Lutzomyia longipalpis (Diptera: Psychodidae) Argentina-Bolivia border: new report and genetic diversity

American visceral leishmaniasis (AVL) has two main scenarios of transmission as follows: scattered cases in rural areas and urban outbreaks. Urban AVL is in active dispersion from the northeastern border of Argentina-Paraguay-Brazil to the South. The presence of Lutzomyia longipalpis was initially reported in urban environments in the northwestern border of the country. The presence of Lu. longipalpis, environmental variables associated with its distribution, and its genetic diversity were assessed in Salvador Mazza, Argentina, on the border with Bolivia. The genetic analysis showed high haplotype diversity, low nucleotide diversity, and low nucleotide polymorphism index. We discuss the hypothesis of an expanding urban population with introgressive hybridisation of older haplogroups found in their path in natural forest or rural environments, acquiring a new adaptability to urban environments, and the possibility of changes in vector capacity.

Respuesta doméstica a las recomendaciones sanitarias de intervención sobre ambiente y perros en una localidad con transmisión de leishmaniasis visceral (Pto. Iguazú, Argentina, 2014­2016) / Domestic response to intervention based on health recommendations on the environment and dogs in a locality with transmission of visceral leishmaniosis (Pto. Iguazú, Argentina, 2014-2016)

Introducción: La leishmaniasis visceral (LV) es una enfermedad parasitaria emergente en Argentina. En Puerto Iguazú, frontera con Brasil y Paraguay, en 2010 se registró presencia del vector y casos caninos; y en 2014-2015 dos casos humanos. Objetivo: Este artículo tiene como objetivo analizar los cambios en el nivel micro escala después de dar a conocer a los convivientes el diagnóstico de LV canina (LVC), informándoles estrategias de manejo ambiental para reducir el contacto con el vector. Método: Es una investigación descriptiva, que indagó en dos momentos (2014 y 2016) una muestra no probabilística distribuida en base al criterio de mejor escenario para la presencia del vector (n = 55) en la que se seleccionaron, luego de un primer rastrillaje entomológico y de diagnóstico veterinario, puntos de muestreo con presencia de vectores y al menos un perro con LVC (n = 6/55). Resultados: Un único hogar implementó las modificaciones sugeridas. Esos cambios no resultaron suficientes para controlar la transmisión. La hipótesis es que las medidas de control requieren intervención a meso escala (el vecindario y no el domicilio), atendiendo al radio real de dispersión de vectores. Conclusiones: El riesgo de infección humana por LV se relaciona con el modo de vida, incluyendo las relaciones interespecie. Las relaciones humano-perro combinan especismo y poshumanismo, acotando la efectividad de la "tenencia responsable" como modelo de vínculo saludable.

Introduction: Visceral leishmaniasis (VL) is an emerging parasitic disease in Argentina. In Puerto Iguazú, border with Brazil and Paraguay, vector and canine cases were registered in 2010; and in 2014 and 2015 there were two human cases. Objective: The objective of this article is to analyze changes at the micro-scale level after informing the cohabitants of the diagnosis of canine LV (LVC), letting them know the environmental management strategies to reduce contact with the vector. Method: It is a descriptive researh, which investigated in two moments (2014 and 2016) a non-probabilistic sample distributed based on the criterion of the best scenario for the presence of the vector (n = 55). Sampling points with the presence of vectors and at least one dog with LVC (n = 6/55) were selected, after a first entomological and veterinary diagnosis raking. Results: A single household implemented the suggested modifications. The changes were not enough to control the transmission. The hypothesis is that the control measures require intervention at a meso-scale (the neighborhood instead of the home), taking into account the real radius of vector dispersion. Conclusions: The risk of human infection due to VL is related to the way of life, including interspecies relationships. The human-dog relationships combine speciesism and post-humanism, which limits the effectiveness of "responsible ownership" as model of a healthy bond.

Lutzomyia longipalpis urbanisation and control

Since the description of Lutzomyia longipalpis by Lutz and Neiva more than 100 years ago, much has been written in the scientific literature about this phlebotomine species. Soares and Turco (2003) and Lainson and Rangel (2005) have written extensive reviews focused on vector-host-parasite interactions and American visceral leishmaniasis ecology. However, during the last two decades, the success of Lu. longipalpis in colonising urban environments and its simultaneous geographical spreading have led to new theoretical and operational questions. Therefore, this review updates the general information about this species and notes the more challenging topics regarding the new scenario of urbanisation-spreading and its control in America. Here, we summarise the literature on these issues and the remaining unsolved questions, which pose recommendations for operational research.

Hourly activity of Lutzomyia neivai in the endemic zone of cutaneous leishmaniasis in Tucumán, Argentina: preliminary results

In the present work, the hourly activity of Lutzomyia neivai was studied in the southern part of the province of Tucumán, Argentina, in an area of transmission of cutaneous leishmaniasis during two months of higher activity. In addition, the variables that influenced the abundance of Lu. neivai were evaluated. A total of 1,146 individuals belonging to Lu. neivai (97 percent) and Lutzomyia migonei (3 percent) were captured. The hourly activity of Lu. neivai was mainly nocturnal, with a bimodal pattern in both months. In January, the variable that most influenced the abundance of Lu. neivai was the temperature, whereas in April, that variable was humidity. These results may contribute to the design of anti-vectorial control measures at a micro-focal scale.

Distribución de vectores de leishmaniasis visceral en la Provincia de Corrientes, 2008 / Distribution of vectors of visceral leishmaniasis in the Province of Corrientes, 2008

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.

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.

Ecoepidemiología de la leishmaniasis cutánea en la Argentina / Eco-epidemiology of cutaneous leishmaniasis in Argentina

Se analizó e integró, desde un enfoque ecoepidemiológico, la literatura publicada sobre leishmaniasis cutánea en la Argentina a partir del primer brote epidémico registrado (1985-1987) y se incorporaron datos inéditos.Se discriminaron tres escalas espacio-temporales de análisis: 1) regional/decadal, 2) focos epidémicos/anual,3) sitio de captura/diaria-mensual. Escala regional: se observó una tendencia creciente de la incidencia, de la transmisión peridoméstica y de la frecuencia y distribución de los brotes (Este-Oeste), concurrente con la dispersión y dominancia de Lutzomyia neivai, vector de Leishmania braziliensis, en ambientes modificados. Escala foco epidémica: se caracterizaron tres escenarios de transmisión: 1) ciclo silvestre/transmisión silvestre, 2) ciclo silvestre/transmisión peridoméstica, 3) ciclo peridoméstico/transmisión peridoméstica rural-periurbana. Se adjudicaron los brotes registrados en Argentina a cada escenario. Escala sitio de captura: se concluyó que la distribución de Lu. neivai es microfocal, metapoblacional con recolonización del peridomicilio desde poblaciones fuente y que presenta una dinámica anual bimodal función de la temperatura y las precipitaciones. Se discuten los resultados de cada escala y categoría en el marco de posibles estrategias de vigilancia y control.

Phlebotominae sand flies associated with a tegumentary leishmaniasis outbreak, Tucumán Province, Argentina

The distribution of sand flies and cases of tegumentary leishmaniasis in the area surrounding JB Alberd city, and the proximities of Catamarca province were studied, after an increase of reported cases from JB Alberdi, Tucumán province, in 2003. Of 14 confirmed cases, 57 percent were females and 57 percent were less than 15 years old, suggesting peridomestic transmission. However, 86 percent of them lived close to the Marapa river forest gallery and related wooded areas. Over 1,013 sand flies were collected; Lutzomyia neivai (Pinto, 1926) was prevalent at all the sites (92.3 percent), while Lutzomyia migonei (França, 1920) (6.7 percent) and Lu. cortelezzii (Brèthes, 1923) (1 percent) were also found. The spatial distribution of Lu. neivai overlapped that of the cases, with higher abundance in microfocal hot spots close to the river in stable vegetated habitats or modified habitats with shadow and animal blood sources. The cumulative outcome of anthropic, ecological and climatic factors could have contributed to the onset of the outbreak.

Após um aumento nos casos notificados na cidade de JB Alberdi, Provincia de Tucumán, no ano de 2003, foram estudados a distribuição de flebotomíneos e casos de leishmaniose tegumentar nos arredores de JB Alberdi, e na área próxima à Província de Catamarca. De 14 casos confirmados, 57 por cento foram mulheres e 57 por cento tinham menos de 15 anos de idade, sugerindo transmissão peridomiciliar. Contudo, 86 por cento dos casos residiam perto da galeria florestal do rio Marapa e perto de ilhas de vegetacão residual. De 1.013 flebotomíneos coletados, Lutzomyia neivai (Pinto, 1926) foi a espécie dominante em todos os sítios (92,3 por cento). Também, se capturaram Lutzomyia migonei (França, 1920) (6,7 por cento) e Lutzomyia cortelezzii (Brèthes, 1923) (1 por cento). A distribuicão espacial de Lu. neivai se sobrepõe com a dos casos com alta abundância em pontos quentes microfocais próximos ao rio, em habitats estáveis com vegetação, ou habitats modificados com sombras e fonte de sangue animal. O efeito acumulativo de fatores antrópicos, ecológicos e climáticos pode ter contribuido à geração do surto epidêmico.