Simposio: Enfermedad de Chagas
SIMPOSIO
Enfermedad de Chagas
COORDINA: Carolina Carrillo
¿Qué podríamos contarles hoy a Carlos Chagas y Berenice Soares de Moura?. Aportes actuales para integrar distintas dimensiones de la problemática del Chagas.
En este simposio se busca abordar la problemática del Chagas, con una mirada integradora, reconociendo tanto su complejidad en distintas dimensiones como la diversidad de miradas y de realidades en diferentes territorios.
Por esto, proponemos iniciar un recorrido que incluye aspectos entomológicos, en relación con el parásito y con la distribución geográfica. Y, reconociendo diferencias y particularidades regionales, salimos del laboratorio, como lo hicieron Carlos Chagas y Salvador Mazza, para un abordaje en terreno, de experiencias situadas, con inclusión de tecnologías, de gestión y de participación comunitaria.
The secret role of reptiles in the wild transmission cycle of Trypanosoma cruzi
BOTTO-MAHAN, Carezza1,2, QUIROGA, Nicol1, SAN JUAN, Esteban1,2, PONCE-REVELLO, Carla1,2, ALIAGA-DURÁN, Consuelo1, SIERRA-ROSALES, Catalina1, SILVA-SUÁREZ Jorge1 & CORREA, Juana P.3
1 Facultad de Ciencias, Universidad de Chile. Santiago, Chile.
2 Research Ring in Pest Insects and Climate Change (PIC2). Santiago, Chile.
3 Facultad de Medicina Veterinaria, Universidad San Sebastián. Concepción, Chile.
E-mail address: cbotto@uchile.cl
The role of birds and reptiles in the transmission cycle of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease, has received considerably less attention than that of mammals. Recently, studies based on molecular analysis have detected the presence of T. cruzi in some lizard species and have also shown that these vertebrates are blood-meal sources for hematophagous insect vectors of the Triatominae subfamily, known as kissing bugs. However, the role of reptiles in the maintenance of T. cruzi, and the route of transmission in these vertebrates remain unknown. In this study, we examine: (i) T. cruzi-infection frequency (i.e., proportion of infected lizards), (ii) infectivity (i.e., proportion of kissing bugs that become infected with T. cruzi when feeding on a lizard), and (iii) consumption of kissing bugs by lizards (i.e., presence of triatomines in lizard feces), in five native lizard species of the genus Liolaemus that inhabit the same environments as the endemic kissing bug Mepraia spinolai in north-central Chile. Field-caught lizards were subjected to xenodiagnosis (using four early-stage nymphs of M. spinolai) to establish infection frequency and infectivity. Lizard feces were collected within 72 hours after capture. Detection of T. cruzi and M. spinolai DNA was performed by real-time PCR. A total of 30 individuals of Liolaemus monticola, 30 of L. fuscus, 30 of L. platei, eight of L. nitidus, and two of L. lemniscatus were analyzed, finding infection frequencies and infectivity ranging from 3.4% to 100%, and 33.3% to 70%, respectively. Preliminarily, lizard feces do not show evidence of M. spinolai DNA but do show T. cruzi DNA. Our results suggest variation in infection frequency and infectivity among Liolaemus species, supporting the idea that some lizard species could function as wild reservoirs of T. cruzi and maintain the transmission cycle even in the absence of mammals, but the route of transmission needs further research.
Keywords: Liolaemus, triatomines, Trypanosoma cruzi infection.
Triatominae citogenomics
PITA, Sebastian1, MORA, Pablo2, RICO-PORRAS, Jose M2, CABRAL-de-MELLO, Diogo C3, BARDELLA, Vanessa B3, NATTERO, Julieta4, ROJAS-de-ARIAS, Antonieta5, PANZERA, Francisco1 & LORITE, Pedro2
1 Facultad de Ciencias, Universidad de la República. Montevideo, Uruguay.
2 Facultad de Ciencias Experimentales, Universidad de Jaén. Jaén, Spain.
3 Instituto de Biociencias, Universidade Estadual Paulista. Rio Claro, Sao Paulo, Brazil.
4 Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Buenos Aires, Argentina.
5 Centro para el Desarrollo de la Investigación Científica (CEDIC). Asunción, Paraguay.
E-mail address: spita@fcien.edu.uy
The genus Triatoma (Hemiptera: Reduviidae) exhibits a relatively conserved karyotypic structure but a remarkable variability in the amount and distribution of constitutive heterochromatin among species and lineages. This heterochromatic fraction, highly dynamic and species-specific, plays a key role in genome architecture and evolutionary diversification. The Triatominae subfamily exhibits a conserved diploid chromosome number but a remarkable variability in the amount, distribution, and composition of constitutive heterochromatin across species, reflecting intense karyotypic dynamism. Satellite DNAs (satDNAs) are key elements driving the evolution of these heterochromatic regions. This study aimed to characterize the repetitive DNA fraction, across different Triatoma species, from different phylogenetic lineages, using the graph-based clustering approach of RepeatExplorer2, among other bioinformatic tools such as RepeatMasker and RepeatProfiler. Additionally, Fluorescence in situ Hybridization (FISH) was used to determine the chromosomal location of satDNA families. Our analyses reveal that satDNA families constitute the major component of the heterochromatin, exhibiting lineage-specific patterns of amplification and chromosomal localization. The satellitome comparison among Triatoma species highlights both the evolutionary conservation of certain ancestral satDNA families and the independent expansion of others, consistent with the «library hypothesis» of satDNA evolution. These findings highlight that different satellitomes have been selectively amplified in distinct Triatoma lineages, shaping the diversity of heterochromatic regions and contributing significantly to the karyotypic evolution within Triatominae..
Keywords: Chagas disease, chromosomes, repetitive DNA.
From ecology to engagement: experiences in Chagas disease surveillance and prevention in contemporary Brazil
SOUZA, Rita C.M.
rita.souza@fiocruz.br
Triatomine Research Group. Belo Horizonte, Minas Gerais, Brazil.
Chagas disease remains a significant public health challenge in Brazil, demanding integrated approaches that combine ecological and epidemiological insights with community participation. The work conducted by the Triatomine Research Group at Fiocruz Minas aims to strengthen entomological surveillance and vector control actions through knowledge production and the development of innovative, effective, and sustainable strategies. To this end, multidisciplinary teams—including students at various academic levels, governmental institutions, and researchers—collaborate to investigate the eco-epidemiological dynamics of vectors, propose participatory surveillance measures, and expand local understanding of disease transmission. Following the certification of Triatoma infestans vector-borne transmission elimination, the decentralization of control actions, combined with limited resources and trained personnel, has compromised the sustainability of targeted program activities. Our research has shown that the presence of native triatomine species, such as Panstrongylus megistus and Triatoma sordida, naturally infected with Trypanosoma cruzi and capable of colonizing domestic environments, continues to pose an infection risk to human populations. Between 2021 and 2024, a total of 167 P. megistus specimens were analyzed from municipalities under the Divinópolis Regional Health Superintendence (MG), with 74.8% collected indoors and 25.1% in peridomestic areas. Human blood was detected in 91 insects (55%), of which 20 (22%) were infected with T. cruzi. Bedrooms had the highest prevalence of human-fed nymphs and adults. In peridomestic settings, birds were the predominant blood source (54.8%), followed by rodents and dogs. Regarding T. sordida, 1455 of 1861 captured specimens were examined, revealing an overall infection rate of 14.4%. The most prevalent T. cruzi discrete typing unit (DTU) was TcI (80%), followed by TcII, TcV, and TcIII. In response to this scenario, the TriatoKey mobile app has proven to be an effective tool for enhancing entomological surveillance by supporting triatomine identification by both health agents and the general public. Additionally, the Memory Game, aimed at children and adolescents, has helped to increase social awareness of the disease and its vectors, reinforcing the role of education in public health surveillance. In conclusion, the integration of research, education, and community engagement emerges as a promising strategy to strengthen surveillance systems and shed light on silent transmission areas, improving the health system’s responsiveness to the contemporary challenges of Chagas disease.
Keywords: Triatomines, Vector control, Health education.
Bugs in the City: The Importance of Community Science in Chagas Disease Prevention
IBARRA-CERDEÑA, Carlos N.1, ESPINAL-PALOMINO, Román1, RIANCHO, Angela1, AKÉ-CHAN, Mariela1, TOLEDO-CHELALA, Lilibeth2 & VALENTÍN, Graciela1
1Departamento de Ecología Humana, Cinvestav, Mérida, Yucatán, México
2Instituto de Investigaciones en Ecosistemas y Sustentabilidad, UNAM, Morelia, Michoacán, México
E-mail address: cibarra@cinvestav.mx
Citizen science has emerged as a strategic tool in public health, particularly for the surveillance of vector-borne diseases such as Chagas disease. However, little is known about which social sectors are willing to participate in such initiatives and how they perceive their value. This study evaluated both public perceptions of citizen science and its practical implementation through a participatory monitoring system focused on kissing bugs in urban and peri-urban areas. A digital survey was distributed to five key social sectors in Mexico—academics, students, healthcare workers, the general population, and individuals affected by Chagas disease—to assess their familiarity with citizen science, willingness to participate, and perceived barriers. A total of 479 responses were collected from 29 Mexican states between 2022 and 2023. In parallel, from 2020 to 2025, we carried out a citizen participation program for the voluntary reporting of domiciliary kissing bugs. Submitted specimens were taxonomically identified and tested for Trypanosoma cruzi infection. Ninety-three percent of respondents agreed that involving the public in science is important, and 87% indicated they would participate in projects related to vector surveillance. Motivations included interest in public health, learning opportunities, and civic engagement, while the main barriers were time constraints and lack of prior knowledge. In the participatory surveillance component, nearly 500 kissing bugs were reported. Of these, 26% tested positive for Trypanosoma cruzi. Most specimens came from recently developed peri-urban areas, but the highest infection prevalence was found in insects collected from central urban neighborhoods. These findings underscore the dual potential of citizen science—as a platform for community engagement and as an effective tool for entomological surveillance. Public attitudes reflect strong support for participatory science, particularly in health-related contexts. The identification of T. cruzi-infected kissing bugs in urban areas highlights the need to integrate citizen involvement into sustainable and locally grounded strategies for Chagas disease prevention and vector monitoring in Latin American cities.
Keywords: Citizen observatory, Public engagement, Chagas disease surveillance, Urban infestation.
Urban Chagas: vector presence and the reality of this issue in the province of San Juan
SALVA, LE1
1 Programa Provincial Control de Enfermedades de Transmisión Vectorial, Ministerio de Salud. San Juan, Argentina.
E-mail address: vectores.saludsj@gmail.com
San Juan Province, with a long history as an endemic area for Chagas disease, is currently facing an evolving epidemiological challenge. The urbanization of the kissing bug (Triatoma infestans) and evidence of acute vector-borne cases in the urban areas of “Gran San Juan” have transformed the landscape of Chagas in the region. The presence of these insects in urban centers underscores the urgency of redefining and adapting existing control and prevention strategies, which have traditionally focused on rural areas. One of the main challenges lies in the presence of Trypanosoma cruzi in kissing bugs captured in urban environments, a phenomenon that reveals an “urban trypanosome route.” Added to this is a high occurrence of seropositive Chagas cases in the human population, as well as significant positivity in canine surveillance. Dogs, as domestic reservoirs of the parasite, act as key indicators of T. cruzi circulation in the environment, and their detection in urban areas raises concerns about transmission to humans. This triad—infected kissing bugs, seropositive humans, and highly positive canines—constitutes a complex and dynamic risk scenario that calls for proactive intervention. In response to this emerging reality, the proposed strategy to address urban Chagas in San Juan focuses on community surveillance and the identification of high-risk areas. This collaborative approach actively involves communities in the detection of kissing bugs and the reporting of possible cases, thereby strengthening local response capacity. A significant advancement in 2023 was the publication of the “Recomendaciones para el control vectorial de Chagas en zonas urbanas” by the “Mesa de Chagas urbano”. This document presents an innovative strategy based on a risk-scoring system that enables the stratification of urban areas according to their vulnerability. By assigning different priority levels, resources can be allocated more efficiently and interventions can be more targeted and effective. This reference framework complements the existing vector control guidelines for rural areas, providing a specific tool adapted to the particularities of the urban context. The complexity of Chagas disease in San Juan is a true reflection of its multifaceted nature in this context of increasing urbanization. Understanding the new transmission scenarios and implementing tailored strategies are crucial to mitigate the impact of this neglected disease.
Keywords: Chagas in San Juan, Urban Chagas, Urban Triatomine-ism
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Triatoma infestans, imagen por Fedaro, CC-SA 4.0, WikimediaCommons (https://commons.wikimedia.org/wiki/File:Triatoma_infestans_macro.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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