ABSTRACT INTRODUCTION During the summer of 2016 different outbreaks of dengue fever occurred in Argentina, and the city of Santo Tomé (Corrientes) had its first one. The objective of this work was to evaluate temporal and spatial distribution of dengue cases registered in the city as well as the actions carried out to interrupt the transmission. METHODS Suspected cases were detected by health personnel, samples confirmed by serological analysis and each positive case georeferenced and classified as autochthonous or imported. The prevention actions were larval block; focal control and spatial spraying; evaluation of larvicides; elimination of water reservoirs; meetings, training and neighborhood assemblies. RESULTS From 148 suspected patients, 52 were confirmed between epidemiological week 3 and 22. The circulating strain was DENV 1. Forty-six percent (24/52) of the cases were autochthonous, concentrated in Sarmiento neighborhood. Twenty-one percent (140/655) of the houses had mosquitoes breeding sites, of which 84 percent (210/251) were positive for Ae. aegypti. DISCUSSION Santo Tomé city had all the conditions for dengue outbreak: susceptible population, presence of the vector and arrival of imported cases. Although the distribution of cases was homogeneous throughout the outbreak, Sarmiento neighborhood showed a clear viral circulation, which was controlled through an interdisciplinary work for action and prevention.

RESUMEN INTRODUCCIÓN Argentina sufrió diferentes brotes de dengue en las reglones más cálidas durante el verano de 2016. En la ciudad de Santo Tomé (Corrientes) se produjo el primer brote. En este marco, el objetivo del trabajo fue evaluar la distribución temporal y espacial de los casos de dengue en Santo Tomé, así como las acciones adoptadas para interrumpir la transmisión. MÉTODOS Los casos sospechosos fueron detectados por el personal sanitario, se confirmaron las muestras por análisis serológico y se georreferenció cada caso positivo, que fue clasificado como autóctono o importado. Las acciones de prevención fueron: bloqueo larval; control focal y rociado espacial; evaluación de larvicidas; descacharrado; charlas, capacitaciones y asamblea barrial. RESULTADOS De 148 pacientes sospechosos se confirmaron 52 entre las semanas epidemiológicas 3 y 22. La cepa circulante fue DENV 1. El 46% (24/52) de los casos fueron autóctonos y se concentraron en el barrio Sarmiento. El 21% (140/655) de las viviendas presentaron criaderos de culícidos, de los cuales el 84% (210/251) resultó positivo para Ae. aegypti. DISCUSIÓN Santo Tomé tuvo todas las condiciones para que se registrara el brote de dengue: población susceptible, presencia del vector y arribo de casos importados. Si bien la distribución de casos fue homogénea durante todo el brote, en el barrio Sarmiento se vio una clara circulación viral, que pudo ser controlada mediante una tarea interdisciplinaria de acción y prevención.

ABSTRACT INTRODUCTION Rickettsiosis, ehrlichiosis and anaplasmosis are caused by obligate intracellular gram-negative bacteria and transmitted by arthropods emerging vector borne diseases. The aim of this work was to determine the species of ticks present in canines of the city of Pergamino and to detect the presence of pathogens from the genera Ehrlichia, Anaplasma and Rickettsia. METHODS A total of 21 Rhipicephalus sanguineus s.l ticks were studied, obtained from canines from different environments of the city of Pergamino. The samples were analyzed by PCR for Rickettsia spp. (gene gltA) and for the genera Ehrlichia/Anaplasma (gene 16sRNA). RESULTS Positivity was detected for Rickettsia spp. in 4.76% of the ticks, being identified by sequencing as Rickettsia massiliae. For the Anaplasmataceae family, positivity was detected for Ehrlichia canis (23.8%) and Anaplasma platys (19.04%). CONCLUSIONS This is the first report on pathogens of zoonotic/veterinary interest belonging to the genera Ehrlichia, Anaplasma and Rickettsia, on Rh. sanguineus s.l ticks in the north of the province of Buenos Aires.

RESUMEN INTRODUCCIÓN Las rickettsiosis, ehrlichiosis y anaplasmosis son causadas por bacterias gramnegativas intracelulares obligadas y transmitidas por artrópodos. El objetivo de este trabajo fue determinar especies de garrapatas presentes en caninos de la ciudad de Pergamino y detectar presencia de patógenos de los géneros Ehrlichia, Anaplasma y Rickettsia. MÉTODOS Se estudiaron 21 garrapatas Rhipicephalus sanguineus s.l obtenidas de caninos de diferentes ambientes de la ciudad de Pergamino. Las muestras fueron analizadas mediante PCR, amplificando un fragmento del gen gltA para Rickettsia spp. y del 16SrRNA para los géneros Ehrlichia/Anaplasma. RESULTADOS Se detectó positividad a Rickettsia spp. en el 4,76%, identificándose por secuenciación a la especie Rickettsia massiliae. Para la familia Anaplasmataceae se detectó positividad para Ehrlichia canis (23,8%) y Anaplasma platys (19,04%). CONCLUSIONES Se trata del primer reporte de patógenos de interés zoonótico y/o veterinario pertenecientes a los géneros Rickettsia, Ehrlichia y Anaplasma en garrapatas Rh. sanguineus s.l para el norte de la provincia de Buenos Aires.

ABSTRACT The Asian tiger mosquito ( Aedes albopictus, Diptera: Culicidae) has spread rapidly in the last 30 years from its native region in Southeast Asia. In Argentina, studies on its potential distribution suggest that this species could be found in temperate zones of the province of Buenos Aires. However, since its initial detection in 1998 Ae. albopictus is bounded to the subtropical province of Misiones. To evaluate the presence and abundance of Ae. albopictus in the Northeast of Argentina, we preliminarily evaluated the presence of this vector by analyzing its presence in tires of 20 cities belonging to the province of Misiones and four cities in Northern Corrientes, and then performed an evaluation of the vector in the towns where the vector was detected. Aedes albopictus was present only in two cities of Misiones: Eldorado and Colonia Aurora. Aedes aegypti and Ae . albopictus accounted for 86% of the individuals collected in the domiciles of both towns. In Colonia Aurora both species were in similar abundances suggesting a co-dominance. The present study extends the austral distribution of Ae. albopictus in Argentina to the city of Colonia Aurora where the highest abundance recorded in Argentina was detected. Nevertheless, the reasons of its bounded distribution in the region are not known.

ABSTRACT The objective of this study was to evaluate the presence of Lutzomyia longipalpis in the Argentine city of Concordia, in the province of Entre Rios, without record of this species despite previous samplings, but with canine cases of visceral leishmaniasis and Lu. longipalpis reports both, from Northern Argentine localities and from the city of Salto, Uruguay, located just across the river and the international border. This study confirms the presence of Lu. longipalpis and Nyssomyia whitmani, related to the risk of visceral and tegumentary leishmaniasis, respectively, in Concordia-Entre Rios. The presence of Lu. longipalpis confirms the ongoing dispersal along the Uruguay river basin. The presence of these species in the study area alerts about the risk of transmission of Leishmania spp.

BACKGROUND Visceral leishmaniasis (VL) is an endemic disease in northeastern Argentina including the Corrientes province, where the presence of the vector and canine cases of VL were recently confirmed in December 2008. OBJECTIVES The objective of this study was to assess the modelling of micro- and macro-habitat variables to evaluate the urban environmental suitability for the spatial distribution of Lutzomyia longipalpis presence and abundance in an urban scenario. METHODS Sampling of 45 sites distributed throughout Corrientes city (Argentina) was carried out using REDILA-BL minilight traps in December 2013. The sampled specimens were identified according to methods described by Galati (2003). The analysis of variables derived from the processing of satellite images (macro-habitat variables) and from the entomological sampling and surveys (micro-habitat variables) was performed using the statistical software R. Three generalised linear models were constructed composed of micro- and macro-habitat variables to explain the spatial distribution of the abundance of Lu. longipalpis and one composed of micro-habitat variables to explain the occurrence of the vector. FINDINGS A total of 609 phlebotominae belonging to five species were collected, of which 56% were Lu. longipalpis. In addition, the presence of Nyssomyia neivai and Migonemya migonei, which are vectors of tegumentary leishmaniasis, were also documented and represented 34.81% and 6.74% of the collections, respectively. The explanatory variable normalised difference vegetation index (NDVI) described the abundance distribution, whereas the presence of farmyard animals was important for explaining both the abundance and the occurrence of the vector. MAIN CONCLUSIONS The results contribute to the identification of variables that can be used to establish priority areas for entomological surveillance and provide an efficient transfer tool for the control and prevention of vector-borne diseases.

Introducción. La leishmaniasis visceral es una enfermedad desatendida de alta letalidad que amerita que se profundice en los estudios locales para diseñar estrategias efectivas de control. En América, su transmisión ya se ha evidenciado en las zonas urbanas, en donde el reservorio principal es el perro doméstico. Las condiciones socioeconómicas, así como las representaciones y las prácticas de los grupos domésticos podrían desempeñar un papel crucial y poco conocido en su transmisión. Objetivo. Analizar las representaciones y las prácticas de prevención y afrontamiento de la leishmaniasis visceral humana y canina, así como los factores socioeconómicos de riesgo. Materiales y métodos. Se hizo un estudio transversal de casos y controles. Se definió´caso´ como un grupo doméstico en el que, al menos, un integrante tuviera antecedentes de leishmaniasis visceral humana y hubiera sido notificado por el Ministerio de Salud Pública. El´control´ se definió como un grupo doméstico sin integrantes con antecedentes de la enfermedad. A partir de la información primaria, se caracterizó demográfica y socialmente a la población, se estableció la calidad de las viviendas, se hizo una clasificación de los conocimientos y las actitudes en torno a la enfermedad, y se describieron las prácticas asociadas al riesgo y la presencia de leishmaniasis visceral canina. Resultados. La mala calidad de la vivienda (p=0,001), las personas del grupo doméstico que permanecían fuera de esta después de las 18 horas (razón de momios, OR ( odds ratio) =4,5; IC 95% 1,69-12,18), la reproducción sin control de la raza canina (OR=15,7; IC 95% 3,91-63,2) y la presencia de leishmaniasis visceral canina en el domicilio (OR=120,3; IC 95% 18,51-728,3), se asociaron positivamente o incrementaron el riesgo de contraer leishmaniasis visceral humana. Conclusión. Se observó que la pobreza estructural constituía un factor social determinante del riesgo, y que aumentaba la probabilidad de contacto entre humanos y vectores por la mala calidad de la vivienda y el hacinamiento. El factor de riesgo más importante para la leishmaniasis visceral humana fue la tenencia en el domicilio de perros con la enfermedad.

Introduction: Visceral leishmaniasis is an often overlooked disease with high lethality rates about which there is need of additional local studies to inform the design of effective control strategies. The urbanization of its transmission has already been verified in America, with domestic dogs being the primary reservoirs and vectors of the disease. Socio-economic conditions, demographics and practices of domestic groups typically present in urban settings may play a specific role in the transmission of the infection, which is still poorly understood. Objective: To analyze the sociodemographic characteristics, risk factors and overall practices concerning prevention and coping strategies of visceral leishmaniasis, in both human beings and canines. Materials and methods: This study utilized a cross-sectional case-control design. Cases were defined as a domestic group where the Public Health Ministry had at least one record of a member with human visceral leishmaniasis. Control cases were defined as a domestic group without a clinical record of the disease. The populations were characterized demographically and socially using primary information sources. Measures of household quality and a ranking of knowledge and attitudes towards visceral leishmaniasis were constructed, and practices associated with the presence, and the risk for canine visceral leishmaniasis were described. Results: Low household quality (p=0.001), a member of the domestic group out of the household after 6:00 pm (OR=4.4; 95% CI: 1.69-12.18), the uncontrolled racial breeding of dogs (OR=15.7; 95% CI: 3.91-63.2), and the presence of infected dogs infected in the household (OR=120.3; 95% CI: 18.51-728.3) were variables positively associated with the risk of infection. Conclusion: We observed certain social risk factors, primarily low household quality and overcrowding, associated with structural poverty that could increase human-vector contact probability. The most important risk factor for human visceral leishmaniasis was the possession of infected dogs in the household.

ABSTRACT A retrospective analytical method is presented, based on theoretical eco-epidemiology, applied on a subnational spatial scale. This method was used here to describe scenarios for the transmission of leishmaniasis in the Argentine province of Misiones— bordering Brazil and Paraguay—and formed the basis for recommendations for surveillance and control appropriate to the subnational scale. An exhaustive search of the literature on leishmaniasis in the province was carried out. Three scenarios for the transmission of cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL) were found, corresponding to three periods: from 1920 to 1997, during which the transmission of CL distributed over time and space was confirmed; 1998 to 2005, during which there were focal outbreaks of CL; and 2006 to 2014, during which outbreaks were also reported and the geographical dispersion of VL was documented. To describe the risk scenarios and the anthropic processes that produce them, the results were summarized and integrated into the social, historical, and bio-ecological context of each period. Surveillance and control recommendations are based on the territory studied. They include establishing active surveillance to monitor possible rising trends in parasitic and vector circulation, conducting studies of any focal outbreak in order to confirm indigenous transmission and severity. Also, it should be a legal requirement for persons responsible for projects that alter the environment to adopt additional control measures, such as studies assessing transmission risk, risk mitigation, early detection, and timely case management.

RESUMEN Se presenta una metodología analítica retrospectiva, basada en el marco teórico de la eco-epidemiología, anclada en una escala espacial subnacional. Esta metodología, aplicada aquí a la caracterización de escenarios de transmisión de la leishmaniasis en la provincia argentina de Misiones —fronteriza con Brasil y Paraguay— permitió fundamentar recomendaciones de vigilancia y control apropiadas a dicha escala. Se realizó una búsqueda exhaustiva de la literatura sobre leishmaniasis en esa provincia y se determinaron tres escenarios de transmisión de leishmaniasis cutánea (LC) y visceral (LV), correspondientes a tres períodos: 1920-1997, en el que se constató la transmisión de LC, dispersa en el tiempo y el espacio; 1998-2005, en el que hubo brotes focales de LC; y 2006-2014 en el que, además, se registraron brotes y se documentó la dispersión geográfica de la LV. Para caracterizar los escenarios de riesgo y los procesos antrópicos que los producen, los resultados se sintetizaron e integraron en el contexto socio-histórico y bio-ecológico de cada período analizado. Se fundamentan recomendaciones de vigilancia y control en el territorio estudiado, entre ellas, establecer una vigilancia activa para monitorear posibles tendencias al incremento de la circulación parasitaria y vectorial y, ante la aparición de un foco, realizar estudios para verificar la transmisión autóctona y la intensidad del evento. Además, se debe establecer la obligación legal de tomar medidas adicionales de control por los responsables de los proyectos que impliquen modificación ambiental, como la realización de estudios de evaluación del riesgo de transmisión, y acciones de mitigación del riesgo, detección temprana y tratamiento oportuno de los casos.

This study aimed to analyse changes in the spatial distribution of Lutzomyia longipalpis in Posadas, an urban area located in northeastern Argentina. Data were obtained during the summer of 2007 and 2009 through two entomological surveys of peridomiciles distributed around the city. The abundance distribution pattern for 2009 was computed and compared with the previous pattern obtained in 2007, when the first human visceral leishmaniasis cases were reported in the city. Vector abundance was also examined in relation to micro and macrohabitat characteristics. In 2007 and 2009, Lu. longipalpis was distributed among 41.5% and 31% of the households in the study area, respectively. In both years, the abundance rates at most of the trapping sites were below 30 Lu. longipalpis per trap per night; however, for areas exhibiting 30-60 Lu. longipalpis and more than 60 Lu. longipalpis, the areas increased in both size and number from 2007-2009. Lu. longipalpis was more abundant in areas with a higher tree and bush cover (a macrohabitat characteristic) and in peridomiciles with accumulated unused material (a microhabitat characteristic). These results will help to prioritise and focus control efforts by defining which peridomiciles display a potentially high abundance of Lu. longipalpis.

Urban visceral leishmaniasis is an emerging zoonosis in Argentina. In the Americas the disease is produced by Leishmania infantum, with dogs as the primary reservoir and phlebotomine sandflies as the vectors. This article presents the experience acquired by professionals from the National Leishmaniasis Program in Argentina as visceral leishmaniasis has emerged and spread, especially in clinical and laboratory diagnosis, disease treatment, vector biology, reservoir management, and conflicts regarding recommendations for infected dogs. Early detection and treatment, along with decentralized and horizontal strategies, will contribute to the decrease in morbidity and mortality associated with visceral leishmaniasis. Control over the transmission and spread of the disease requires integral environmental management and responsible dog ownership. The interests and discourses put into conflict by visceral leishmaniasis are discussed in the framework of the human-dog relationship, and the search for a consensus-based risk discourse is proposed.

La leishmaniasis visceral urbana es una zoonosis emergente en Argentina. En América es producida por Leishmania infantum, con el perro como reservorio principal e insectos flebotomíneos como vectores. En este artículo se presenta el conocimiento acumulado a partir de su emergencia y dispersión en el país, por los referentes del Programa Nacional de Leishmaniasis, en el diagnóstico clínico y de laboratorio, tratamiento, biología de vectores, manejo de reservorio, y el conflicto generado con las acciones recomendadas en relación con los perros infectados. La detección temprana y el tratamiento precoz, con estrategias descentralizadas y horizontales, contribuirán a disminuir la morbimortalidad asociada a la leishmaniasis visceral. El control de su transmisión y dispersión requiere de un manejo ambiental integral y la tenencia responsable de perros. Se discuten los intereses y discursos en conflicto generados por la leishmaniasis visceral en el marco de la relación humano-perro, proponiendo la búsqueda de un discurso consensuado de riesgo.

Urban visceral leishmaniasis is an emerging zoonosis in Argentina. In the Americas the disease is produced by Leishmania infantum, with dogs as the primary reservoir and phlebotomine sandflies as the vectors. This article presents the experience acquired by professionals from the National Leishmaniasis Program in Argentina as visceral leishmaniasis has emerged and spread, especially in clinical and laboratory diagnosis, disease treatment, vector biology, reservoir management, and conflicts regarding recommendations for infected dogs. Early detection and treatment, along with decentralized and horizontal strategies, will contribute to the decrease in morbidity and mortality associated with visceral leishmaniasis. Control over the transmission and spread of the disease requires integral environmental management and responsible dog ownership. The interests and discourses put into conflict by visceral leishmaniasis are discussed in the framework of the human-dog relationship, and the search for a consensus-based risk discourse is proposed.

La leishmaniasis visceral urbana es una zoonosis emergente en Argentina. En América es producida por Leishmania infantum, con el perro como reservorio principal e insectos flebotomíneos como vectores. En este artículo se presenta el conocimiento acumulado a partir de su emergencia y dispersión en el país, por los referentes del Programa Nacional de Leishmaniasis, en el diagnóstico clínico y de laboratorio, tratamiento, biología de vectores, manejo de reservorio, y el conflicto generado con las acciones recomendadas en relación con los perros infectados. La detección temprana y el tratamiento precoz, con estrategias descentralizadas y horizontales, contribuirán a disminuir la morbimortalidad asociada a la leishmaniasis visceral. El control de su transmisión y dispersión requiere de un manejo ambiental integral y la tenencia responsable de perros. Se discuten los intereses y discursos en conflicto generados por la leishmaniasis visceral en el marco de la relación humano-perro, proponiendo la búsqueda de un discurso consensuado de riesgo.

The distribution of Lutzomyia longipalpis is heterogeneous with a pattern of high abundance areas (HAAs) embedded in a matrix of low abundance areas (LAAs). The objective of this study was to describe the variability in the abundance of Lu. longipalpis at two different spatial levels and to analyse the relationship between the abundance and multiple environmental variables. Of the environmental variables analysed in each household, the condition that best explained the differences in vector abundance between HAA-LAA was the variable "land_grass", with greater average values in the peridomestic environments within the LAA, and the variables "#sp tree", "#pots" and "dist_water" that were higher in the HAA. Of the environmental variables analysed in the patches, the variable "unpaved_streets" was higher in the LAAs and the variable "prop_inf_dogs" was higher in the HAAs. An understanding of the main environmental variables that influence the vector distribution could contribute to the development of strategies for the prevention and control of visceral leishmaniasis (VL). This is the first work in which environmental variables are analysed at the micro-scale in urban areas at the southern edge of the current range of Lu. longipalpis. Our results represent a significant contribution to the understanding of the abundance of the vector in the peridomestic habitats of the region.

Phlebotomine captures were performed in February 2010 in Salto (Salto department) and Bella Unión-Cuarein (Artigas department), Uruguay. Bella Unión is located across the Paraná River from Monte Caseros, Argentina, where a focus of canine visceral leishmaniasis (VL) was reported in 2009. No VL cases have ever been recorded in Uruguay and the last reported capture of Phlebotominae was in 1932 (Lutzomyia cortelezzii and Lutzomyia gaminarai). Light traps were placed in peridomestic environments, and Lutzomyia longipalpis, the main vector of visceral leishmaniasis, was found in Salto and Bella Unión. This is a first report of an area of potential VL transmission in Uruguay. Active and coordinated surveillance is required immediately the Uruguay-Argentina-Brazil border area.

In this study, a genotypification of Leishmaniawas performed using polimerase chain reaction-restriction fragment length polymorfism (PCR-RFLP) and sequencing techniques to identify species of Leishmaniaparasites in phlebotomine sand flies and dogs naturally infected. Between January-February of 2009, CDC light traps were used to collect insect samples from 13 capture sites in the municipality of Posadas, which is located in the province of Misiones of Argentina. Sand flies identified as Lutzomyia longipalpiswere grouped into 28 separate pools for molecular biological analysis. Canine samples were taken from lymph node aspirates of two symptomatic stray animals that had been positively diagnosed with canine visceral leishmaniasis. One vector pool of 10 sand flies (1 out of the 28 pools tested) and both of the canine samples tested positively for Leishmania infantumby PCR and RFLP analysis. PCR products were confirmed by sequencing and showed a maximum identity with L. infantum. Given that infection was detected in one out of the 28 pools and that at least one infected insect was infected, it was possible to infer an infection rate at least of 0.47% for Lu. longipalpisamong the analyzed samples. These results contribute to incriminate Lu. longipalpis as the vector of L. infantumin the municipality of Posadas, where cases of the disease in humans and dogs have been reported since 2005.

Visceral leishmaniasis (VL) is a relevant parasitic disease in public health, produced by Leishmania infantum chagasi. Since the urbanization and emergence in Southern Brazil and Paraguay, the vector Lutzomyia longipalpis in Formosa, 2004, and the first human visceral leishmaniasis case in Misiones, 2006, have been reported in Argentina. Due to the reports of canine VL, a search of the vector in the Province of Corrientes, contiguous to Misiones, was performed during December 2008. Standarized trapping detected 376 Lu. longipalpis in Ituzaingó, Virasoro, Santo Tomé, Garruchos, Riachuelo, Corrientes and Monte Caseros localities. The risk of autochtonous vectorial transmission was then confirmed in the Province of Corrientes. The distribution of vectors in populated urban areas, with intense transit of canine reservoirs from localities with high transmission, and the existence of infected reservoirs, also implies epidemic risk.

La leishmaniasis visceral es una parasitosis de importancia en salud pública, producida por Leishmania infantum chagasi. A partir de la urbanización y emergencia en el sur de Brasil y Paraguay, se notificó la presencia del insecto vector Lutzomyia longipalpis en la Argentina; en Formosa, 2004, y en Misiones el primer caso humano en 2006. La notificación de casos de reservorios caninos infectados en la provincia de Corrientes, contigua a Misiones, determinó la búsqueda del vector. Mediante trampeos estandarizados en diciembre del 2008 se capturaron 376 Lu. longipalpis en Ituzaingó, Virasoro, Santo Tomé, Garruchos, Riachuelo, Corrientes y Monte Caseros. Se confirma el riesgo de transmisión vectorial autóctona de leishmaniasis visceral en la provincia de Corrientes. La distribución de vectores en áreas urbanas densamente pobladas, con intenso tránsito de reservorios caninos desde zonas de alta transmisión, y la presencia de reservorios infectados, implica a su vez riesgo epidémico.