Simposio: Leishmaniasis

SIMPOSIO

Leishmaniasis

COORDINA: Ma. Soledad Santini

Leishmaniasis en el Cono Sur: Vigilancia, prevención y control desde la perspectiva de una sola salud

La leishmaniasis comprende un complejo de enfermedades parasitarias causadas por protozoos del género Leishmania, transmitidas por flebótomos de la familia Psychodidae. En las Américas, se han identificado al menos 54 especies de flebótomos (Phlebotominae) con potencial vectorial. Su distribución y dinámica de transmisión están profundamente influenciadas por factores ambientales y climáticos, que afectan tanto la biología de los vectores como sus interacciones con los hospedadores humanos y animales. Los cambios en el uso del suelo, la deforestación, la urbanización no planificada y el aumento de las temperaturas modifican los hábitats de los flebótomos, facilitando su expansión hacia zonas periurbanas y urbanas. Estos escenarios emergentes, especialmente en contextos de vulnerabilidad social y ambiental, requieren respuestas integrales, adaptativas e intersectoriales.
Este simposio propone un abordaje regional de la leishmaniasis en el Cono Sur, enmarcado en el paradigma de Una Salud (One Health), integrando perspectivas ecológicas, clínicas, sociales e institucionales. Representantes de diversos países de América Latina compartirán experiencias y estrategias innovadoras:

  • Anayansi Valderrama abordará la leishmaniasis cutánea desde una perspectiva de Una Salud – Panamá.
  • Rafaella Albuquerque presentará el uso de collares impregnados con insecticidas como herramienta de control de la leishmaniasis visceral dentro del enfoque de Una Salud – Brasil.
  • Daniel Salomón ofrecerá una mirada histórica y prospectiva de la leishmaniasis en Argentina (1985–2025), con foco en propuestas de vigilancia integrada – Argentina.
  • Elizabeth Rangel discutirá la vigilancia y el control vectorial frente al cambio climático y las transformaciones ambientales – Brasil.

El simposio tiene como objetivo fortalecer el intercambio regional y promover la articulación entre la evidencia científica, las políticas públicas y la acción territorial. Se destacará el rol de las instituciones públicas en la planificación, implementación y sostenibilidad de estrategias de vigilancia, prevención y control, especialmente en territorios expuestos a crecientes riesgos ambientales y sanitarios.

Palabras clave: Leishmaniasis, Phlebotominae, cambio ambiental.

Transdisciplinary research of Leishmania spp. transmission networks under anthropogenic pressure, Darién region

VALDERRAMA, Anayansi & GONZÁLEZ, Marlin1

1Gorgas Memorial Institute for Health Studies, Panama City, Panama

The Darién region represents a critical epidemiological hotspot where intense human and animal migration creates optimal conditions for pathogen spillover events. This study addresses the complex dynamics of leishmaniasis transmission through an interdisciplinary One Health approach, integrating veterinary, biological, and medical expertise to understand zoonotic disease risks in vulnerable populations. To identify vector and reservoir species in the study area using molecular markers, characterize circulating Leishmania strains, and implement community-based surveillance strategies following One Health principles in a high-migration zone prone to spillover events. An interdisciplinary team of veterinarians, biologists, and physicians conducted field sampling and molecular analysis using advanced genetic markers. The study implemented the «Science in Your Community» strategy, combining laboratory diagnostics with community engagement and educational interventions. Samples from potential vectors and reservoir species were analyzed for Leishmania identification and characterization. Molecular analysis revealed the presence of vectors Lutzomyia panamensis and Lutzomyia gomezi, along with Leishmania (Viannia) panamensis and Leishmania (Viannia) naiffi strains, including co-infections with Wolbachia endosymbiont. Significantly, we identified Leishmania infection in two bat species, Glossophaga soricina and Carollia perspicillata, expanding the known reservoir spectrum beyond previously documented sloths, dogs, and opossums. This discovery has profound implications for understanding transmission dynamics in a region characterized by constant population movement and ecological disturbance. The identification of chiropteran reservoirs fundamentally alters our understanding of leishmaniasis ecology in migration corridors, as bats possess greater dispersal capacity than terrestrial reservoirs, potentially expanding the geographic risk range. The interdisciplinary One Health approach proved essential for comprehending the complex host-pathogen-vector interactions in this high-risk spillover zone. The creation of the DEZED ONE diploma program demonstrates how scientific collaboration can be institutionalized to address emerging zoonotic threats. These findings emphasize the critical importance of integrated surveillance systems in regions where human and animal migration patterns create conditions conducive to pathogen emergence and spread. The community engagement component highlights that effective spillover prevention requires not only scientific understanding but also active participation of at-risk populations in surveillance and control measures.

Keywords: Leishmania, One Health, interdisciplinary surveillance

The use of insecticide-impregnated collars for visceral leishmaniasis control: A One Health perspective

SILVA, Rafaella Albuquerque1

1 Department of Communicable Diseases, Ministry of Health, Brasília, Federal District, Brazil
E-mail address: rafaas28@gmail.com

Visceral leishmaniasis is a vector-borne disease with a complex transmission chain, involving the interaction of vectors with natural reservoirs and susceptible hosts, facilitated by environmental factors that promote this interaction. Brazil is the country with the highest number of VL cases in the Americas, accounting for 90% of reported cases. Among the strategies for controlling this disease in Brazil, the use of insecticide-impregnated collars (IIC) in priority areas stands out. This tool targets the canine population and has proven effective in reducing cases in dogs and humans, as well as decreasing the vector population, thereby reinforcing the One Health approach.  The adoption of a new strategy for VL control in the country requires monitoring its effectiveness and potential side effects beyond the intended impact. Approximately 45 municipalities have implemented this measure in Brazil, and 13 have completed at least four collar distribution cycles. Accordingly, this presentation will aim to analyze various aspects of Lutzomyia longipalpis behavior and biology, such as presence, distribution, abundance, and natural infection in relation to IIC use. Furthermore, considering that the use of IICs may contribute to the emergence of resistance in sandflies, the presentation will also include the establishment of a baseline susceptibility for six Lu. longipalpis populations in areas already using or planning to use insecticide-impregnated collars.  

Keywords: Lutzomyia longipalpis, visceral leishmaniasis, resistance, insecticide-impregnated collars

Leishmaniasis Argentina 1985, 2005, 2025

SALOMÓN, Oscar D1,2,3, QUINTANA María G,1,2,4,5

1 Red de investigación de las leishmaniasis en Argentina. 2 Consejo Nacional de Investigaciones Científicas y Técnicas. 3 Instituto Nacional de Medicina Tropical, ANLIS, Puerto Iguazú. 4 Instituto Superior de Entomología, Universidad Nacional de Tucumán, SM Tucumán. 5 Instituto Nacional de Medicina Tropical, ANLIS, San Miguel de Tucumán. odanielsalomon@gmail.com

Less than two decades after Leishman’s discovery, and Ross’s description of the parasite and authorship of the generic name Leishmania, a paper on ‘leishmaniosis’ in Jujuy-Tucuman was published in 1916-1917. In 1925 Nicolle, together with Mazza, Paterson and Alvarado, succeeded in culturing the parasite in Argentina from patients using the medium he had developed in Tunisia. After these pioneering works, academic and health system interest in the subject waned by 1940, and the last published capture of Phlebotominae was in 1953, although dedicated professionals in the endemic area continued to diagnose isolated cases. In 1985 an outbreak of cutaneous leishmaniasis (CL) in northern Salta gave rise to the Multidisciplinary Research Project on Leishmaniasis in Argentina coordinated by the Fatala Chabén Institute, financed by the TDR/WHO. From this project and its participating professionals, in relation to entomological aspects, focal studies were carried out with up to 4 months in the field, and systematic collection campaigns in the historic transmission area, applying since 1997 the eco-epidemiological approach proposed by Susser and Susser a year earlier. Based on the information and the new epidemiological situation the creation of the National Leishmaniasis Programme was promoted, and in its first federal meeting in 2005, after the registration of the visceral leishmaniasis vector in the urban area of Clorinda, the creation of the National Leishmaniasis Network-REDILA was proposed, integrating researchers and students from the whole endemic-epidemic area. Thus, 1985 and 2005 are symbolic milestones of a continuous process that responds to the contextual dynamics of socio-demographic marginality, epidemiological priorities and the deserved recognition of the precursors who worked since the beginning of the 20th century. Based on research coordinated by REDILA, of the 13 species of Phlebotominae recorded for Argentina until 1960, 46 are now recorded (3 new to science), distributed in 13 provinces, and its assemblages have been characterised according to phytogeographic province and ecotope. Periodic collections in areas with the highest probability of dispersal and reports of canine cases were used to track urban Lutzomyia longipalpis-Visceral Leishmaniasis (VL) southwards, characterising their populations by pheromone and haplogroups. Infection with Leishmania braziliensis, L. infantum and L. amazonensis was genotyped by molecular biology from potential vectors and reservoirs. In relation to vector ecology and exposure risk, the edge effect (CL) was described, breeding sites, hourly activity, spatio-temporal distribution and association with landscape and climatic variables at different scales were modelled. This knowledge was integrated into differentiated multiscale and multisectoral preventive monitoring proposals for urban VL and CL due to environmental modification. REDILA today integrates professionals from eight provinces, a PAHO/WHO Collaborating Center and a PAHO regional reference center, and international cooperation projects.

Key words: Ecoepidemiology, Networks, Surveillance. 

SURVEILLANCE AND IMPACTS OF CLIMATE CHANGES ON VECTORS OS LEISHMANISIS

RANGEL, Elizabeth Ferreira1, AFONSO, Margarete Martins dos Santos1, COSTA, Simone Miranda1, CARVALHO, Bruno Moreira1, VIEIRA, Vanessa Rendeiro1 & MAGALHÃES, Mônica de Avelar Figueiredo Mafra2 

1Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil.
2Instituto de Comunicação e Informação Científica e Tecnológica em Saúde, FIOCRUZ, Rio de Janeiro, RJ, Brazil.
E-mail address: efrangel@ioc.fiocruz.br

Leishmaniasis represents a significant global public health problem, especially in tropical and subtropical regions, with high endemicity in Brazil, where it manifests mainly as American Visceral Leishmaniasis (AVL) and American Cutaneous Leishmaniasis (ACL). Transmitted by infected sand flies, Lutzomyia longipalpis (the main vector of AVL) and Nyssomyia whitmani (the  main vector of ACL). Recent studies indicate that climate change, such as rising temperatures and changes in precipitation patterns, are expanding the areas of ecological suitability for these insects, enhancing the spread of transmission. Thus, this study aimed to assess the spatial distribution of sand flies, leishmaniasis vectors, in temporal slices, considering scenarios of climate change and deforestation, correlating such events with the spread of the diseases. A survey of the distribution of vectors in Brazil was carried out and georeferenced for using models analyses and projections. Ecological niche models showed that Ny. whitmani and Lu. longipalpis tend to intensify their presence in southeastern Brazil, while species such as Ny. intermedia and Ny. neivai may be reduced in this region, migrating to the northeast and south. In addition, deforestation and changes in land use have facilitated contact between vectors, wild reservoirs, and human populations, increasing the risk of outbreaks. American Visceral Leishmaniasis is a concern due to its high lethality, with cases concentrated in urban and peri-urban areas, where the adaptation of Lu. longipalpis to human-modified environments is evident. Epidemiological data highlights the correlation between deforested areas, agricultural expansion, and increasing in human cases, reinforcing the need for integrated surveillance strategies that consider climatic, socioeconomic, and environmental variables. Municipal vulnerability to transmission is aggravated by inequalities in access to health services and vector control measures. Projections for 2041-2060, under global warming scenarios (RCP 8.5), suggest stability in the distribution of Lu. longipalpis in the Southeast of the country, with possible expansion of Migonemyia migonei (secondary vector of leishmaniasis) to the South, while Bichromomyia flaviscutellata would increase its occurrence in the Atlantic Forest. These changes require adaptive public policies, such as monitoring vectors in receptive regions and the integration of predictive models with public health actions aligned with the Sustainable Development Goals. The climatic, ecological and social factors highlight the urgency of interdisciplinary approaches to mitigate the impact of leishmaniasis in the context of accelerated environmental changes.

Keywords: Leishmaniasis, Sand flies, Environmental Changes.

Créditos de las imágenes utilizadas en esta página web
Phlebotomus pappatasi, imagen por James Gathany (Centros para el Control y la Prevención de Enfermedades), Dominio Público, Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Phlebotomus_pappatasi_bloodmeal_continue2.jpg) | Las imágenes de las personas miembro de los distintos comités de LA SOVE RELCOV 2025 así como las imágenes de los/as oradores/as fueron provistas por las mismas personas para uso exclusivo en esta página web. Los/as autores/as de estas imágenes se reservan el derecho de uso y reproducción de las mismas.

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Lunes 27
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