Leishmaniasis en Bolivia, revisión y estado actual en Tarija, frontera con Argentina / Leishmaniasis en Bolivia. Comprehensive review and current status in Tarija, in the border with Argentina

Introducción. En 1997, en el departamento de Tarija, Bolivia, situado en la frontera con Argentina, se notificó por primera vez la presencia de pacientes con úlceras en las partes descubiertas de la piel, cuyas características clínicas y epidemiológicas correspondían a leishmaniasis. Objetivo. Describir y comprobar la presencia de leishmaniasis en Tarija, sexto departamento endémico en Bolivia. Materiales y métodos. Se hizo un estudio del brote (noviembre de 1998 a diciembre de 2002) y un estudio longitudinal (1997 a 2018) en humanos; además, se capturaron Phlebotominae y potenciales reservorios. Resultados. Se registraron 1.250 pacientes de leishmaniasis; 190 y 249 casos, en los brotes de 1998 y 2002, respectivamente, con periodos interepidémicos de 37 casos como promedio anual. El 68 % de los enfermos eran pobladores migrantes del altiplano asentados en viviendas precarias cercanas al bosque residual; el sexo predominante fue el masculino (2/1). El grupo etario económicamente activo (15 a 49 años) fue el más afectado (363/584, 62 %). Hubo 124/584 (21 %) menores de 15 años, 33/584 de menos de cuatro años. En 51/584 (8,7 %) pacientes se presentaron lesiones mucosas. Se aisló y caracterizó Leishmania (V.) braziliensis de úlceras mucosas de perros enfermos y se capturó abundantemente la especie antropofílica Nyssomyia neivai, incriminada como probable vector. Conclusiones. En 1997 se comprobó por primera vez la presencia de leishmaniasis tegumentaria en el municipio de Bermejo y, en el 2018, ya se había extendido a cuatro municipios: Padcaya, Caraparí, Entre Ríos y Yacuiba, en dirección noreste del departamento de Tarija.

Introduction: In the department of Tarija in the Bolivian-Argentine border, human cases with ulcers on uncovered parts of the skin plus clinical and epidemiological characteristics related to leishmaniasis were reported for the first time in 1997. Objective: To describe and to verify the presence of leishmaniasis in Tarija, sixth endemic department in Bolivia. Materials and methods: We conducted both an outbreak study (November, 1998, to December, 2002) and a longitudinal study (1997 to 2018) in humans, as well as captures of Phlebotominae and potential reservoirs. Results: A total of 1,250 patients were registered; in the outbreaks, 190 (1998) to 249 cases (2002) were reported and inter-epidemic periods with 37 cases as an annual average; 68% of the patients were highland migrants who inhabited precarious housing near residual forests. The predominant sex was male (ratio 2:1); the most affected group (363/584 cases, 62%) was the economically active (15 to 49 years old); 124/584 cases (21%) were children under 15 years old, 33/584 of them were under 4 years old; 51 patients/584 (8.7%) had mucosal lesions. Leishmania (V.) braziliensis was isolated and characterized from mucous ulcers of sick dogs. Nyssomyia neivai, an abundant anthropophilic species incriminated as a probable vector, was captured. Conclusions: The initial 1997 leishmaniosis presence in the municipality of Bermejo had spread out over four municipalities in 2018 (Padcaya, Caraparí, Entre Ríos, and Yacuiba), northeast of the department of Tarija.

Performance of rapid tests for canine visceral leishmaniasis diagnosis in Argentina

To diagnose dogs infected by Leishmania infantum rK39 rapid diagnosis test is widely used in the Americas, while dual path platform (DPP) was recently adopted by Brazil. In this study we assessed the performance of rK39-RDT and DPP tests in recent urban transmission scenarios of Argentina. The sensitivity and specificity were evaluated with a sera panel and field samples, taken as true infected those from parasitological and/or PCR positive tests. Since none of these tests can be taken as a gold standard, the performance was also evaluated using Latent Class Analysis, a statistical modeling technique which allows to estimating sensitivity and specificity defining a latent class variable as the reference standard. The sensitivity of both tests in the panel was around 92% (symptomatic dogs 96%, asymptomatic 83%), while the sensitivity in field samples of rK39-RDT was 77%, and DPP 98% (mean in symptomatic dogs 89%, asymptomatic 82%). The specificity was similar for both tests and samples, around 98%. Therefore, these tests are acceptable for program dog population-based studies, as spatial stratification, focus intervention and follow up, and they could be used for individual screening and confirmation of clinical presumptive diagnosis in polysymptomatic dogs. The inability to discriminate between immunity and actual infectiousness suggest that a combination with other non-immunological based tests will be required for highly sensitive/specific diagnosis in order to targeting control measures in individual reservoirs from public health perspective, as for individual management from animal health perspective.

Para diagnosticar perros infectados por Leishmania infantum, en las Américas se utiliza ampliamente la prueba rápida rK39, mientras que DPP fue adoptado recientemente por Brasil. En este estudio se evaluó el desempeño de las pruebas rK39-RDT y DPP en escenarios de transmisión urbana reciente en Argentina. La sensibilidad y especificidad se evaluaron con un panel de sueros y muestras de campo, considerando muestras infectadas verdaderas aquellas con pruebas parasitológicas y/o de PCR positivas. Como ninguna de estas pruebas puede considerarse estándar de oro, el desempeño también se evaluó mediante análisis de clases latentes, una técnica de modelado estadístico que permite estimar sensibilidad y especificidad definiendo una variable de clase latente como estándar. La sensibilidad de ambas pruebas en el panel fue de alrededor del 92% (perros sintomáticos 96%, asintomáticos 83%), mientras que la sensibilidad en muestras de campo fue rK39-RDT: 77%, y DPP 98% (media en perros sintomáticos 89%, asintomáticos 82%). La especificidad fue similar para ambas pruebas y muestras, cerca de 98%. Por lo tanto, estas pruebas son aceptables para estudios programáticos caninos de base-poblacional, como estratificación espacial, intervención de foco y seguimiento, y podrían utilizarse para el tamizaje individual y la confirmación del diagnóstico clínico presuntivo en perros poli-sintomáticos. La incapacidad de discriminar entre inmunidad e infectividad real sugiere que se requerirá una combinación con otras pruebas, de base no inmunológica, para un diagnóstico suficientemente sensible/específico que permita definir las medidas de control en reservorios individuales, tanto para salud pública, como para la gestión individual en salud animal.

Visceral Leishmaniasis in Bolivia: Current Status

Abstract INTRODUCTION In Bolivia, before 1982 there were no records of visceral leishmaniasis (VL) cases that would allow us to review and describe the temporospatial occurrence of VL by ecoregions in provinces and departments of Bolivia to evaluate its impact on public health, risk of outbreaks, or dispersion. METHODS This update on VL in Bolivia is based on research, reviews, and retrospective literature analyses of online data and libraries and institutional reports, from 1939 to the present. RESULTS In Bolivia, 56 cases of VL have been reported. Until 2014, only three endemic departments had been identified (La Paz, Santa Cruz, and Tarija). Since then, further cases have been recorded in Pando, Cochabamba, and Beni, and in Chuquisaca in 2015. In Yungas, a VL focus was confirmed by isolating and comparing parasites from human and dog cases, and from the Lu. longipalpis vector. VL cases from seven departments, involving 12 different ecoregions were located within the Amazon and Plata basins. CONCLUSIONS We confirmed that dogs are its primary reservoir, and Lutzomyia longipalpis is its main vector (currently dispersed in six departments). The primary vectors in areas where Lutzomyia longipalpis is absent are Migonemyia migonei and Lutzomyia cruzi.

Las vacunas contra el dengue ¿una realidad para la Argentina? / Dengue vaccines. A reality for Argentina?

Los brotes de dengue se suceden anualmente en Argentina desde el año 1998. Existen vacunas contra esta enfermedad en distintos grados de desarrollo que han sido probadas en países endémicos. La más avanzada hasta el momento fue autorizada para su comercialización en tres países de América Latina, para niños mayores de 9 años. En este artículo se discuten los beneficios e inconvenientes de las vacunas, así como los desafíos para la implementación de una estrategia de vacunación. Asimismo, se plantea la necesidad de una estratificación de riesgo con nuevos criterios y visión multidisciplinaria como un camino posible para evaluar la pertinencia de un programa de vacunación en las áreas con mayor riesgo de transmisión, y/o en individuos con mayor riesgo de dengue grave. Se sugiere también que la definición del estatus de endemicidad debe tomar en cuenta a las realidades locales. Por último, este artículo propone una discusión amplia de las evidencias, impacto esperado y aspectos instrumentales que estarían involucrados en la incorporación de una vacuna contra el dengue, ya en mercado o en desarrollo, en el programa nacional de inmunizaciones, y especialmente a qué subpoblaciones debería ser dirigida para que la estrategia de inmunización sea costo-efectiva.

Dengue outbreaks have occurred yearly in Argentina since 1998. A number of candidate vaccines have been tested in endemic countries. The most advanced one was licensed in three countries of Latin America for children over 9 years of age. In the present article the benefits and drawbacks of these vaccines as well as the challenges for the implementation of a vaccination strategy in Argentina are discussed. Furthermore, a risk stratification strategy with new criteria and a multidisciplinary vision is suggested as a possible path for the assessment of the pertinence of a vaccination program in areas showing the highest risk of dengue transmission and/or for people at the greatest risk of developing severe dengue. It is also suggested that the definition regarding the status of endemicity should take into account the local realities. Finally, this paper proposes a broad discussion on the evidences, the expected impact and instrumental aspects that would be involved in the incorporation of a dengue vaccine, marketed or in development, into the national immunization program, and especially which subpopulation should be targeted for the immunization strategy to be cost-effective.

Diphyllobothrium sp. en Canis familiares de la región del subtrópico argentino (Puerto Iguazú, Misiones) / Diphyllobothrium sp. in Canis familiaris from the subtropical area of Argentina (Puerto Iguazú, Misiones)

En este trabajo se informa el hallazgo de huevos de Diphyllobothrium sp. en ejemplares de Canis familiaris (perro doméstico) de Puerto Iguazú, una ciudad subtropical de la provincia de Misiones, Argentina. Durante 2013, en el marco de un relevamiento de la fauna parasitológica de los perros de Puerto Iguazú, se detectaron dos casos positivos en la búsqueda de huevos de Diphyllobothrium sp. La materia fecal de los perros fue recolectada en frascos con formol al 10% y procesada mediante las técnicas de sedimentación de Telemann y de flotación de Sheather. Dado que Misiones no forma parte de la zona endémica de difilobotriasis y considerando, además, su ubicación fronteriza, este hallazgo reviste gran importancia para la salud pública. Se señala la necesidad de actualizar el estado de conocimiento sobre el ciclo de vida de estos parásitos identificando el rango de hospederos intermediarios y definitivos, su potencial zoonótico y la situación epidemiológica en áreas no endémicas

This paper reports the first finding of Diphyllobothrium sp. eggs in Canis familiaris (domestic dog) from Puerto Iguazú, a subtropical city of Misiones province, Argentina. In 2013, two positive cases of Diphyllobothrium sp. eggs were detected during an annual parasitological survey of dogs. Dog feces were collected in vials containing 10% formalin and processed using Telemann's sedimentation and Sheather's flotation techniques. The two cases were detected in rural areas of the municipality. Since Misiones is not a part of the endemic area of diphyllobothriasis and given the fact that it is located in the three-border area of Argentina, Brazil and Paraguay, we consider this finding of great importance to public health. We stress the need for updating the current knowledge about the life cycle of these parasites considering the range of intermediate and definitive hosts, their zoonotic potential, and the epidemiological situation in non-endemic areas

Leishmaniasis visceral en la Argentina: Notificación y situación vectorial (2006-2012) / Visceral leishmaniasis in Argentina: Cases notification and distribution of vectors (2006-2012)

La leishmaniasis visceral (LV) en la Argentina se notifica obligatoriamente a través del Sistema Nacional de Vigilancia de la Salud (SNVS). El análisis de la notificación muestra un total de 103 casos distribuidos en cuatro provincias, siendo Misiones la de mayor casuística con un total de 80 casos en 15 localidades, desde mayo 2006 hasta julio de 2012. Los niños de 0 a 15 años de edad son el grupo con mayor incidencia. En el año 2004 fue registrado por primera vez el riesgo de LV urbana endémica en la provincia de Formosa tras el hallazgo del vector Lutzomyia longipalpis. En el año 2006 la provincia de Misiones registra casos de LV humana, LV canina, y la provincia de Corrientes en el verano 2008-2009. En Santiago del Estero los casos de LV humana y LV canina en el año 2008 estuvieron asociados posiblemente a vectores secundarios. En el año 2010 Lu. longipalpis fue hallado en Chajarí, Entre Ríos, mostrando su dispersión hacia el sur. Por ello, para conocer la distribución del riesgo, entre enero y abril del 2011 se realizó búsqueda sistemática del vector de LV en 13 localidades de las provincias de Entre Ríos, Santa Fe y Santiago del Estero, totalizando 275 trampas/noche. Se comprobó la colonización de Lu. longipalpis, en la localidad de Chajarí. En Santiago del Estero no se encontró Lu. longipalpis por lo que Migonemyia migonei sigue incriminada como vector putativo de LV en esta región.

Visceral leishmaniasis (VL) is a notifiable disease in Argentina. Every new case diagnosed must be reported to the National Health Surveillance System. In the period 2006-2012, a total of 103 cases have been notified in four provinces: Entre Rios, Santa Fe, Misiones and Santiago del Estero. Misiones has the largest amount of cases: a total of 80, detected in 15 towns from May 2006 to July 2012. The highest incidence is observed in children (less than 15 years of age). In 2004 the vector Lutzomyia longipalpis was detected for the first time in Formosa Province. Cases of human and canine VL, as well as the presence of the canine vector were reported in 2006 in the province of Misiones, and in 2008-2009 in the province of Corrientes. In Santiago del Estero cases of human and canine VL (2008) were possibly associated with secondary vectors. In 2010 Lu longipalpis was found in Entre Rios, showing its dispersal to the south. Between January and April 2011 a systematic search of the VL vector was carried out in 13 towns, in Entre Ríos, Santa Fe and Santiago del Estero Provinces (275 traps/night). The colonization of the vector Lu longipalpis was proved in Chajarí town (Entre Rios), but not in Santiago del Estero Province, where Migonemyia migonei appears as a putative LV vector.

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.

Distribución de Lutzomyia longipalpis en la Mesopotamia Argentina, 2010 / Distribution of Lutzomyia longipalpis in the Argentine Mesopotamia, 2010

El primer caso autóctono de leishmaniasis visceral (LV) en la Argentina se notificó en el año 2006 en Posadas, Misiones, y en el verano 2008-2009 se comprobó la dispersión del vector de LV, Lutzomyia longipalpis y casos de LV canina en la provincia de Corrientes. Para conocer la distribución del riesgo, entre febrero y marzo del 2010 se realizó la búsqueda sistemática del vector de LV en 18 localidades de las provincias de Entre Ríos, Corrientes y en la ciudad de Puerto Iguazú, Misiones, totalizando 313 trampas/noche. Se comprobó la presencia de Lu. longipalpis, por primera vez, en las localidades de Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá y Bella Vista (Corrientes), y en Puerto Iguazú (Misiones). En Santo Tomé y Monte Caseros (Corrientes) se volvió a registrar la presencia del vector, y se obtuvieron las trampas con más ejemplares, 830 y 126 Lu. longipalpis trampa/sitio/noche respectivamente. Los resultados muestran que el vector de la LV urbana, continúa dispersándose en el territorio argentino. Simultáneamente, la propagación del parásito, y los consecuentes casos de LV humana se asocian al aumento de reservorios, perros infectados con o sin clínica, debidos al tránsito humano.

The first case of visceral leishmaniasis (VL) in Argentina was reported in 2006 in Posadas, Misiones. During the summer 2008-2009 Lutzomyia longipalpis, the VL vector, and canine VL cases were already spread along the province of Corrientes. In order to know the distribution of VL risk, systematic captures of the vector were performed between February and March 2010, in 18 areas of the provinces of Entre Ríos and Corrientes, and the city of Puerto Iguazú, Misiones, with a total of 313 traps/night. We confirmed the presence of Lu. longipalpis, for the first time in Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá and Bella Vista (Corrientes), and Puerto Iguazú (Misiones). In Santo Tome and Monte Caseros (Corrientes), where the vector had been previously reported, traps with more samples were obtained with 830 and 126 Lu. Longipalpis trap/site/night respectively. These results show that the vector of urban VL continues spreading in the Argentine territory. Simultaneously, the spread of the parasite and the resulting human VL cases are associated with the dispersion of reservoirs, infected dogs, with or without clinical symptoms or signs, due to human transit.

Sex pheromone and period gene characterization of Lutzomyia longipalpis sensu lato (Lutz & Neiva) (Diptera: Psychodidae) from Posadas, Argentina

Lutzomyia longipalpis s.l. is the primary vector of Leishmania (L.) infantum in the New World. In this study, male Lutzomyia longipalpis specimens from Posadas, Argentina were characterized for two polymorphic markers: the male sex pheromone and the period (per) gene. The male sex pheromone was identified as (S)-9-methylgermacrene-B, the same compound produced by Lu. longipalpis from Paraguay and many populations from Brazil. The analysis of per gene sequences revealed that the population from Argentina is significantly differentiated from previously studied Brazilian populations. Marker studies could contribute to the understanding of the distribution and spread of urban American visceral leishmaniasis, thus aiding in the design of regional surveillance and control strategies.

Phlebotomine sand flies (Diptera: Psychodidae) of the province of Chaco, Argentina

The phlebotomine sandflies of the province of Chaco, Argentina, are poorly known, with reports from more than 40 years or captures related with outbreaks of leishmaniasis. In here, Mycropygomyia peresi (Mangabeira) is reported for the first time in Argentina, extending the known dstribution of Migonemyia migonei (França), Evandromyia sallesi (Galvão & Coutinho), Mycropygomyia quinquefer (Dyar), Brumptomyia brumpti (Larousse) y Nemapalpus spp to the province of Chaco. Mg. migonei, together with Nyssomyia neivai (Pinto), Evandromyia cortelezzii (Brèthes), and Psathyromyia shannoni (Dyar) also captured in Chaco, were incriminated as vectors of Leishmania in Argentina.

Visceral leishmaniasis in border areas: clustered distribution of phlebotomine sand flies in Clorinda, Argentina

Three years after the first report of Lutzomyia longipalpis in Clorinda, Argentina, a border city near Asunción, Paraguay, the city was surveyed again. Lu. longipalpis was found clustered in the same neighbourhoods in 2007 as in 2004, even though the scattered distribution of canine visceral leishmaniasis was more related to the traffic of dogs through the border.

Phlebotominae (Diptera: Psycodidae) fauna in the Chaco region and Cutaneous Leishmaniasis transmission patterns in Argentina

In Argentina, the incidence of American Cutaneous Leishmaniasis (ACL) has shown a steady increase over the last few decades. In the Chaco biogeographical region, specifically, several outbreaks of ACL were recently reported in addition to the usual time-space scattering of ACL cases. However, little is known about the sandfly composition in the eastern, humid Chaco (HC) region or the western, dry Chaco (DC) region. Therefore, phlebotomine captures were performed throughout this region and an analysis of the distribution of reported ACL cases was conducted in order to assess the vector diversity in ACL endemic and epidemic scenarios in the Chaco region. The results support the hypothesis of two distinct patterns: (1) the DC, where Lutzomyia migonei was the most prevalent species, had isolated ACL cases and a zoonotic cycle; (2) the HC, where Lutzomyia neivai was the most prevalent species, had an increase in ACL incidence and outbreaks and an anthropozoonotic cycle. The epidemic risk in the Chaco region may be associated with the current climate trends, landscape modification, connection with other ACL foci, and Lu. neivai predominance and abundance. Therefore, changes in sandfly population diversity and density in the Chaco region are an indicator of emergent epidemic risk in sentinel capture sites.

Urban distribution of Phlebotominae in a cutaneous leishmaniasis focus, Argentina

Urbanization and vector domestication are currently proposed as factors that contributed to the recent increase of American cutaneous leishmaniasis (ACL). Is likely also urban transmission? Oran is the main city in the Argentinean hyper-endemic area of ACL, and human cases in urban residences are usually reported. In order to assess the spatial distribution of risk, phlebotomine traps were located in different environments of Oran. A total of 7,787 sand flies were captured: Lutzomyia neivai (98.1 percent), Lutzomyia migonei (1.2 percent), Lutzomyia cortelezzii (0.7 percent), and one Lutzomyia shannoni. During the season of transmission (April-May) a single sand fly was obtained in one out of five urban sites, while a trap in a peri-urban pigsty captured up to 2,985 Lu. neivai/night. Captures performed in the other season of vector activity (September-October) revealed that small-scale changes in the pigsty environment resulted in noticeable changes in the abundance of Lu. neivai. In addition, in a new neighbourhood, on the fringe of the city, 1,073 Lu. neivai/site were captured in the forested edge but one in the yard of the houses. Therefore, in this urban ACL focus the human-vector effective contact risk is still associated with peri-urban vegetation and ecotone modifications despite the urban residence of the cases.

Phlebotominae: vectores de leishmaniasis en las provincias de Santa Fe y Entre Ríos, Argentina / Phlebotominae: vectors of leishmaniasis in the provinces of Santa Fe and Entre Ríos, Argentina

La transmisión de leishmaniasis tegumentaria (LT) se incrementó desde 1985 en 9 provincias argentinas. Santa Fe y Entre Ríos en dicho período no notificaron casos de transmisión autóctona comprobada, sin embargo en el año 2003 ocurrió un brote epidémico en Bella Vista, Corrientes, localidad que se encuentra en un área con continuidad ecológica y contigüidad geográfica con ambas provincias. Por ello, para determinar el riesgo potencial de transmisión de LT en las áreas próximas y al sur de Bella Vista se realizaron capturas de Phlebotominae en febrero del 2004, colectándose sobre las márgenes del río Paraná en Santa Fe (El Rabón, Villa Ocampo, Cayastá) y en Entre Ríos (La Paz, La Celina-Villa Urquiza) 860 ejemplares de Lutzomyia neivai (99.5%) y Lu. migonei (0.5 %), ambas especies con capacidad vectorial para Leishmania (V.) braziliensis. En Tartagal, Santa Fe, las capturas fueron consistentes con el paisaje de «chaco¼ residual: 7 ejemplares de Lu. nerivai, Lu. migonei y Lu. cortelezzii. Se destaca el riesgo potencial de transmisión epidémica de LT en estas provincias, especialmente por la tropicalización progresiva hacia el sur de la selva en galleria paranaense. Se recomiendan actividades de vigilancia clínica y vectorial.

The transmission of tegumentary leishmaniasis (TL) has increased in 9 provinces of Argentina since 1985. Santa Fe and Entre Ríos did not record in this period autochtonous probed cases: however, an epidemic outbreak took place in 2003 in Bella Vista, Corrientes, located in an area with ecological continuity and contiguous to both provinces. In order to evaluate the potential risk of transmission of LT, Phlebotominae were captured at locations close to and southern from Bella Vista during February 2004. The traps located on the shores of Parana river in Santa Fe (El Rabón, Villa Ocampo, Cayastá), and Entre Ríos (La Paz. La Celina-Villa Urquiza) captured 860 individuals of Lutzomyia neivai (99.5%) and Lu. migonei (0.5 %), both species with vectorial capacity for Leishmania (V.) braziliensis. In Tartagal, Santa Fe, the captures were consistent with the residual «chaco¼ landscape, 7 individuals of Lu. nerivai, Lu. migonei and Lu. cortelezzii. The risk of LT epidemic transmission in these provinces is highlighted, mainly due to the progressive southern tropicalization of the paranaense gallery forest. Clinical and entomological surveillance is recommended.

Transmision de la leishmaniasis tegumentaria en la Argentina / Transmission of tegumentary leishmaniasis in Argentina

La leishmaniasis tegumentaria ha experimentado en Argentina, desde 1985, un incremento de casos totales, de la frecuencia, intensidad y distribución de brotes epidémicos, y de la incidencia relativa en mujeres y en niños. Es necesario caracterizar los nuevas circunstancias de transmisión generadas en las últimas décadas para el diseño de estrategias apropiadas de control. Con dicho objeto, basados en indicadores epidemiológicos, entomológicos y en el análisis cualitativo de imágenes satelitales, se describen cuatro brotes epidémicos tomados como casos de estudio: Urugua-í (2004), Esperanza (1998), Alberdi (2003) y Monteros-Simoca (2004). A partir de dichas descripciones se caracterizaron cuatro ciclos: a) silvestre con transmisión en vegetación primaria o residual; b) silvestre con transmisión eventual peridoméstica por alteración deparches de vegetación residual; c) silvestre con transmisión peridoméstica por contigüidad con vegetación residual; d) peridoméstico en ambientes rurales, periurbano ruralizado o interfase urbano-rural. Todos los brotes epidémicos ocurridos desde 1985 se correspondieron con uno de estos ciclos, demostrando ser hasta el momento una tipificación abarcativa de la transmisión de leishmaniasis tegumentaria en la Argentina. De esta manera se categorizaron cuatro patrones epidémicos en el país, destacando a su vez la utilidad del análisis cualitativo, de datos de terreno e imágenes satelitales, como herramientas para comprender la epidemiología de la enfermedad y poder desarrollar medidas adecuadas de prevención y control.

The total cases of tegumentary leishmaniasis in Argentina increased since 1985, as the frequency, intensity and geographic distribution of the epidemic outbreaks, and the relative incidence in women and children. The characterization of the new scenarios of transmission generated in the last decades is needed for the design of appropriate control measures. With this aim, four outbreaks were described as case studies, based on epidemiological and entomological data together with the qualitative analysis of satellite imaginery: Urugua-í (2004), Esperanza (1998), Alberdi (2003) and Monteros-Simoca (2004). These descriptions allowed to define four scenarios of transmission according to a cycle: a) sylvatic with transmission in primary or residual vegetation; b) sylvatic with eventual peridomestic transmission due to changes within patches of residual vegetation; c) sylvatic with peridomestic transmission in domiciles contiguous with the residual vegetation; and d) peridomestic in rural, ruralized periurban or urban-rural interfase environment. All the epidemic outbreaks since 1985 were consistent with the scenarios characterized here, indicating that the tipification is comprehensive of the transmission of tegumentary leishmaniasis in Argentina up to now. In conclusion, four scenarios of epidemic outbreaks were defined for Argentina, while it is highlighted the qualitative analysis of field and remote sensing data as a tool to understand the epidemiology of the disease, and so to develop adequate measures for prevention and control.

Lutzomyia longipalpis in Clorinda, Formosa province, an area of potential visceral leishmaniasis transmission in Argentina

Phlebotomine captures were performed during 2004 in Clorinda, Argentina. Clorinda is located across the branches of the Paraguay river in front of Asunción city, Paraguay. Reports of canine and human visceral leishmaniasis in Asunción have been increasing since 1997, however neither leishmaniasis cases nor sand flies were ever recorded from Clorinda. Light traps were located in migration paths (bridges, port), and peridomestic environments of Clorinda and surrounding localities. Lutzomyia longipalpis was found in Clorinda and Puerto Pilcomayo, first report in a potential visceral leishmaniasis transmission area for Argentina. Active surveillance is required immediately in the localities involved and the surrounding area.

Envenenamiento por picaduras de abeja / Poisoning by bee sting

Dentro de las patologías humanas producidas por animales con la capacidad de inocular veneno, las picaduras de abeja producen el mayor número de accidentes por animales en muchos países, superando a menudo en mortalidad a los producidos por serpientes, escorpiones y arañas. El cuadro clínico por la picadura de estos himenópteros puede consistir en fenómenos alérgicos o en cuadros de envenenamiento. Estos últimos se producen por el ataque de enjambres constituyendo un hecho grave que puede comprometer la vida. En el sujeto envenenado pueden observarse hemólisis, rabdomiólisis e insuficiencia renal, que junto a otras alteraciones sistémicas pueden conducir a la muerte. El conocimiento de los acontecimientos fisiopatológicos que se producen ante los ataques masivos de abejas es de suma importancia para el personal de salud dado que hasta la fecha no existen antivenenos que hayan demostrado tener eficacia clínica comprobada. En esta revisión se consideran los aspectos biológicos de las abejas y de la composición de su veneno relacionado con la ocurrencia y severidad de los accidentes, así como datos epidemiológicos de utilidad para enfrentarse a este tipo de cuadro.

Among the human pathologies produced by venomous animals, bee stings constitute the largest number of accidents in several countries, exceeding the mortality rate caused by other venomous animals such as snakes, spiders or scorpions. The clinical picture after the bee sting may include anaphylaxis or poisoning. The latter is produced by massive attacks and is a serious problem that may put the patient's life at risk. People that are poisoned display hemolysis, rhabdomiolysis and acute renal failure that together with other systemic failures can bring about death. The knowledge of the physiopathological mechanisms involved in the massive attack of bees is crucial for health care professionals as to date we do not ha ve antivenoms with proven clinical efficacy. In this review we include the bee's biological aspects, venom composition and its relation with the occurrence and severity of accidents as well as epidemiological data that can be useful for this type of accidents.

Phlebotominae sand flies in Paraguay. Abundance distribution in the Southeastern region

From September 1993 to August 2001, 7,190 phlebotomine were collected with CDC light trap in an endemic area for human leishmaniasis, in the departments of Misiones and Itapúa, Paraguay. Eleven species were identified: Lutzomyia neivai (93.7 percent), L. whitmani (4.1 percent), and L. fischeri, L. shannoni, L. migonei, L. misionensis, L. cortelezzii, L. pessoai, L. alphabetica, Brumptomyia avellari and B. guimaraesi (less than 1 percent). The last three species are new records for the country. The biodiversity and phlebotomine abundance were associated with the proximity to primary forest or gallery forest, but L. neivai was also found in peridomestic periurban environment. L. neivai was found throughout the year, and showed a period of higher activity from September to April (spring to fall) with a unimodal or bimodal pattern in relation to the annual rainy peaks during the summer. Background literature about phlebotomine from Paraguay has been reviewed

A first record of Phlebotominae from Argentinean Patagonia (Diptera: Psychodidae: Phlebotominae)

A species of the Lutzomyia oswaldoi group is recorded from the Valcheta stream basin, Somuncura plateau, Patagonia. It represents the World southermost record of a species of Phlebotominae, apparently supporting the hypothesis about the relictual character of several components of the Somuncura plateau biota, particularly for those species belonging to the Paranaense lineages

Ecological aspects of Phebotomine (Diptera, Psychodidae) in an endemic area of tegumentary leishmaniasis in the Northeastern Argentina, 1993-1998

The first epidemic tegumentary leishmaniasis outbreak in the province of Misiones was recorded in 1998, in the locality of Puerto Esperanza. Phlebotominae collected in the region, previously or simultaneously to the outbreak (September 1993-December 1998) showed that the species Lutzomyia intermedia s. l. was prevalent (94 percent, n 6,150) at all the sites sampled with miniature light trap (10) and Shannon trap (3). L. pessoai, L. whitmani, L. migonei, L. shannoni, L. fischeri, L. misionensis, Brumptomyia avellari and B. guimaraesi were also captured. Sand fly distribution in time and space suggests that in the province of Misiones (1) the species already present before 1990 could give rise to the epidemic by the density/dispersion fluctuation of their local populations; (2) the abundance of L. intermedia s. l. was associated with environments with ecotones of primary-secondary vegetation, close to water bodies and with moderate human disturbance; (3) this species showed, towards the end of 1997, peaks of exceptional abundance, subsequent to rainfall peaks in 1996. This increase in abundance of potential vector sand fly populations close to houses with colonizable surroundings could have generated the 1998 epidemic outbreak