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.

Chagas disease or American trypanosomiasis is, together with geohelminths, the neglected disease that causes more loss of years of healthy life due to disability in Latin America. Chagas disease, as determined by the factors and determinants, shows that different contexts require different actions, preventing new cases or reducing the burden of disease. Control strategies must combine two general courses of action including prevention of transmission to prevent the occurrence of new cases (these measures are cost effective), as well as opportune diagnosis and treatment of infected individuals in order to prevent the clinical evolution of the disease and to allow them to recuperate their health. All actions should be implemented as fully as possible and with an integrated way, to maximise the impact. Chagas disease cannot be eradicated due because of the demonstrated existence of infected wild triatomines in permanent contact with domestic cycles and it contributes to the occurrence of at least few new cases. However, it is possible to interrupt the transmission ofTrypanosoma cruziin a large territory and to eliminate Chagas disease as a public health problem with a dramatic reduction of burden of the disease.

O objetivo foi detectar a infecção do Trypanosoma cruzi em 32 crianças nacidas de 16 jovens mulheres cronicamente infectadas e tratadas com benzinadol, em Salta, Argentina. Testes foram feitos para avaliar a eficácia após 14 anos do tratamento. Ao final do seguimento 87.5% das mulheres foram não reativas ao EIA, 62.5% ao IHA e 43.8% ao IFA. 62.5% das mulheres foram não reativas de acordo a 3 ou 2 testes serológicos. Nenhuma criança infectada foi detectada entre os recém-nascidos de mães tratadas antes da gravidez.

The objective was to detect Trypanosoma cruzi infection in 32 children in Salta, Argentina, born to 16 chronically infected young women who were treated with benznidazole. Tests were performed to assess the efficacy of treatment after 14 years. At the end of the follow up, 87.5% of the women were non-reactive to EIA tests, 62.5% to IHA and 43.8% to IFA. 62.5% of the women were non-reactive according to two or three serological tests. No infected children were detected among the newborns of mothers treated before their pregnancy.

The purpose of this review is to describe research findings regarding chronic Chagas disease in Argentina that have changed the standards of care for patients with Trypanosoma cruzi infection. Indirect techniques (serological tests) are still the main tools for the primary diagnosis of infection in the chronic phase, but polymerase chain reaction has been shown to be promising. The prognosis of patients with heart failure or advanced stages of chagasic cardiomyopathy is poor, but a timely diagnosis during the initial stages of the disease would allow for prescription of appropriate therapies to offer a better quality of life. Treatment of T. cruzi infection is beneficial as secondary prevention to successfully cure the infection or to delay, reduce or prevent the progression to disease and as primary disease prevention by breaking the chain of transmission. Current recommendations have placed the bulk of the diagnostic and treatment responsibility on the Primary Health Care System. Overall, the current research priorities with respect to Chagas disease should be targeted towards (i) the production of new drugs that would provide a shorter treatment course with fewer side effects; (ii) the development of new tools to confirm cure after a full course of treatment during the chronic phase and (iii) biomarkers to identify patients with a high risk of developing diseases.

OBJECTIVE: To assess the seroprevalence, household risk factors, and entomological indicators, in order to frame control measures in 11 Sanitary Jurisdictions of the state. MATERIAL AND METHODS: This study included 281 towns, 2 526 households, and 9782 individuals. Data were collected using a questionnaire. Blood was obtained in filter paper and a search for triatomines was conducted inside of and around dwellings. Prevalence rates were used to quantify exposure to risk factors and seropositivity. Odds ratios with 95% confidence intervals and Mantel-Haenszel chi-squared tests were obtained. Multivariate analysis was performed with unconditional logistic regression, variables included in the model were those that had a p-value up to 0.20 in the bivariate analysis. The etiologic fraction in the exposed was also obtained. RESULTS: The prevalence of Chagas disease was between 0 and 2.8%. Jurisdictions at a higher risk were Tuxpan, Panuco and Cordoba; Orizaba showed no risk. The main household risk factors were palma/zacate (palmtree, grass leaves) roof and walls, dirt floor, the presence of the vector, and ventilation. CONCLUSIONS: Epidemiological surveillance should emphasize health education, housing improvement, and use of insecticides.

OBJETIVO: Identificar la seroprevalencia de enfermedad de Chagas, los factores de riesgo de la vivienda e índices entomológicos, para proponer medidas de control en 11 jurisdicciones sanitarias del estado de Veracruz. MATERIAL Y MÉTODOS: Entre 1997 y 2001 se hizo un estudio transversal cuya muestra quedó integrada por 281 localidades, 2 526 viviendas y 9 782 individuos. Se aplicó un cuestionario sobre factores de riesgo, se tomó sangre en papel filtro y se buscaron triatominos en el intra y peridomicilio. Se obtuvo la prevalencia de exposición a factores de riesgo y de seropositividad para la enfermedad. Se hizo análisis bivariado mediante la razón de momios, ji de Mantel y Haenszel e intervalo de confianza a 95% como prueba de significancia estadística. El análisis multivariado se hizo mediante la regresión logística no condicional y se incluyeron las variables que durante el análisis bivariado mostraron un valor de p hasta de 0.20. El impacto potencial se estimó con base en la fracción etiológica en expuestos. RESULTADOS: La prevalencia de enfermedad de Chagas fluctuó entre 0 y 2.8%. Las jurisdicciones con mayor riesgo fueron Tuxpan, Pánuco y Córdoba, y sin riesgo, Orizaba. Los principales factores de riesgo de la vivienda fueron el techo y muro de palma/zacate y piso de tierra, así como la presencia del vector y la ventilación. CONCLUSIONES: Es necesario realizar vigilancia epidemiológica basada en educación para la salud, mejoramiento de la vivienda y uso de insecticidas.

OBJECTIVE: To assess the seroprevalence, household risk factors, and entomological indicators, in order to frame control measures in 11 Sanitary Jurisdictions of the state. MATERIAL AND METHODS: This study included 281 towns, 2 526 households, and 9782 individuals. Data were collected using a questionnaire. Blood was obtained in filter paper and a search for triatomines was conducted inside of and around dwellings. Prevalence rates were used to quantify exposure to risk factors and seropositivity. Odds ratios with 95% confidence intervals and Mantel-Haenszel chi-squared tests were obtained. Multivariate analysis was performed with unconditional logistic regression, variables included in the model were those that had a p-value up to 0.20 in the bivariate analysis. The etiologic fraction in the exposed was also obtained. RESULTS: The prevalence of Chagas disease was between 0 and 2.8%. Jurisdictions at a higher risk were Tuxpan, Panuco and Cordoba; Orizaba showed no risk. The main household risk factors were palma/zacate (palmtree, grass leaves) roof and walls, dirt floor, the presence of the vector, and ventilation. CONCLUSIONS: Epidemiological surveillance should emphasize health education, housing improvement, and use of insecticides.

OBJETIVO: Identificar la seroprevalencia de enfermedad de Chagas, los factores de riesgo de la vivienda e índices entomológicos, para proponer medidas de control en 11 jurisdicciones sanitarias del estado de Veracruz. MATERIAL Y MÉTODOS: Entre 1997 y 2001 se hizo un estudio transversal cuya muestra quedó integrada por 281 localidades, 2 526 viviendas y 9 782 individuos. Se aplicó un cuestionario sobre factores de riesgo, se tomó sangre en papel filtro y se buscaron triatominos en el intra y peridomicilio. Se obtuvo la prevalencia de exposición a factores de riesgo y de seropositividad para la enfermedad. Se hizo análisis bivariado mediante la razón de momios, ji de Mantel y Haenszel e intervalo de confianza a 95% como prueba de significancia estadística. El análisis multivariado se hizo mediante la regresión logística no condicional y se incluyeron las variables que durante el análisis bivariado mostraron un valor de p hasta de 0.20. El impacto potencial se estimó con base en la fracción etiológica en expuestos. RESULTADOS: La prevalencia de enfermedad de Chagas fluctuó entre 0 y 2.8%. Las jurisdicciones con mayor riesgo fueron Tuxpan, Pánuco y Córdoba, y sin riesgo, Orizaba. Los principales factores de riesgo de la vivienda fueron el techo y muro de palma/zacate y piso de tierra, así como la presencia del vector y la ventilación. CONCLUSIONES: Es necesario realizar vigilancia epidemiológica basada en educación para la salud, mejoramiento de la vivienda y uso de insecticidas.

We assessed the distribution of Trypanosoma cruzi infection in peridomestic triatomines collected manually at a district-wide scale in rural villages around Olta, Western Argentina, and typed the isolated strains according to their pathogenicity to laboratory mice. Of 1623 triatomines examined, only 14 (0.9%) were infected with T. cruzi based on microscopical examination of feces. The prevalence of T. cruzi infection was 0.8% in Triatoma infestans, 2.3% in T. guasayana, and nil in T. garciabesi, T. platensis, and T. eratyrusiformis. Local transmission occurred in kitchens, store-rooms and goat corrals or nearby, though at very low levels. T. cruzi was detected by at least one parasitological method in 11 (79%) of 14 microscope-positive bugs. Hemoculture was the most sensitive method (67%) followed by culture of organ homogenates, histopathology or xenodiagnosis of inoculated suckling mice (55-58%), and culture of microscope-positive bug feces (46%). The evidence suggests that most of the isolated T. cruzi strains would be myotropic type III. Our study establishes for the first time that peridomestic, microscope-positive T. guasayana nymphs were actually infected with T. cruzi, and may be implicated as a putative secondary vector of T. cruzi in domestic or peridomestic sites.

OBJECTIVE: To compare the effectiveness of a single residual spraying of pyrethroids on the occurrence and abundance of Triatoma infestans in peridomestic ecotopes in rural La Rioja. METHODS: A total of 667 (32.8%) peridomestic sites positive for T. infestans in May 1999 were randomly assigned to treatment within each village, sprayed in December 1999, and reinspected in December 2000. Treatments included 2.5% suspension concentrate (SC) deltamethrin in water at 25 mg active ingredient (a.i.)/m² applied with: (a) manual compression sprayers (standard treatment) or (b) power sprayers; (c) 1.5% emulsifiable concentrate (EC) deltamethrin at 25 mg a.i./m²; and (d) 10% EC cis-permethrin at 170 mg a.i./m². EC pyrethroids were diluted in soybean oil and applied with power sprayers. All habitations were sprayed with the standard treatment. FINDINGS: The prevalence of T. infestans 1-year post-spraying was significantly lower in sites treated with SC deltamethrin applied with manual (24%) or power sprayers (31%) than in sites treated with EC deltamethrin (40%) or EC permethrin (53%). The relative odds of infestation and catch of T. infestans 1-year post-spraying significantly increased with the use of EC pyrethroids, the abundance of bugs per site before spraying, total surface, and host numbers. All insecticides had poor residual effects on wooden posts. CONCLUSION: Most of the infestations probably originated from triatomines that survived exposure to insecticides at each site. Despite the standard treatment proving to be the most effective, the current tactics and procedures fail to eliminate peridomestic populations of T. infestans in semiarid rural areas and need to be revised.

OBJETIVO: Comparar la efectividad de un único rociamiento de acción residual de piretroides contra la presencia y abundancia de Triatoma infestans en ecotopos peridomésticos en La Rioja rural. MÉTODOS: Un total de 667 (32,8%) sitios peridomésticos positivos para T. infestans en mayo de 1999 fueron asignados aleatoriamente a tratamiento dentro de cada aldea, rociados en diciembre de 1999, y reinspeccionados en diciembre de 2000. Las opciones de tratamiento fueron una suspensión concentrada (SC) de deltametrina al 2,5% en agua a razón de 25 mg ai/m² aplicada mediante: (a) pulverizadores manuales de compresión (tratamiento ordinario) o (b) pulverizadores eléctricos; (c) un concentrado emulsionable (CE) al 1,5% de deltametrina a 25 mg ai/m²; y (d) un CE al 10% de cis-permetrina a 170 mg ai/m². Los CE de piretroides se diluyeron en aceite de soja y se aplicaron con pulverizadores eléctricos. Todas las viviendas se rociaron aplicando el tratamiento ordinario. RESULTADOS: La prevalencia de T. infestans al cabo de un año del rociamiento fue significativamente menor en los sitios tratados con SC de deltametrina aplicada con pulverizadores manuales (24%) o eléctricos (31%) que en los sitios tratados con CE de deltametrina (40%) o CE de permetrina (53%). Las posibilidades relativas de infestación y captura de T. infestans al cabo de un año del rociamiento aumentaban sensiblemente con el uso de CE de piretroides, la abundancia de insectos por sitio antes del rociamiento, la superficie total y el número de huéspedes. Todos los insecticidas tuvieron un escaso efecto residual en los postes de madera. CONCLUSIÓN: La mayoría de las infestaciones se debieron probablemente a triatominos que sobrevivieron a la exposición a los insecticidas en cada sitio. A pesar de que el tratamiento ordinario demostró ser el más eficaz, los procedimientos y tácticas actuales no logran eliminar las poblaciones peridomésticas de T. infestans en las zonas rurales semiáridas, y deberían por tanto ser revisados.

OBJECTIF: Comparer l'efficacité d'une pulvérisation rémanente unique de pyréthrinoïdes sur la présence et l'abondance de Triatoma infestans dans les écotopes péridomestiques du district rural de La Rioja. MÉTHODES: Un total de 667 sites péridomestiques (soit 32,8 %) où la présence de T. infestans avait été décelée en mai 1999 ont été tirés au sort dans chacun des villages pour être traités; la pulvérisation a eu lieu en décembre 1999, et ils ont été de nouveau inspectés en décembre 2000. Le traitement était le suivant : suspension concentrée à 2,5 % de deltaméthrine dans l'eau, épandue à la dose de 25 mg de substance active /m², appliquée au moyen : a) d'un pulvérisateur à pression préalable actionné manuellement (traitement classique) ou b) d'un pulvérisateur à moteur ; c) concentré émulsifiable à 1,5 % de deltaméthrine, épandu à la dose de 25 mg de substance active /m² ; d) concentré émulsifiable à 10 % de cis-perméthrine, épandu à la dose de 170 mg de substance active /m². Les concentrés émulsifiables de pyréthrinoïdes ont été dilués dans l'huile de soja et épandus au moyen de pulvérisateurs à moteur. Dans toutes les habitations l'épandage a été fait selon la méthode classique. RÉSULTATS: Un an après la pulvérisation, la fréquence de T. infestans était nettement plus faible dans les sites traités par la deltaméthrine en suspension concentrée appliquée manuellement (24 %) ou au moyen de pulvérisateurs à moteurs (31 %) que dans les sites traités par le concentré émulsifiable de deltaméthrine (40 %) ou de perméthrine (53 %). Un an après la pulvérisation, la probabilité relative d'infestation ou de capture de T. infestans était nettement augmentée par les facteurs suivants : utilisation d'une concentré émulsifiable de pyréthrinoïde, abondance des triatomes sur le site avant pulvérisation, surface totale et nombre d'hôtes. Tous les insecticides avaient peu d'effet rémanent sur les poteaux en bois. CONCLUSION: La plupart des infestations sont probablement dues à des triatomes qui ont survécu à l'exposition aux insecticides dans chacun des sites. Même si le traitement classique se révèle être le plus efficace, la stratégie et les méthodes actuelles ne parviennent pas à éliminer les populations péridomestiques de T. infestans en milieu rural semi-aride ; elles devront être révisées.

A multicenter, randomized, triple blind and controlled trial was designed to determine whether the combination with thioctic acid (TA), an antioxidant agent, can reduce the intolerance rate to Benznidazol (BZ) in patients infected with Trypanosoma cruzi. Four regimens were assigned randomly for 3 age intervals, administrating placebo or TA orally at daily doses of 50 to 100 mg in association with BZ at a dose of 5 mg/k/day for 30 days. In some, medication was given during a run-in period. Safety controls were carried out on days 10, 20, 37 and 52 days after therapy initiation. A total of 249 patients between 15 and 44 years old were enrolled. At the end of the trial, 70.3% of the patients had completed the treatment, while 17.7% required its suspension due to BZ related adverse reactions. The proportion of individuals affected with at least one side effect ranged from 54.8% to 58%; however, none were serious. Reported side effects included: cutaneous maculopapular rush (28%), pruritus (13.6%), headache (8%), epigastralgia (6.2%), fever (6.2%), fatigue (4.3%), nausea (4%), myalgias (4.3%), others (21.5%). The incidence of these reactions did not differ significantly among the 4 therapeutic regimens, nor even among the age intervals considered. It can be concluded that the association with TA did not prevent the occurrence of adverse reactions related to BZ administration. However, a single month cycle of this parasiticide permitted a high compliance rate to therapy among infected outpatients.

Se realizó un ensayo clínico controlado, multicéntrico, a triple ciego, para evaluar si el tratamiento oral combinado del ácido tióctico (AT), reduce la incidencia de los efectos secundarios asociados al tratamiento con benznidazol (BZ) en pacientes infectados con Trypanosoma cruzi. Cuatro esquemas fueron asignados al azar pareados por edad, administrando placebo o AT por vía oral a razón de 50-100 mg día a dosis e intervalos variables (con y sin período pre-inducción) en combinación con BZ a dosis de 5 mg/kg/día por 30 días. Se realizaron evaluaciones en los días 10, 20, 37 y 52 de iniciado el tratamiento. Fueron enrolados 249 pacientes con edades entre 15 y 44 años. El 70.3% de los pacientes completó el tratamiento y el 17.7% restante debió suspender la medicación por causas relacionadas al BZ. La proporción de personas afectadas por al menos un efecto adverso, fue semejante entre los 4 grupos: entre 54.8 y 58%, aunque en ninguno de ellos resultó de carácter grave. Las manifestaciones clínicas adversas fueron: exantema morbiliforme (28%); prurito (13.6%); cefalea (8%); epigastralgia (6.2%); fiebre (6.2%); astenia (4.3%); náuseas (4.0%); mialgias (4.3%); vómitos (3.2%); otros (21.5%). La incidencia de experiencias adversas no difirió significativamente entre los 4 esquemas terapéuticos, ni entre los diferentes intervalos de edad de los pacientes. La asociación con ácido tióctico no demostró prevenir las manifestaciones de intolerancia a este agente. No obstante, la administración de BZ en un ciclo mensual único a pacientes infectados logró una elevada tasa de adherencia al tratamiento ambulatorio.

Este trabalho tem como objetivo avaliar fatores considerados de risco para adquirir leishmaniose cutânea em Salta, área de maior transmissão da Argentina. Aplicou-se um estudo de caso-coorte com observações entre junho de 1989 e dezembro de 1992. Aos casos e aos controles selecionados se realizou: a) um questionário sócio-demográfico; b) descrição das características da vivenda e peridomicílio; c) um exame físico de pele e mucosa nasal e bucal; d) intradermorreação de Montenegro. A análise multivariada mostrou um risco significativo para fatores extradomiciliares (realizar atividades de vaqueira, dormir no lugar de trabalho, ir caçar) e domiciliares (dormir fora do quarto, presença de três ou mais suínos no quintal da casa e existência de janelas sem fechaduras). Esta associação permitiu pela primeira vez em Salta (Argentina), identificar fatores de risco vinculados com a transmissão de leishmaniose na unidade domiciliária.

The objective of this work was evaluate risk factors for acquiring cutaneous leishmaniasis in Salta, the region with the greatest indices of transmission in Argentina. A Case-cohort study was realized from June 1989 to December 1992. The procedures performed on cases and controls included: a) socio-demographic questionnaire; b) domestic and peridomestic environment description; c) physical exam of skin and nasal and oral mucosal; d) Montenegro Skin Test. Multivariate analysis showed a significant risk for factors outside the home (cattle management, hunting, sleeping at the work place) and while at home (sleeping outside of the bedroom, presence of three or more pigs in the yard and windows that cannot be locked in the closed position). This association allowed the identification of risk factors linked to the transmission of leishmaniasis in the home for the first time in Salta (Argentina).

Factors related to the characteristics of Hantavirus pulmonary syndrome in Argentina are described. Factors from different scientific fields converge to form the syndrome's analytical framework. Some of these factors are the history of spatial occupation, work and production structures, human migration patterns, ethnic composition, reservoir dynamics and its relationship to the different circulating viruses, and human behavior. Furthermore, the multiple factors are expressed in three ecological frameworks, associated with three different geographical regions of Argentina: 1) Northwest; 2) Central ("wet Pampa"); and 3) South Andean. In order to understand the actual causality of health or disease as an interaction of many factors, research on the primary biological, social, and environmental determinants of diseases should attend to the complexity of variable relationships in each region. The multiple-factor convergence approach allows for the design of appropriate strategies to improve the population's health status. Therefore, strategies should be developed and transferred by multidisciplinary teams, while their sustainability should be assured by community participation beginning with the earliest steps of research onward.

Se describen algunos factores que habrían favorecido a caracterizar la expresión del Síndrome Pulmonar por Hantavirus en Argentina. Estos factores muestran diversos orígenes que van desde los procesos de ocupación del espacio y de producción, la estructura laboral, el patrón de migración humana, la etnia, la dinámica de reservorios y su relación con los tipos de virus, y el comportamiento del hombre. Estos factores se expresan en tres marcos ecológicos asociados a diferentes regiones geográficas de Argentina: 1) Noroeste, 2) Central (Pampa húmeda) y 3) Sur Andina. Este complejo escenario obliga a abordar con la misma complejidad las investigaciones, para identificar determinantes primarios, biológicos, sociales y ambientales, causales de salud o enfermedad en su estrecha interacción y no individualmente. Este abordaje permitirá diseñar estrategias apropiadas para mejorar las condiciones de salud. Las mismas deberían ser diseñadas y transferidas por equipos transdisciplinarios de investigación, donde la participación de la comunidad desde las primeras etapas de desarrollo es esencial para la sustentabilidad de la estrategia.

Factors related to the characteristics of Hantavirus pulmonary syndrome in Argentina are described. Factors from different scientific fields converge to form the syndrome's analytical framework. Some of these factors are the history of spatial occupation, work and production structures, human migration patterns, ethnic composition, reservoir dynamics and its relationship to the different circulating viruses, and human behavior. Furthermore, the multiple factors are expressed in three ecological frameworks, associated with three different geographical regions of Argentina: 1) Northwest; 2) Central ("wet Pampa"); and 3) South Andean. In order to understand the actual causality of health or disease as an interaction of many factors, research on the primary biological, social, and environmental determinants of diseases should attend to the complexity of variable relationships in each region. The multiple-factor convergence approach allows for the design of appropriate strategies to improve the population's health status. Therefore, strategies should be developed and transferred by multidisciplinary teams, while their sustainability should be assured by community participation beginning with the earliest steps of research onward.

Se describen algunos factores que habrían favorecido a caracterizar la expresión del Síndrome Pulmonar por Hantavirus en Argentina. Estos factores muestran diversos orígenes que van desde los procesos de ocupación del espacio y de producción, la estructura laboral, el patrón de migración humana, la etnia, la dinámica de reservorios y su relación con los tipos de virus, y el comportamiento del hombre. Estos factores se expresan en tres marcos ecológicos asociados a diferentes regiones geográficas de Argentina: 1) Noroeste, 2) Central (Pampa húmeda) y 3) Sur Andina. Este complejo escenario obliga a abordar con la misma complejidad las investigaciones, para identificar determinantes primarios, biológicos, sociales y ambientales, causales de salud o enfermedad en su estrecha interacción y no individualmente. Este abordaje permitirá diseñar estrategias apropiadas para mejorar las condiciones de salud. Las mismas deberían ser diseñadas y transferidas por equipos transdisciplinarios de investigación, donde la participación de la comunidad desde las primeras etapas de desarrollo es esencial para la sustentabilidad de la estrategia.

O trabalho mostra o padrão epidemiológico da leishmaniose tegumentar em uma área no norte de Salta, Argentina. A prevalência e incidência foram estimadas através de um estudo transversal e dois estudos de seguimento durante dois anos consecutivos. A Intrademorreação de Montenegro (IDRM) foi aplicada a 7.336 pessoas no estudo de base. A prevalência e incidência entre 1990 e 1992 da infecção (IDRM reativa) foi de 38‰ pessoas e 4,5‰ pessoas/ano respectivamente. O exame físico realizado em 264 pacientes com IDRM reativa durante 3 anos, revelaram que apenas 130 casos (49,2%) tiveram algum signo evidente de infecção (cicatriz ou lesão), com uma apresentação clínica compatível a leishmaniosis. Nosso trabalho mostrou que após o surto epidêmico em 1985, a transmissão na área de estudo retornou aos níveis endêmicos em 1992, e também demonstrou a presença da infecção assintomática na região.

This work describes the epidemiological pattern of tegumentary leishmaniasis in an area north of Salta, Argentina. The prevalence and incidence were estimated by means of a cross-sectional study and two follow-up studies during two consecutive years. The Montenegro Skin Test (MST) was administered to 7336 subjects at baseline. The prevalence and incidence between 1990 and 1992 of infection (MST reactive) was 38‰ persons and 4.5‰ persons/year respectively. The prevalence and incidence of tegumentary leishmaniasis (presence of clinical signs) was 1.8‰ and 0.8‰ persons/year, respectively. A physical examination performed on 264 patients with MST reactive during three years revealed that 130 cases (49.2%) had some evident sign of infection (scar and/or lesion), with a clinical presentation compatible with leishmaniasis. Our study demonstrated that after the epidemic outbreak of 1985 the transmission in the study area returned to endemic levels in 1992, and also demonstrated the presence of the asymptomatic infection in the area.

A quality assurance program of the Chagas' disease laboratory network of Argentina has been conducted by the National Reference Center since 1988, with the aim of assessing the reliability of serologic test results. Chagas' disease is endemic in Argentina, but the prevalence of seropositivity for Trypanosoma cruzi among 18- to 20-year-old men decreased from 5.8% in 1981 to 1.8% in 1994. About 600 laboratories form the Chagas' disease laboratory network, with main central laboratories in each of the 24 provinces in Argentina. The quality assurance program promotes regular use of good laboratory practice and internal and external quality control to improve performance of the participants; it also provides technical assistance and guidelines. Eventual corrective measures are discussed in workshops. Results of the first external evaluation by proficiency testing of serum panels and confirmation of results for 58 of the main laboratories reveal that from 1988 to 1994 the rate of agreement has increased.

El Centro Nacional de Referencia ha llevado a cabo desde 1988 un programa de garantía de calidad en la red de laboratorios para el diagnóstico de la enfermedad de Chagas en Argentina. El propósito ha sido evaluar la confiabilidad de los resultados de la prueba serológica. La enfermedad de Chagas es endémica en Argentina, pero la prevalencia de seropositividad a Trypanosoma cruzi en hombres de 18 a 24 años bajó de 5,8% en 1981 a 1,8% en 1994. Alrededor de 600 laboratorios forman la red para el diagnóstico de la enfermedad de Chagas, que cuenta con un laboratorio central en cada una de las 24 provincias argentinas. El programa para la garantía de la calidad promueve la aplicación continua de las buenas prácticas de laboratorio y se vale de controles de calidad internos y externos para mejorar el rendimiento de los participantes. También provee asistencia técnica y sienta parámetros normativos. Cualquier enmienda que resulte necesaria se discute en talleres de trabajo. Los resultados de la primera evaluación externa en que investigó la exactitud de las pruebas serológicas y la confirmación de los resultados obtenidos en 58 de los principales laboratorios revelan que de 1988 a 1994 la tasa de concordancia mejoró.