it is still endemic in Latin America. Heart transplantation is a therapeutic option for patients with end-stage Chagas' cardiomyopathy. Nevertheless, reactivation may occur after transplantation, leading to higher morbidity and graft dysfunction. This study aimed to identify risk factors for Chagas' disease reactivation episodes.
This investigation is a retrospective cohort study of all Chagas' disease heart transplant recipients from September 1985 through September 2004. Clinical, microbiologic and histopathologic data were reviewed. Statistical analysis was performed with SPSS (version 13) software.
Sixty-four (21.9%) patients with chronic Chagas' disease underwent heart transplantation during the study period. Seventeen patients (26.5%) had at least one episode of Chagas' disease reactivation, and univariate analysis identified number of rejection episodes (p = 0.013) and development of neoplasms (p = 0.040) as factors associated with Chagas' disease reactivation episodes. Multivariate analysis showed that number of rejection episodes (hazard ratio = 1.31; 95% confidence interval [CI]: 1.06 to 1.62; p = 0.011), neoplasms (hazard ratio = 5.07; 95% CI: 1.49 to 17.20; p = 0.009) and use of mycophenolate mofetil (hazard ratio = 3.14; 95% CI: 1.00 to 9.84; p = 0.049) are independent determinants for reactivation after transplantation. Age (p = 0.88), male gender (p = 0.15), presence of rejection (p = 0.17), cytomegalovirus infection (p = 0.79) and mortality after hospital discharge (p = 0.15) showed no statistically significant difference.
Our data suggest that events resulting in greater immunosuppression status contribute to Chagas' disease reactivation episodes after heart transplantation and should alert physicians to make an early diagnosis and perform pre-emptive therapy. Although reactivation led to a high rate of morbidity, a low mortality risk was observed.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 07/2008; 27(6):597-602. · 3.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: New World leishmaniasis is an important endemic disease and public health problem in developing countries. The increase in ecologic tourism has extended this problem to developed countries. Few drugs have emerged over the past 50 years, and drug resistance has increased, such that the cure rate is no better than 80% in large studies. Despite these data, there has been no systematic review with a meta-analysis of the therapy used in this important tropical disease. The aim of this study was to determine the best drug management in the treatment of cutaneous leishmaniasis (CL) in Latin America based on the best studies published in the medical literature. METHODS: MEDLINE, LILACS, EMBASE, Web of Science, and Cochrane Library databases were searched to identify articles related to CL and therapy. Articles with adequate data on cure and treatment failure, internal and external validity information, and more than four patients in each treatment arm were included. RESULTS: Fifty-four articles met our inclusion criteria and 12 were included in the meta-analysis. Pentavalent antimonials were the most studied drugs, with a total of 1150 patients, achieving a cure rate of 76.5%. The cure rate of pentamidine was similar to that of pentavalent antimonials. Other drugs showed variable results, and all demonstrated an inferior response. CONCLUSION: Although pentavalent antimonials are the drugs of choice in the treatment of CL, pentamidine showed similar results. Nevertheless, several aspects, such as cost, adverse effects, local experience, and availability of drugs to treat CL, must be considered when determining the best management of this disease, especially in developing countries where resources are scarce.
International journal of dermatology 03/2008; 47(2):109-24. · 1.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Leishmaniasis causes significant morbidity and mortality and thus constitutes a serious public health problem. Even though it has long been endemic in developing countries, in recent years the economic globalization and the increased volume of international travel have extended its prevalence in developed countries. In addition, native populations may be exposed to the infection through blood transfusion and the use of blood products produced from infected asymptomatic individuals. Mucosal leishmaniasis (ML) is a chronic form of this infection, which attacks the mucosa. In most cases this form of leishmaniasis results from the metastatic spread of Leishmania (Viannia) braziliensis from cutaneous lesions. It is a healthcare issue because of its wide demographic distribution, its association with significant morbidity levels, and because of the pressing concern that tourists who travel to endemic areas might present the disease even years later. The treatment currently available for ML is based on drugs such as pentavalent antimony-containing compounds, amphotericin B deoxycholate and pentamidine and often guarantees a satisfactory clinical response. Nevertheless, it also frequently provokes serious side effects. This review offers a critical analysis of the drugs now available for the treatment of ML as also of the future prospects for the treatment of the disease.