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Objetivo. Sistematizar, evaluar y sintetizar la investigación original específica en México sobre la zoonosis por Trypano-soma cruzi, los vectores (Triatominae: Hemiptera: Reduviidae) y la enfermedad de Chagas (EC). Material y métodos. La investigación original fue identificada con PRISMA mediante cuatro sistemas de búsqueda, usando criterios de inclusión, se realizó la asignación a 14 áreas temáticas y fue evaluada mediante criterios técnicos. Resultados. De un total de 1 410 registros, fueron elegidos 659 (46.7%) para la valoración técnica, de los cuales, 221 (15.7%) fueron incluidos como las evidencias de mayor calidad. El buscador PubMed contribuyó con 95% de los registros, mientras que los buscadores BibTri, Lilacs y Scielo aportaron 5%. La tasa de publicación fue constante de 1950 a 1990, con un incremento exponencial de 1995 a 2020. La alta calidad de publicaciones incrementó de 5.3% en 1990 hasta 49.8% en 2020. Los temas de aspectos sistémicos, económicos, antropológicos y sociales de la EC en México fueron los menos representados (8%). Conclusiones. En las dos últimas décadas en México ha incrementado la investigación científica. Sin embargo, son notables las caren- cias en las áreas para poder fundamentar la política pública sanitaria en cuanto a la atención, la prevención y el control de la EC en el país.

During an infection the immune system produces pathogen-specific antibodies. These antibody repertoires become specific to the history of infections and represent a rich source of diagnostic markers. However, the specificities of these antibodies are mostly unknown. Here, using high-density peptide arrays we examined the human antibody repertoires of Chagas disease patients. Chagas disease is a neglected disease caused by Trypanosoma cruzi, a protozoan parasite that evades immune mediated elimination and mounts long-lasting chronic infections. We describe a proteome-wide search for antigens, characterised their linear epitopes, and show their reactivity on 71 individuals from diverse human populations. Using single-residue mutagenesis we revealed the core functional residues for 232 of these epitopes. Finally, we show the diagnostic performance of identified antigens on challenging samples. These datasets enable the study of the Chagas antibody repertoire at an unprecedented depth and granularity, while also providing a rich source of serological biomarkers.

During an infection, the immune system produces pathogen-specific antibodies. With time, these antibody repertoires become specific to the history of infections and represent a rich source of diagnostic markers. However, the specificities of these antibodies are mostly unknown. Here, using high-density peptide arrays we examined the specificities of human antibody repertoires of Chagas disease patients. Chagas disease is a neglected disease caused by Trypanosoma cruzi, a protozoan parasite that evades immune mediated elimination and mounts long-lasting chronic infections. We describe here the first proteome-wide search for antigens and epitopes and their seroprevalence at the individual level and across human populations. In a first discovery screening of 2.84 million short peptides spanning two T. cruzi proteomes we found 3,868 distinct antigenic protein regions. Further analysis of repertoires from 71 individuals provided information on their seroprevalence and showed a large fraction of private epitopes of low seroprevalence (IMPACT STATEMENTThis work reveals the diversity and extent of antibody specificities in Chagas Disease and provides a wealth of well-defined antigenic markers for diagnosis and development of serological applications for this neglected infectious disease.

Chagas disease (CD) is caused by the parasite Trypanosoma cruzi and affects 6–7 million people worldwide. The diagnosis is still challenging, due to extensive parasite diversity encompassing seven genotypes (TcI-VI and Tcbat) with diverse ecoepidemiological, biological, and pathological traits. Chemotherapeutic intervention is usually effective but associated with severe adverse events. The development of safer, more effective therapies is hampered by the lack of biomarker(s) (BMKs) for the early assessment of therapeutic outcomes. The mammal-dwelling trypomastigote parasite stage expresses glycosylphosphatidylinositol-anchored mucins (tGPI-MUC), whose O-glycans are mostly branched with terminal, nonreducing α-galactopyranosyl (α-Gal) glycotopes. These are absent in humans, and thus highly immunogenic and inducers of specific CD anti-α-Gal antibodies. In search for α-Gal-based BMKs, here we describe the synthesis of neoglycoprotein NGP11b, comprised of a carrier protein decorated with the branched trisaccharide Galα(1,2)[Galα(1,6)]Galβ. By chemiluminescent immunoassay using sera/plasma from chronic CD (CCD) patients from Venezuela and Mexico and healthy controls, NGP11b exhibited sensitivity and specificity similar to that of tGPI-MUC from genotype TcI, predominant in those countries. Preliminary evaluation of CCD patients subjected to chemotherapy showed a significant reduction in anti-α-Gal antibody reactivity to NGP11b. Our data indicated that NGP11b is a potential BMK for diagnosis and treatment assessment in CCD patients.

We assess a body of work that has attempted to use co-occurrence networks to infer the existence and type of biotic interactions between species. Although we see considerable interest in the approach as an exploratory tool for understanding patterns of co-occurrence of species, we note and describe numerous problems in the step of inferring biotic interactions from the co-occurrence patterns. These problems are both theoretical and empirical in nature, and limit confidence in inferences about interactions rather severely. We examine a series of examples that demonstrates striking discords between interactions inferred from co-occurrence patterns and previous experimental results and known life-history details.

Background: A question of epidemiological relevance in Chagas disease studies is to understand Trypanosoma cruzi transmission cycles and trace the origins of (re)emerging cases in areas under vector or disease surveillance. Conventional parasitological methods lack sensitivity whereas molecular approaches can fill in this gap, provided that an adequate sample can be collected and processed and a nucleic acid amplification method can be developed and standardized. We developed a duplex qPCR assay for accurate detection and quantification of T. cruzi satellite DNA (satDNA) sequence in samples from domestic and sylvatic mammalian reservoirs. The method incorporates amplification of the gene encoding for the interphotoreceptor retinoid-binding protein (IRBP), highly conserved among mammalian species, as endogenous internal amplification control (eIAC), allowing distinction of false negative PCR findings due to inadequate sample conditions, DNA degradation and/or PCR interfering substances. Results: The novel TaqMan probe and corresponding primers employed in this study improved the analytical sensitivity of the assay to 0.01 par.eq/ml, greater than that attained by previous assays for Tc I and Tc IV strains. The assay was tested in 152 specimens, 35 from 15 different wild reservoir species and 117 from 7 domestic reservoir species, captured in endemic regions of Argentina, Colombia and Mexico and thus potentially infected with different parasite discrete typing units. The eIACs amplified in all samples from domestic reservoirs from Argentina and Mexico, such as Canis familiaris, Felis catus, Sus scrofa, Ovis aries, Equus caballus, Bos taurus and Capra hircus with quantification cycles (Cq´s) between 23 and 25. Additionally, the eIACs amplified from samples obtained from wild mammals, such as small rodents Akodon toba, Galea leucoblephara, Rattus rattus, the opossums Didelphis virginiana, D. marsupialis and Marmosa murina, the bats Tadarida brasiliensis, Promops nasutus and Desmodus rotundus, as well as in Conepatus chinga, Lagostomus maximus, Leopardus geoffroyi, Lepus europaeus, Mazama gouazoubira and Lycalopex gymnocercus, rendering Cq´s between 24 and 33. Conclusions: This duplex qPCR assay provides an accurate laboratory tool for screening and quantification of T. cruzi infection in a vast repertoire of domestic and wild mammalian reservoir species, contributing to improve molecular epidemiology studies of T. cruzi transmission cycles. Fil: Wehrendt, Diana Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Gómez Bravo, Andrea. Fundación Mundo Sano; Argentina Fil: Ramirez Gomez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Cura, Carolina Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Pech May, Angélica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina Fil: Ramsey, Janine M.. Instituto Nacional de Salud Pública; México Fil: Abril, Marcelo. Fundación Mundo Sano; Argentina Fil: Guhl, Felipe. Universidad de los Andes; Colombia Fil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina

Vector-borne Chagas disease is endemic to the Americas and imposes significant economic and social burdens on public health. In a previous contribution, we presented an automated identification system that was able to discriminate among 12 Mexican and 39 Brazilian triatomine (Hemiptera: Reduviidae) species from digital images. To explore the same data more deeply using machine-learning approaches, hoping for improvements in classification, we employed TensorFlow, an open-source software platform for a deep learning algorithm. We trained the algorithm based on 405 images for Mexican triatomine species and 1,584 images for Brazilian triatomine species. Our system achieved 83.0 and 86.7% correct identification rates across all Mexican and Brazilian species, respectively, an improvement over comparable rates from statistical classifiers (80.3 and 83.9%, respectively). Incorporating distributional information to reduce numbers of species in analyses improved identification rates to 95.8% for Mexican species and 98.9% for Brazilian species. Given the ‘taxonomic impediment’ and difficulties in providing entomological expertise necessary to control such diseases, automating the identification process offers a potential partial solution to crucial challenges.

Chagas disease, caused by the protozoan Trypanosoma cruzi, affects more than 6 million people worldwide. Following a mostly asymptomatic acute phase, the disease progresses to a long-lasting chronic phase throughout which life-threatening disorders to the heart and/or gastrointestinal tract will manifest in about 30% of those chronically infected. During the chronic phase, the parasitemia is low and intermittent, while a high level of anti-T. cruzi antibodies persist for years. These two features hamper post-chemotherapeutic follow-up of patients with the tools available. The lack of biomarkers for timely assessment of therapeutic response discourages a greater use of the two available anti-parasitic drugs, and complicates the evaluation of new drugs in clinical trials. Herein, we investigated in a blinded case-control study the serological reactivity over time of a group of parasite-derived antigens to potentially address follow up of T. cruzi chronically infected subjects after treatment. We tested PFR2, KMP11, HSP70, 3973, F29 and the InfYnity multiplexed antigenic array, by means of serological assays on a multi-national retrospective collection of samples. Some of the antigens exhibited promising results, underscoring the need for further studies to determine their potential role as treatment response biomarkers.

Factores socioculturales y ambientales afectan el contacto en el paisaje entre triatominos infectados con Trypanosoma cruzi y la población humana, etiología de la enfermedad de Chagas. En este trabajo se analizan los efectos de la estructura del paisaje sobre la presencia de triatominos (vectores) en asentamientos humanos de una zona rural de Oaxaca, México. Mediante la búsqueda y colecta participativa de vectores, se calcularon índices de infestación en 35 localidades, en 2005 y en 2015. Se elaboró cartografía de cubierta y uso de suelo para ambas fechas y se estimó la cobertura de cada cubierta dentro de diez áreas de influencia. Se encontraron dos especies principales en el ambiente doméstico: Triatoma dimidiata Haplogrupo 2 (Hg2) y Triatoma mazzottii. La altitud, la densidad de vivienda y el área de bosque tropical son factores que permitieron explicar la presencia de cualquier de triatominos en ambiente doméstico. Se identificaron zonas prioritarias para implementar acciones a corto y mediano plazo y así atender casos actuales y detener la incidencia de esta zoonosis.

descripción no proporcionada por scopus, ISGlobal work is supported by the Departament d’Universitats i Recerca de la Generalitat de Catalunya, Spain (AGAUR; 017SGR00924) and by the Instituto de Salud Carlos III (ISCIII) RICET Network for Cooperative Research in Tropical Diseases (ISCIII; RD16/0027/0004 - PI1290) and FEDER. MJP research is supported by the Ministry of Health, Government of Catalonia (PERIS 2016-2010 SLT008/18/00132). ICA, JG, and FT are supported by the grant number U01AI129783 from the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH). ICA is also partly supported by the grant number 5U54MD007592 from the National Institute on Minority Health and Health Disparities (NIMHD), NIH. MCL and MCT were supported by ISCIII RICET grant RD16/0027/0005 - PI1290 and FEDER and by grants SAF2016-81003-R and SAF2016-80998-R from the Spanish “Programa Estatal I+D+i (MINECO)”. AA's work was supported by the Italian Ministry of Health “Fondi Ricerca Corrente - Linea 3, progetto 9” to IRCCS Sacro Cuore Don Calabria Hospital. JR was supported by CONACyT Fossis grant #261006. The Drugs for Neglected Diseases initiative (DNDi) is grateful to its donors, public and private, who have provided funding to DNDi since its inception in 2003. A full list of DNDi's donors can be found at http://www.dndi.org/donate/donors/. FIND is grateful to its donors, public and private, who have helped bring innovative new diagnostics for diseases of poverty. A full list of FIND’s donors can be found at: https://www.finddx.org/partners-donors/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Climate change can influence the geographical range of the ecological niche of pathogens by altering biotic interactions with vectors and reservoirs. The distributions of 20 epidemiologically important triatomine species in North America were modelled, comparing the genetic algorithm for rule-set prediction (GARP) and maximum entropy (MaxEnt), with or without topographical variables. Potential shifts in transmission niche for Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) (Chagas, 1909) were analysed for 2050 and 2070 in Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. There were no significant quantitative range differences between the GARP and MaxEnt models, but GARP models best represented known distributions for most species [partial-receiver operating characteristic (ROC) > 1]; elevation was an important variable contributing to the ecological niche model (ENM). There was little difference between niche breadth projections for RCP 4.5 and RCP 8.5; the majority of species shifted significantly in both periods. Those species with the greatest current distribution range are expected to have the greatest shifts. Positional changes in the centroid, although reduced for most species, were associated with latitude. A significant increase or decrease in mean niche elevation is expected principally for Neotropical 1 species. The impact of climate change will be specific to each species, its biogeographical region and its latitude. North American triatomines with the greatest current distribution ranges (Nearctic 2 and Nearctic/Neotropical) will have the greatest future distribution shifts. Significant shifts (increases or decreases) in mean elevation over time are projected principally for the Neotropical species with the broadest current distributions. Changes in the vector exposure threat to the human population were significant for both future periods, with a 1.48% increase for urban populations and a 1.76% increase for rural populations in 2050.

This study explores the present day distribution of Lutzomyia longipalpis in relation to climate, and transfers the knowledge gained to likely future climatic conditions to predict changes in the species' potential distribution. We used ecological niche models calibrated based on occurrences of the species complex from across its known geographic range. Anticipated distributional changes varied by region, from stability to expansion or decline. Overall, models indicated no significant north' south expansion beyond present boundaries. However, some areas suitable both at present and in the future (e.g., Pacific coast of Ecuador and Peru) may offer opportunities for distributional expansion. Our models anticipated potential range expansion in southern Brazil and Argentina, but were variably successful in anticipating specific cases. The most significant climate-related change anticipated in the species' range was with regard to range continuity in the Amazon Basin, which is likely to increase in coming decades. Rather than making detailed forecasts of actual locations where Lu. longipalpis will appear in coming years, our models make interesting and potentially important predictions of broader-scale distributional tendencies that can inform heath policy and mitigation efforts. Fil: Peterson, A. Townsend. University of Kansas. Biodiversity Research Center; Estados Unidos Fil: Campbell, Lindsay P.. University of Kansas. Biodiversity Research Center; Estados Unidos Fil: Moo Llanes, David A.. Instituto Nacional de Salud Pública; México Fil: Travi, Bruno. University of Texas; Estados Unidos Fil: González, Camila. Universidad de los Andes; Colombia Fil: Ferro, María Cristina. Instituto Nacional de Salud; Colombia Fil: Melim Ferreira, Gabriel Eduardo. Fundación Oswaldo Cruz; Brasil Fil: Brandão Filho, Sinval P.. Fundación Oswaldo Cruz; Brasil Fil: Cupolillo, Elisa. Fundación Oswaldo Cruz; Brasil Fil: Ramsey, Janine. Instituto Nacional de Salud Pública; México Fil: Leffer, Andreia Maruruto Chernaki. Universidade de Sao Paulo; Brasil Fil: Pech May, Angélica del Rosario. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina Fil: Shaw, Jeffrey J.. Universidade de Sao Paulo; Brasil

Lutzomyia longipalpis is a complex of species which has a wide but discontinuous distribution from southeastern Mexico to northern Argentina and Uruguay. To date, eight mitochondrial haplogroups have been identified along its distribution although key environmental tolerances and ecological niche models have been analyzed only at the complex level. The aim of the present study was to analyze whether genetic diversification using three mitochondrial genes of the Lu. longipalpis complex is associated with niche divergence and to explore evolution of distributional projections of all haplogroups between the Last Glacial Maximum (LGM; 21,000 yrs ago) and the present. Current occurrence of all haplogroups was used to develop ecological niche models (ENM) and these were projected in both periods to quantify and identify geographic area shifts. Environmental space was used to estimate niche similarity between major clades and pairwise between individual haplogroups. The two major Lu. longipalpis clades (Mex, CA, Col and Ven vs Arg and Bra) had significantly different environmental space, indicating niche divergence. Environmental space overlap of southern haplogroups was variable, with divergent niche, except between Arg and ArgBra. The most suitable regions for the ArgBra haplogroup were northeastern and southeastern Brazil, and the Gran Chaco region. In contrast, ENM of haplogroups within the northern major clade have significantly similar niche, with highest geographic ENM suitability along both the Caribbean and Pacific coasts. The intensity and coverage of high suitability areas in the LGM decreased for most haplogroups in the present. Integrating ENM and phylogenetic analyses has allowed us to test hypotheses of niche similarity between Lu. longipalpis haplogroups and major clades, and to identify conserved distributional areas of haplogroups since the LGM, with the exception of Arg. Evidence for distributional shifts and overlap of haplogroups is important to analyze Leishmaniasis´ eco-epidemiology and to successfully monitor and control transmission. Fil: Moo Llanes, David A.. Instituto Nacional de Salud Pública. Centro Regional de Investigación en Salud Pública; México Fil: Pech May, Angélica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Instituto Nacional de Salud Pública. Centro Regional de Investigación en Salud Pública; México. Administracion Nacional de Laboratorios E Institutos de Salud "dr. Carlos G. Malbran". Instituto Nacional de Medicina Tropical.; Argentina Fil: Montes de Oca Aguilar, Ana Celia. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados; México Fil: Salomón, Oscar Daniel. Administracion Nacional de Laboratorios E Institutos de Salud "dr. Carlos G. Malbran". Instituto Nacional de Medicina Tropical.; Argentina. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina Fil: Ramsey, Janine. Instituto Nacional de Salud Pública. Centro Regional de Investigación en Salud Pública; México

Chagas disease is a zoonotic infectious disease, produced by the parasite Trypanosoma cruzi. Infection results principally from contact with parasite-contaminated bug feces, deposited during a triatomine vector’s blood meal. The vectors are ubiquitous in conserved and human-transformed landscapes, since they inhabit sylvatic mammal nests, but persist and disperse among human communities. Exposure to infected vectors occurs both in conserved habitats and along human-transformation gradients. Several studies have focused on biological determinants, but only a handful of studies analyze sociocultural determinants of transmission. We explore cultural and social patterns within landscapes that affect human exposure in Mayan populations of Yucatan state. Primary factors contributing to vector exposure are: the lack of knowledge regarding the consequences of insect blood feeding habits, houses susceptible to bug infestation, farming and land-use practices, hunting, and rural migration. Gender affects the differential contribution of all of these factors. Exposure is aggravated by deficient infection diagnosis and treatment options, which raise risk for all transmission modes (vector-borne, congenital, blood transfusion and organ transplant, or oral).

These recommendations on practices for stakeholder engagement build on the knowledge and experience of practitioners and subject-matter experts from a large variety of fields. They aim to provide teams involved in the development of area-wide vector control methods with guidance on how to design community and stakeholder engagement programmes as part of their development pathway. Area-wide vector control methods are not new in concept [1]. For example, the use of natural predators for biocontrol of agricultural pests or public intervention for the treatment of water bodies with larvicides are current area-wide applications. Thus, new approaches under development—such as those using sterile-male techniques, Wolbachia, or gene drive—can build upon well-established development pathways. These methods offer the benefit of providing vector control for all inhabitants of a specific treated area without individual or group biases related to economic means, level of education, etc. Although this benefit can be a great advantage, multiperson or community-applied interventions may not offer individuals the chance to ‘opt out’ of a home or area receiving the intervention [2]. There may be aspects of the research in which individuals can choose to participate or not (for example, during the collection of mosquitoes or other insects from houses), but the research or technique developed will, at some stage, require the deployment of the tools in selected sites, and residents of those sites may not be able to ‘opt out’ of these phases in the same way that individuals can decline to be part of a vaccine field trial. Therefore, although these methods may differ greatly in scope and impact, the processes for their development and use share commonalities that provide a basis for asserting a broadly applicable framework for engagement. The framework set out below attempts to leverage these commonalities to provide a starting point that may be useful to a very wide variety of projects working in this field while retaining sufficient flexibility to be tailored as appropriate to local circumstances Some methods, such as gene drives and environmentally persistent Wolbachia methods, involve modifications to vector species that could persist and disseminate through a population over time and space. This means that the scale of the human communities affected can be quite large fairly early on in the development process and may persist or increase over time. Thus, testing of area-wide vector control methods does not conform to the familiar clinical trial model employing individual informed consent [3], and a different set of research ethics considerations is required. Trial authorisation by the hosting community and, potentially, peripheral communities that may be affected may be necessary. Therefore, identification of key stakeholders and community representatives is vital, and early and ongoing engagement with them is essential. This type of engagement can enable the sharing of knowledge, experience, and perceptions between the project and its stakeholders to help ensure that the pathways for development respond to the expectations of communities and other stakeholders, that the tools developed are ultimately effective and appropriate and meet the needs and preferences of users and other potential beneficiaries, and that accountability is established for trial outcomes and eventual disease mitigation. The recommendations may serve not only for projects involved in the development of new area-wide vector control methods but also as a benchmark to shape the expectations of a wider range of stakeholders, including project funders, communities, the media, and policy makers and regulators, about what projects will and should deliver. More broadly, shared recommendations can help facilitate the alignment of approaches of different projects and provide a clear pathway for other projects entering the field. These recommendations also describe ways in which projects can engage with stakeholders to meet other requirements for their research, including community acceptance for specific activities or phases of the research that may be necessary for the research to be able to proceed. However, the ability to implement these recommendations hinges on the availability of appropriate funding. Many of the suggested activities and approaches will be resource intensive. Therefore, funders are encouraged to make adequate supplies available for stakeholder engagement at every stage of the development process.

Rebuttal to Stephens et al. (2019), as part of a debate format.

Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata. Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in parasite transmission related to lineage sorting within the matrix. Intriguingly, TcIa is dominant in terrestrial small wildlife in the sylvatic habitat and is the only parasite DTU found in D. virginiana in the domestic habitat, although its frequency remained constant in sylvatic and ecotone vectors. Bats have a key role in TcVI dispersal from the sylvatic habitat, while dogs, sheep, and humans are drivers of TcVI between domestic and ecotone habitats. Overall, our results allow us to conclude that T. cruzi transmission is dependent on host availability within a highly permeable landscape in Zoh Laguna. Fil: López Cancino, Sury Antonio. Instituto Nacional de Salud Pública; México Fil: Tun Ku, Ezequiel. Instituto Nacional de Salud Pública; México Fil: De la Cruz Felix, Himmler Keynes. Instituto Nacional de Salud Pública; México Fil: Ibarra Cerdena, Carlos Napoleón. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados; México; Fil: Izeta Alberdi, Amaia. Instituto Nacional de Salud Publica; México Fil: Pech May, Angélica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentina. Instituto Nacional de Salud Publica; México Fil: Mazariegos Hidalgo, Carlos Jesús. Instituto Nacional de Salud Publica; México Fil: Valdez Tah, Alba Rocio. El Colegio de la Frontera Sur; México Fil: Ramsey, Janine. Instituto Nacional de Salud Publica; México

Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs) were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission.

Background The Triatoma phyllosoma complex of Trypanosoma cruzi vectors (Triatominae: Reduviidae) is distributed in both Neotropical and Nearctic bioregions of Mexico. Methods Volatile organic compounds emitted by disturbed Triatoma longipennis, Triatoma pallidipennis and Triatoma phyllosoma, and from their Brindley’s and metasternal glands, were identified using solid-phase microextraction coupled with gas chromatography-mass spectrometry. Results Disturbed bugs and the metasternal glands from T. phyllosoma released or had significantly fewer compounds than T. longipennis and T. pallidipennis. Isobutyric acid was the most abundant compound secreted by disturbed bugs of the three species, while Brindley’s glands of all species produced another four compounds: propanoic acid, isobutyric acid, pentyl butanoate, and 2-methyl hexanoic acid. Two novel compounds, both rose oxide isomers, were produced in MGs and released only by disturbed females of all three species, making this the first report in Triatominae of these monoterpenes. The principal compound in MGs of both sexes of T. longipennis and T. phyllosoma was 3-methyl-2-hexanone, while cis-rose oxide was the principal compound in T. pallidipennis females. The major components in male effluvia of T. pallidipennis were 2-decanol and 3-methyl-2-hexanone. Conclusion Discriminant analysis of volatile organic compounds was significant, separating the three species and was consistent with morphological and genetic evidence for species distinctions within the complex.

Nine sandfly species (Diptera: Psychodidae) are suspected or proven vectors of Leishmania spp. in the North and Central America region. The ecological niches for these nine species were modelled in three time periods and the overlaps for all time periods of the geographic predictions (G space), and of ecological dimensions using pairwise comparisons of equivalent niches (E space), were calculated. Two Nearctic, six Neotropical and one species in both bioregions occupied a reduced number of distribution areas. The ecological niche projections for most sandfly species other than Lutzomyia shannoni and Lutzomyia ovallesi have not expanded significantly since the Pleistocene. Only three species increase significantly to 2050, whereas all others remain stable. Lutzomyia longipalpis shared a similar ecological niche with more species than any other, although both L. longipalpis and Lutzomyia olmeca olmeca had conserved distributions over time. Climate change, at both regional and local levels, will play a significant role in the temporal and spatial distributions of sandfly species. Fil: Moo Llanes, David A.. Universidad Nacional Autónoma de México; México Fil: Pech May, Angélica del Rosario. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina Fil: Ibarra Cerdeña, C. N.. Cinvestav Unidad Merida; México. Universidad Nacional Autónoma de México; México Fil: Rebollar Téllez, E. A.. Universidad Autónoma de Nuevo León; México Fil: Ramsey, Janine. Instituto Nacional de Salud Pública/crisp; México

The most neglected aspects of Chagas disease (CD) have been patient care and treatment. Despite recent progress in the development of potentially improved drugs, there is no consensus among different research groups on the lack of therapeutic response markers to evaluate efficacy of newly proposed drugs early after treatment. A systematic review of current evidence regarding molecules which are potential biomarkers for therapeutic response has been conducted using quality assessment and target responses as primary criteria. The review provides a panorama of the cumulative evidence and specific needs for development of a battery of complementary biomarkers which together fulfill ideal or acceptable criteria to evaluate early responses to treatment for chronic CD. There are several marker candidates which together may fulfill acceptable criteria to indicate the efficacy of a trypanocidal treatment. Data from ongoing studies are considered essential to improve assessment of existing markers and to identify those for early follow-up of treated patients. Fil: Pinazo, Maria Jesús. Universidad de Barcelona; España Fil: Thomas Carazo, María del Carmen. Consejo Superior de Investigaciones Científicas; España Fil: Bua, Jacqueline Elena. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Perrone, Alina Elizabeth. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Viotti, Rodolfo Jorge. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; Argentina Fil: Ramsey, Janine. Instituto Nacional de Salud Pública. Centro Regional de Investigación en Salud Pública; México Fil: Ribeiro, Isabela. Drugs for Neglected Diseases Initiative; Suiza Fil: Sosa-estani, Sergio Alejandro. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: López, Manuel Carlos. Consejo Superior de Investigaciones Científicas; España Fil: Gascon, Joaquim. Universidad de Barcelona; España

Treatment for Chagas disease with currently available medications is recommended universally only for acute cases (all ages) and for children up to 14 years old. The World Health Organization, however, also recommends specific antiparasite treatment for all chronic-phase Trypanosoma cruzi-infected individuals, even though in current medical practice this remains controversial, and most physicians only prescribe palliative treatment for adult Chagas patients with dilated cardiomyopathy. The present opinion, prepared by members of the NHEPACHA network (Nuevas Herramientas para el Diagnóstico y la Evaluación del Paciente con Enfermedad de Chagas/New Tools for the Diagnosis and Evaluation of Chagas Disease Patients), reviews the paradigm shift based on clinical and immunological evidence and argues in favor of antiparasitic treatment for all chronic patients. We review the tools needed to monitor therapeutic efficacy and the potential criteria for evaluation of treatment efficacy beyond parasitological cure. Etiological treatment should now be mandatory for all adult chronic Chagas disease patients. Fil: Viotti, Rodolfo Jorge. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Peron"; Argentina Fil: Alarcón de Noya, B.. Universidad Central de Venezuela. Instituto de Medicina Tropical; Venezuela Fil: Araujo Jorge, T.. Ministerio de Salud de Brasil. Fundacion Oswaldo Cruz; Brasil Fil: Grijalva, M. J.. Pontificia Universidad Católica del Ecuador. Centro de Investigación de Enfermedades Infecciosas; Ecuador. Ohio University. Tropical Disease Institute; Estados Unidos Fil: Guhl, F.. Universidad de los Andes. Centro de Investigaciones en Microbiología y Parasitología Tropical; Colombia Fil: López, M. C.. Consejo Superior de Investigaciones Científicas. Instituto de Parasitología y Biomedicina "Lopez Neyra"; España Fil: Ramsey, J. M.. Instituto Nacional de Salud Pública. Centro Regional de Investigación en Salud Pública; México Fil: Ribeiro, I.. Drugs for Neglected Diseases Initiative; Suiza Fil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina Fil: Sosa Estani, S.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina Fil: Torrico, F.. Universidad Mayor de San Simón; Bolivia Fil: Gascon, J.. Centro de Investigación en Salud Internacional de Barcelona; España

Background The evolutionary history and ecological associations of Trypanosoma cruzi, the need to identify genetic markers that can distinguish parasite subpopulations, and understanding the parasite’s evolutionary and selective processes have been the subject of a significant number of publications since 1998, the year when the first DNA sequence analysis for the species was published. Methods The current analysis systematizes and re-analyzes this original research, focusing on critical methodological and analytical variables and results that have given rise to interpretations of putative patterns of genetic diversity and diversification of T. cruzi lineages, discrete typing units (DTUs), and populations, and their associations with hosts, vectors, and geographical distribution that have been interpreted as evidence for parasite subpopulation specificities. Results Few studies use hypothesis-driven or quantitative analysis for T. cruzi phylogeny (16/58 studies) or phylogeography (10/13). Among these, only one phylogenetic and five phylogeographic studies analyzed molecular markers directly from tissues (i.e. not from isolates). Analysis of T. cruzi DTU or lineage niche and its geographical projection demonstrate extensive sympatry among all clades across the continent and no significant niche differences among DTUs. DTU beta-diversity was high, indicating diverse host assemblages across regions, while host dissimilarity was principally due to host species turnover and to a much lesser degree to nestedness. DTU-host order specificities appear related to trophic or microenvironmental interactions. Conclusions More rigorous study designs and analyses will be required to discern evolutionary processes and the impact of landscape modification on population dynamics and risk for T. cruzi transmission to humans. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1918-2) contains supplementary material, which is available to authorized users.

Contemporary patterns of land use and global climate change are modifying regional pools of parasite host species. The impact of host community changes on human disease risk, however, is difficult to assess due to a lack of information about zoonotic parasite host assemblages. We have used a recently developed method to infer parasite-host interactions for Chagas Disease (CD) from vector-host co-occurrence networks. Vector-host networks were constructed to analyze topological characteristics of the network and ecological traits of species’ nodes, which could provide information regarding parasite regional dispersal in Mexico. Twenty-eight triatomine species (vectors) and 396 mammal species (potential hosts) were included using a data-mining approach to develop models to infer most-likely interactions. The final network contained 1,576 links which were analyzed to calculate centrality, connectivity, and modularity. The model predicted links of independently registeredTrypanosoma cruzihosts, which correlated with the degree of parasite-vector co-occurrence. Wiring patterns differed according to node location, while edge density was greater in Neotropical as compared to Nearctic regions. Vectors with greatest public health importance (i.e., Triatoma dimidiata,T. barberi,T. pallidipennis,T. longipennis, etc), did not have stronger links with particular host species, although they had a greater frequency of significant links. In contrast, hosts classified as important based on network properties were synanthropic mammals. The latter were the most common parasite hosts and are likely bridge species between these communities, thereby integrating meta-community scenarios beneficial for long-range parasite dispersal. This was particularly true for rodents, >50% of species are synanthropic and more than 20% have been identified asT. cruzihosts. In addition to predicting potential host species using the co-occurrence networks, they reveal regions with greater expected parasite mobility. The Neotropical region, which includes the Mexican south and southeast, and the Transvolcanic belt, had greatest potential activeT. cruzidispersal, as well as greatest edge density. This information could be directly applied for stratification of transmission risk and to design and analyze human-infected vector contact intervention efficacy.

OBJECTIVE To explore the pillars of community resilience in a region where Chagas disease is endemic, with the aim of promoting participatory processes to deal with this condition from the resilience of the population. METHODS Qualitative study using ethnographic record and six interviews of focus groups with young people, women and men. The research was carried out in a rural area of the state of Morelos, Mexico, between 2006 and 2007. We carried out educational sessions with the population in general, so that residents could identify the relationship between the vector Triatoma pallidipennis, the parasite (Trypanosoma cruzi), symptoms, and preventive actions for Chagas disease. The ethnographic record and groups were analyzed based on Taylor and Bogdan’s modification, and the focus was to understand the socio-cultural meanings that guide the speeches and activities of residents in relation to the pillars of community resilience. RESULTS The population felt proud of belonging to that location and three pillars of community resilience were clearly identified: collective self-esteem, cultural identity, and social honesty. Having these pillars as bases, we promoted the participation of the population concerning Chagas disease, and a Community Action Group was formed with young people, adult men and women, and social leaders. This Group initiated actions of epidemiological and entomological surveillance in the community to deal with this problem. CONCLUSIONS It is necessary to create more experiences that deepen the understanding of the pillars of community resilience, and how they contribute to enhance participation in health to deal with Chagas disease. RESUMEN OBJETIVO Explorar los pilares de la resiliencia comunitaria en una región en la que la enfermedad de Chagas es endémica, con la finalidad de partir de la resiliencia de la población para impulsar procesos participativos para enfrentar este padecimiento. MÉTODOS Estudio cualitativo que utilizó registro etnográfico y seis entrevistas de grupos focales con jóvenes, mujeres y hombres adultos. La investigación se efectúo en una localidad rural del Estado de Morelos, México, entre 2006 y 2007. Se efectuaron sesiones educativas con la población en general, para que los habitantes identificaran la relación entre el vector Triatoma pallidipennis, el parásito (Trypanosoma cruzi), la sintomatología y acciones preventivas para la enfermedad de Chagas. El registro etnográfico y los grupos fueron analizados con base en una modificación de Taylor y Bogdan, y el foco fue comprender los significados socioculturales que guían los discursos y actividades de los pobladores en relación a los pilares de la resiliencia comunitaria. RESULTADOS La población se sentía orgullosa de pertenecer a esa localidad y se identificaron con claridad tres pilares de la resiliencia comunitaria: autoestima colectiva, identidad cultural y honestidad social. Tomando como base estos pilares, se impulsó la participación de la población en torno a la enfermedad de Chagas, y se formó un Grupo de Acción Comunitaria con jóvenes, hombres y mujeres adultos, y líderes sociales. Este Grupo inició acciones de vigilancia epidemiológica y entomológica en la comunidad para hacer frente a esta problemática. CONCLUSIONES Es necesario generar más experiencias que profundicen en la comprensión de los pilares de resiliencia comunitaria, y en la manera en que estos contribuyen a potenciar la participación en salud para enfrentar la enfermedad de Chagas.

In this study, we evaluated the responses of Triatoma dimidiata Latreille (Hemiptera: Reduviidae) to volatiles emitted by conspecific females, males, mating pairs and metasternal gland (MG) extracts with a Y-tube olfactometer. The volatile compounds released by mating pairs and MGs of T. dimidiata were identified using solid-phase microextraction and coupled gas chromatography-mass spectrometry (GC-MS). Females were not attracted to volatiles emitted by males or MG extracts; however, they preferred clean air to their own volatiles or those from mating pairs. Males were attracted to volatiles emitted by males, females, mating pairs, pairs in which the male had the MG orifices occluded or MG extracts of both sexes. However, males were not attracted to volatiles emitted by pairs in which the female had the MG orifices occluded. The chemical analyses showed that 14 and 15 compounds were detected in the headspace of mating pairs and MG, respectively. Most of the compounds identified from MG except for isobutyric acid were also detected in the headspace of mating pairs. Both females and males were attracted to octanal and 6-methyl-5-hepten-2-one, and males were attracted to 3,5-dimethyl-2-hexanol. Males but not females were attracted to a seven-compound blend, formulated from compounds identified in attractive MG extracts.

Development of new genetic approaches to either interfere with the ability of mosquitoes to transmit dengue virus or to reduce vector population density requires progressive evaluation from the laboratory to contained field trials, before open field release. Trials in contained outdoor facilities are an important part of this process because they can be used to evaluate the effectiveness and reliability of modified strains in settings that include natural environmental variations without releasing mosquitoes into the open field. We describe a simple and cost-effective semi-field system designed to study Aedes aegypti carrying a dominant lethal gene (fsRIDL) in semi-field conditions. We provide a protocol for establishing, maintaining, and monitoring stable Ae. aegypti population densities inside field cages.