The multiplicity of epidemiological scenarios shown by Chagas Disease, derived from multiple transmission routes of the aetiological agent, occurring on multiple geo-ecobiosocial settings determines the complexity of the disease and reveal the difficulties for its control. From the first description of the link between the parasite, the vector and its domestic habitat and the disease that Carlos Chagas made in 1909, the epidemiological scenarios of the American Trypanosomiasis has shown a dynamic increasing complexity. These scenarios changed with time and geography because of new understandings of the disease from multiple studies, because of policies change at the national and international levels and because human movements brought the parasite and vectors to new geographies. Paradigms that seemed solid at a time were broken down, and we learnt about the global dispersion of Trypanosoma cruzi infection, the multiplicity of transmission routes, that the infection can be cured, and that triatomines are not only a health threat in Latin America. We consider the multiple epidemiological scenarios through the different T. cruzi transmission routes, with or without the participation of a Triatominae vector. We then consider the scenario of regions with vectors without the parasite, to finish with the consideration of future prospects.

Abstract Mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. Diag nosis of maternal infection and the newborn is achieved by a combination of serological tests, clinical features and ultrasound images. An early diagnosis of maternal infection allows treatment that offers a reduction both in transmission rate and risk of congenital damage. The aim of this expert consensus was to review the scientific literature which would enable an update of the clinical practice guideline of prevention, diagnosis and treatment of congenital toxoplasmosis in our country.

Resumen La transmisión vertical de la infección por Toxoplasma gondii ocurre cuando la madre se infecta por primera vez en el transcurso del embarazo. El diagnóstico de la infección materna y la del re cién nacido se logra con el conjunto de pruebas serológicas, hallazgos clínicos y ecográficos. El reconocimiento temprano de la infección materna permite un tratamiento que reduce la tasa de transmisión y el riesgo de daño en el producto de la concepción. El objetivo de este consenso de expertos fue revisar la literatura científica para actualizar las recomendaciones de práctica clínica respecto de la prevención, el diagnóstico y el tratamiento de la toxoplasmosis congénita en nuestro país.

O objetivo do trabalho consistiu em identificar a soroprevalência da infecção por Trypanosoma cruzi em crianças em idade escolar em localidades das províncias de Salta e de Chaco. O trabalho foi realizado em 44 escolas da cidade de Salta, em paragens de San Carlos; em 10 escolas de La Unión e em 7 escolas de Taco Pozo. O mesmo tem um desenho de corte transversal. Tomada de amostra: foi realizada por punção capilar com equipamentos Serokit e a confirmação dos casos soropositivos ou duvidoso por punção venosa e obtenção de soro, para realizar HAI e ELISA. Os casos soropositivos confirmados foram tratados com Benznidazole® durante 60 dias em doses de 5-7 mg/kg/dia. Para a análise estatística foram preparadas tabelas com frequências absolutas e relativas. Analisaram-se 17.884 crianças detectando 159 soropositivos, sendo a maior soroprevalência na cidade de La Unión e a menor na cidade de Salta. Aplicou-se o tratamento a 93 crianças, (71,54%) da cidade e na área rural se trataram todos os casos. A via de infecção vetorial foi a de maior predominância nas mães (64,47%). Conclui-se que embora a soroprevalência tenha sido menor na cidade de Salta do que nas áreas rurais, é necessário continuar com a vigilância.

The aim of this work was to identify seroprevalence of Trypanosoma cruzi infection in school-age children who live in localities from Salta and Chaco. This work was conducted in the following schools: 44 located in Salta city, 10 in La Unión, 7 in Taco Pozo, and several in rural spots around San Carlos town. The design was cross-sectional and the samples were taken by capillary punction with Serokit equipment. Seropositive cases were confirmed by HAI and ELISA performed on serum obtained by venous punction. Confirmed seropositive cases were treated with Benznidazol® for 60 days in doses of 5-7 mg/kg/day. Tables with absolute and relative frequencies were made for statistical analysis. It resulted that the number of school-aged children analyzed was 17,884, 159 being seropositive. The highest seroprevalence was detected in La Unión and the lowest in Salta city. Treatment was given to 93 children (71.54%) from Salta city, while every child was treated in rural areas. Infections in mothers was vector-borne mainly (64.47%). It can be concluded that even though seroprevalence was lower in the city of Salta than in rural areas, it is important to continue monitoring for Chagas disease.

El objetivo del trabajo consistió en identificar la seroprevalencia de la infección por Trypanosoma cruzi en niños en edad escolar en localidades de las provincias de Salta y Chaco. Se trabajó en 44 escuelas de la ciudad de Salta, en parajes de San Carlos; en 10 escuelas de La Unión y en 7 escuelas de Taco Pozo. El trabajo tiene un diseño de corte transversal. La toma de muestra se realizó por punción capilar con equipos Serokit, y la confirmación de los casos seropositivos o dudosos por punción venosa, y obtención de suero, para realizar HAI y ELISA. Los casos seropositivos confirmados fueron tratados con Benznidazol® durante 60 días en dosis de 5-7mg/kg/ día. Para el análisis estadístico se elaboraron tablas con frecuencias absolutas y relativas. Se analizaron 17.884 escolares y se detectaron159 seropositivos, siendo la mayor seroprevalencia en la localidad de La Unión y la menor en la ciudad de Salta. Se aplicó tratamiento a 93 niños (71,54 %) de la ciudad y en el ámbito rural se trataron todos los casos. La vía de infección vectorial fue la de mayor predominio en las madres (64,47%). Se concluye que aunque la seroprevalencia fue menor en la ciudad de Salta que en las zonas rurales, es necesario continuar con la vigilancia.

Abstract: Background: The episodes of bronchial obstruction at early age constitute a frequent problem in Pediatrics. The aim of this study was to evaluate the prevalence of recurrent wheezing in infants in Buenos Aires City, as well as to identify any associated factors. Methods: Cross-sectional study performed from 2011 to 2012 in the Children Hospital Ricardo Gutiérrez, Buenos Aires City, as part of the International Study of Wheezing in Infants. A validated questionnaire was applied to parents of infants aged between 12 and 15 months. The prevalence of wheezing, mostly the recurrent episodes (three or more), and their probable associated factors were evaluated. Data were statistically analyzed with χ2, Fisher's test, binary and logistics multiple regression analysis. The significance level was 0.05. Results: Over 1063 infants, 58.9% (confidence interval (CI) 95% 55.9-61.9) presented at least one episode of wheezing and 26.3% (CI95% 23.8-29.9) three or more episodes (recurrent wheezing). Risk factors associated to wheezing were male gender (p = 0.001), six or more episodes of cold during the first year of life (p < 0.0001), age at first cold < 4 months (p < 0.0001); pneumonia (p < 0.0001) and smoking during pregnancy (tobacco) (p = 0.01). For recurrent wheezing, risk factors we considered as six or more episodes of cold during the first year of life (p < 0.0001), early (< 4 month of age) onset wheezing (p < 0.0001) and nocturnal wheezing (p < 0.0001). Conclusions: The prevalence of recurrent wheezing among infants in Buenos Aires Ciy was high (26.3%). Some identified associated factors can be preventable.

Resumen: Introducción: Los episodios de obstrucción bronquial a temprana edad constituyen un problema frecuente en pediatría. El objetivo de este estudio, además de conocer la prevalencia de sibilancias recurrentes en lactantes de Buenos Aires, fue identificar los factores asociados. Métodos: Estudio de tipo transversal realizado durante 2011 y 2012, en el Hospital de Niños Ricardo Gutiérrez, Buenos Aires, como parte del Estudio Internacional de Sibilancias en Lactantes, mediante una encuesta validada para padres de lactantes de 12 a 15 meses. Se evaluó la prevalencia de sibilancias, fundamentalmente de tipo recurrentes (tres o más episodios) y los posibles factores asociados. El análisis estadístico se realizó por prueba de χ2, prueba de Fisher y análisis de regresión logística univariada y multivariada. El nivel de significación fue de 0.05. Resultados: De 1063 lactantes, el 58.9% (intervalo de confianza (IC) 95% 55.9-61.9) presentaron al menos un episodio de sibilancia y el 26.3% (IC 95% 23.8-29.9), tres o más episodios (sibilancias recurrentes). Los factores vinculados a padecer al menos un episodio de sibilancia fueron el sexo masculino (p = 0.001), seis o más resfríos en el primer año (p < 0.0001), edad del primer resfrío < 4 meses (p < 0.0001), neumonía (p < 0.0001), tabaquismo durante el embarazo (p = 0.01). Los factores relacionados con sibilancias recurrentes fueron seis o más resfríos en el primer año de vida (p < 0.0001), tener el primer episodio de sibilancia antes del cuarto mes de vida (p < 0.0001) y sibilancias nocturnas (p < 0.0001). Conclusiones: La prevalencia de sibilancias recurrentes en Buenos Aires es alta (26.3%). Algunos de los factores asociados serían prevenibles.

Introdução. A doença de Chagas é uma das principais causas de insuficiência cardíaca e sua identificação precoce pode ajudar a identificar pacientes com risco de progressão da doença. Strain longitudinal bidimensional (Str2D) poderia ser uma ferramenta útil para a detecção de disfunção ventricular esquerda incipiente. Objetivos. Analise se strain longitudinal dimensional pode detectar anormalidades em pacientes assintomáticos, sem patologia demonstrável por métodos convencionais na doença de Chagas. Materiais e métodos. Estudo transversal de 45 pacientes com idade inferior a 65 anos em uma área rural endêmica de doença de Chagas sem comprovada patologia (cardiopatia não evidente: CNE) versus 33 pacientes do grupo controle. Em todos os pacientes do estudo foi feita por dois métodos sorológicos, exame clínico, eletrocardiograma e ultrasom Doppler do coração: diâmetro diastólico do ventrículo esquerdo (DDVE), área do átrio esquerdo (AE), fração de ejeção do ventrículo esquerdo (Fey) por Simpson, excursão de anel tricúspide (TAPSE), relação E/A mitral (E/A), E/e' ratio, S tecido (S') do ventrículo esquerdo (VE) e do ventrículo direito (VD), Str2D de cada segmento VI e strain geral. Estatística: variáveis quantitativas de distribuição normal foram comparadas pelo teste t e qualitativa com o teste qui-quadrado. Variabilidade intra e interobservador para r Pearson e coeficiente de correlação intraclasse (CCI). Resultados. Idade, sexo e ecocardiograma Doppler convencional (DDVI, Fey, AE, TAPSE, E/A, E/e') não mostraram diferenças estatisticamente significativas. Strain global e strain dos segmentos do VE apicais apresentaram diferenças significativas entre os pacientes com doença de Chagas sem doença comprovada e seus controles; embora estes valores caem dentro da faixa considerada fisiológica. Variabilidade intra-observador da strain global (r de Pearson: 0,93 e CCI: 0,93) e inter-observador (coeficiente r de Pearson 0,89 e um CCI: 0,88). Conclusões. Os resultados deste estudo poderiam mostrar uma lesão miocárdica incipiente em pacientes com sorologia positiva para doença de Chagas sem cardiopatia demonstrada. A hipótese de trabalho de que só o tempo e um longo seguimento irão confirmar.

Introduction. Chagas disease is a major cause of heart failure and early identification may help identify patients at risk for disease progression. The two-dimensional longitudinal strain (Str2D) could be a useful tool for detecting incipient left ventricular dysfunction. Objectives. Analyze whether longitudinal dimensional strain can detect abnormalities in asymptomatic patients without demonstrable pathology by conventional methods in Chagas disease. Materials and Methods. Cross-sectional study of 45 patients under age 65 years in an endemic rural area with Chagas disease without proven pathology (non evident cardiopathy: NEC) versus 33 control patients. In all patients study was made by two serologic methods, clinical examination, electrocardiogram and Doppler ultrasound of the heart: diastolic diameter of the left ventricle (LVDD), left atrial area (LAA), left ventricle ejection fraction (Fey) by Simpson, excursion of tricuspid ring (TAPSE), E/A mitral ratio (E/A), E/e' ratio, S tissue (S') of left ventricular (LV) and right ventricular (RV), Str2D of each segment LV and global strain. Statistics: Normal distribution quantitative variables were compared using t test and qualitative variables with chi square test. Intra- and inter-observer variability for r Pearson and intra-class correlation coefficient (ICC). Results. Age, sex and conventional Doppler echocardiography (LVDD, Fey, LAA, TAPSE, E/A, E/e') showed no statistically significant differences. Global strain and strain of the apical LV segments showed significant differences between patients with Chagas disease without proven disease and their controls, although these values fall within ranges considered physiological. Intraobserver variability of global strain (Pearson's r 0.93 and ICC: 0.93) and interobserver (Pearson coefficient r of 0.89 and an ICC: 0.88). Conclusions. In a group of asymptomatic patients with Chagas disease without apparent cardiac involvement (NEC stage), the Str2D was lower compared with healthy individuals, suggesting the existence of subtle myocardial damage in these patients. Hypotheses that only time can confirm and track.

Introducción. La enfermedad de Chagas es una causa importante de insuficiencia cardíaca y su identificación precoz puede ayudar a identificar pacientes en riesgo de progresión de la enfermedad. El strain bidimensional longitudinal (Str2D) podría ser una herramienta útil para detectar disfunción ventricular izquierda incipiente. Objetivos. Analizar si el strain puede detectar alteraciones en pacientes asintomáticos y sin patología demostrable por los métodos convencionales en la enfermedad de Chagas. Materiales y métodos. Estudio transversal de 45 pacientes menores de 65 años de zona rural con enfermedad de Chagas, sin patología demostrada frente a 33 individuos sanos (controles). En todos realizamos serología por dos métodos, examen clínico, electrocardiograma y eco-Doppler cardíaco: diámetro diastólico del ventrículo izquierdo (DDVI), área auricular izquierda (AI), fracción de eyección del ventrículo izquierdo (Fey) por Simpson, excursión sistólica del plano del anillo tricuspídeo (TAPSE), E/A mitral (E/A), E/e', S tisular (S´) de ventrículo izquierdo (VI) y ventrículo derecho (VD), Str2D de cada segmento del VI y strain global. Estadística: variables cuantitativas de distribución normal se compararon mediante test de t y cualitativas con test de chi cuadrado. Variabilidad intra e interobservador por r de Pearson y coeficiente de correlación intraclase.Resultados. Edad, sexo y eco-Doppler convencional (DDVI, Fey, AI, TAPSE, E/A, E/e') no mostraron diferencias estadísticamente significativas. El strain global y el strain de los segmentos apicales del VI evidenciaron diferencias significativas entre pacientes con enfermedad de Chagas sin cardiopatía demostrada (SCD) y controles, aunque dichos valores se encuadran dentro de rangos considerados fisiológicos. Variabilidad intraobservador del strain global (r de Pearson: 0,93 y CCI: 0,93) e interobservador (coeficiente r de Pearson 0,89 y un CCI: 0,88). Conclusiones. Los hallazgos del estudio muestran reducción significativa del strain longitudinal global y distal, compatible con un daño miocárdico incipiente en los pacientes con serología positiva para enfermedad de Chagas sin cardiopatía demostrada, hipótesis de trabajo que sólo el tiempo y un prolijo seguimiento podrán confirmar.

The primary objective of this study was to estimate the prevalence of this disease in women of childbearing age and children treated at health centres in underserviced areas of the city of Buenos Aires. Demographic and Chagas disease status data were collected. Samples for Chagas disease serology were obtained on filter paper and the reactive results were confirmed with conventional samples. A total of 1,786 subjects were screened and 73 positive screening results were obtained: 17 were from children and 56 were from women. The Trypanosoma cruzi infection risk was greater in those individuals who had relatives with Chagas disease, who remember seeing kissing bugs, who were of Bolivian nationality or were born in the Argentine province of Santiago del Estero. The overall prevalence of Chagas disease was 4.08%. Due to migration, Chagas disease is currently predominantly urban. The observed prevalence requires health programme activities that are aimed at urban children and their mothers. Most children were infected congenitally, which reinforces the need for Chagas disease screening of all pregnant women and their babies in Argentina. The active search for new cases is important because the appropriate treatment in children has a high cure rate.

It is currently unknown whether treatment of Chagas disease decreases the risk of congenital transmission from previously treated mothers to their infants. In a cohort of women with Chagas disease previously treated with benznidazole, no congenital transmission of the disease was observed in their newborns. This finding provides support for the treatment of Chagas disease as early as possible.

Neurocysticercosis (NC) is a central nervous system disease caused by Cysticercus cellulosae, the larvae of Taenia solium. NC is found worldwide, and endemic in Latin America and Asia. In 1993, 11 adult patients with NC were reported in Buenos Aires, 8 from Bolivia and the rest from Argentina. Pediatric cases reported in Argentina have been from inner provinces or from rural areas. The purpose of the present article is to present the first autochthonous pediatric case, with local source of contagion in the city of Buenos Aires, and to alert regarding the possibility that the city become an endemic area, due to the migratory movements leading to establishment of asymptomatic carriers of Taenia solium in the urban area.

La neurocisticercosis es la enfermedad parasitaria del sistema nervioso central provocada por la larva de Taenia solium, denominada Cysticercus cellulosae. Es una enfermedad universal, endémica en países de Latinoamérica y Asia. En 1993, en la provincia de Buenos Aires se comunicaron 11 casos de neurocisticercosis en pacientes adultos, 8 provenientes de Bolivia y 3 del interior de nuestro país. En la Argentina, los casos pediátricos comunicados son oriundos de países limítrofes o del interior del país. El propósito del presente artículo es presentar el primer caso pediátrico autóctono, con fuente de contagio local en la Ciudad de Buenos Aires y alertar sobre la posibilidad de que una región como ésta, ingrese dentro del área endémica, producto de los movimientos migratorios internos y externos, y del asentamiento de portadores de la parasitosis en el perímetro urbano.

The mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. The prenatal and early postnatal diagnosis can only be achieved by serological testing. Serologic tests have different sensitivities, specificities and complexities, so that different tests in more than one blood sample are necessary for the diagnosis. Serological follow-up of the infants should be conducted during the first year of life or until the diagnosis of congenital toxoplasmosis can be ruled out. Treatment recommendations try to reduce the transmission rate and the risk of congenital damage. Congenital toxoplasmosis incidence rate is approximately 5 per 1000 births, but can be reduced to 0.5 per 1000 with an active screening program. The aim of this consensus group was to review the scientific literature on congenital toxoplasmosis and prepare a statement on prevention, diagnosis and treatment that should be implemented in our country.

La transmisión de la infección por Toxoplasma gondii de la madre al hijo ocurre cuando la madre se infecta por primera vez en el transcurso del embarazo. Tanto el diagnóstico prenatal, como el del primer año de vida se basa en pruebas serológicas; y la mayoría de las veces es necesario realizar más de una de estas pruebas ya que tienen distintos porcentajes de sensibilidad y/o especificidad así como distintos niveles de complejidad. El recién nacido requiere seguimiento serológico en el primer año de vida o hasta que se descarte el diagnóstico de toxoplasmosis congénita. El diagnóstico temprano de la infección, en la mujer embarazada, permite un tratamiento oportuno y se indica con el propósito de reducir la tasa de transmisión y el daño congénito. Es posible que con un programa activo, de prevención y tratamiento temprano, se pueda reducir la tasa de incidencia de la toxoplasmosis congénita de alrededor del 5 por mil nacimientos a 0.5 por mil. El objetivo de este consenso fue revisar la literatura científica para la prevención, el diagnóstico y el tratamiento de la toxoplasmosis congénita, para que se pueda implementar en nuestro país.

The presence of circulating immune complexes formed by IgM and IgG (CIC-IgM and CIC-IgG) was investigated, using antigen-specific enzyme-immunoassays (ELISA), in 30 patients with acute Chagas' disease who showed parasitemia and inoculation chagoma. Control population consisted of patients with chronic T. cruzi infection (30), acute toxoplasmosis 10), leishmaniasis (8), rheumatoid arthritis (3) and healthy individuals with negative serology for Chagas* disease (30). Acute chagasic patients were 100% CIC-IgG and 96.66% CIC-IgM positive whereas immunofluorescence tests yielded 90% and 86.66% of positivity for specific IgG and IgM antibodies, respectively. Chronic patients were 68% CIC-IgG and 0% CIC-IgM positive. The 30 negative and the 21 cross-reaction controls proved negative for ELISA (CIC-IgM and CIC-IgG). The high sensitivity of ELISA assays would allow early immunologic diagnosis, as well as prompt treatment, of acute T. cruzi infection, thus eliminating the problem of the false-positive and false-negative results which affects traditional methods for detection of circulating antibodies.

Se investigo la presencia de complejos inmunes circulantes formados por IgM e IgG (CIC-IgM y CIC-IgG), utilizando enzimoinmu-noensayos ELISA) antígeno-específicos, en 30 pacientes con enfermedad de Chagas aguda que presentaban parasitemia y chagoma de inocu-lación. La población control estaba formada por pacientes con infección crônica por T. cruzi (30), toxoplasmosis aguda (10), leishmaniasis (8), artritis reumatoidea (3) e individuos sanos con serología negativa para Chagas (30). Los pacientes chagásicos agudos fueron 100% CIC-IgG y 96,66% CIC-IgM positivos, mientras que Ias pruebas de inmunofluorescencia para anti-cuerpos específicos de tipo IgG e IgM mostra-ron 90% y 86,66% de positividad, respectivamente. Los pacientes crônicos fueron 68% CIC-IgG y 0% CIC-IgM positivos. El resto de los controles arrojaron resultados negativos por ELISA CIC-IgM y CIC-IgG). La alta sensibilidad dei ELISA permitiria un diagnóstico inmunológico temprano, como así también un tra-tamiento inmediato, de la infeccin aguda por T. cruzi, eliminando así el problema de resultados falsos-positivos y falsos-negativos que afecta a los métodos tradicionales para detección de anticuerpos circulantes.