ABSTRACT
In situ immunofluorescence assay (ISIFA) was developed for the selection for treatment of chronically infected chagasic patients and their follow-up. Trypomastigotes flash fixed in situ on microscopic slides with 0.025% glutaraldehyde were used as antigen. ISIFA results were compared with complement-mediated lysis (CoML), membrane immunofluorescence (MbIFA), immunofluorescence assay (IFA) with epimastigotes, and xenodiagnosis (XENO). ISIFA was able to distinguish nontreated chagasic patients (geometric mean titer [GMT] = 180) and treatment failures (GMT = 160) from those considered successfully treated (GMT = 25). ISIFA revealed a high sensitivity and titers of 80 or higher detected 98.6% of patients with active infections, even in those with negative XENO, CoML, or MbIFA. Specificity evaluated in 63 sera from other infections, including leishmaniasis and autoimmune diseases, was 98%. IFA used in routine diagnostic procedures exhibited similar results in all groups, irrespective of therapy.
Subject(s)
Chagas Disease/diagnosis , Adult , Antibodies, Protozoan , Biomarkers , Chagas Disease/immunology , Child , Female , Fluorescent Antibody Technique, Indirect , Glutaral , Humans , Male , Middle Aged , Protozoan Proteins/immunology , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
The uncertainties in the ethiological treatment of Chagas' Disease are consequence of the lack of entire knowledge of its pathogeny and the no existence of a healing criterium. There is a consensus that antiparasite drugs should be in the acute phase of the infection, regardless of the infection route, in new crisis, in patients under immunosuppression and in organs transplantation. There is still controversy regarding subacute, chronic or indetermined phase or cases with mild cardia/digestive forms, not included in the situations listed above neither in a research protocol. The treatment includes oral benzonidazol 5 mg/kg/dat, bid or tid for 60 days. In 71 patients monitored in this fashion, the authors have found 60% of negative xenodiagnostic at the end of treatment It is still necessary, however, to continue to investigate and accomplishing more randomized trials to confirm the efficacy of such method, and also to try to obtain effective and less toxic agents. It is also fundamental to standardize a more reliable healing criterium.
Subject(s)
Chagas Cardiomyopathy/drug therapy , Nitroimidazoles/therapeutic use , Trypanocidal Agents/therapeutic use , Acute Disease , Administration, Oral , Adolescent , Adult , Chagas Cardiomyopathy/etiology , Child , Chronic Disease , Female , Humans , Male , Middle Aged , PrognosisABSTRACT
Normally specific treatment of chronic Chagas' disease begins only after a positive parasitological diagnosis has been established. Xenodiagnosis, hemoculture and complement mediated lysis were associated, and repeated, as an attempt to increase the number of selected candidates for specific treatment. Thirty six chronic chagasic patients were submitted to two series of the above tests, with a minimal interval of 60 days. In the first series of tests sensitivity of xenodiagnosis and hemoculture were 30.5% and 8.3% respectively. Processing of a second sample increased sensitivity to 36.1% (xenodiagnosis) and 19.4% (hemoculture); 47.2% were shown to be positive by at least one of these tests. From the positive cases, 29.4% were consistently negative in the complement mediated lysis test, and 17.6% exhibited discordant results, positive on one occasion and negative on the other. Among patients with negative parasitological tests, 47.4% had negative complement mediated lysis tests, 31.5% exhibited discordant results and 15.8% were positive. We conclude that complement mediated lysis test is not a method of choice in the selection of candidates for specific treatment of Chagas' disease in view of the observed variability of results. At this moment, parasitological test, in spite of a low sensitivity, are a safer tool for the clinician.
Subject(s)
Blood/parasitology , Chagas Disease/diagnosis , Complement Fixation Tests , Animals , Antibodies, Protozoan/analysis , Humans , Male , Trypanosoma cruzi/immunologySubject(s)
Chagas Disease/transmission , Animals , Animals, Wild/parasitology , Brazil , Chagas Disease/epidemiology , Child , Humans , MaleABSTRACT
Os autores realizaram ensaios terapeuticos com um antiarritmico, a propafenona, em pacientes chagasicos com extrassistolia ventricular estavel, sendo esta considerada como a extrasistolia cujo numero nao sofreu variacao superior a 20% em tres avaliacoes previas ao uso da droga, realizadas a intervalos de uma semana. A casuistica constou de 20 pacientes chagasicos que foram avaliados antes e depois da terapeutica, atraves da eletrocardiografia dianamica e do eletrocardiograma convencional Obteve-se reducao significativa e acentuada no numero de extra-sistoles na 2a. semana de terapeutica em todos os pacientes. Os autores sugerem que o uso da propafenona por via oral nos esquemas propostos, parece ser opcao eficaz na terapeutica da extra-sistolia ventricular de pacientes chagasicos
Subject(s)
Propiophenones , Cardiac Complexes, Premature , Chagas CardiomyopathyABSTRACT
Descreve-se novo caso autoctone de tripanossomiase americana no litoral Sul do Estado de Sao Paulo, Brasil. De maneira semelhante a nota anterior, as evidencias sugerem a transmissao por contaminacao no manuseio de carcacas de mamiferos silvestres utilizados na alimentacao. Este achado confirma a hipotese da existencia de nivel endemico regional
