Presence of Trypanosoma cruzi TcI and Trypanosoma dionisii in sylvatic bats from Yucatan, Mexico.

BACKGROUND: Chagas disease is caused by Trypanosoma cruzi, whose genetic structure is divided into six discrete typing units (DTUs) known as TcI-TcVI. In the Yucatan Peninsula, Mexico, information regarding the DTUs circulating in wild mammals is scarce, while this is important knowledge for our understanding of T. cruzi transmission dynamics. METHODS: In the current study, we sampled wild mammals in a sylvatic site of the Yucatan Peninsula and assessed their infection with T. cruzi by PCR. Then, for infected mammals, we amplified and sequenced nuclear and mitochondrial T. cruzi genetic markers for DTU identification. RESULTS: In total, we captured 99 mammals belonging to the orders Chiroptera, Rodentia and Didelphimorphia. The prevalence of infection with T. cruzi was 9% (9/99; 95% CI [5, 16]), and we identified TcI in a Jamaican fruit bat, Artibeus jamaicensis. Moreover, we fortuitously identified Trypanosoma dionisii in another Jamaican fruit bat and detected an unidentified Trypanosoma species in a third specimen. While the latter discoveries were not expected because we used primers designed for T. cruzi, this study is the first to report the identification of T. dionisii in a bat from Yucatan, Mexico, adding to a recent first report of T. dionisii in bats from Veracruz, and first report of this Trypanosoma species in Mexico. CONCLUSION: Further research is needed to enhance our knowledge of T. cruzi DTUs and Trypanosoma diversity circulating in wildlife in Southeastern Mexico.

From molecules to ecosystems: Insights into a network of interactions for a Chagas disease outbreak using Triatoma brasiliensis as natural samplers.

Exploring the dynamics of disease transmission involves an understanding of complex interactions within the eco-epidemiologic framework. In the context of Chagas disease (CD), elements are mainly represented by the interactions among the pathogen, insect vector, host, humans and the environment. We performed quantitative and qualitative analyses on a dataset derived from 98 Triatoma brasiliensis infected by trypanosomatids, which were linked to a CD outbreak in the semi-arid region of northeastern Brazil. We extracted invertebrate-derived DNA (iDNA) from these insects, comprising 18 populations around the outbreak area, each indicative of various strata of anthropogenic influence. Food source (FS) diversity, representing potential parasite reservoirs, was determined through mitochondrial gene (cyt b) sequencing of vertebrates, and parasite genotyping was accessed using fluorescent amplified fragment barcodes (FFLB) of trypanosomatids. We also assessed the residents' awareness of breeding sites for CD vectors in the inspected houses. The quantification of Trypanosoma cruzi was estimated via real-time PCR and is denominated here as the average parasite load (PL) per insect (T. cruzi/intestinal unit). We aimed to address vector-parasite-host-environment interactions that were discussed based on their significance among the components. Notably, among the significant interactions, we observed that the PL in the insects was significantly influenced by FS. Infected insects that fed on the classic reservoir, Didelphis albiventris, and Galea spixii exhibited higher PLs, compared to those that fed on Kerodon rupestris (p < 0.04)-a primary host. While D. albiventris is already recognized as a synanthropic species, we propose that G. spixii may also be undergoing a synanthropic process. Conversely, domestic cats are frequently identified as FS in infected insects from the sylvatic environment, suggesting a possible change in their behavior towards a wild state. Therefore, we propose that neglected anthropogenic actions have facilitated the reciprocal (sylvatic-peridomestic) circulation of T. cruzi-especially noted for TcI because it was predominant in insects found in peridomestic environments. Residents are often unaware of the existence of insect breeding grounds near their homes, particularly when it involves the storage of materials without planning for use, such as piles of tiles, bricks and wood. Although indirect inferences about the interaction among vector-parasite-host-environment are still incipient, we highlight the potential use of vectors as natural samplers of biological and ecological components in transmitting the disease.

Competencias en salud ambiental y cambio climático en estudiantes universitarios / Competences in environmental health and climate change in university students

El deterioro del medio ambiente ha acelerado el cambio climático (CC) afectando mútiples escenarios, el aumento de la temperatura ha conllevado a la proliferación de diversas enfermedades trasmitidas por vectores de importancia a nivel de salud pública. Como objetivo, se propuso determinar la cultura ecosaludable ante el cambio climático en estudiantes del Área Ciencias de la Educación, Universidad Nacional Experimental Rómulo Gallegos (UNERG), Calabozo, Venezuela 2022. El estudio fue cuantitativo exploratorio no experimental de corte transversal con una muestra de 180 estudiantes. Para la recolección de datos se aplicó el Cuestionario de Dimensiones Ambientales (CDA) compuesto de 75 ítems distribuidos en tres dimensiones; conocimientos, actitudes, emociones y comportamientos. El análisis de los datos fue por estadística descriptiva con porcentajes a través del programa Epidat 3.0. Como resultado, 63% indicó la importancia atribuida de los elementos de ecosalud afectados sobre el agua y 55% al calentamiento global. No obstante, solo 12% indicó la educación como un elemento de ecosalud afectado por el cambio climático, así mismo, en la dimensión de conocimientos se encontró 54,50% a CSN, 6,50% a CPR y 39,50% a CEA, en la dimensión de actitudes y emociones se encontró 55,50% a la subcategoria TD, 44,00% a CVA y 36,50% a E, finalmente, en la dimensión de comportamiento, se evidenció 36,50% a la subategoria de PC, 29,00% a IC y 20,00% a PI. Se debe evitar el daño ambiental a través del cambio de comportamiento individual que debe ser enseñado desde los recintos universitarios(AU)

The deterioration of the environment has accelerated climate change (CC) affecting multiple scenarios, the increase in temperature has led to the proliferation of various diseases transmitted by vectors of importance at the public health level. As an objective, it was proposed to determine the eco-healthy culture in the face of climate change in students of the Educational Sciences Area, Rómulo Gallegos National Experimental University (UNERG), Calabozo, Venezuela 2022. The study was quantitative, exploratory, non-experimental, cross-sectional with a sample of 180 students. For data collection, the Environmental Dimensions Questionnaire (CDA) was applied, consisting of 75 items distributed in three dimensions; knowledge, attitudes and emotions and behaviors. Data analysis was by descriptive statistics with percentages through the Epidat 3.0 program. As a result, 63% indicated the importance attributed to the affected ecohealth elements on water and 55% on global warming. However, only 12% indicated education as an element of ecohealth affected by climate change, likewise, in the knowledge dimension, 54.50% were found to CSN, 6.50% to CPR and 39.50% to CEA, in the dimension of attitudes and emotions, 55.50% were found in the TD subcategory, 44.00% in CVA and 36.50% in E, finally, in the behavior dimension, 36.50% were found in the subcategory of PC, 29.00% to IC and 20.00% to PI. Environmental damage must be avoided through individual behavior change that must be taught from university campuses(AU)

The long-term impact of an Ecohealth intervention: Entomological data suggest the interruption of Chagas disease transmission in southeastern Guatemala.

Triatoma dimidiata is the main vector of Chagas disease in southern Mexico, Central America and northern South America. As a native vector, it moves readily among domestic, peri­domestic and sylvatic environments, making it difficult to control only using insecticide as this requires regular application, and re-infestation frequently occurs. Other social innovation alternatives such as those based on Ecohealth principles can be used to tackle the dynamics of the disease in an integral way. We asked whether an Ecohealth intervention, implemented beginning in 2001 in a highly infested village, 41.8%, in southeastern Guatemala, was sustainable in the long term. This intervention included initial insecticide treatments, followed by making low-cost house improvements to eliminate transmission risk factors such as repairing cracked walls, covering dirt floors with a cement-like substance and moving domestic animals outside. We assessed the long-term sustainability through entomological and house condition surveys, as well as an analysis of community satisfaction. We found over a 19-year period, infestation with T. dimidiata was reduced to 2.2% and maintained at a level below the level (8%) where vector transmission is unlikely. This long-term maintenance of low infestation coincided with a large proportion of villagers (88.6%) improving their houses and completing other aspects of the Ecohealth approach to maintain the village at low risk for Chagas transmission. There was unanimous satisfaction among the villagers with their houses, following improvements using the Ecohealth method, which likely played a role in the long-term persistence of the modifications. Although the infestation has remained low, 11 years following the last intervention and as the population grew there has been an increase in the proportion of "at-risk" houses, to 33%, pointing out the necessity of maintaining vigilance. The Ecohealth approach is a low-cost, sustainable approach for the long-term control of vector-borne Chagas disease. We recommend this approach including ongoing community monitoring and institutional response for the long-term, integrated control of Chagas disease.

Participação e transdisciplinaridade em Ecosaúde: a perspectiva da análise de redes sociais / Participation and transdisciplinarity in Ecohealth: a social network analysis perspective

Resumo A Ecosaúde usa abordagens participativas e transdisciplinares com o intuito de compreender as inter-relações entre os componentes dos sistemas socioecológicos e como estas interações influenciam a saúde das populações humanas. O objetivo do artigo é usar a Análise de Redes Sociais (ARS) para entender o papel das relações de colaboração entre os diversos atores envolvidos nos processos participativos e transdisciplinares em projetos de Ecosaúde. Apresentamos um conjunto de indicadores de ARS para caracterizar a evolução e a equidade de participação e diferenciar a inter e a transdisciplinaridade. A análise foi feita com base na rede de colaboração entre os atores da Iniciativa de Liderança em Ecosaúde para as Enfermidades Transmitidas por Vetores (ETV) na América Latina e Caribe. O processo participativo ficou mais intenso ao longo do projeto, com mais sujeitos envolvidos e um número crescente de colaborações. A cooperação entre os atores das ciências sociais, ambientais e da saúde é pouco equitativa; assim, predominam as ciências da saúde. Os poucos cientistas ambientais presentes estão, porém, ativamente envolvidos em colaborações interdisciplinares. A abordagem tem aplicação ampla para estudar a participação e a transdisciplinaridade em projetos sobre saúde e meio ambiente.

Abstract Ecohealth uses participatory and transdisciplinary approaches to understand the relationships between the components of socio-ecological systems and how these interactions influence the health of human populations. This article aims to use Social Network Analysis (SNA) to understand the role of collaborative relationships between the various actors involved in participatory and transdisciplinary processes in Ecohealth projects. We present a set of SNA indicators to characterize the evolution and equity of participation and to differentiate inter- and transdisciplinarity. The analysis was based on the collaboration network among the members of the Iniciativa Para el Liderazgo y Desarrollo del Campo de Ecosalud y Enfermedades Transmitidas por Vectores (ETV) en América Latina y el Caribe. The participatory process intensified throughout the project, with more individuals involved and increasing collaborations. Cooperation between members from social, environmental, and health sciences is unbalanced and health scientists predominate. The few environmental scientists are, however, actively involved in interdisciplinary collaborations. The proposed approach has wide application to study participation and transdisciplinarity in projects about health and environment.

From the Approach to the Concept: One Health in Latin America-Experiences and Perspectives in Brazil, Chile, and Colombia.

Professionals throughout the world have been working to assess the interdisciplinary interaction and interdependence between health and wellbeing in a constantly changing environment. The One Health concept was developed to encourage sustainable collaborative partnerships and to promote optimal health for people, animals, plants, the environment, and the whole planet. The dissemination of scientific discoveries and policies, by working directly with diverse communities, has been one of the main goals for Global One Health. The One Health concept has also been referred or related to as "One Medicine, One Medicine-One Health, One World-One Health, EcoHealth," and Planetary Health," depending on each fundamental view and approach. In Latin America, despite the concept still being discussed among health professionals and educators, several One Health initiatives have been used daily for more than decades. One Health action has been applied especially in rural and underserved urban areas where low socioeconomic status, lack of health professionals, and scarcity of medical resources may require professionals to work together. Local communities from diverse social and economic statuses, including indigenous populations have been working with institutions and social organizations for many years, accomplishing results through grassroots movements. These "bottom-up" socio-community approaches have also been tools for the prevention and control of diseases, such practice has preceded the One Health concepts in Latin American countries. It is strongly believed that collaborative, multidisciplinary, political, and economic initiatives with prosocial focus may become investments toward obtaining significant results in the face of global, economic and health challenges; working for a healthier world with inclusivity, equity, and equality. In this study, it is briefly presented how the One Health approach has been initiated and developed in Latin America, highlighting the events and actions taken in Brazil, Chile, and Colombia.

One Decade of Environmental Disasters in Brazil: The Action of Veterinary Rescue Teams.

Based on the interdisciplinary concept of One Health, EcoHealth, and Planetary Health, this paper focuses on participatory knowledge-to-action approaches by relating one decade of environmental disasters in Brazil with the action of veterinary rescue teams, aiming to give support to future disaster preparedness. This paper will present the historic actions of teams rescuing animal that are victims of environmental disasters, in addition to addressing the need for contingency plans and response management in these types of events. The main events in Brazilian states where veterinary rescue teams participated were, chronologically, as follows: 2011 flood and landslide (Rio de Janeiro); 2012 flood (Acre, Minas Gerais, and Pará); 2015 dam break (Minas Gerais); 2017 flood (Minas Gerais) and forest fire (Minas Gerais and Goiás); 2019 dam break and evacuation (Minas Gerais) and flood (Bahia); 2020 flood (Espírito Santo and Minas Gerais) and forest fires (Mato Grosso and Mato Grosso do Sul). The Brazilian disasters that had a large global repercussion were the ruptures of the ore dams in Marina (2015) and Brumadinho (2019), both in the State of Minas Gerais. The role of veterinarians in these events was recognized by the Federal Council of Veterinary Medicine (CFMV) after their performance in Mariana, Minas Gerais (2015), and in 2020, the CFMV approved the National Mass Disaster Contingency Plan Involving Animals. The work of veterinarians in interaction with other professionals in environmental disasters proved to be effective and necessary for the rescue of animals and for planning and giving support to disaster preparedness in the future.

Severe airport sanitarian control could slow down the spreading of COVID-19 pandemics in Brazil.

BACKGROUND: We investigated a likely scenario of COVID-19 spreading in Brazil through the complex airport network of the country, for the 90 days after the first national occurrence of the disease. After the confirmation of the first imported cases, the lack of a proper airport entrance control resulted in the infection spreading in a manner directly proportional to the amount of flights reaching each city, following the first occurrence of the virus coming from abroad. METHODOLOGY: We developed a Susceptible-Infected-Recovered model divided in a metapopulation structure, where cities with airports were demes connected by the number of flights. Subsequently, we further explored the role of the Manaus airport for a rapid entrance of the pandemic into indigenous territories situated in remote places of the Amazon region. RESULTS: The expansion of the SARS-CoV-2 virus between cities was fast, directly proportional to the city closeness centrality within the Brazilian air transportation network. There was a clear pattern in the expansion of the pandemic, with a stiff exponential expansion of cases for all the cities. The more a city showed closeness centrality, the greater was its vulnerability to SARS-CoV-2. CONCLUSIONS: We discussed the weak pandemic control performance of Brazil in comparison with other tropical, developing countries, namely India and Nigeria. Finally, we proposed measures for containing virus spreading taking into consideration the scenario of high poverty.

Snakebite envenoming from an Ecohealth perspective.

Snakebite envenomings occur in complex ecological, social, economic, cultural, and political contexts. Hence, the understanding of this public health issue demands systemic and holistic approaches. Ecohealth constitutes a valuable paradigm to study snakebites, as it emphasizes on the close linkages between ecosystems, society, and health. This essay highlights some of the areas in the field of snakebite envenoming that could greatly benefit from an Ecohealth approach based on trans-disciplinary research, systems thinking, and the involvement of stakeholders at many levels. Ecohealth focuses not only on the generation of knowledge through research, but also in the translation of knowledge into actions.

Species-level drivers of mammalian ectoparasite faunas.

Traditionally, most studies have described the organization of host-parasite interaction networks by considering only few host groups at limited geographical extents. However, host-parasite relationships are merged within different taxonomic groups and factors shaping these interactions likely differ between host and parasite groups, making group-level differences important to better understand the ecological and evolutionary dynamics of these interactive communities. Here we used a dataset of 629 ectoparasite species and 251 species of terrestrial mammals, comprising 10 orders distributed across the Nearctic and Neotropical regions of Mexico to assess the species-level drivers of mammalian ectoparasite faunas. Specifically, we evaluated whether body weight, geographical range size and within-range mammal species richness (i.e. diversity field) predict mammal ectoparasite species richness (i.e. degree centrality) and their closeness centrality within the mammal-ectoparasite network. In addition, we also tested if the observed patterns differ among mammal orders and if taxonomic closely related host mammals could more likely share the same set of ectoparasites. We found that ectoparasite species richness of small mammals (mainly rodents) with large proportional range sizes was high compared to large-bodied mammals, whereas the diversity field of mammals had no predictive value (except for bats). We also observed that taxonomic proximity was a main determinant of the probability to share ectoparasite species. Specifically, the probability to share ectoparasites in congeneric species reached up to 90% and decreased exponentially as the taxonomic distance increased. Further, we also detected that some ectoparasites are generalists and capable to infect mammalian species across different orders and that rodents have a remarkable role in the network structure, being closely connected to many other taxa. Hence, because many rodent species have synanthropic habits they could act as undesired reservoirs of disease agents for humans and urban animals. Considering the reported worldwide phenomenon of the proliferation of rodents accompanying the demographic decrease or even local extinction of large-bodied mammal species, these organisms may already be an increasing health threat in many regions of the world.

Morphological variability and ecological characterization of the Chagas disease vector Triatoma dimidiata (Hemiptera: Reduviidae) in El Salvador.

There are 8 million people with Chagas disease worldwide and in El Salvador approximately 39% of the population is at risk of contracting the disease. One of the principal challenges in mitigating Chagas is evaluating the role of the vector ecology of triatomine species in the transmission of the Trypanosoma cruzi parasite in anthropogenically modified habitats, where new patterns of transmission frequently arise. Field studies of triatomine vector ecology in El Salvador have largely focused on describing parameters that contribute to infestation patterns, which may themselves be rooted in the morphological variability that exists in triatomine populations. The objective of this study was to evaluate the morphology of the vector species Triatoma dimidiata with respect to the characteristics of the ecological landscape the vector inhabits throughout El Salvador. We used image analyses to evaluate T. dimidiata morphological variability and then used Geographic Information Systems to intersect the morphological point-data with map layers containing different environmental characteristics. Our study found that the variation in the size, shape, and coloration of T. dimidiata varied in relation to elevation, Holdridge life zone, soil type and land use. We further characterize the local morphological adaptations of T. dimidiata with respect to the local ecological, biological, and geographical conditions in El Salvador. We suggest that future studies consider a molecular exploration of local T. dimidiata species complex in El Salvador, especially since morphological studies of triatomine species complex have found that variability correlate with the genetic variability of the population.

Disentangling Trypanosoma cruzi transmission cycle dynamics through the identification of blood meal sources of natural populations of Triatoma dimidiata in Yucatán, Mexico.

BACKGROUND: In the Yucatán Peninsula, Mexico, Triatoma dimidiata is the main vector of Trypanosoma cruzi, the causative agent of Chagas disease. Little effort has been made to identify blood meal sources of T. dimidiata in natural conditions in this region, although this provides key information to disentangle T. cruzi transmission cycles and dynamics and guide the development of more effective control strategies. We identified the blood meals of a large sample of T. dimidiata bugs collected in different ecotopes simultaneously with the assessment of bug infection with T. cruzi, to disentangle the dynamics of T. cruzi transmission in the region. METHODS: A sample of 248 T. dimidiata bugs collected in three rural villages and in the sylvatic habitat surrounding these villages was used. DNA from each bug midgut was extracted and bug infection with T. cruzi was assessed by PCR. For blood meal identification, we used a molecular assay based on cloning and sequencing following PCR amplification with vertebrate universal primers, and allowing the detection of multiple blood meals in a single bug. RESULTS: Overall, 28.7% of the bugs were infected with T. cruzi, with no statistical difference between bugs from the villages or from sylvatic ecotopes. Sixteen vertebrate species including domestic, synanthropic and sylvatic animals, were identified as blood meal sources for T. dimidiata. Human, dog and cow were the three main species identified, in bugs collected in the villages as well as in sylvatic ecotopes. Importantly, dog was highlighted as the main blood meal source after human. Dog was also the most frequently identified animal together with human within single bugs, and tended to be associated with the infection of the bugs. CONCLUSIONS: Dog, human and cow were identified as the main mammals involved in the connection of sylvatic and domestic transmission cycles in the Yucatán Peninsula, Mexico. Dog appeared as the most important animal in the transmission pathway of T. cruzi to humans, but other domestic and synanthropic animals, which most were previously reported as important hosts of T. cruzi in the region, were evidenced and should be taken into account as part of integrated control strategies aimed at disrupting parasite transmission.

Efecto de la educación comunitaria para control integrado del Triatoma Dimidiata (Hemiptera: Reduviidae) / EEffect of community education in an integrate control for Triatoma dimidiata (Hemiptera: Reduviidae) / EEffect of community education in an integrate control for Triatoma dimidiata (Hemiptera: Reduviidae)

Introduction: The Mesoamerican endemic specieTriatoma dimidiata is the main vector of Chagas disease in Central America, after the elimination of an introduced vector Rhodnius prolixus. The traditional method of vector control using insecticides results in reinfestation. An integrated Ecohealth approach, including education, house improvements and domestic animal management was shown effective for long-term control ofT. dimidiata, and it was applied in several villages in Guatemala. Objective: To evaluate the changes in community practices after an Ecohealth intervention in La Prensa, Olopa Chiquimula. Methods: Through three surveys, we measured risk factors associated withT. dimidiatainfestation, the infestation index, blood sources of T. dimidiata, the presence of Trypanosoma cruzi were analyzed using PCR. Statistics analysis included Wilcoxon signed-rank tests, Mc-Nemar test, Chi-square test and Fisher exact test to compare the surveys. Results: Over the years, risk factors associated with the presence of T. dimidiata and population density of the vector were observed. We found a decrease in consumption of human blood and the parasite in the vector population. However, we found the consumption of bird blood meal increased Conclusions: Our results provide evidence that an ecohealth approach for an endemic Chagas vector has impact on reducing vector-human contact, possibly by influencing people's behavior. Increasing the community knowledge about these risk factors can be an effective strategy to further reduce the risk of house reinfestation and Chagas transmission(AU)

Introducción: La especie endémica mesoamericana Triatoma dimidiata es el vector principal de la enfermedad de Chagas en América Central, después de la eliminación de un vector introducido Rhodnius prolixus. El método tradicional de control de vectores que utiliza insecticidas resulta en reinfestación. Se demostró que un enfoque integrado de ecosalud, que incluye la educación, mejorías en el hogar y manejo de animales domésticos, es efectivo para el control a largo plazo del T. dimidiata, y se aplicó en varias aldeas de Guatemala. Objetivo: evaluar los cambios en las prácticas comunitarias después de una intervención de ecosalud en La Prensa, Olopa Chiquimula. Métodos: a través de tres encuestas, se midieron los factores de riesgo asociados con la infestación de T. dimidiata, el índice de infestación, las fuentes sanguíneas de T. dimidiata y la presencia de Trypanosoma cruzi. Estas encuestas se analizaron mediante PCR. El análisis estadístico incluyó pruebas de Wilcoxon de rango con signo, la prueba de Mc-Nemar, la prueba de Chi-cuadrado y la prueba exacta de Fisher para comparar las encuestas. Resultados: A lo largo de los años, se observaron factores de riesgo asociados con la presencia de T. dimidiata y la densidad de población del vector. Encontramos una disminución del parásito en la población de vectores y en el consumo de sangre humana. Sin embargo, encontramos que aumentó el consumo de harina de sangre de aves. Conclusiones: Nuestros resultados proporcionan evidencia de que un enfoque de ecosalud para un vector de Chagas endémico impacta en la reducción del contacto vector-humano, posiblemente al influir en el comportamiento de las personas. Aumentar el conocimiento de la comunidad sobre estos factores de riesgo puede ser una estrategia efectiva para reducir aun más el riesgo de reinfestación en la casa y la transmisión de Chagas(AU)

Protein mass spectrometry detects multiple bloodmeals for enhanced Chagas disease vector ecology.

Chagas disease, a neglected tropical disease endemic in Latin America, is caused by the protozoan parasite Trypanosoma cruzi and is responsible for significant health impacts, especially in rural communities. The parasite is transmitted by insect vectors in the Triatominae subfamily and due to lack of vaccines and limited treatment options, vector control is the main way of controlling the disease. Knowing what vectors are feeding on directly enhances our understanding of the ecology and biology of the different vector species and can potentially aid in engaging communities in active disease control, a concept known as Ecohealth management. We evaluated bloodmeals in rural community, house-caught insect vectors previously evaluated for bloodmeals via DNA analysis as part of a larger collaborative project from three countries in Central America, including Guatemala. In addition to identifying bloodmeals in 100% of all samples using liquid chromatography tandem mass spectrometry (LC-MS/MS) (n = 50), strikingly for 53% of these samples there was no evidence of a recent bloodmeal by DNA-PCR. As individual vectors often feed on multiple sources, we developed an enhanced detection pipeline, and showed the ability to quantify a bloodmeal using stable-isotope-containing synthetic references peptides, a first step in further exploration of species-specific bloodmeal composition. Furthermore, we show that a lower resolution mass spectrometer is sufficient to correctly identify taxa from bloodmeals, an important and strong attribute of our LC-MS/MS-based method, opening the door to using proteomics in countries where Chagas disease is endemic.

Residual survival and local dispersal drive reinfestation by Triatoma dimidiata following insecticide application in Guatemala.

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and transmitted by triatomine insect vectors. In Guatemala, insecticide spraying is an integral part of management of the main vector, Triatoma dimidiata. Spraying typically has low efficacy, which may be due to incomplete elimination from infested houses, within-village dispersal, or influx from other villages or sylvan environments. To evaluate how these mechanisms contribute to reinfestation, we conducted a time-course analysis of T. dimidiata infestation, abundance and household genetic structure in two nearby villages in Jutiapa, Guatemala; houses in the first village were surveyed, treated with insecticide if infested and then re-surveyed at eight and 22 months following spraying, while the second village served as an untreated control to quantify changes associated with seasonal dispersal. Insects were genotyped at 2-3000 SNP loci for kinship and population genetic analyses. Insecticide application reduced overall infestation and abundance, while the untreated village was stable over time. Nevertheless, within two years 35.5% of treated houses were reinfested and genetic diversity had largely recovered. Insects collected from reinfested houses post-spraying were most closely related to pre-spray collections from the same house, suggesting that infestations had not been fully eliminated. Immigration by unrelated insects was also detected within a year of spraying; when it occurred, dispersal was primarily local from neighboring houses. Similar dispersal patterns were observed following the annual dispersal season in the untreated village, with high-infestation houses serving as sources for neighboring homes. Our findings suggest that the efficacy of pyrethroid application is rapidly diminished by both within-house breeding by survivors and annual cycles of among-house movement. Given these patterns, we conclude that house structural improvements, an integral part of the Ecohealth approach that makes houses refractory to vector colonization and persistence, are critical for long-term reduction of T. dimidiata infestation.

Ecosystem Research Experience with Two Indigenous Communities of Colombia: The Ecohealth Calendar as a Participatory and Innovative Methodological Tool.

Eco-bio-social factors may increase or decrease a community's susceptibility to vector-borne disease transmission. Traditional studies have contributed information about the association between eco-bio-social factors and health outcomes, but few have provided this information in an integrative way characterizing annual dynamics among indigenous communities. Transdisciplinary research was conducted with the Bari of Karikachaboquira and the Wayúu of Marbacella and El Horno, using qualitative and participatory methods, including seasonal graphics, semi-structured interviews, geo-referencing routes, and participatory observation. The information was triangulated and discussed with local actors in order to validate and complement the results. An ecohealth calendar was obtained for each community, linking the socioecological dynamics to specific diseases, especially malaria. Local dynamics can change, depending on environmental conditions, and these determine the presence or absence of diseases. For both communities, the rainy season is the period with the greatest proliferation of mosquitoes (including Anopheles spp.), during which malaria cases occur. The ecohealth calendar integrates eco-bio-social information from local communities, through participatory and potentially empowering processes, into a comprehensive layout. This can break down the conceptual, demographic, and cultural barriers in the context of community-based interventions and research to action based on an ecosystem framework.

The Role of Gender in Chagas Disease Prevention and Control in Honduras: An Analysis of Communication and Collaboration Networks.

In Honduras, where Chagas disease is a serious health and environmental concern, prevention measures face the challenge of achieving widespread and long-term sustainable adoption by communities. The article integrates social network analysis and a gender-sensitive approach to understand the role of men and women in the implementation of a community-level intervention, based on the adoption of housing improvements to reduce the presence of the insect vector. A total of 108 people in the community of El Salitre were interviewed. Data were collected on socio-demographic characteristics, participation in project activities, communication and collaboration networks related to Chagas disease prevention, knowledge of Chagas disease, and adoption of housing improvements techniques. Communication mostly occurred between the same gender individuals and was associated with knowledge of Chagas disease. Socioeconomic status, Chagas disease knowledge, and collaboration with men were associated with women adopting housing improvements. For men, however, participation in project activities, formal education, and collaboration with women were associated with adoption. These findings suggest that men and women were driven by distinct concerns, interests, and motivations when adopting new Chagas disease prevention strategies. Participatory community interventions that seek to generate health knowledge and foster collaborations to reduce health risk should address gender differences.

Intervención educativa para modificar conocimientos, actitudes y prácticas sobre la malaria en escolares indígenas Ye´kwana / Educational intervention to modify knowledge, attitudes and practices about malaria in Ye´kwana schools

En zonas endémicas y remotas con población indígena vulnerable, es necesario aplicar medidas que contribuyan a contrarrestar el aumento de la malaria, adicionales al diagnóstico temprano, tratamiento y control vectorial. Se evalúa el cambio en niveles de conocimiento, actitudes y prácticas (CAP) en relación a la prevención y control de la malaria en una población escolar indígena de nivel primario, luego de la aplicación de un proyecto pedagógico de aula. Se realizó una evaluación cuantitativa, siguiendo un diseño cuasi-experimental, tipo preintervención y postintervención de carácter exploratorio, con población escolar de 3er y 4to grado,en cinco comunidades del pueblo Ye´kwana de la cuenca del río Caura (Estado Bolívar, Venezuela). Docentes interculturales bilingües, previo consentimiento informado, realizaron la intervención educativa y evaluaron resultados con el uso de un cuestionario sobre conocimientos, actitudes y prácticas traducido al Ye´kwana. Se analizaron los datos de la intervención mediante prueba de rangos con signo de Wilcoxon para datos pareados (prueba de dos colas), antes de la intervención (T1), al finalizar la misma (T2) y un tiempo después de la intervención (T3=45-60 días). En el intervalo T1-T3 se registraron cambios positivos y mejoras significativas (P<0,05) en todas las preguntas de conocimiento, y en el área de actitud hubo cambios no significativos. En el área de práctica para el control de la malaria, las respuestas registradas fueron mixtas. Los resultados indican que el proyecto pedagógico de aula evaluado puede ser muy útil en la prevención y control de la malaria, desde las escuelas comunitarias indígenas.

In remote areas with endemic and vulnerable indigenous population, it is necessary to implement measures that help to offset the increase of malaria, in addition to theearly diagnosis, treatment and vector control. Here, we evaluate a classroom project to change levels of knowledge, attitudes and practices (KAP) in relation to the prevention and control of malaria in amerindian school population of primary level. We carried out a quantitative assessment, under a quasi-experimental “before and after” design, with children from 3rd and 4th grades in five Ye'kwana communities inthe Caura River Basin (Bolivar State, Venezuela). According to previously informed community consent, intercultural bilingual teachers performed and evaluated results of the educational intervention using a questionnaire on knowledge, attitudes and practices translated into Ye'kwana language. Intervention data were analyzed by Wilcoxon signed pairedtests. We compared differences between before intervention (T1), immediately after (T2), and also some time afterthe intervention (T3 = 45-60 days).In the T1-T3 interval significant improvements (P<0.05) were recorded in all questions of knowledge and a positive, non-significant changes in all attitude questions. Changes in practices for malaria prevention were mixed.The results show thepotentialforthe classroom-teaching project tested toassist in the prevention and control of malaria at indigenous community schools.

Intrusive versus domiciliated triatomines and the challenge of adapting vector control practices against Chagas disease

Chagas disease prevention remains mostly based on triatomine vector control to reduce or eliminate house infestation with these bugs. The level of adaptation of triatomines to human housing is a key part of vector competence and needs to be precisely evaluated to allow for the design of effective vector control strategies. In this review, we examine how the domiciliation/intrusion level of different triatomine species/populations has been defined and measured and discuss how these concepts may be improved for a better understanding of their ecology and evolution, as well as for the design of more effective control strategies against a large variety of triatomine species. We suggest that a major limitation of current criteria for classifying triatomines into sylvatic, intrusive, domiciliary and domestic species is that these are essentially qualitative and do not rely on quantitative variables measuring population sustainability and fitness in their different habitats. However, such assessments may be derived from further analysis and modelling of field data. Such approaches can shed new light on the domiciliation process of triatomines and may represent a key tool for decision-making and the design of vector control interventions.