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Bats have been reported as hosts of the Trypanosoma cruzi protozoan, the etiologic agent of American trypanosomiasis, an endemic zoonotic disease in México.To describe T. cruzi infection in bats from the states of Campeche and Yucatán, México.Captures were made from March to November, 2017, at three sites in Yucatán and one in Campeche. Up to four mist nets on two consecutive nights were used for the capture. The bats' species were identified and euthanasia was performed to collect kidney and heart samples for total DNA extraction. Trypanosoma cruzi infection was detected by conventional PCR with the amplification of a fragment belonging to the T. cruzi DNA nuclear.Eighty-six bats belonging to five families (Vespertilionidae, Noctilionidae, Mormoopidae, Phyllostomidae, and Molossidae) and 13 species (Rhogeessa aeneus, Noctilio leporinus, Pteronotus davyi, P. parnellii, Artibeus jamaicensis, A. lituratus, A. phaeotis, Glossophaga soricina, Carollia sowelli, Chiroderma villosum, Uroderma bilobatum, Sturnira parvidens, and Molossus rufus) were captured. Infection frequency by PCR was 30,2% (26/86) detected only in the renal tissue. The infected species were P. parnellii, G. soricina, A. lituratus, A. jamaicensis, S. parvidens, C. villosum, and R. aeneus.Our results confirmed the participation of several bat species as hosts in the T. cruzi transmission cycle in the region. Further studies are necessary to establish the importance of these animals in the zoonotic transmission of T. cruzi.Introducción. Los murciélagos se han reportado como huéspedes del protozoario Trypanosoma cruzi, agente etiológico de la tripanosomiasis americana, enfermedad zoonótica endémica en México. Objetivo. Describir la infección con T. cruzi en murciélagos capturados en los estados de Campeche y Yucatán, México. Materiales y métodos. Se realizaron capturas de marzo a noviembre de 2017 en tres sitios de Yucatán y uno de Campeche. Para la captura se emplearon hasta cuatro redes de niebla por dos noches consecutivas. Se identificó la especie de los murciélagos capturados y se les practicó la eutanasia para recolectar muestras de riñón y corazón, utilizadas posteriormente en la extracción de ADN total. La infección con T. cruzi se detectó por la amplificación con PCR convencional de un fragmento perteneciente al ADN nuclear de T. cruzi. Resultados. Se capturaron 86 murciélagos pertenecientes a cinco familias (Vespertilionidae, Noctilionidae, Mormoopidae, Phyllostomidae, Molossidae) y 13 especies (Rhogeessa aeneus, Noctilio leporinus, Pteronotus davyi, P. parnellii, Artibeus jamaicensis, A. lituratus, A. phaeotis, Glossophaga soricina, Carollia sowelli, Chiroderma villosum, Uroderma bilobatum, Sturnira parvidens y Molossus rufus). La PCR mostró una frecuencia de infección de 30,2 % (26/86), detectada únicamente en tejido renal. Las especies infectadas fueron P. parnellii, G. soricina, A. lituratus, A. jamaicensis, S. parvidens, C. villosum y R. aeneus. Conclusiones. Los resultados confirmaron la participación de varias especies de murciélagos como huéspedes en el ciclo de transmisión de T. cruzi en la región. Es necesario realizar más estudios para determinar la importancia de estos animales en la transmisión zoonótica de T. cruzi.

During a 3000 kms-exploratory fieldtrip along the peninsula of Baja California, Mexico, we used mice-baited traps in search of Triatominae. Specimens of Paratriatoma hirsuta and Dipetalogaster maxima were collected.

International audience; Most neglected tropical diseases (NTDs) are intrinsically embedded within the One Health approach: NTD researchers have already been dealing with multidisciplinary and intersectoral work for decades simply because it is essential for understanding and controlling the usually complex transmission of the pathogens causing NTDs.This long experience has already enrooted the idea of the horizontal integration of research, control, elimination and eradication strategies. The ongoing epidemiological transitions of most NTDs urges pursuing and amplifying the development of co-constructed multidisciplinary and intersectoral research initiatives for improving control/elimination/eradication processes. Lessons from NTDs may also be useful for other diseases targeted by ongoing One Health initiatives.

The multiplicity of epidemiological scenarios shown by Chagas Disease, derived from multiple transmission routes of the aetiological agent, occurring on multiple geo-ecobiosocial settings determines the complexity of the disease and reveal the difficulties for its control. From the first description of the link between the parasite, the vector and its domestic habitat and the disease that Carlos Chagas made in 1909, the epidemiological scenarios of the American Trypanosomiasis has shown a dynamic increasing complexity. These scenarios changed with time and geography because of new understandings of the disease from multiple studies, because of policies change at the national and international levels and because human movements brought the parasite and vectors to new geographies. Paradigms that seemed solid at a time were broken down, and we learnt about the global dispersion of Trypanosoma cruzi infection, the multiplicity of transmission routes, that the infection can be cured, and that triatomines are not only a health threat in Latin America. We consider the multiple epidemiological scenarios through the different T. cruzi transmission routes, with or without the participation of a Triatominae vector. We then consider the scenario of regions with vectors without the parasite, to finish with the consideration of future prospects.

The objective of this study was to molecularly characterize Mexican isolates of T. cruzi obtained from infected triatomine bugs (the vectors of T. cruzi) and to evaluate their susceptibility to Nifurtimox (NFX).Three isolates obtained from Triatoma dimidiata (collected in the State of Veracruz) and one isolate obtained from Triatoma bassolsae (collected in the State of Puebla) were molecularly characterized and the expression of genes associated with natural resistance to NFX was analyzed by qPCR.Molecular characterization by PCR showed that isolates Zn3, Zn5, and SRB1 belong to the DTU TcI, while isolate Sum3 belongs to TcIV. The latter was also confirmed by sequencing of mitochondrial genes. Isolate Zn5 was the most sensitive to treatment with NFX (IC50, 6.8 μM), isolates SRB1 and Zn3 were partially resistant (IC50, 12.8 μM and 12.7 μM) and isolate Sum3 showed a high degree of resistance to NFX (IC50, 21.4 µM). We also found an association between decreased NTR1 or OYE gene expression with NFX resistance.Our results also evidenced a high variability in the susceptibility to NFX of these T. cruzi isolates Central and Southeastern Mexico, suggesting the presence of naturally resistant isolates circulating in the country. These results have important implications for defining treatment policies for patients with Chagas disease.

Background: Triatoma dimidiata is a vector of the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. Phenotypic plasticity allows an organism to adjust its phenotype in response to stimuli or environmental conditions. Understanding the effect of T. cruzi on the phenotypic plasticity of its vectors, known as triatomines, has attracted great interest because of the implications of the parasite-triatomine interactions in the eco-epidemiology and transmission of the parasite. We investigated whether the infection of the vector with T. cruzi can change the antennal phenotype of sylvatic, domestic, and laboratory-reared populations of T. dimidiata. Methods: The abundance of each type of sensillum (bristles, basiconic, thick- and thin-walled trichoid) on the antennae of T. cruzi-infected and non-infected T. dimidiata reared in the laboratory or collected in sylvatic and domestic ecotopes were measured under light microscopy and compared using Kruskal–Wallis non-parametric tests and Permutational Multivariate Analysis of Variance. Results: We found significant differences between sensilla patterns of infected and non-infected insects within sylvatic and domestic populations. Conversely, we found no significant differences between sensilla patterns of infected and non-infected insects within the laboratory-reared population. Besides, our results show that the infection with T. cruzi affects the sexual dimorphism linked to antennal phenotype in sylvatic and domestic populations. Conclusion: These differences could be linked, for infected insects, to higher efficiency in the perception of odor molecules related to the search of distant mates and hosts and for flight dispersal in search of new habitats, and the possibility of a positive effect on population dynamics and on the vectorial transmission of T. cruzi.

OBJECTIVE To analyse the ecological and social factors involved in infestation of houses by Triatoma dimidiata in a rural locality of Veracruz, Mexico, where active transmission of the parasite is occurring. METHODS A survey was applied to the households of the locality to obtain sociodemographic data. In parallel, T. dimidiata insects were collected during one year through community participation. Using PCR, the insects were genotyped, their infection status was assessed, and parasite genotypes infecting the insects were identified. The vector's blood meal sources were identified using a polymerase-heteroduplex chain reaction assay. RESULTS Seasonal variations in the patterns of infestation by T. dimidiata were observed. An overall infestation rate of 19.46%, a colonisation index of 9.09%, a dispersion rate of 22.15% and a synanthropy index of 80.6% were found. The collected insects were identified as ITS-2 group 2 insects, and a natural infection with T. cruzi of 54.35% was found. TcI and no-TcI genotypes of T. cruzi were found in infected insects. Factors such as rain (P = 0.0006) and temperature (P

Las técnicas de diagnóstico por imagen son métodos no invasivos o mínimamente invasivos que permiten la visualización de órganos internos y el estudio de su función. Incluyen la ecografía, radiología, tomografía computarizada, resonancia magnética y medicina nuclear, entre otras. El diagnóstico por imagen se ha convertido en un componente esencial en las investigaciones científicas que requieren el seguimientoin vivo de cambios patológicos. En esta revisión, presentamos estas técnicas y sus aplicaciones para el estudio de la infección por Trypanosoma cruzi, parásito causante de la enfermedad de Chagas; con énfasis en la ecografía, la técnica más ampliamente empleada por su bajo costo y la única que proporciona imágenes en tiempo real. La ecografía se utiliza actualmente en el Centro de Investigaciones Regionales “Dr. Hideyo Noguchi” de la Universidad Autónoma de Yucatán, para el estudio de la infección por T. cruzien el modelo murino. Ha demostrado ser útil para la evaluación in vivodecambios morfológicos y funcionales del corazón, el estudio de la progresión de la infección y la efectividad de nuevos fármacos. Adicionalmente, las imágenes obtenidas nos han permitido el desarrollo de sistemas automatizados auxiliares en el diagnóstico de la infección, los cuales se encuentran en fase experimental. La ecografía es útil para responder preguntas que aún permanecen sin explorar sobre la enfermedad de Chagas como, el estudio de la progresión del daño órganos durante la infección.

The genus Triatoma contains numerous species, principal or secondary vectors of Chagas disease, which have been included in the three main lineages of Triatomini tribe based on morphological and biogeographical characteristics: North American, South American, and T. dispar complex. The three members of the T. dispar complex are distributed in Ecuador. This complex has been scarcely studied through molecular approaches, and the taxonomic position of this complex is not confirmed. In this study, we explored the phylogenetic relationships within the genus Triatoma, including five species from North and Central America, six from South America, and the three species belonging to the T. dispar complex. Partial sequences of four mitochondrial genes (Cyt b, COII, 16S-rRNA, 12S-rRNA) and two nuclear genes (18S-rRNA, ITS2) were obtained from 74 specimens. Phylogenetic trees were built with concatenated and single sequences through maximum likelihood (ML), maximum parsimony (MP), and Bayesian methods. The trees built using concatenated sequences showed three main branches (clusters) highly supported by significant bootstrap values; the T. dispar complex appeared as a monophyletic group separate from species of North and Central American origin and South American origin. On the contrary, for each gene tree, the three main clusters were not always significantly supported, mostly because genetic information is dramatically reduced when a single gene is considered. Consequently, concatenation of genes gives relevant results and is highly recommended for further in-depth examination of the relationships of several species and complexes of triatomines that remain unresolved. Moreover, our current molecular data fully revealed the division of genus Triatoma into at least three main genetic groups.

Unicellular eukaryotes of the Trypanosomatidae family include human and animal pathogens that belong to the Trypanosoma and Leishmania genera. Diagnosis of the diseases they cause requires the sampling of body fluids (e.g., blood, lymph, peritoneal fluid, cerebrospinal fluid) or organ biopsies (e.g., bone marrow, spleen), which are mostly obtained through invasive methods. Body fluids or appendages can be alternatives to these invasive biopsies but appropriateness remains poorly studied. To further address this question, we perform a systematic review on clues evidencing the presence of parasites, genetic material, antibodies, and antigens in body secretions, appendages, or the organs or proximal tissues that produce these materials. Paper selection was based on searches in PubMed, Web of Science, WorldWideScience, SciELO, Embase, and Google. The information of each selected article (n = 333) was classified into different sections and data were extracted from 77 papers. The presence of Trypanosomatidae parasites has been tracked in most of organs or proximal tissues that produce body secretions or appendages, in naturally or experimentally infected hosts. The meta-analysis highlights the paucity of studies on human African trypanosomiasis and an absence on animal trypanosomiasis. Among the collected data high heterogeneity in terms of the I2 statistic (100%) is recorded. A high positivity is recorded for antibody and genetic material detection in urine of patients and dogs suffering leishmaniasis, and of antigens for leishmaniasis and Chagas disease. Data on conjunctival swabs can be analyzed with molecular methods solely for dogs suffering canine visceral leishmaniasis. Saliva and hair/bristles showed a pretty good positivity that support their potential to be used for leishmaniasis diagnosis. In conclusion, our study pinpoints significant gaps that need to be filled in order to properly address the interest of body secretion and hair or bristles for the diagnosis of infections caused by Leishmania and by other Trypanosomatidae parasites.

The implementation of sustainable control strategies aimed at disrupting the transmission of vector-borne pathogens requires a comprehensive knowledge of the vector ecology in the different eco-epidemiological contexts, as well as the local pathogen transmission cycles and their dynamics. However, even when focusing only on one specific vector-borne disease, achieving this knowledge is highly challenging, as the pathogen may exhibit a high genetic diversity and multiple vector species or subspecies and host species may be involved. In addition, the development of the pathogen and the vectorial capacity of the vectors may be affected by their midgut and/or salivary gland microbiome. The recent advent of Next-Generation Sequencing (NGS) technologies has brought powerful tools that can allow for the simultaneous identification of all these essential components, although their potential is only just starting to be realized. We present a metabarcoding approach that can facilitate the description of comprehensive host-pathogen networks, integrate important microbiome and coinfection data, identify at-risk situations, and disentangle the transmission cycles of vector-borne pathogens.This powerful approach should be generalized to unravel the transmission cycles of any pathogen and their dynamics, which in turn will help the design and implementation of sustainable, effective, and locally adapted control strategies.

Background: For several years, the wild populations of Triatoma infestans, main vector of Trypanosoma cruzi causing Chagas disease, have been considered or suspected of being a source of reinfestation of villages. The number of sites reported for the presence of wild T. infestans, often close to human habitats, has greatly increased, but these data are scattered in several publications, and others obtained by our team in Bolivia have not been published yet. Methodology/principal findings: Herein is compiled the largest number of wild sites explored for the presence of T. infestans collected with two methods The standardized methods aimed to determine the relationship between wild T. infestans and the ecoregion, and the directed method help to confirm the presence/absence of triatomines in the ecoregions. Entomological indices were compared between ecoregions and an environmental niche modelling approach, based on bioclimatic variables, was applied. The active search for wild T. infestans in Bolivia suggests a discontinuous distribution from the Andean valleys to the lowlands (Chaco), while the models used suggest a continuous distribution between the two regions and very large areas where wild populations remain to be discovered. The results compile the description of different habitats where these populations were found, and we demonstrate that the environmental niches of wild and domestic populations, defined by climatic variables, are similar but not equivalent, showing that during domestication, T. infestans has conquered new spaces with wider ranges of temperature and precipitation. Conclusions/significance: The great diversity of wild T. infestans habitats and the comparison of their ecological niches with that of domestic populations confirm the behavioural plasticity of the species that increase the possibility of contact with humans. The result of the geographical distribution model of the wild populations calls for more entomological vigilance in the corresponding areas in the Southern Cone countries and in Bolivia. The current presentation is the most comprehensive inventory of wild T. infestans-positive sites that can be used as a reference for further entomological vigilance in inhabited areas. Fil: Brenière, Simone Frédérique. Pontificia Universidad Catolica del Ecuador; Ecuador. INTERTRYP - Cirad; Francia Fil: Buitrago, Rosio. INTERTRYP - Cirad; Francia. Instituto Nacional de Laboratorios de Salud; Bolivia Fil: Waleckx, Etienne. Universidad Autónoma de Yucatán; México Fil: Depickère, Stéphanie. INTERTRYP - Cirad; Francia. Instituto Nacional de Laboratorios de Salud; Bolivia. Universidad Mayor de San Andrés; Bolivia Fil: Sosa, Victor. INTERTRYP - Cirad; Francia. Gobierno Autónomo Departamental de Santa Cruz. Dirección de Recursos Naturales. Secretaria de Desarrollo Sostenible y Medio Ambiente; Bolivia Fil: Barnabé, Christian. INTERTRYP - Cirad; Francia Fil: Gorla, David Eladio. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

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.

Background In Mexico, estimates of Chagas disease prevalence and burden vary widely. Updating surveillance data is therefore an important priority to ensure that Chagas disease does not remain a barrier to the development of Mexico's most vulnerable populations. Methodology/Principal findings The aim of this systematic review and meta-analysis was to analyze the literature on epidemiological surveys to estimate Chagas disease prevalence and burden in Mexico, during the period 2006 to 2017. A total of 2,764 articles were screened and 36 were retained for the final analysis. Epidemiological surveys have been performed in most of Mexico, but with variable study scale and geographic coverage. Based on studies reporting confirmed cases (i.e. using at least 2 serological tests), and taking into account the differences in sample sizes, the national estimated seroprevalence of Trypanosoma cruzi infection was 3.38% [95%CI 2.59–4.16], suggesting that there are 4.06 million cases in Mexico. Studies focused on pregnant women, which may transmit the parasite to their newborn during pregnancy, reported an estimated seroprevalence of 2.21% [95%CI 1.46–2.96], suggesting that there are 50,675 births from T. cruzi infected pregnant women per year, and 3,193 cases of congenitally infected newborns per year. Children under 18 years had an estimated seropositivity rate of 1.51% [95%CI 0.77–2.25], which indicate ongoing transmission. Cases of T. cruzi infection in blood donors have also been reported in most states, with a national estimated seroprevalence of 0.55% [95%CI 0.43–0.66]. Conclusions/Significance Our analysis suggests a disease burden for T. cruzi infection higher than previously recognized, highlighting the urgency of establishing Chagas disease surveillance and control as a key national public health priority in Mexico, to ensure that it does not remain a major barrier to the economic and social development of the country's most vulnerable populations.

The mechanisms of infection and dispersion of Trypanosoma cruzi among animals, especially in the sylvatic environment, are still not entirely clear, and various aspects of the transmission dynamics of this parasite in the sylvatic environment are still unknown. T. cruzi is a parasite with a great biological and genetic diversity that infects a wide variety of hosts, therefore, transmission cycles of this parasite are complex. The objective of this study was to determine the prevalence of T. cruzi infection and analyze the genetic variability of the discrete typing units (DTUs) of the parasite in three non-human primate species (Alouatta palliata, Alouatta pigra, and Ateles geoffroyi) in southeastern Mexico. A total of one hundred sixty-four serum samples (42 samples of A. pigra, 41 samples of A. palliata (free-ranging) and 81 samples of A. geoffroyi (hosted in care centers)) were analyzed for the detection of anti -T. cruzi antibodies by ELISA assays. The seroprevalence of infection was 23.39% in A. palliata, 21.40% in A. pigra and 16.27% in A. geoffroyi. Additionally, presence of parasite DNA was assessed by PCR, and the identification of DTUs was performed by real-time PCR coupled to High Resolution Melting (qPCRHRM). Different DTUs (TcI, TcII, TcIII, TcV and TcVI) were found in the analyzed monkeys. In addition, infection of monkeys was not associated with age or gender, but it was associated with the species. This study reveals the risk of infection in the study area and that the different DTUs of the parasite can coexist in the same habitat, indicating that T. cruzi transmission in the study area is very complex and involves many ecological factors. However, there is a need for long-term studies of host-parasite interactions to provide a solid understanding of the ecology of these species and to understand the dispersion strategies of T. cruzi.

Background Chagas disease, caused by the parasite Trypanosoma cruzi, is mainly transmitted by blood-sucking bugs called triatomines. In the Yucatán Peninsula, Mexico, the main vector of T. cruzi is Triatoma dimidiata. While this species may colonize houses in other regions, it is mostly intrusive in Yucatán: it generally lives in sylvan and peridomestic areas, and frequently enters inside homes, likely attracted by potential vertebrate hosts, without establishing colonies. Bugs collected inside homes have a low nutritional status, suggesting that they cannot efficiently feed inside these houses. We hypothesized that this low nutritional status and limited colonization may be associated, at least in part, with the local practice in Mayan communities to sleep in hammocks instead of beds, as this sleeping habit could be an obstacle for triatomines to easily reach human hosts, particularly for nymphal instars which are unable to fly. Methods We used an experimental chamber in which we placed a miniature bed in one side and a miniature hammock on the other side. After placing a mouse enclosed in a small cage on the bed and another one in the hammock as baits, T. dimidiata bugs were released in the chamber and their activity was video recorded during the night. Results T. dimidiata adults and nymphs were able to reach the mouse in bed significantly more often than the mouse in hammock (Binomial test, P

BackgroundIn Mexico, estimates of Chagas disease prevalence and burden vary widely. Updating surveillance data is therefore an important priority to ensure that Chagas disease does not remain a barrier to the development of Mexico’s most vulnerable populations.Methodology/Principal FindingsThe aim of this systematic review was to analyze the literature on epidemiological surveys to estimate Chagas disease prevalence and burden in Mexico, during the period 2006 to 2017. A total of 2,764 articles were screened and 38 were retained for the final analysis. Epidemiological surveys have been performed in most of Mexico, but with variable geographic coverage. Based on studies reporting confirmed cases, i.e. using at least 2 serological tests, the national seroprevalence of Trypanosoma cruzi infection was 2.26% [95% Confidence Interval (CI) 2.12-2.41], suggesting that there are 2.71 million cases in Mexico. Studies focused on pregnant women, which may transmit the parasite to their newborn during pregnancy, reported a seroprevalence of 1.00% [95% CI 0.87-1.14], suggesting that there are 22,930 births from T. cruzi infected pregnant women per year, and 1,445 cases of congenitally infected newborns per year. Children under 18 years had a seropositivity rate of 1.49% [95% CI 1.20-1.85], which indicate ongoing transmission. Finally, cases of T. cruzi infection in blood donors have also been reported in most states, with a national seroprevalence of 0.51% [95% CI 0.49-0.53].Conclusions/SignificanceOur analysis suggests a disease burden for T. cruzi infection higher than previously recognized, highlighting the urgency of establishing Chagas disease surveillance and control as a key national public health priority in Mexico, to ensure that it does not remain a major barrier to the economic and social development of the country’s most vulnerable populations.Author summaryIn Mexico, estimates of Chagas disease prevalence and burden vary widely due to the ecology and epidemiology of this disease resulting of many geographical, ecological, biological, and social interactions. Better data are thus urgently needed to help develop appropriate public health programs for disease control and patient care. In this study we analyzed published data on T. cruzi seroprevalence infection in Mexico between 2006 and 2017. This systematic review shows a national seroprevalence of T. cruzi infection of 2.26% [95%CI 2.12-2.41], with over 2.71 million cases in Mexico, which is higher than previously recognized. The presence of T. cruzi infection in specific subpopulations such as pregnant women, children and blood donors also informs on specific risks of infection and call for the implementation of well-established control interventions. This work confirms the place of Mexico as the country with the largest number of cases, highlighting the urgency of establishing Chagas disease control as a key national public health priority.

Trypanosoma cruzi is the agent of Chagas disease, transmitted by hematophagous triatomine vectors. Establishing transmission cycles is key to understand the epidemiology of the disease, but integrative assessments of ecological interactions shaping parasite transmission are still limited. Current approaches also lack sensitivity to assess the full extent of this ecological diversity. Here we developed a metabarcoding approach based on next-generation sequencing to identify triatomine gut microbiome, vertebrate feeding hosts, and parasite diversity and their potential interactions. We detected a dynamic microbiome in Triatoma dimidiata, including 23 bacterial orders, which differed according to blood sources. Fourteen vertebrate species served as blood sources, corresponding to domestic, synantropic and sylvatic species, although four (human, dog, cow and mice) accounted for over 50% of blood sources. Importantly, bugs fed on multiple hosts, with up to 11 hosts identified per bug, indicating very frequent host-switching. A high clonal diversity of T. cruzi was detected, with up to 20 haplotypes per bug. This analysis provided much greater sensitivity to detect multiple blood meals and multiclonal infections with T. cruzi, which should be taken into account to develop transmission networks, and characterize the risk for human infection, eventually leading to a better control of disease transmission.

Non-domiciliated intrusive triatomine vectors are responsible for a low but significant transmission of Trypanosoma cruzi to humans. Their control is a challenge as insecticide spraying is of limited usefulness, and alternative strategies need to be developed for a sustainable control. We performed a non-randomized controlled trial of an Ecohealth intervention based on window insect screens and community participation to reduce house infestation by Triatoma dimidiata in two rural villages in Yucatan, Mexico. Efficacy of the intervention was measured over a three years follow-up period and entomological indicators showed that the proportion of triatomines found inside houses was significantly reduced in houses with insect screens, which effectively kept more bugs on the outside of houses. Using a previously developed model linking entomological data to the prevalence of infection in human, we predicted that the intervention would lead to a 32% reduction in yearly incidence and in the prevalence of T. cruzi infection. The cost for the coverage of all the windows of a house was of comparable magnitude to what families currently spend on various domestic insecticide, and most screens were still in good conditions after three years. In conclusion, the Ecohealth approach proposed here is effective for the long-term and sustainable control of intrusive T. dimidiata vectors in the Yucatan peninsula, Mexico. This strategy may also be easily adapted to other intrusive triatomine species as well as other regions/countries with comparable eco-epidemiological settings, and would be an excellent component of a larger integrated program for the control of a variety of other vector-borne diseases, bringing additional benefits to the communities. Our results should encourage a further scaling-up of our implementation strategy in additional villages in the region., Author summary Intrusive triatomine bugs such as Triatoma dimidiata in the Yucatan peninsula, Mexico, are responsible for the transmission of Trypanosoma cruzi to humans, which can lead to Chagas disease. The control of these bugs is a challenge as insecticide spraying is poorly effective, and alternative strategies need to be developed for a sustainable control. We tested a novel Ecohealth approach, based on window insect screens manufacture and installation through community participation to reduce the presence of bugs inside houses. The proportion of triatomines found inside houses was significantly reduced in houses with insect screens, which effectively kept more bugs on the outside of houses. We estimated that the intervention would lead to a 32% reduction in new cases of infection each year and in the prevalence of T. cruzi infection. The low cost of the intervention and the durability of screens further indicate that the proposed Ecohealth approach is effective for the long-term and sustainable control of intrusive T. dimidiata vectors in the Yucatan peninsula, Mexico. This strategy may also be easily adapted to other bug species and regions with similar characteristics and sould be expanded in additional villages in the region.

International audience; 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. Chagas disease is a major public health problem in the Americas, where it affects seven-eight million people (WHO 2014). The pathogenic agent is a protozoan parasite, Trypanosoma cruzi, mainly transmitted to humans and other mammals through the contaminated faeces of blood-sucking insects called triatomines (Hemiptera: Redu-viidae), also known as " kissing bugs ". Control of Chagas disease relies on the treatment of infected patients and prevention of transmission is based mainly on vector control. Currently, more than 140 species of triatomines are recognised. Over half of them have been shown to be naturally or experimentally infected with T. cruzi, but all are suspected to be able to transmit the parasite (or " serve as vectors ") (Bargues et al. 2010). Nevertheless, not all the triatomine species are considered important vectors of T. cruzi. Vector competence varies considerably between the different species/populations of triatomines and depends on multiple criterions. Among these, the level of domiciliation, which is understood as the level of adaptation to human and its domestic environment, is one of the most important, as it defines the level of human-vector contacts (Dujardin et al. 2002). Indeed, species highly adapted to and able to colonise human dwellings are more likely to actively contribute to the transmission of T. cruzi to humans than species that are only found in sylvatic environment. While the domiciliation of triatomine spe-cies/populations is clearly a gradual evolutionary process (Schofield et al. 1999), it has important implications for the design and efficacy of vector control interventions. To date, vector control is mainly achieved through indoor residual insecticide spraying, initially designed to target triatomine species living inside human dwellings and highly adapted to the domestic environment (i.e. domicil-iated or domesticated). However, it is becoming increasingly clear that triatomine species presenting lower levels of domiciliation are also playing an important role in T. cruzi transmission to humans and thus need to be taken into account by vector control programs in many regions. The efficacy of conventional insecticide spraying may indeed be directly affected by the level of domiciliation of triatomines and alternative control strategies thus need to be considered against nondomiciliated species/popula-tions. These populations are a potential source of continuous house infestation and post-spraying re-infestation, making the control by insecticide spraying unsustainable, even in areas where transmission is primarily due to highly domiciliated vectors. The level of domiciliation/intru-sion of triatomine species thus needs to be clearly defined in operative terms to allow for its precise evaluation and the design of effective vector control interventions. In this review, we examine how the domiciliation/ intrusion level of different triatomine species/popula-tions 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.

Received 7 August 2014; revised 13 October 2014; accepted 13 October 2014Background:Non-domiciliated (intrusive) triatomine vectors remain a challenge for the sustainability ofChagas disease vector control as these triatomines are able to transiently (re-)infest houses. One of the best-characterizedexamplesisTriatomadimidiatafromtheYucatanpeninsula,Mexico,whereadultinsectsseasonallyinfest houses between March and July.Methods: We focused our study on three rural villages in the state of Yucatan, Mexico, in which we performeda situation analysis as a first step before the implementation of an ecohealth (ecosystem approach to health)vector control intervention.Results: The identification of the key determinants affecting the transient invasion of human dwellings byT. dimidiata was performed by exploring associations between bug presence and qualitative and quantitativevariables describing the ecological, biological and social context of the communities. We then used a participa-tory action research approach for implementation and evaluation of a control strategy based on window insectscreens to reduce house infestation by T. dimidiata.Conclusions: This ecohealth approach may represent a valuable alternative to vertically-organized insecticidespraying. Further evaluation may confirm that it is sustainable and provides effective control (in the sense oflimiting infestation of human dwellings and vector/human contacts) of intrusive triatomines in the region.Keywords: Chagas disease, Community participation, Triatoma dimidiata, Vector control

A dozen specimens of the oribatid mite Archegozetes magnus (Trhypochthoniidae) were collected from the Chagas disease vector Triatoma dimidiata (Hemiptera: Reduviidae), in Teya, Yucatán, Mexico. This is the first report of phoresy by an oribatid mite on a hemipteran. Fil: Waleckx, Etienne. Laboratorio de Parasitología Centro Inv. Regional; México Fil: Montalvo-Balam, Teresa de Jesús. Laboratorio de Parasitología Centro Inv. Regional; México Fil: Pinzón Canul, Aaron. Laboratorio de Parasitología Centro Inv. Regional; México Fil: Arnal, Audrey. Laboratorio de Parasitología Centro Inv. Regional; México Fil: Marti, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Martínez, Pablo A.. Departamento de Biología, Facultad de Ciencias Exactas; Argentina

Trypanosoma cruzi is the causative agent of Chagas disease, a Neglected Tropical Disease affecting 8 million people in the Americas. Triatomine hematophagous vectors feed on a high diversity of vertebrate species that can be reservoirs or dead-end hosts, such as avian species refractory to T. cruzi. To understand its transmission dynamics in synanthropic and domesticated species living within villages is essential to quantify disease risk and assess the potential of zooprophylaxis. We developed a SI model of T. cruzi transmission in a multi-host community where vector reproduction and parasite transmission depend on a triatomine blood-feeding rate accounting for vector host preferences and interference while feeding. The model was parameterized to describe T. cruzi transmission in villages of the Yucatan peninsula, Mexico, using the information about Triatoma dimidiata vectors and host populations accumulated over the past 15 years. Extensive analyses of the model showed that dogs are key reservoirs and contributors to human infection, as compared to synanthropic rodents and cats, while chickens or other domesticated avian hosts dilute T. cruzi transmission despite increasing vector abundance. In this context, reducing the number of dogs or increasing avian hosts abundance decreases incidence in humans by up to 56% and 39%, respectively, while combining such changes reduces incidence by 71%. Although such effects are only reached over >10-years periods, they represent important considerations to be included in the design of cost-effective Integrated Vector Management. The concomitant reduction in T. cruzi vector prevalence estimated by simulating these zooprophylactic interventions could indeed complement the removal of colonies from the peridomiciles or the use of insect screens that lower vector indoor abundance by ~60% and ~80%. These new findings reinforce the idea that education and community empowerment to reduce basic risk factors is a cornerstone to reach and sustain the key objective of interrupting Chagas disease intra-domiciliary transmission., Author summary ‘Chagas disease’ (CD) is a Neglected Tropical Disease endemic in 21 American countries that is caused by a parasite, Trypanosoma cruzi, transmitted to vertebrates including humans by triatomine bugs. The main strategy to restrain CD burden consists of spraying insecticides in human dwellings. However, vector control failures and emerging insecticide resistance require complementing strategies. One such strategy could be to change the human associated host community so that the abundance of parasite ‘reservoirs’ decreases and those of parasite ‘dead-ends’ increases. This requires careful quantitative evaluation using specifically tailored mathematical models. By doing so, we showed that reducing the abundance of reservoir dogs and increasing those of avian hosts that cannot be infected by T. cruzi can lower new human infections by up to 56% and 39%. Although such effects take time to manifest themselves, our results suggest that ‘zooprophylaxis’ can be part of an integrated and sustainable disease management.

A recent study by Cartelle Gestal et al. reported an analysis of data from the Ministry of Public Health on the epidemiological situation of neglected tropical diseases in Ecuador [1]. Based on a misleading definition of Chagas disease cases not corresponding to that of the Ministry of Public Health [2], the authors concluded that the government had mounted successful control campaigns, and as a result Chagas disease (among others) had been effectively controlled as no cases in children under age five had been reported since 2009. Ecuador is thus identified as one of the first countries to control Chagas disease. While we certainly agree that efforts have been made in terms of Chagas disease surveillance and control campaigns in Ecuador, a more comprehensive analysis of available data, from both the Ministry of Public Health and the literature, provides a very different picture, and the claim that Chagas disease is controlled made by Cartelle Gestal et al. seems largely inadequate and sends an equivocal message which can undermine current control efforts. As mentioned in this study, the Chagas disease control program in the country was formally established in 2003–2004, in response to recommendations from a technical consultation through PAHO/WHO [3] and field studies [4,5]. This consultation and data provided a baseline to prioritize activities. It reported a national seroprevalence of Trypanosoma cruzi infection of 1.38%, corresponding to 165–170,000 seropositive patients in the country. Three regions were prioritized: the coastal region (seroprevalence of 1.99%), the Amazon region (1.75%) and the southern highlands (0.65%). The incidence was estimated at 36 cases/100,000 inhabitants/year, resulting in 4,400 new cases each year [3]. Today, the most recent estimates from the WHO suggest the presence of nearly 200,000 seropositive patients and a current incidence of 14 cases/100,000 inhabitants/year [6]. An in depth analysis of the complete records from the Ministry of Public Health from 2004–2014, indicates a total of 915 reported human cases in the country, with a major increase over the years followed by a decrease in the past two years [7]. This increase reflects the efforts at improving the epidemiologic surveillance program, but it is clear that there is still significant underreporting of cases in the country. Indeed, several independent and recent seroprevalence studies in different regions and communities point out relatively high levels of seroprevalence of T. cruzi infection (ranging from 0.6 to 13.3%), and persistent active parasite transmission, as evidenced by the detection of seropositive children [8–12]. Additionally, there are reports of Chagas disease cases in regions where the Ministry of Public Health has no records of patients, further highlighting current underreporting [5,11,12]. Furthermore, while during the last decade Ecuador has achieved near 100% blood screening coverage for T. cruzi infection, the 15 participating blood banks regularly report seropositive blood donors to the External Performance Evaluation of Serological Screening Program administered by the Pontifical Catholic University of Ecuador. The vector control program was effectively started in 2004. However, due to limited human and financial resources, there have been important variations in the geographic coverage of the surveillance and control activities from year to year [7]. Importantly, a total of 12 provinces have not been included in these activities, representing an area larger than the covered provinces. Therefore, the available data do not correspond to a systematic national coverage, and thus still present an incomplete picture of the current transmission of Chagas disease in Ecuador. In the 11 provinces in which surveillance and control activities have been performed, house infestation by triatomines is still observed in many regions [7,13]. While vector control activities have had a significant effect and allowed reducing the infestation level, particularly in coastal Ecuador, these need to be sustained to avoid reinfestation and provide long-term effects. Also, while insecticide spraying may be effective against Triatoma dimidiata, a possibly domiciliated species which is poised for elimination in Ecuador, alternative control strategies may be needed against intrusive triatomine species such as Rhodnius ecuadoriensis or Panstrongylus howardi or for occasional exposure outside of homes [14–19]. Moreover, no formal vector control intervention has been implemented in the Amazon region, where nearly half of the cases of the country seem to originate [7], and active transmission still occurs through triatomine species including Rhodnius robustus and R. pictipes [8,9]. Especially in the Amazon, human activities (deforestation, urbanization) disturb the natural balance between the vectors, their wild hosts and the parasite, favoring the emergence of new transmission cycles in which humans may be included [8,9,11,20]. An accurate description of the situation of Chagas disease in Ecuador should mention that access to diagnosis throughout the country is limited and case detection during the last two decades has been sporadic and geographically restricted. Indeed, only one laboratory in the whole country, at the Instituto Nacional de Investigacion en Salud Publica (INSPI), performs official confirmation of anti-T. cruzi seropositivity and releases Nifurtimox for the treament of patients. In fact, we believe that lack of awareness by health care personnel in areas with active vectorial transmission, combined with lack of diagnostic capacity elsewhere in the country, have resulted in a gross under reporting of cases in Ecuador. Taken together, these data and studies highlight that Chagas disease is all but controlled in Ecuador, contrary to what is stated by Cartelle Gestal et al. While it is clear that disease surveillance and vector control activities from the Ministry of Public Health have improved over the years, these need to (i) reach national coverage to ensure the inclusion of all endemic provinces, and (ii) be sustained to ensure that what has been achieved can result in long-term control of the disease. These represent a clear challenge at a time when the Ministry of Public Health is undergoing major structural reorganization and many of its activities are being decentralized or interrupted. Indeed, there is a decrease in reported human cases and in vector controls activities observed in the past two years in Ecuador [7], which may reflect the interruption of the National Chagas Program and the Servicio Nacional de Control y Vigilancia de Enfermedades Transmitidas por Vectores Artropodos (SNEM) in late 2015. Their actions have not been replaced yet, so that there is currently no Chagas vector control program in the country. This can strongly jeopardize the results achieved so far and may be a lost opportunity to eliminate vectorial transmission with domiciliated vectors in some regions of Ecuador. Finally, as in many other countries in Latin America, current activities for Chagas disease control in Ecuador still need to improve treatment access and care for Chagas disease patients [21–23] as well as to better understand the importance of congenital transmission in the epidemiology of the disease [9,24]. Thus, control of Chagas disease in the country will only be reached if the programs from the Ministry of Public Health are strengthened and expanded. The National Chagas disease control programs in other Latin America countries such as Brazil, Argentina, or Colombia (among others) can provide key examples of successful strategies for Chagas disease surveillance and control, as well as of the challenges encountered for their implementation. Additionally, research needs to be performed to further expand our understanding of triatomine infestation and T. cruzi transmission cycles in the different specific endemic areas, to help further tailor surveillance and interventions. More than claiming that Chagas disease is controlled, we need to promote further political commitment to sustain current achievements in Chagas disease surveillance and control in Ecuador and to ensure that the goals of the London declaration on neglected tropical diseases [25] are met in the near future.

Trypanosoma cruzi, the causative agent of Chagas disease, presents wide genetic diversity. Currently, six discrete typing units (DTUs), named TcI to TcVI, and a seventh one called TcBat are used for strain typing. Beyond the debate concerning this classification, this systematic review has attempted to provide an inventory by compiling the results of 137 articles that have used it. A total of 6,343 DTU identifications were analyzed according to the geographical and host origins. Ninety-one percent of the data available is linked to South America. This sample, although not free of potential bias, nevertheless provides today’s picture of T. cruzi genetic diversity that is closest to reality. DTUs were genotyped from 158 species, including 42 vector species. Remarkably, TcI predominated in the overall sample (around 60%), in both sylvatic and domestic cycles. This DTU known to present a high genetic diversity, is very widely distributed geographically, compatible with a long-term evolution. The marsupial is thought to be its most ancestral host and the Gran Chaco region the place of its putative origin. TcII was rarely sampled (9.6%), absent, or extremely rare in North and Central America, and more frequently identified in domestic cycles than in sylvatic cycles. It has a low genetic diversity and has probably found refuge in some mammal species. It is thought to originate in the south-Amazon area. TcIII and TcIV were also rarely sampled. They showed substantial genetic diversity and are thought to be composed of possible polyphyletic subgroups. Even if they are mostly associated with sylvatic transmission cycles, a total of 150 human infections with these DTUs have been reported. TcV and TcVI are clearly associated with domestic transmission cycles. Less than 10% of these DTUs were identified together in sylvatic hosts. They are thought to originate in the Gran Chaco region, where they are predominant and where putative parents exist (TcII and TcIII). Trends in host-DTU specificities exist, but generally it seems that the complexity of the cycles and the participation of numerous vectors and mammal hosts in a shared area, maintains DTU diversity., Author Summary Trypanosoma cruzi, the causative agent of Chagas disease, has been classified into six genetic groups (discrete typing units, DTUs) named TcI-TcVI and a seventh one called TcBat. Currently, several genetic molecular markers are used to classify the strains after their isolation in culture or directly from biological samples. The current inventory compiling the published works aiming to identify the DTUs of T. cruzi strains accumulated a total of 6,343 identifications. Although this inventory is not free of sampling bias, like all samples, it is the largest sampling to date and hence likely represents the closest picture of the current diversity of T. cruzi strains (i) circulating throughout the endemic area from the southern United States to Argentina and (ii) circulating in vectors as well as in wild and domestic mammals, and humans. Data analysis helps identify trends and provides a basis for further comparisons of new data, in a context where human factors (migration, vector control, urbanization, deforestation, agricultural expansion, resource exploitation) influence the epidemiological patterns of Chagas disease.

International audience; For tequila production, blue agave heads are cooked to hydrolyse their fructan content and release fermentable carbohydrates. However, this hydrolysis is not complete and the juice generated during cooking (cooking honey) contains fructans incompletely hydrolysed. Several distilleries perform an additional acidic hydrolysis on honey to improve fermentable carbohydrate recovery, but this treatment presents many disadvantages. As an alternative, we describe an enzymatic treatment with Fructozyme L, a preparation of inulinases. Optimal laboratory conditions for agave fructan hydrolysis using this preparation were 60 degrees C and a pH of 4.0-5.0. A concentration of 0.02% (V/V of honey) was needed to achieve more than 90% of fructan hydrolysis in the honey, after a 12 h treatment. These conditions were validated by two industrial trials during which enzymatic hydrolysates were successfully fermented and distilled, and volatile compound composition and sensory qualities of the tequila were assured. (C) 2010 Elsevier Ltd. All rights reserved.

Wild populations of Triatoma infestans, the main vector of Chagas disease in the Southern Cone countries, may be involved in reinfestation of human dwellings, limiting the success of vector-control campaigns in Bolivia. Knowledge of the distribution of these populations remains incomplete. We report here the detection of T. infestans wild populations in large areas in the department of La Paz, Bolivia. Among 18 sylvatic areas investigated, 17 were positive with T. infestans specimens. The infection rate of captured T. infestans with Trypanosoma cruzi was 85.7% in adult specimens. These results expand the geographical distribution of wild populations of T. infestans; it may be distributed throughout the Inter-Andean Dry Forest eco-region of Bolivia. The current information allows us to propose the hypothesis that a sylvatic origin of the reinfestation is located in the valleys of La Paz.