Chagas Disease: Seroprevalence and Associated Factors in Indigenous Communities of the Southern Limit of Argentine Chaco.

Chagas disease is more prevalent in socially vulnerable communities in the Gran Chaco Eco-region. The study evaluated the seroprevalence of Chagas disease and associated factors between May 2014 and September 2015, in indigenous communities of Santa Fe, Argentina, in the southern Chaco. Lysate ELISA and indirect hemagglutination tests were used to detect antibodies against Trypanosoma cruzi, and recombinant ELISA was used in the case of disagreement. Household surveys were conducted with the head of household about risk factors for the disease. Serological tests were conducted on 298 people from three indigenous communities, 127 male and 171 female. Seroprevalence was 18.5%. A total of 64 surveys were conducted; 82.8% of the heads of household were male, with a median age of 39 years, and 61.0% had not completed primary school. In 35.9% of the households, there was at least one member of the cohabiting group infected with T. cruzi. The level of education of the head of household showed a statistically significant association with Chagas disease (OR = 3.43), among all the risk factors studied. The prevalence of infection is lower than that of other indigenous communities of the Gran Chaco, probably because environmental conditions are moderating and disfavoring the establishment of the insect vector in homes, but also because of socioeconomic differences with the rest of the eco-region. Beyond this, serological controls are needed to prevent vertical transmission.

Seroprevalence of Chagas disease in urban and rural indigenous populations of the south of Gran Chaco.

BACKGROUND: In Latin America, Chagas disease is endemic, with a high prevalence in rural indigenous communities and an increasing prevalence in urban areas owing to migration from rural areas with active vector transmission. This study aimed to assess differences in the prevalence of Chagas disease in urban and rural moqoit communities, one of the main ethnic indigenous groups in the south of Gran Chaco. METHODS: A seroprevalence study was conducted in six moqoit populations in the Santa Fe province, Argentina. The variables studied were serology results for Chagas disease, residents of urban or rural areas, age, and sex. RESULTS: The results showed that 9.26% of the 702 volunteers evaluated and 18.32% of the 131women of childbearing potential were seropositive. According to the calculated prevalence ratio, the prevalence of Chagas disease in urban communities was6.41 (95% confidence inverval: 3.73-11.02) times higher than that in rural communities: 21.59% in urban communities vs. 3.37%in rural communities. CONCLUSIONS: The seroprevalence found in the moqoit community was higher than the estimated level for the general population of the same region, with a greater impact in urban areas than in rural areas. The urbanization of groups of people with poor socio-sanitary conditions in the second half of the 20th century could have caused this higher seroprevalence of Chagas disease.

Seroprevalence of Chagas disease in urban and rural indigenous populations of the south of Gran Chaco

ABSTRACT Background: In Latin America, Chagas disease is endemic, with a high prevalence in rural indigenous communities and an increasing prevalence in urban areas owing to migration from rural areas with active vector transmission. This study aimed to assess differences in the prevalence of Chagas disease in urban and rural moqoit communities, one of the main ethnic indigenous groups in the south of Gran Chaco. Methods: A seroprevalence study was conducted in six moqoit populations in the Santa Fe province, Argentina. The variables studied were serology results for Chagas disease, residents of urban or rural areas, age, and sex. Results: The results showed that 9.26% of the 702 volunteers evaluated and 18.32% of the 131women of childbearing potential were seropositive. According to the calculated prevalence ratio, the prevalence of Chagas disease in urban communities was6.41 (95% confidence inverval: 3.73-11.02) times higher than that in rural communities: 21.59% in urban communities vs. 3.37%in rural communities. Conclusions: The seroprevalence found in the moqoit community was higher than the estimated level for the general population of the same region, with a greater impact in urban areas than in rural areas. The urbanization of groups of people with poor socio-sanitary conditions in the second half of the 20th century could have caused this higher seroprevalence of Chagas disease.

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

[Seroprevalence of Chagas´Disease in older than 14 years old in rural Chaco areas of Santa Fe Province.] / Seroprevalencia de Chagas en mayores de 14 años de áreas rurales del Chaco Santafesino.

Introduction: Chagas´Disease (CD) is endemic en Chaco Región. It is unknown the seroprevalence in population older than 14 years old from rural Chaco areas of Santa Fe Province. This study aimed to determine the seroprevalence of and socio-environmental factors associated with CD in inhabitants >14 years old of rural Chaco areas of Santa Fe, Argentina. Methods: A cross-sectional study was conducted between 2010 and 2015, in people over 14 years old, in the rural districts of the Chaco region, in the North of Santa Fe Province, Argentina. Blood serology for Trypanosoma cruzi antibodies based on two serological tests, and a third in case of discordance, were analized. Semi-structured survey was administered. Association between CD and socio-environmental variables were analyzed using prevalence ratios with 95% confidence intervals. Results: A total of 749 individual were analyzed, with an average of 29.5 years. The seroprevalence was 24.70% (26.69% in women and 20.26% in men). Socio-environmental variables showed association with Trypanosoma cruzi seropositive. The seroprevalence was 7.83 times higher in the children of mothers who had not reached secondary education. Conclusions: Chaco region of Santa Fe is endemic for CD, as well as other provinces of the Region. The low level of education is the more important conditioning for this endemic disease.

Introducción: Introducción. La Enfermedad de Chagas (ECh) es endémica en la Región del Chaco. Se desconoce su seroprevalencia en mayores de 14 años de áreas rurales del Chaco Santafesino. El objetivo del trabajo fue determinar la seroprevalencia de ECh en mayores de 14 años de áreas rurales del Chaco Santafesino, Argentina, y su asociación con factores de riesgo epidemiológico. Métodos: Se realizó un estudio transversal entre 2010 y 2015, en personas mayores de 14 años, los distritos rurales de la región del Chaco, en el Norte de la Provincia de Santa Fe, Argentina. Se determinó la prevalencia de anticuerpos contra Trypanosoma cruzi mediante dos pruebas serológicas, realizando una tercera en caso de discordancia. Se realizaron encuestas semiestructuradas sobre variables socioambientales. Se analizó la asociación entre ECh y variables socioambientales mediante la razón de prevalencias con un intervalo de confianza del 95%. Resultados: Se estudió una muestra de 749 personas, con una media de edad de 29,5 años. La seroprevalencia fue de 24,70% (26,69% en mujeres y 20,26% en hombres). Se halló asociación estadísticamente significativa entre las variables socioambientales y la seroprevalencia. La seroprevalencia fue 7,83 veces mayor en los hijos de madres que no habían alcanzado la educación secundaria. Conclusiones: La región del Chaco Santafesino es endémica para Chagas, al igual que otras provincias de la Región. El bajo nivel de instrucción materno es el condicionante más importante para esta endemia

Conocimientos sobre la enfermedad de Chagas en estudiantes de Enfermería de Argentina / Knowledge about Chagas disease in Nursing students of Argentina

Introducción: La enfermedad de Chagas es uno de principales problemas de Salud Pública de Latinoamérica. La deficiencia en la formación de los profesionales de la salud es un factor que contribuye a su persistencia y dificulta su prevención y control. Objetivos: Valorar el nivel de conocimientos sobre los distintos aspectos de la enfermedad de Chagas, con que se gradúan en enfermería en una región endémica con transmisión vectorial controlada. Métodos: Se realizó un estudio descriptivo transversal, mediante una encuesta anónima y voluntaria sobre diferentes aspectos del Chagas, a 133 estudiantes del último año de la Escuela de Enfermería de Santa Fe, Argentina, en el año 2015. Se calcularon la media, valores mínimos y máximos para las variables cuantitativas, y frecuencias absolutas y relativas para las cualitativas. Resultados: Todos los alumnos aceptaron participar de la encuesta (133/133). El promedio de edad fue de 28 años. El 83,5 por ciento fueron mujeres y el 16,5 por ciento varones. El 82,7 por ciento identificaron a los vectores y 100 por ciento conocieron como transmiten, 7,5 por ciento conocieron otras vías de transmisión. El 92,5 por ciento reconoció el área de riesgo vectorial, pero minimizaron la prevalencia en el país y fuera del área de riesgo vectorial. Los conocimientos sobre clínica y tratamiento fueron 38,3 por ciento y 27,1 por ciento respectivamente. Conclusiones: Los estudiantes de enfermería se encuentran capacitados para la prevención de la Enfermedad de Chagas por vía vectorial, pero se deben reforzar los conocimientos en otros aspectos para colaborar en el control de la endemia(AU)

Introduction: Chagas disease is one of the main public health problems in Latin America. The deficiency in the training of health professionals is a factor that contributes to its persistence and hinders its prevention and control. Objectives: To assess the level of knowledge about the different aspects of Chagas disease, with which graduate complete the Nursing major in an endemic region with controlled vector transmission. Methods: A cross-sectional, descriptive study was carried out, using an anonymous and voluntary survey about different aspects of Chagas disease, conducted on 133 students of the last academic year at the School of Nursing of Santa Fe, Argentina, in 2015. We calculated the mean, the minimum and maximum values ​​for quantitative variables, and the absolute and relative frequencies for qualitative ones. Results: All students agreed to participate in the survey (133/133). The average age was 28 years. 83.5 percent were women and 16.5 percent were men. 82.7 percent identified the vectors and 100 percent knew the transmission way, 7.5 percent knew other transmission routes. 92.5 percent recognized the vector risk area, but they minimized the prevalence in the country and outside the vector risk area. Their knowledge about clinical aspects and treatment were 38.3 percent and 27.1 percent, respectively. Conclusions: Nursing students are trained to prevent vector-borne Chagas disease, but knowledge in other aspects must be strengthened to help control the endemic disease (AU)

Chagas pediátrico en áreas rurales de la provincia de Santa Fe / Pediatric chagas disease in rural areas of Santa Fe province

INTRODUCCIÓN: la enfermedad de Chagas continúa siendo un importante problema de salud pública en la ecoregión del Gran Chaco. El norte de la provincia de Santa Fe, correspondiente al Sur de dicha región, se encuentra bajo control entomológico. Dado que se trata de una infección crónica, la seroprevalencia de esta endemia enniños es un marcador de la situación actual de la infección. OBJETIVOS:Determinar la seroprevalencia de infección chagásica en poblaciónpediátrica del Chaco santafesino. MÉTODOS: Se realizó un estudiodescriptivo de corte transversal sobre seroprevalencia de infección chagásica en niños de 5 a 14 años de edad. Comprendió un área aproximada de 38 000 km2 de distritos rurales de los departamentos 9 de Julio y Vera en la provincia de Santa Fe, y se llevó a cabo entre noviembre de 2010 y abril de 2013. RESULTADOS: Se muestreó al71,5% de los niños de la región (3765/5266). La prevalencia fue de1,8% (67/3765). Varió de 5,5% a 0% entre los distintos distritos. De5 a 9 años, fue 1,2% (21/1769); de 10 a 14 años, 2,3% (46/1996).CONCLUSIONES: La seroprevalencia hallada fue inferior a la de otrosestudios en el Gran Chaco. Se observa una gran heterogeneidad en laprevalencia entre los distritos, aun entre los vecinos. La distribución noobedecería a factores climáticos, sino a factores sociales y a la influenciade la actividad antrópica en cada localidad.

INTRODUCTION: chagas disease remains a major public health problem in the Gran Chaco region. The north of Santa Fe province, being the south of this region, is under entomologicalsurveillance. Being a chronic infection, the seroprevalence of this endemic disease in children serves as a marker of the current status. OBJECTIVES: To determine the seroprevalence of Chagasdisease in the pediatric population of Chaco region in Santa Fe. METHODS: A descriptive, cross-sectional seroprevalence study on Chagas infection was conducted for children aged 5-14 years old. It considered an area of 38 000 km2 belonging to ruraldistricts of 9 de Julio and Vera departments in Santa Fe province,between November 2010 and April 2013. RESULTS: The sampling included 71.5% of the children in the region (3765/5266). There was a prevalence of 1.8% (67/3765), ranged from 5.5% to 0% among districts. For 5-9 years, it was 1.2% (21/1769); for 10-14 years, 2.3% (46/1996). CONCLUSIONS: The seroprevalence was lower than in other studies performed in the Gran Chaco. A large heterogeneity is observed in the prevalence among districts, even among neighboring districts. The distribution does not seem to be due to climatic factors, but to social factors and the influence of human activity in each location.

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.

Epidemiología de la enfermedad de Chagas en menores en riesgo de la provincia de Santa Fe / Epidemiology of Chagas disease in children at risk in Santa Fe province

INTRODUCCION: El Chagas es una endemia prevalente en áreas rurales latinoamericanas por la persistencia del vector. El tratamiento etiológico es más efectivo en el período agudo (oligosintomático) y en menores de 15 años en cualquier etapa. En la provincia de Santa Fe, los departamentos 9 de Julio y Vera presentan un alto riesgo de transmisión por la presencia de vinchucas, con mayor peligro en las zonas rurales. En la periferia de la ciudad de Santa Fe (departamento La Capital) podría haber menores infectados por antecedentes migratorios.OBJETIVO: Diagnosticar niños de 1 a 15 años que residen en zona de riesgo o con antecedente migratorio, estimar probables vías de infección y comparar la prevalencia con trabajos anteriores.METODOS: Se realizó un estudio seroepidemiológico en escuelas de los distritos Garabato y Fortín Olmos (Vera), Gato Colorado (9 de Julio) y en la escuela ComCaia de Recreo (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.RESULTADOS: No se hallaron seropositivos en Recreo (prevalencia 0%, 0/130). La prevalencia fue de 1% (6/604) en Garabato; 1,88% (13/688) en Fortín Olmos y 3% (12/399) en Gato Colorado. Esto significó una disminución con respecto al último estudio: Garabato 11,2% (año 2000), Fortín Olmos 14,6% (2004), Gato Colorado 6,3% (2006). La vía de infección más frecuente sería la congénita, seguida por la vectorial.CONCLUSIONES: Pese a que la prevalencia disminuyó, se deben continuar las acciones de control tanto para la vía vectorial como para la congénita.

INTRODUCTION: Chagas is an endemic disease prevalent in Latin American rural areas due to the persistence of the vector. Eiological treatment is more effective un acute phase (oligosymptomatic) and in people younger than 15 years in any stage. In Santa Fe province, 9 de Julio and Vera departments are at high risk of transmission by the presence of triatomines, with greater risk in rural areas. On the outskirts of Santa Fe city (La Capital department) , there may be infected children due to migration background.OBJECTIVE: To diagnose children aged 1 to 15 years living in a risk area or with migrant background, to estimate the most probable way/s of infection and to compare the prevalence with previous works.METHODS: A seroepidemiological study was conducted in schools of the districts Garabato and Fortín Olmos (Vera), Gato Colorado (9 de Julio) and the school ComCaia in Recreo (La Capital). A survey 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.RESULTS: No seropositives were found in Recreo (prevalence 0%, 0/130). The prevalence was 1% (6/694) in Garabato; 1.88% (13/688) in Fortín Olmos, and 3% (12/399) in Gato Colorado. This meant a decrease compared to the previous studies: Garabato 11.2% (2000), Fortín Olmos 14.6% (2004), Gato Colorado 6.3% (2006). The most probable way of infection was the congenital, followed by the vector one.CONCLUSIONS: Although the prevalence decreased, it is necessary to continue with these actions to prevent both vector and congenital transmission.

Epidemiología de la enfermedad de Chagas en menores en riesgo de la provincia de Santa Fe / Epidemiology of Chagas disease in children at risk in Santa Fe province

INTRODUCCION: El Chagas es una endemia prevalente en áreas rurales latinoamericanas por la persistencia del vector. El tratamiento etiológico es más efectivo en el período agudo (oligosintomático) y en menores de 15 años en cualquier etapa. En la provincia de Santa Fe, los departamentos 9 de Julio y Vera presentan un alto riesgo de transmisión por la presencia de vinchucas, con mayor peligro en las zonas rurales. En la periferia de la ciudad de Santa Fe (departamento La Capital) podría haber menores infectados por antecedentes migratorios.OBJETIVO: Diagnosticar niños de 1 a 15 años que residen en zona de riesgo o con antecedente migratorio, estimar probables vías de infección y comparar la prevalencia con trabajos anteriores.METODOS: Se realizó un estudio seroepidemiológico en escuelas de los distritos Garabato y Fortín Olmos (Vera), Gato Colorado (9 de Julio) y en la escuela ComCaia de Recreo (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.RESULTADOS: No se hallaron seropositivos en Recreo (prevalencia 0%, 0/130). La prevalencia fue de 1% (6/604) en Garabato; 1,88% (13/688) en Fortín Olmos y 3% (12/399) en Gato Colorado. Esto significó una disminución con respecto al último estudio: Garabato 11,2% (año 2000), Fortín Olmos 14,6% (2004), Gato Colorado 6,3% (2006). La vía de infección más frecuente sería la congénita, seguida por la vectorial.CONCLUSIONES: Pese a que la prevalencia disminuyó, se deben continuar las acciones de control tanto para la vía vectorial como para la congénita.

INTRODUCTION: Chagas is an endemic disease prevalent in Latin American rural areas due to the persistence of the vector. Eiological treatment is more effective un acute phase (oligosymptomatic) and in people younger than 15 years in any stage. In Santa Fe province, 9 de Julio and Vera departments are at high risk of transmission by the presence of triatomines, with greater risk in rural areas. On the outskirts of Santa Fe city (La Capital department) , there may be infected children due to migration background.OBJECTIVE: To diagnose children aged 1 to 15 years living in a risk area or with migrant background, to estimate the most probable way/s of infection and to compare the prevalence with previous works.METHODS: A seroepidemiological study was conducted in schools of the districts Garabato and Fortín Olmos (Vera), Gato Colorado (9 de Julio) and the school ComCaia in Recreo (La Capital). A survey 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.RESULTS: No seropositives were found in Recreo (prevalence 0%, 0/130). The prevalence was 1% (6/694) in Garabato; 1.88% (13/688) in Fortín Olmos, and 3% (12/399) in Gato Colorado. This meant a decrease compared to the previous studies: Garabato 11.2% (2000), Fortín Olmos 14.6% (2004), Gato Colorado 6.3% (2006). The most probable way of infection was the congenital, followed by the vector one.CONCLUSIONS: Although the prevalence decreased, it is necessary to continue with these actions to prevent both vector and congenital transmission.

[Distribution of Lutzomyia longipalpis in the Chaco region, Argentina, 2010]. / Distribución de Lutzomyia longipalpis en el Chaco Argentino, 2010.

The appearance of the vector of visceral leishmaniasis (VL) Lutzomyia longipalpis in the province of Formosa in 2004 was associated with urban epidemic risk for the first time in Argentina. During 2006, vectors, canine and human cases of VL were reported in the province of Misiones, and in summer 2008-2009, in the province of Corrientes. In Santiago del Estero province in 2008, cases of human and canine VL were associated with secondary vectors. Therefore, with the aim to know the current distribution of VL risk in the Chaco region, systematic captures of the vector were performed between January and April 2010 in 30 localities of Formosa and Chaco, and in the city of Reconquista, province of Santa Fe (224 traps/night). Lu. longipalpis was reported for the first time in the cities of Resistencia and Puerto Antequera (Chaco). Clorinda and Puerto Pilcomayo (Formosa) are the localities where the traps with more individuals were obtained, 158 and 241 Lu. longipalpis trap / site / night respectively. These results showed that the vector of urban epidemic VL is still spreading in Argentina, and already reached the province of Chaco. Sporadic cases reported in the Chaco region, transmitted by secondary vectors as Lu. migonei would also increase due to intensified surveillance, and the dispersion of the parasite associated with the transit of asymptomatic or symptomatic infected dogs.

Distribución de Lutzomyia longipalpis en el Chaco Argentino, 2010 / Distribution of Lutzomyia longipalpis in the Chaco region, Argentina, 2010

El riesgo de leishmaniasis visceral (LV) urbana epidémica se registró por primera vez en la Argentina en el año 2004, por presencia del vector Lutzomyia longipalpis en la provincia de Formosa, la provincia de Misiones registra casos de LV humana, LV canina y vector en el año 2006, y la provincia de Corrientes en el verano 2008-2009. En la provincia de Santiago del Estero los casos de LV humana y LV canina en el año 2008 estuvieron asociados posiblemente a vectores secundarios. Por ello, para conocer la distribución del riesgo en la región del Chaco, entre enero y abril del 2010 se realizó la búsqueda sistemática del vector de LV en 30 localidades de las provincias de Formosa, Chaco y en la ciudad de Reconquista, Santa Fe (224 trampas/noche). Se comprobó la presencia de Lu. longipalpis, por primera vez, en las localidades de Resistencia y Puerto Antequera (Chaco). En Clorinda y Puerto Pilcomayo (Formosa) se obtuvieron las trampas con más ejemplares, 158 y 241 Lu. longipalpis trampa/sitio/noche respectivamente. Los resultados muestran que el vector de la LV urbana epidémica continúa dispersándose en el territorio argentino, habiendo ingresado a la provincia de Chaco. La notificación de casos esporádicos en la región chaqueña, transmitidos por vectores secundarios, como Lu. migonei, podría aumentar también debido a la vigilancia intensificada, y a la dispersión del parásito asociada al tránsito de perros infectados, sintomáticos o asintomáticos.

The appearance of the vector of visceral leishmaniasis (VL) Lutzomyia longipalpis in the province of Formosa in 2004 was associated with urban epidemic risk for the first time in Argentina. During 2006, vectors, canine and human cases of VL were reported in the province of Misiones, and in summer 2008-2009, in the province of Corrientes. In Santiago del Estero province in 2008, cases of human and canine VL were associated with secondary vectors. Therefore, with the aim to know the current distribution of VL risk in the Chaco region, systematic captures of the vector were performed between January and April 2010 in 30 localities of Formosa and Chaco, and in the city of Reconquista, province of Santa Fe (224 traps/night). Lu. longipalpis was reported for the first time in the cities of Resistencia and Puerto Antequera (Chaco). Clorinda and Puerto Pilcomayo (Formosa) are the localities where the traps with more individuals were obtained, 158 and 241 Lu. longipalpis trap / site / night respectively. These results showed that the vector of urban epidemic VL is still spreading in Argentina, and already reached the province of Chaco. Sporadic cases reported in the Chaco region, transmitted by secondary vectors as Lu. migonei would also increase due to intensified surveillance, and the dispersion of the parasite associated with the transit of asymptomatic or symptomatic infected dogs.

Occurrence of aspergillus flavus strains aflatoxins in corn from Santa Fe, Argentina / Incidencia de cepas de aspergillus flavus y aflatoxinas en maíz de Santa Fe, Argentina

It has been demostrated in several agricultural regions all around the world that Aspergillus flavus can infect corn grains and produce aflotoxins even before the harvest. It is also known that the incidence and levels of contamination of cereals factora. In the present work, the incidence of aflotoxins in corn grain from the central and northern areas os Santa Fe province in Argentina was studied. The relationship between the extent of kernel infection by the fungus and the persence of aflotoxins in the samples was examinated. The isolation and identification of A.flavus were carried aot by plating dilutions of the ground kernels on dichloran-rose bengal-chloramphenicol agar (DRBC). Simultaneously, kernels were superficially sterilized with 10 per cent commercial CIONa and planed on potato-dextrose-chloramphenicol agar (PDA+C). The analysis of aflatoxins B1, B2 G1 and G2 was performed by thin layer chromatography (TLC) according with Norma IRAM 14803 (Argentina). A.flavus Link: Fr. was identified in 63.3 per cent of the corn samples. Colonized kernels ranged from 2.5 to 25 per cent and counts on DRBC were in the order of 10 elevado a la 3 CFU/g. Two samples colonized by A.flavus contained aflatoxins B1 and B2 (50 µg/kg of aflotoxins B2, respectively). One sample contained only aflatoxins B1 (22 µ/Kg). According to these results, it may concluded that the incidence of A.flavus observed constitutes a call in attention with respect to the conditions required for storage and transportation of the grains, to minimize the proliferation of the fungus and the production of aflatoxins in these atages. Although the incidence of aflotoxins in the samples of agrains was rather low, the levels of aflotoxins Bi recorded in the samples were higher than those recommended or given as adivsory levels for human foods, by most countries in the world

Regional distribution of fusarium strains in corn from the providence of Santa Fe, Argentina

Se identificaron a nivel de especie cepas de fusarium aisladas de granos de maíz provenientes de diferentes campos del área centro-norte de la provincia de Santa Fe, Argentina, estudiandose su distribución y prevalencia en esta región. Se examinaron muestras de granos secos de reciente cosecha y almacenados de post-cosecha. El aislamiento de las cepas de fusarium se llevó a cabo mediante plaqueo directo de los granos en agar papa-dextrosacloranfenicol (PDA + CAF) y se registraron los porcentajes de granos colonizados por las diferentes especies. Para su identificación, se efectuaron cultivos monospóricos en agar PDA y SNA para inducir la formación de esporodoquios. Se realizaron observaciones macro y microscópicas a los 4,8 y 14 días de incubación a temperatura ambiente (22º-25ºC). La prevalencia de fusarium en las muestras fue del 100 porciento. El 29 porciento de las mismas se colonizó por más de una especie. Se identificaron f. moniliforme, en el 52,6 porciento de las muestras, f. subglutinans- f.graminearum, en el 29 porciento y f. oxysporum en el 2,6 porciento. La primera especie, presentó los niveles más altos de granos colonizados (7,5-52,5 porciento). Según los reportes en la literatura, referente a las diferentes especies aisladas, consideramos conveniente orientar posteriores estudios de prevalencia de micotoxinas de fusarium en granos de maíz de la región, hacia los tricorecenostipo B, zearalenoma, moniliformina y fumonisima