Trypanocidal therapy among children infected by Trypanosoma cruzi. Serological and electrocardiographic changes over a mean twenty-five-years follow-up period.

This study compared the serological and electrocardiographic evolution among patients with chronic T. cruzi infection treated during childhood or left untreated. A retrospective cohort study was conducted during a mean follow-up period of 25 years in 82 patients: half of them underwent treatment (nifurtimox 8, benznidazole 33) before being 15 years old, whereas the other half remained untreated. During the follow-up, negative seroconversion occurred in 92.7% of the treated children, while all the untreated ones remained positive for conventional serology. At baseline, 2 patients from each group had electrocardiographic abnormalities. During the study period, 4/41 (9.75%) and 9/41 (21.95%) of treated and untreated patients displayed an altered electrocardiogram, respectively. In multivariate analyses, the probability of developing electrocardiographic abnormalities was significantly reduced among treated patients (OR = 0.18, 95% CI = 0.04-0.79; p = 0.023). Electrocardiographic abnormalities attributable to Chagas cardiomyopathy were seen in 3 patients from the untreated group (complete right bundle branch block + left anterior fascicular block, frequent ventricular extrasystole, and left anterior fascicular block). The remarkable seronegativization seen in Benznidazole and Nifurtimox recipients underlines the parasiticidal effect of both compounds. Such demonstration along with the fact that CCC-related alterations were only present in the untreated group, reinforces the view of trypanocidal treatment in chronically T. cruzi-infected children as decreasing the risk for cardiomyopathy development.

Levels of anti-B13 antibodies over time in a cohort of chronic infected by Trypanosoma cruzi. Its relationship with specific treatment and clinical status.

The immunodominant B13 protein of Trypanosoma cruzi is found on the surface of trypomastigotes and exhibits cross-reactivity with the human cardiac myosin heavy chain; for which antibodies against this parasitic antigen may be involved in the development of disease pathology. In a cohort of chronically T. cruzi-infected adults, undergoing trypanocidal treatment, or not, we, therefore, decided to evaluate the levels of anti-B13 antibodies (ELISA-B13) and its eventual relationship with heart complaints. Two hundred twenty-eight serum samples from 76 chronically infected adults with an average follow-up of 24 years were analyzed. Thirty of them had received trypanocidal treatment. Among treated patients, anti-B13 Ab levels in successive samples showed a significant decrease in reactivity as the years after treatment increased (ANOVA test, p = 0.0049). At the end of the follow-up, 36.7% became non-reactive for ELISA B13. Untreated patients did not have significant variations in the level of anti-B13 antibodies during follow-up. None of the treated patients had electrocardiographic changes compatible with chronic chagasic cardiomyopathy, whereas 21.7% of those undergoing no treatment did show such kind of pathological electrocardiogram tracings. ELISA-B13 was reactive in all cases with heart involvement. Among untreated patients, there were no significant differences in anti-B13 antibodies when comparing individuals without proven pathology with those with chronic chagasic cardiomyopathy. Although treatment with trypanocidal drugs was followed by decreased anti-B13 antibody levels, such assessment was unhelpful in differentiating the evolution of chronic chagasic heart disease.

Higher congenital transmission rate of Trypanosoma cruzi associated with family history of congenital transmission.

INTRODUCTION: Congenital transmission (CT) of Trypanosoma cruzi has led to globalization of Chagas disease and its growing relevance as a public health problem. Although the occurrence of CT has been associated with several factors, its mechanisms are still unknown. This study aimed to analyze the geographical and familiar variables of mothers and their association with CT of Chagas disease in a population living in non-endemic areas of Argentina for the last decades. METHODS: We developed a retrospective cohort study in a sample of 2120 mother-child pairs who attended three reference centers in the cities of Buenos Aires, Santa Fe, and Salta between 2002 and 2015. RESULTS: The highest CT rates were observed in children born to Argentinean mothers (10.7%) and in children born to mothers from Buenos Aires (11.7%). Considering the areas of origin of the mothers, those from areas of null-low risk for vector-borne infection had higher CT rates than those from areas of medium-high risk (11.1% vs 8.2%). We also observed a significant intra-familiar "cluster effect," with CT rates of 35.9% in children with an infected sibling, compared to 8.2% in children without infected siblings (RR=4.4 95% CI 2.3-8.4). CONCLUSIONS: The associations observed suggest a higher CT rate in children born to mothers who acquired the infection congenitally, with familiar antecedents, and from areas without the presence of vectors. These observations are considered new epidemiological evidence about Chagas disease in a contemporary urban population, which may contribute to the study of CT and may also be an interesting finding for healthcare professionals.

Atención pre y post-natal de la infección por Trypanosoma Cruzi en centros de atención primaria de la salud en Santa Fe / Pre and post-natal care of Trypanosoma Cruzi infection in primary health care centers in Santa Fe

Los objetivos de este trabajo fueron evaluar el seguimiento de hijos de mujeres infectadas por Trypanosoma cruzi en los Centros de Atención Primaria (CAPS) e identificar las barreras para la detección precoz de Chagas connatal y de infecciones crónicas. Mediante un estudio descriptivo se evaluó el seguimiento de los hijos de mujeres infectadas. Se usaron los sistemas informáticos SISA y SICAP para identificar las mujeres embarazadas infectadas y los CAPS de referencia. Se coordinó con profesionales de los CAPS para evaluar el seguimiento de los hijos y, con la maternidad del Hospital Cullen para informar los nacimientos, realizar control clínico y recabar datos para los controles posteriores. Para relevar las dificultades que limitan el diagnóstico y tratamiento temprano, se utilizó un método de tipo exploratorio a través de encuestas online e implementación de talleres al personal de los CAPS. Se visitaron 10 CAPS a los cuales concurrieron 17 madres y 44 hijos. Tenían diagnóstico en el CAPS, 25/44 (56,8%) hijos: 22 con serología (-) para Chagas luego de los 10 meses de vida y; 2 niños estaban infectados con T. cruzi y fueron tratados con benznidazol. Una niña de 6 meses fue tratada sin confirmar infección. No tenían control en los CAPS, 19 niños: 17 tuvieron serología (-), edad promedio 7±5,8 y; 2 niñas de 3 y 7 años fueron seropositivas, ytratadas con nifurtimox.Nacieron 22 hijos de madres infectadas 100% tuvo microstrout (-) previo al egreso de la maternidad. De los 10 niños mayores al año de vida 6 fueron (-) y 4 no se localizaron. El personal de los CAPS expresó necesidad de capacitación; ausencia de articulación entre especialidades médicas; poca experiencia en relación al tratamiento en crónicos; escasa búsqueda de casos. Se desarrollaron 13 talleres con la participación activa de 83 integrantes de los CAPS. Toda la información se compartió con el Programa Provincial de Chagas. Se enfatiza la necesidad de la formación continua como estrategia de prevención

Chagas congénito en atención primaria de la salud en la Provincia de Santa Fe / Congenital Chagas disease in primary health care in Santa Fe province

Actualmente, la transmisión transplacentaria es la vía más frecuente de infección por Trypanosoma cruzi. El diagnóstico y tratamiento temprano de hijos infectados evita el riesgo de desarrollar miocardiopatía y las niñas dejan de ser potenciales fuentes de transmisión congénita. En este estudio se evaluó el seguimiento de hijos de mujeres infectadas por T. cruzi en Centros de Salud de la provincia de Santa Fe. Se estudiaron 19 madres y sus 51 hijos. 45% (23/51) de los hijos no habían sido estudiados previamente, y de éstos 21/23 resultaron negativos mientras que dos niñas de 3 y 7 años estaban infectadas. Los 28 niños restantes ya habían sido estudiados en los Centros de Salud, siendo positivas dos gemelas de 22 meses y una niña de 9 años; los otros 25/28 hijos no estaban infectados. Un 47% (9/19) de las madres tenían como único antecedente la serología materna positiva, y de las 4 mujeres que transmitieron la infección, tres pertenecían a este grupo. La edad promedio de diagnóstico fue: 20±6 años en las madres y 7,4±6,7 años en los hijos. Se requieren estrategias sanitarias que favorezcan el estudio para la infección por T. cruzi en mujeres antes del embarazo y el seguimiento de todos los hijos para no perder la oportunidad de tratamiento

Transplacental transmission is currently the most frequent route of infection by Trypanosoma cruzi. Early diagnosis and treatment of infected children avoids the risk of developing cardiomyopathy, and girls are no longer potential sources of congenital transmission. This study evaluated the follow-up of children of women infected with T. cruzi in Primary Care Centres of the province of Santa Fe. Nineteen mothers and their 51 children were studied. Among the 51 children, 23 had no previous diagnosis (45%). Of these, 21 were negative while 2 girls, ages 3 and 7, were infected. The remaining 28 children already had a diagnosis at the Health Centres, with 2 twins of 22 months and a 9-year-old girl who were positive; the other 25 children were not infected. Among the 19 mothers, 9 (47%) had the positive maternal serology as the only antecedent. Of the 4 women who transmitted the infection, 3 belonged to this group. The average age of diagnosis was: 20 ± 6 years in mothers and 7.4 ± 6.7 years in children. Health strategies are required to promote the detection of infected women before pregnancy and the monitoring of all children so as not to miss the opportunity for treatment

Higher congenital transmission rate of Trypanosoma cruzi associated with family history of congenital transmission

Abstract INTRODUCTION: Congenital transmission (CT) of Trypanosoma cruzi has led to globalization of Chagas disease and its growing relevance as a public health problem. Although the occurrence of CT has been associated with several factors, its mechanisms are still unknown. This study aimed to analyze the geographical and familiar variables of mothers and their association with CT of Chagas disease in a population living in non-endemic areas of Argentina for the last decades. METHODS: We developed a retrospective cohort study in a sample of 2120 mother-child pairs who attended three reference centers in the cities of Buenos Aires, Santa Fe, and Salta between 2002 and 2015. RESULTS: The highest CT rates were observed in children born to Argentinean mothers (10.7%) and in children born to mothers from Buenos Aires (11.7%). Considering the areas of origin of the mothers, those from areas of null-low risk for vector-borne infection had higher CT rates than those from areas of medium-high risk (11.1% vs 8.2%). We also observed a significant intra-familiar "cluster effect," with CT rates of 35.9% in children with an infected sibling, compared to 8.2% in children without infected siblings (RR=4.4 95% CI 2.3-8.4). CONCLUSIONS: The associations observed suggest a higher CT rate in children born to mothers who acquired the infection congenitally, with familiar antecedents, and from areas without the presence of vectors. These observations are considered new epidemiological evidence about Chagas disease in a contemporary urban population, which may contribute to the study of CT and may also be an interesting finding for healthcare professionals.

Maternal risk factors for the transmission of congenital chagas disease

The present article looks at the association between the epidemiological history of women infected with Trypanosoma cruzi and the risk of vertical transmission. Eighty-three chronically infected mothers and their 237 children were studied, using a cohort design. All patients reside in Santa Fe city, Argentina. Twenty-five women transmitted the infection to 38 children. The potential risk factors evaluated in the mothers were exposure to vector transmission, blood transfusion history, maternal seropositivity, parasitemia and age at birth of the child. 72% (18/25) of the mothers who transmitted the infection to their children, had little or no contact with the vector, while only 28% (7/25) of the mothers presented a history of medium or high risk of vector infection. The differences were significant (p < 0.05). Forty-one percent of the women who presented maternal history as the probable route of infection, transmitted the parasite to more than one child (1.86 ± 0.33; CI95% = 1.03-2.68). In addition, the most frequent history, among the women who transmitted the disease to their children, was the absence of exposure to vector transmission and transfusion with unknown maternal serology. The route of infection was probably transplacental. These observations suggest that there are family genetic characteristics involved in vertical transmission. The parasite was found in 71% of the mothers who transmitted the infection to their children and were able to perform xenodiagnoses. After controlling for the other variables, the logistic regression analysis showed that xenodiagnosis (+) is a risk factor for congenital transmission; the relative risk was 12.2 (95% confidence interval: 2.9 - 50.1). No differences were found when analyzing the mother's age and transfusion history. The highest risk of congenital transmission was associated with detectable parasitemia and less maternal exposure to the vector.

Course of serological tests in treated subjects with chronic Trypanosoma cruzi infection: A systematic review and meta-analysis of individual participant data.

OBJECTIVE: To determine the course of serological tests in subjects with chronic Trypanosoma cruzi infection treated with anti-trypanosomal drugs. METHODS: A systematic review and meta-analysis was conducted using individual participant data. Survival analysis and the Cox proportional hazards regression model with random effects to adjust for covariates were applied. The protocol was registered in the PROSPERO database (http://www.crd.york.ac.uk/PROSPERO; CRD42012002162). RESULTS: A total of 27 studies (1296 subjects) conducted in eight countries were included. The risk of bias was low for all domains in 17 studies (63.0%). Nine hundred and thirteen subjects were assessed (149 seroreversion events, 83.7% censored data) for enzyme-linked immunosorbent assay (ELISA), 670 subjects (134 events, 80.0% censored) for indirect immunofluorescence assay (IIF), and 548 subjects (99 events, 82.0% censored) for indirect hemagglutination assay (IHA). A higher probability of seroreversion was observed within a shorter time span in subjects aged 1-19 years compared to adults. The chance of seroreversion also varied according to the country where the infection might have been acquired. For instance, the pooled adjusted hazard ratio between children/adolescents and adults for the IIF test was 1.54 (95% confidence interval 0.64-3.71) for certain countries of South America (Argentina, Bolivia, Chile, and Paraguay) and 9.37 (95% confidence interval 3.44-25.50) for Brazil. CONCLUSIONS: The disappearance of anti-T. cruzi antibodies was demonstrated along the course of follow-up. An interaction between age at treatment and country setting was found.

Simple methodology to directly genotype Trypanosoma cruzi discrete typing units in single and mixed infections from human blood samples.

Different DNA markers to genotype Trypanosoma cruzi are now available. However, due to the low quantity of parasites present in biological samples, DNA markers with high copy number like kinetoplast minicircles are needed. The aim of this study was to complete a DNA assay called minicircle lineage specific-PCR (MLS-PCR) previously developed to genotype the T. cruzi DTUs TcV and TcVI, in order to genotype DTUs TcI and TcII and to improve TcVI detection. We screened kinetoplast minicircle hypervariable sequences from cloned PCR products from reference strains belonging to the mentioned DTUs using specific kDNA probes. With the four highly specific sequences selected, we designed primers to be used in the MLS-PCR to directly genotype T. cruzi from biological samples. High specificity and sensitivity were obtained when we evaluated the new approach for TcI, TcII, TcV and TcVI genotyping in twenty two T. cruzi reference strains. Afterward, we compared it with hybridization tests using specific kDNA probes in 32 blood samples from chronic chagasic patients from North Eastern Argentina. With both tests we were able to genotype 94% of the samples and the concordance between them was very good (kappa=0.855). The most frequent T. cruzi DTUs detected were TcV and TcVI, followed by TcII and much lower TcI. A unique T. cruzi DTU was detected in 18 samples meantime more than one in the remaining; being TcV and TcVI the most frequent association. A high percentage of mixed detections were obtained with both assays and its impact was discussed.

Trypanocide treatment of women infected with Trypanosoma cruzi and its effect on preventing congenital Chagas.

With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment before pregnancy. Their children were studied to detect congenital infection. Among 354 "chronically infected mother-biological child" pairs, 132 were treated women and 222 were untreated women. Among the children born to untreated women, we detected 34 infected with T. cruzi (15.3%), whose only antecedent was maternal infection. Among the 132 children of previously treated women, no infection with T. cruzi was found (0.0%) (p<0.05). Among 117 mothers with clinical and serological follow up, 71 had been treated and 46 were untreated. The women were grouped into three groups. Group A: 25 treated before 15 years of age; Group B: 46 treated at 15 or more years of age; Group C: untreated, average age of 29.2 ± 6.2 years at study entry. Follow-up for Groups A, B and C was 16.3 ± 5.8, 17.5 ± 9.2 and 18.6 ± 8.6 years respectively. Negative seroconversion: Group A, 64.0% (16/25); Group B, 32.6% (15/46); Group C, no seronegativity was observed. Clinical electrocardiographic alterations compatible with chagasic cardiomyopathy: Group A 0.0% (0/25); B 2.2% (1/46) and C 15.2% (7/46). The trypanocidal treatment of women with chronic Chagas infection was effective in preventing the congenital transmission of Trypanosoma cruzi to their children; it had also a protective effect on the women's clinical evolution and deparasitation could be demonstrated in many treated women after over 10 years of follow up.

Infección chagásica en niños de cuatro distritos de riesgo de la provincia de Santa Fe / Chagas infection in children of four districts at risk in Santa Fe province / Infecgáo chagasica em changas de quatro distritos de risco da provincia de Santa Fe

El objetivo del presente estudio fue investigar infección chagásica en niños de 1 a 15 años que residen en zona de riesgo vectorial o con antecedentes migratorios en la provincia de Santa Fe, estimar la/s vía/s más probable/s de infección y comparar la prevalencia con trabajos anteriores. Se realizó un estudio seroepidemiológico en escuelas de los Distritos Garabato, Fortín Olmos y Gato Colorado y la escuela de la comunidad Com Caia del Departamento La Capital. A los seropositivos se les realizó una encuesta para determinar las probables vías de infección. Se comparó la prevalencia actual con la del último control de cada distrito. No se hallaron seropositivos en Com Caia (prevalencia 0%, 0/130). La prevalencia en Garabato fue 1,0% (6/604), Fortín Olmos 1,9% (13/688), Gato Colorado 3,0% (12/399). Disminuyó respecto de los últimos estudios: Garabato 11,2% (año 2000), Fortín Olmos 14,6% (2004), Gato Colorado 6,3% (2006). La vía de infección que se sospecha más frecuente es la congÞnita, seguida por la vectorial. Se concluye que, a pesar de la disminución de la prevalencia, se deben continuar las acciones de control, principalmente por vías vectorial y congÞnita.(AU)

The aim of the present study was to diagnose Chagas infection in children 1 to 15 years of age living in a risk area or with migrant background in Santa Fe province, to estimate the most probable way of infection and to compare the prevalence with previous works. A seroepidemiological study was conducted in schools in the districts Garabato, Fortin Olmos and Gato Colorado and the community Com Caia in La Capital Department. An inquiry was conducted in positive patients to determine the most probable way of infection. The current prevalence was compared with the last control in each district. No seropositive were found in Com Caia (prevalence 0%, 0/130). In Garabato the prevalence was 1.0% (6/604), Fortin Olmos 1.9% (13/688), Gato Colorado 3.0% (12/399). It decreased in comparison with the latest study: Garabato 11.2% (2000), Fortin Olmos 14.6% (2004), Gato Colorado 6.3% (2006). The most suspected way of infection was congenital, followed by vector one. We conclude that, although the prevalence decreased, it must be continued mainly vector and congenital controls actions.(AU)

O objetivo deste estudo foi investigar a infecgáo chagásica em criangas de 1 a 15 anos que moram em zona de risco vetorial ou com antecedentes de migragáo na provincia de Santa Fe, estimar a/as via/s mais provável/veis de infecgáo e comparar prevalencia com trabalhos anteriores. Foi realizado um estudo soroepidemiológico em escolas nos distritos Garabato, Fortin Olmos e Gato Colorado e na escola da comunidade Com Caia no departamento La Capital. Os soropositivos foram entrevistados para determinar as prováveis vias da infecgáo. A prevalencia atual foi comparada com a do último controle em cada distrito. Náo foram encontrados soropositivos em Com Caia (prevalencia 0%, 0/130). A prevalencia em Garabato foi 1,0% (6/604), Fortin Olmos 1,9% (13/688), Gato Colorado 3,0% (12/399). Diminuiu a respeito dos últimos estudos: Garabato 11,2% (ano 2000), Fortin Olmos 14,6% (2004), Gato Colorado 6,3% (2006). A via de infecgáo que se suspeita como sendo a mais frequente é a congenita, seguida pela vetorial. Concluise que, apesar da diminuigáo da prevalencia, devem continuar sendo realizadas agoes de controle, principalmente por vias vetorial e congenita.(AU)

Infección chagásica en niños de cuatro distritos de riesgo de la provincia de Santa Fe / Chagas' infection in children of four districts at risk in Santa Fe province / Infecgáo chagasica em changas de quatro distritos de risco da provincia de Santa Fe

El objetivo del presente estudio fue investigar infección chagásica en niños de 1 a 15 años que residen en zona de riesgo vectorial o con antecedentes migratorios en la provincia de Santa Fe, estimar la/s vía/s más probable/s de infección y comparar la prevalencia con trabajos anteriores. Se realizó un estudio seroepidemiológico en escuelas de los Distritos Garabato, Fortín Olmos y Gato Colorado y la escuela de la comunidad Com Caia del Departamento La Capital. A los seropositivos se les realizó una encuesta para determinar las probables vías de infección. Se comparó la prevalencia actual con la del último control de cada distrito. No se hallaron seropositivos en Com Caia (prevalencia 0%, 0/130). La prevalencia en Garabato fue 1,0% (6/604), Fortín Olmos 1,9% (13/688), Gato Colorado 3,0% (12/399). Disminuyó respecto de los últimos estudios: Garabato 11,2% (año 2000), Fortín Olmos 14,6% (2004), Gato Colorado 6,3% (2006). La vía de infección que se sospecha más frecuente es la congènita, seguida por la vectorial. Se concluye que, a pesar de la disminución de la prevalencia, se deben continuar las acciones de control, principalmente por vías vectorial y congènita.

The aim of the present study was to diagnose Chagas infection in children 1 to 15 years of age living in a risk area or with migrant background in Santa Fe province, to estimate the most probable way of infection and to compare the prevalence with previous works. A seroepidemiological study was conducted in schools in the districts Garabato, Fortin Olmos and Gato Colorado and the community Com Caia in La Capital Department. An inquiry was conducted in positive patients to determine the most probable way of infection. The current prevalence was compared with the last control in each district. No seropositive were found in Com Caia (prevalence 0%, 0/130). In Garabato the prevalence was 1.0% (6/604), Fortin Olmos 1.9% (13/688), Gato Colorado 3.0% (12/399). It decreased in comparison with the latest study: Garabato 11.2% (2000), Fortin Olmos 14.6% (2004), Gato Colorado 6.3% (2006). The most suspected way of infection was congenital, followed by vector one. We conclude that, although the prevalence decreased, it must be continued mainly vector and congenital controls actions.

O objetivo deste estudo foi investigar a infecgáo chagásica em criangas de 1 a 15 anos que moram em zona de risco vetorial ou com antecedentes de migragáo na provincia de Santa Fe, estimar a/as via/s mais provável/veis de infecgáo e comparar prevalencia com trabalhos anteriores. Foi realizado um estudo soroepidemiológico em escolas nos distritos Garabato, Fortin Olmos e Gato Colorado e na escola da comunidade Com Caia no departamento La Capital. Os soropositivos foram entrevistados para determinar as prováveis vias da infecgáo. A prevalencia atual foi comparada com a do último controle em cada distrito. Náo foram encontrados soropositivos em Com Caia (prevalencia 0%, 0/130). A prevalencia em Garabato foi 1,0% (6/604), Fortin Olmos 1,9% (13/688), Gato Colorado 3,0% (12/399). Diminuiu a respeito dos últimos estudos: Garabato 11,2% (ano 2000), Fortin Olmos 14,6% (2004), Gato Colorado 6,3% (2006). A via de infecgáo que se suspeita como sendo a mais frequente é a congenita, seguida pela vetorial. Concluise que, apesar da diminuigáo da prevalencia, devem continuar sendo realizadas agoes de controle, principalmente por vias vetorial e congenita.

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease.

This work compared the time at which negative seroconversion was detected by conventional serology (CS) and by the ELISA-F29 test on a cohort of chronic chagasic patients treated with nifurtimox or benznidazole. A retrospective study was performed using preserved serum from 66 asymptomatic chagasic adults under clinical supervision, and bi-annual serological examinations over a mean follow-up of 23 years. Twenty nine patients received trypanocide treatment and 37 remained untreated. The ELISA-F29 test used a recombinant antigen which was obtained by expressing the Trypanosoma cruzi flagellar calcium-binding protein gene in Escherichia coli. Among the untreated patients, 36 maintained CS titers. One patient showed a doubtful serology in some check-ups. ELISA-F29 showed constant reactivity in 35 out of 37 patients and was negative for the patient with fluctuating CS. The treated patients were divided into three groups according to the CS titers: in 13 they became negative; in 12 they decreased and in four they remained unchanged. ELISA-F29 was negative for the first two groups. The time at which negativization was detected was significantly lower for the ELISA-F29 test than for CS, 14.5 ± 5.7 and 22 ± 4.9 years respectively. Negative seroconversion was observed in treated patients only. The results obtained confirm that the ELISA-F29 test is useful as an early indicator of negative seroconversion in treated chronic patients.

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease / Avaliação do tratamento tripanossomicida em coorte de adultos chagásicos crônicos através de técnicas sorológicas convencionais e ELISA-F29

This work compared the time at which negative seroconversion was detected by conventional serology (CS) and by the ELISA-F29 test on a cohort of chronic chagasic patients treated with nifurtimox or benznidazole. A retrospective study was performed using preserved serum from 66 asymptomatic chagasic adults under clinical supervision, and bi-annual serological examinations over a mean follow-up of 23 years. Twenty nine patients received trypanocide treatment and 37 remained untreated. The ELISA-F29 test used a recombinant antigen which was obtained by expressing the Trypanosoma cruzi flagellar calcium-binding protein gene in Escherichia coli. Among the untreated patients, 36 maintained CS titers. One patient showed a doubtful serology in some check-ups. ELISA-F29 showed constant reactivity in 35 out of 37 patients and was negative for the patient with fluctuating CS. The treated patients were divided into three groups according to the CS titers: in 13 they became negative; in 12 they decreased and in four they remained unchanged. ELISA-F29 was negative for the first two groups. The time at which negativization was detected was significantly lower for the ELISA-F29 test than for CS, 14.5 ± 5.7 and 22 ± 4.9 years respectively. Negative seroconversion was observed in treated patients only. The results obtained confirm that the ELISA-F29 test is useful as an early indicator of negative seroconversion in treated chronic patients.

Este trabalho comparou os tempos de soroconversão negativos obtidos pela sorologia convencional (CS) e teste ELISA-F29 em uma coorte de pacientes chagásicos crônicos tratados com nifurtimox ou benznidazol. Um estudo retrospectivo foi realizado com soro preservado de 66 adultos chagásicos assintomáticos com acompanhamento clínico e sorológico semestral ao longo de um seguimento médio de 23 anos. 29 pacientes receberam tratamento tripanossomicida e 37 outras permaneceram sem tratamento. O teste ELISA-F29 usou um antígeno recombinante obtido por expressão do gene de uma proteína flagelar de Trypanosoma cruzi de ligação de cálcio em Escherichia coli. Entre os pacientes não tratados, 36 mantiveram os títulos da CS. Um paciente apresentou sorologia duvidosa em alguns controles. ELISA-F29 apresentou reatividade constante em 35/37 e foi negativo no paciente com CS flutuante. Os pacientes tratados foram agrupados de acordo com os títulos da CS, em três grupos: 13 tornaram-se negativos, 12 diminuíram e quatro permaneceram inalterados. ELISA-F29 foi negativo nos dois primeiros grupos. O tempo de negativização foi significativamente menor para o teste ELISA-F29 do que para CS (14,5 ± 5,7 e 22 ± 4,9 anos, respectivamente). A soroconversão negativa foi observada somente nos pacientes tratados. Os resultados obtidos confirmam que o teste ELISA-F29 é útil como um indicador precoce de soronegativação em pacientes crônicos tratados.

Perspectiva interdisciplinaria para el abordaje de una enfermedad infecciosa: chagas o tripanosomiasis americana / Interdisciplinary perspective to approach an infectious disease: american trypanosomiasis or chagas disease

La enfermedad de Chagas, producida por elTrypanosomacruziy transmitida por un insecto triatomino, es de grancomplejidad. En el control de esta endemia no puedeconsiderarse la enfermedad como un hecho individualy sólo biológico. Entre sus múltiples componentes debeconsiderarse la relación de los sujetos con el hábitat, losmodos de producción, las condiciones culturales, lasrelaciones sociales y las formas organizativas.Como profesionales del campo de la salud intentamosnuevos enfoques que integran diferentes miradas disciplinaresy modos de intervención distintos, donde ôel otroö recuperesu ser sujeto y no esté convocado a desempeñar un merorol de paciente. Posiciones que implican favorecer procesosparticipativos, escuchar a los propios protagonistas (mujerescon Chagas, equipos de salud, referentes comunitarios)recuperar sus peculiares visiones, poner en palabras lo nodicho sobre esta enfermedad silenciosa y silenciada, y develarlo que el Chagas esconde. Constituye una herramientaimportante a la hora de pensar propuestas de trabajo.(AU)

Chagas disease, caused by Trypanosoma cruzi and transmitted by a triatomine insectis extremely complicated. When controlling this endemic disease, the disease cannot beconsidered as an individual and merely biological fact. Among its many components therelationship of individuals to the habitat, production modes, cultural conditions, socialrelationships and organizational forms must be considered.As health professionals we present new approaches that integrate different disciplinesand modes of intervention, where ôthe otherö recovers his/her individual being and isnot merely called upon to play a role as a patient. Positions that encourage participativeprocesses involving listening to the protagonists themselves (women with Chagas, healthteams, community references), recovering their unique visions, communicating what isnot said about this silent and hushed up disease, and revealing what Chagas hides areimportant tools when thinking about work proposals.(AU)

Perspectiva interdisciplinaria para el abordaje de una enfermedad infecciosa: chagas o tripanosomiasis americana / Interdisciplinary perspective to approach an infectious disease: american trypanosomiasis or chagas disease

La enfermedad de Chagas, producida por elTrypanosomacruziy transmitida por un insecto triatomino, es de grancomplejidad. En el control de esta endemia no puedeconsiderarse la enfermedad como un hecho individualy sólo biológico. Entre sus múltiples componentes debeconsiderarse la relación de los sujetos con el hábitat, losmodos de producción, las condiciones culturales, lasrelaciones sociales y las formas organizativas.Como profesionales del campo de la salud intentamosnuevos enfoques que integran diferentes miradas disciplinaresy modos de intervención distintos, donde “el otro” recuperesu ser sujeto y no esté convocado a desempeñar un merorol de paciente. Posiciones que implican favorecer procesosparticipativos, escuchar a los propios protagonistas (mujerescon Chagas, equipos de salud, referentes comunitarios)recuperar sus peculiares visiones, poner en palabras lo nodicho sobre esta enfermedad silenciosa y silenciada, y develarlo que el Chagas esconde. Constituye una herramientaimportante a la hora de pensar propuestas de trabajo.

Chagas disease, caused by Trypanosoma cruzi and transmitted by a triatomine insectis extremely complicated. When controlling this endemic disease, the disease cannot beconsidered as an individual and merely biological fact. Among its many components therelationship of individuals to the habitat, production modes, cultural conditions, socialrelationships and organizational forms must be considered.As health professionals we present new approaches that integrate different disciplinesand modes of intervention, where “the other” recovers his/her individual being and isnot merely called upon to play a role as a patient. Positions that encourage participativeprocesses involving listening to the protagonists themselves (women with Chagas, healthteams, community references), recovering their unique visions, communicating what isnot said about this silent and hushed up disease, and revealing what Chagas hides areimportant tools when thinking about work proposals.

Humoral immune response against P2ß from Trypanosoma cruzi in persons with chronic Chagas disease: its relationship with treatment against parasites and myocardial damage.

We investigated the relationship between potentially pathogenic antibodies against a Trypanosoma cruzi ribosomal protein (P2ß) and the evolution of Chagas disease and the effect of trypanocidal treatment on these variables. Seventy-eight patients with chronic Chagas disease who were followed-up for more than 20 years were divided into three groups: 30 asymptomatic persons undergoing specific treatment (group A), 37 asymptomatic persons not undergoing specific treatment (group B), and 11 patients with chronic chagasic cardiomyopathy (CCC) who were not treated. Five patients in group B showed evolution to myocardial abnormalities. Among persons with CCC, six showed no changes; the remaining persons showed progression of cardiac involvement. Levels of antibodies to P2ß in persons in group A decreased from their initial values. This finding was not observed in persons in groups B and C. Comparisons at the end of the follow-up showed lower amounts of antibodies to P2ß in groups A and C. These findings support the benefits of specific treatment during chronic infection.

Utilidad de la técnica de aglutinación directa en el diagnóstico de la infección chagásica / Usefulness of the direct agglutination test for the diagnosis of chagasic infection

La técnica de aglutinación directa para diagnóstico de infección chagásica es sencilla y económica. Tiene buena sensibilidad y especificidad cuando es utilizada junto con otras técnicas serológicas y/o parasitológicas. Ha sido reemplazada por otras reacciones de mayor rapidez en los resultadosy más fácil lectura (ELISA, hemaglutinación indirecta). Actualmente es difícil conseguir equipos comerciales. Se presentan en el siguiente trabajo una serie de casos que muestran la utilidad de la aglutinación directa para determinar precozmente infección aguda y/o congénita y para diferenciarinfecciones agudas de crónicas.

The direct agglutination technique for chagasic infection diagnosis is easy to perform and inexpensive. It has good sensitivity and specificity when used in conjunction with other serological and/or parasitological techniques. It has been replaced with other reactions with faster results and easiness to read (i.e. immunoenzymatic assay (ELISA) and indirect hemagglutination). Currently it is difficult to obtaincommercial kits. In the present paper we present a series of cases that show the usefulness of the direct agglutination test to early determine acute and/or congenital infection and to differentiate acute from chronic infections.

Confirman la utilidad de la quimioterapia específica en la enfermedad de Chagas crónica / Confirmation of the usefulness of chemotherapy in the treatment of chronic Chagas disease

La evaluación del tratamiento tripanocida en adultos con enfermedad de Chagas crónica requiere estudios de seguimiento muy prolongados. Ciento doce adultos con infección crónica por T. cruzi, asintomáticos, residentes en la Ciudad de Santa Fe fueron evaluados durante 23 años en promedio mediante estudios parasitológicos, serológicos y clínicos. De ellos, 55 fueron tratados (27 con nifurtimox y 28 con benznidazol) y 57 permanecieron sin tratar. Se demostró la eficacia del tratamiento específico en el 45.5% de los pacientes tratados, por su negativización parasitológica y serológica convencional persistente, acompañada de un efecto preventivo en la evolución del daño miocárdico. En este grupo tratado, otro 23.6% de los infectados presentaron serología dudosa o seroconversión negativa completa en el último control. Estos probablemente se incorporen en los próximos años al grupo de pacientes curados. En los infectados que no recibieron tratamiento específico se observó que la serología convencional permaneció siempre positiva y que las alteraciones electrocardiográficas compatibles con miocardiopatía chagásica crónica fueron 5 veces mayores que la que presentó el grupo de pacientes tratados.(AU)

Confirman la utilidad de la quimioterapia específica en la enfermedad de Chagas crónica / Confirmation of the usefulness of chemotherapy in the treatment of chronic Chagas disease

La evaluación del tratamiento tripanocida en adultos con enfermedad de Chagas crónica requiere estudios de seguimiento muy prolongados. Ciento doce adultos con infección crónica por T. cruzi, asintomáticos, residentes en la Ciudad de Santa Fe fueron evaluados durante 23 años en promedio mediante estudios parasitológicos, serológicos y clínicos. De ellos, 55 fueron tratados (27 con nifurtimox y 28 con benznidazol) y 57 permanecieron sin tratar. Se demostró la eficacia del tratamiento específico en el 45.5% de los pacientes tratados, por su negativización parasitológica y serológica convencional persistente, acompañada de un efecto preventivo en la evolución del daño miocárdico. En este grupo tratado, otro 23.6% de los infectados presentaron serología dudosa o seroconversión negativa completa en el último control. Estos probablemente se incorporen en los próximos años al grupo de pacientes curados. En los infectados que no recibieron tratamiento específico se observó que la serología convencional permaneció siempre positiva y que las alteraciones electrocardiográficas compatibles con miocardiopatía chagásica crónica fueron 5 veces mayores que la que presentó el grupo de pacientes tratados.