ABSTRACT
El objetivo del presente estudio es efectuar el análisis del impacto de la vigilancia en sus diferentes modalidades en el control de la infección por T. cruzi y la densidad vectorial (Triatoma infestans). Material y métodos: El trabajo fue desarrollado en el Departamento de Capayán, en la provincia de Catamarca, Argentina. Se seleccionaron aleatoriamente 5 comunidades rurales y 3 comunidades peri-urbanas para desarrollar el estudio. Indicadores utilizados: a) infestación domiciliaria en los meses 24, 48 y 96; y b) Infección por T.cruzi de menores de 14 años. Resultados: Se observa persistencia de triatomineos durante el periodo de seguimiento y cuando se comparan los datos del estudio de base (2007) con los obtenidos en el año 2009 y 2012 existe significancia estadística (p <0.04) entre áreas. Se capturaron 1.89 insectos/intradomicilio en áreas con vigilancia activa versus 5.21 insectos/intradomicilio en áreas donde la misma no existió. Se demuestra la existencia de infecciones recientes en niños menores de 4 años e hijos de mujeres negativas para T. cruzi en áreas sin vigilancia activa (3 niños). Conclusión: En la presente investigación se demuestra el impacto de la vigilancia activa en sus diferentes modalidades por la no existencia de casos nuevos vectoriales en el período de seguimiento. (AU)
The aim of this study is to perform the analysis of the impact of surveillance in its various forms in the control of infection by T. cruzi and vector density (Triatoma infestans). Material and Methods: The work was developed in the Department of Capayán, in the Province of Catamarca, Argentina. Eight rural communities were selected to develop the study. Indicators used: a) house infestation in 24 months, 48 and 96; b) T. cruzi infection in children under 14 years. Results: Persistence of triatomine It is observed during the monitoring period as the baseline study (2007) thus obtained in 2009 compared to 2012 there is statistical significance (p <0.04) between areas. 1.89 insect / intradomicile were captured in areas with active surveillance versus 5.21 insect/intradomicile in areas where it did not exist. The existence of recent infections in children under four years of negative women and children for T. cruzi in areas without active surveillance (3 children) is demonstrated. Conclusion: In this research, the impact of active surveillance in its various forms by Vector exists no new cases in the follow-up period shown. (AU)
Subject(s)
Humans , Child , Adolescent , Trypanosoma cruzi , Chagas Disease/epidemiology , Vector Control of Diseases , Epidemiological Monitoring , Argentina , Housing Sanitation , National Health ProgramsABSTRACT
This study reports on the standardization of an enzyme-linked immunosorbent assay (ELISA) for detecting specific antibodies anti-Trypanosoma cruzi in naturally infected dogs. Sera from 182 mongrel dogs of all ages residing in four rural villages in Santiago del Estero, Argentina, were collected in November 1994 and preserved in buffered neutral glycerin. All sera were tested by indirect hemagglutination test (IHAT), indirect immunofluorescence test (IFAT), and ELISA using the flagellar fraction of T. cruzi as antigen. Dog sera from an area without vectorial transmission were used to calculate ELISA specificity and cut-off-value. Eighty-six percent of sera had concordant results for all tests. All sera reactive for IHAT and IFAT were also rective for ELISA, except in one case. Sera tested by ELISA when diluted 1:200 allowed a clearer division between non-reative and reactive sera than when 1:100 with greater agreement among serologic techniques. The specificity of ELISA was 96,2 per cent. Among 34 adult dogs with a positive xenodiagnosis, sensitivity was 94 per cent both for ELISA and IFAT. ELISA is the first choice for screening purposes and one of the pair of techniques recommended for diagnostic studies in dog populations.
Subject(s)
Animals , Dogs , Antibodies , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique, Indirect , Hemagglutination Tests , Trypanosoma cruzi/immunology , Argentina , Dogs/parasitology , Chagas Disease/immunologyABSTRACT
his paper reports on the standardization of four serological reactions currently used in human serodiagnosis for the detection of anti-Trypanosoma cruzi antibodies in naturally and experimentally infected dogs. Indirect immunofluorescence test (IFAT) and hemagglutination test (IHAT) were standardized, and complement fixation test (CFT) and direct agglutination test (DAT) were used for diagnostic confirmation. Four hundred and eighty one mongrel dogs that were studied by xenodiagnosis were used: (1) parasitemic dogs of two localities of endemic area (EA) of Santiago del Estero province in Argentina (n = 134); (2) non-parasitemic dogs of the same area (n = 285); (3) dogs experimentally infected with T. cruzi in the patent period (n = 6); (4) non-infected dogs (n = 56) which were born in the city of Buenos Aires (BA), one non-EA for Chagas' disease. For IFAT, parasitemic dogs EA showed 95 per cent of reactive sera. Non parasitemic dogs EA showed 77 per cent of non reactive sera. None sera from BA were reactive for dilutions higher than four. For IHAT, 84 per cent of sera of parasitemic dogs EA showed serological reactivity and among non parasitemic dogs BA, 61 per cent were non reactive, while the remainder showed at most titres of 1/16. The cut-off titres for IFAT and IHAT were 1/16 and 1/32 respectively, and for CFT and DAT 1/1 and 1/128 respectively. Sensitivity for IFAT, IHAT, CF and DAT were 95 per cent , 84 per cent , 97 per cent and 95 per cent respectively
Subject(s)
Animals , Dogs , Antibodies, Protozoan/analysis , Serologic Tests/standards , Trypanosoma cruzi/immunology , Agglutination Tests , Complement Fixation Tests , Chagas Disease/diagnosis , Fluorescent Antibody Technique , Hemagglutination Tests , Sensitivity and SpecificityABSTRACT
En este trabajo se intento dilucidar el papel que juega la inmunidad celular en la enfermedad del raton infectado con dosis bajas T.cruzi, comparando el curso de la infeccion de ratones congenitamente atimicos (nu/nu) con sus hermanos de camada fenotipicamente normales (nu/+). Para esto se infectaron ratones de ambos grupos de 4 semanas de edad, por via intraperitoneal con 5000 o 5 tripomastigotes de sangre. El curso de la enfermedad fue mas severo en los ratones atimicos, con parasitemia significativamente mas alta y promedio de sobrevida menor que en los controles inmunocompetentes, sugiriendo que en este caso, los linfocitos timodependientes tienen un papel importante en la defensa contra la infeccion con T. cruzi
Subject(s)
Chagas Disease , Thymus Gland , Immunity, CellularABSTRACT
Reseña conocimientos en su mayoría obtenidos experimentalmente en animalesde laboratorio, y en humanos, sobre los mecanismos de defensa en la enfermedad de Chagas: respuesta inmune humoral; papel de los anticuerpos en la transferencia pasiva de sueros; lisis de Trypanosoma cruzi; citoxicidad mediada por anticuerpos; y, papel de los macrófagos en la infección. Queda por comprobar la relación existente entre el trabajo experimental en animales de laboratorio y las observaciones en la infección humana, y, entre esos mecanismos de defensa y la lesión humana