Lower richness of small wild mammal species and chagas disease risk

Wildfire, deforestation and health in tropical rainforest areas: a scoping review protocol

INTRODUCTION

Wildfires and deforestation potentially have direct effects on multiple health outcomes as well as indirect consequences for climate change. Tropical rainforest areas are characterised by high rainfall, humidity and temperature, and they are predominantly found in low-income and middle-income countries. This study aims to synthesise the methods, data and health outcomes reported in scientific papers on wildfires and deforestation in these locations.

METHODS AND ANALYSIS

We will carry out a scoping review according to the Joanna Briggs Institute's (JBI) manual for scoping reviews and the framework proposed by Arksey and O'Malley, and Levac et al. The search for articles was performed on 18 August 2023, in 16 electronic databases using Medical Subject Headings terms and adaptations for each database from database inception. The search for local studies will be complemented by the manual search in the list of references of the studies selected to compose this review. We screened studies written in English, French, Portuguese and Spanish. We included quantitative studies assessing any human disease outcome, hospitalisation and vital statistics in regions of tropical rainforest. We exclude qualitative studies and quantitative studies whose outcomes do not cover those of interest. The text screening was done by two independent reviewers. Subsequently, we will tabulate the data by the origin of the data source used, the methods and the main findings on health impacts of the extracted data. The results will provide descriptive statistics, along with visual representations in diagrams and tables, complemented by narrative summaries as detailed in the JBI guidelines.

ETHICS AND DISSEMINATION

The study does not require an ethical review as it is meta-research and uses published, deidentified secondary data sources. The submission of results for publication in a peer-reviewed journal and presentation at scientific and policymakers' conferences is expected.

STUDY REGISTRATION

Open Science Framework (https://osf.io/pnqc7/).

Oral Chagas Disease in Colombia-Confirmed and Suspected Routes of Transmission

Chagas disease (CD) remains endemic throughout many regions of Colombia despite implementing decades of vector control strategies in several departments. Some regions have had a significant decrease in vectorial transmission, but the oral ingestion of Trypanosoma cruzi through consumption of contaminated food and drink products is increasingly described. This form of transmission has important public health relevance in Colombia due to an increase in reported acute CD cases and clinical manifestations that often lead to significant morbidity and mortality. Oral CD in Colombia has been associated with the consumption of contaminated fruit juices, such as palm wine, sugar cane, or tangerine juice and water for consumption, or contaminated surfaces where food has been prepared. Another interesting route of oral transmission includes ingestion of unbeknownst infected armadillos' blood, which is related to a traditional medicine practice in Colombia. Some earlier reports have also implemented consumption of infected bush meat as a source, but this is still being debated. Within the Amazon Basin, oral transmission is now considered the principal cause of acute CD in these regions. Furthermore, new cases of acute CD are now being seen in departments where CD has not been documented, and triatomine vectors are not naturally found, thus raising suspicion for oral transmission. The oral CD could also be considered a food-borne zoonosis, and odoriferous didelphid secretions have been implemented in contaminating the human dwelling environment, increasing the risk of consumption of infectious metacyclic trypomastigotes. In this article, we will discuss the complex transmission dynamics of oral CD in Colombia and further examine the unique clinical manifestations of this route of infection. New insights into the oral transmission of Trypanosoma cruzi are being discovered in Colombia, which can help bring increased awareness and a better understanding of this neglected tropical disease to reduce the burden of CD throughout Latin America.

Space-environment relationship in the identification of potential areas of expansion of Trypanosoma cruzi infection in Didelphis aurita in the Atlantic Rainforest

Ecological Niche Modeling is widely used for animals, but rarely for understanding the parasite ecology. Trypanosoma cruzi is a heterogeneous and widely dispersed multi-host parasite. Didelphis aurita is a generalist species, both in terms of diet and environments. We modeled the D. aurita niche and T. cruzi infection in the Brazilian Atlantic Rainforest, using the models of two common vector species (Triatoma vitticeps and Panstrongylus megistus) as biotic variables, predicting their occurrence. Records of T. cruzi infected and non-infected D. aurita were analyzed through climate and landscape approaches by the Ecoland method. Models for each triatomine species and infected and noninfected D. aurita were produced considering climate and landscape: resolution of ~1km2 selected by Pearson's correlation [-0.7≤α≤0.7]. For modeling, seven algorithms available in ModleR package were used. True Skill Statistic was used to evaluate the models' performance (≥ 0.7). T. vitticeps indicates that there is a spatial dependence with warm areas in the southeastern region while P. megistus presented a distribution with high environmental suitability concentrated in the Southeast. High values of climatic suitability, landscape and potential presence of T. vitticeps and P. megistus were considered necessary, but not sufficient for the presence of D. aurita infected by T. cruzi. Climate models showed an ecological niche with suitability variations homogeneous, and landscape models showed a distribution of habitat conditions along the biome, with a fragmented profile and heterogeneous between locations. Ecoland demonstrated that D. aurita has different degrees of impact on its role in the enzootic cycle in different locations of the Atlantic Rainforest. Associating the models with the Ecoland method allowed the recognition of areas where D. aurita are important T. cruzi reservoirs. Areas of high suitability for the presence of marsupials are a necessary, but not sufficient for D. aurita to act as a reservoir for T. cruzi.

Interrogating the transmission dynamics of Trypanosoma cruzi (Trypanosomatida, Trypanosomatidae) by Triatoma venosa (Hemiptera: Reduviidae) after the elimination of vector transmission by Rhodnius prolixus in Boyacá eastern Colombia

Chagas disease (CD) is a parasitic zoonosis (Trypanosoma cruzi) that is endemic in Colombia. Vector control of Rhodnius prolixus, the main domestic T. cruzi vector, has been achieved in a large part of the area with historically vector transmission of CD. It is necessary to understand the ecological behavior characteristics of local native vectors to ensure sustainability of the vector control programs. To evaluate the long-term success of a recent vector control campaign in the Boyacá department (Colombia), we used a combined strategy of entomological surveillance with co-existing canine surveillance from ten rural villages within six municipalities of the Tenza valley region (Boyacá, Colombia): Chinavita, Garagoa, Guateque, Somondoco, Sutatenza and Tenza, with historical reports of R. prolixus and secondary vectors. Collected triatomines and canine whole blood were analyzed for T. cruzi infection and genotyping. Triatomine bugs specimens were evaluated for blood meal source. Canine serology was performed using two distinct antibody assays. In total, 101 Triatoma venosa were collected by active search in domestic and peridomestic habitats. A natural infection prevalence of 13.9% (14/101) and four feeding sources were identified: human, dog, rat, and hen. A frequency infection of 46.5% (40/87) was observed from two independent serological tests and T. cruzi DNA was detected in 14 dogs (16.4%). Only TcIsylvatic DTU was detected. The results suggest that T. venosa present eco-epidemiological characteristics to maintain the transmission of T. cruzi in Tenza valley. This species has reinfested the intervened households and it has an active role in domestic and peridomestic transmission of T. cruzi due to their infection rates and feeding behavior. Therefore, this species should be considered as epidemiologically relevant for vector control strategies. Moreover, there is a need for human serological studies to have a close up of risk they are exposed to.

Trypanosomatid Richness Among Rats, Opossums, and Dogs in the Caatinga Biome, Northeast Brazil, a Former Endemic Area of Chagas Disease

Parasites are important components of the immense n-dimensional trophic network that connects all living beings because they, among others, forge biodiversity and deeply influence ecological evolution and host behavior. In this sense, the influence of Trypanosomatidae remains unknown. The aim of this study was to determine trypanosomatid infection and richness in rats, opossums, and dogs in the semiarid Caatinga biome. We submitted DNA samples from trypanosomatids obtained through axenic cultures of the blood of these mammals to mini exon multiplex-PCR, Sanger, and next-generation sequencing targeting the 18S rDNA gene. Phylogenetic analyses were performed to identify genetic diversity in the Trypanosomatidae family. Shannon, Simpson, equability, and beta-diversity indices were calculated per location and per mammalian host. Dogs were surveyed for trypanosomatid infection through hemocultures and serological assays. The examined mammal species of this area of the Caatinga biome exhibited an enormous trypanosomatid species/genotypes richness. Ten denoised Operational Taxonomic Units (ZOTUs), including three species (Trypanosoma cruzi, Trypanosoma rangeli and Crithidia mellificae) and one Trypanosoma sp. five genotypes/lineages (T. cruzi DTU TcI, TcII, and TcIV; T. rangeli A and B) and four DTU TcI haplotypes (ZOTU1, ZOTU2, ZOTU5, and ZOTU10 merged), as well as 13 Amplicon Sequence Variants (ASVs), including five species (T. cruzi, T. rangeli, C. mellificae, Trypanosoma dionisii, and Trypanosoma lainsoni), five genotypes/lineages (same as the ZOTUs) and six DTU TcI haplotypes (ASV, ASV1, ASV2, ASV3, ASV5 and ASV13), were identified in single and mixed infections. We observed that trypanosomatids present a broad host spectrum given that species related to a single host are found in other mammals from different taxa. Concomitant infections between trypanosomatids and new host-parasite relationships have been reported, and this immense diversity in mammals raised questions, such as how this can influence the course of the infection in these animals and its transmissibility. Dogs demonstrated a high infection rate by T. cruzi as observed by positive serological results (92% in 2005 and 76% in 2007). The absence of positive parasitological tests confirmed their poor infectivity potential but their importance as sentinel hosts of T. cruzi transmission.

Chagas Immunochromatographic Rapid Test in the Serological Diagnosis of Trypanosoma cruzi Infection in Wild and Domestic Canids

Canis lupus familiaris (domestic dog) represents a reliable sentinel for the occurrence of a well-established transmission cycle of Trypanosoma cruzi among wild mammals in the surroundings and, consequently, where the risk of human infection exists. Serological diagnosis is the chosen method to identify T. cruzi infection in dogs that, in Brazil, rarely present positive parasitological tests. The use of recombinant chimeric parasitic antigens results in a sensitive and specific serological diagnostic test in contrast to the use of crude T. cruzi antigens. Our objective was to evaluate the Chagas/Bio-Manguinhos Lateral Flow Immunochromatographic Rapid Test (Chagas-LFRT) for the diagnosis of T. cruzi infection in domestic dogs and the potential of application of this diagnostic platform to wild canid species. Two recombinant proteins (IBMP-8.1 and IBMP-8.4) that displayed the best performance in the enzyme immunoassay (ELISA) in previous studies were tested in a platform with two diagnostic bands. A panel of 281 dog serum samples was evaluated: 133 positive for T. cruzi by serological diagnosis, including 20 samples with positive blood cultures belonging to different discrete typing units (DTUs); 129 negative samples; and 19 samples from dogs infected by other trypanosomatids: Leishmania infantum, Trypanosoma rangeli, Trypanosoma caninum and Crithidia mellificae, in addition to samples infected by Anaplasma platys, Dirofilaria immitis and Erlichia sp. that were employed to evaluate eventual cross-reactions. We also evaluated the Chagas-LFRT to detect T. cruzi infection in 9 serum samples from six wild canid species. We observed that the intensity pattern of the bands was directly proportional to the serological titer observed in IFAT. The sensitivity was 94%, the specificity was 91% according to the ROC curve, and the defined cutoff was an optical density of 4.8. The agreement obtained was considered substantial by the kappa analysis (84%). From T. cruzi positive hemoculture samples, 88.9% were positive by Chagas-LFRT. The test was efficient in recognizing infections by five of the six T. cruzi DTUs. Cross-reactions were not observed in infections by L. infantum, T. rangeli, T. caninum and D. immitis; however, they were observed in sera of dogs infected by Crithidia mellificae, Anaplasma sp. and Erlichia sp. A strong reaction was observed when serum samples from wild canids were submitted to the Protein A affinity test, confirming its applicability for these species. This test will allow rapid preventive actions in areas with high risk to the emergence of Chagas disease in a safer, reliable, low-cost and immediate manner, without the need for more complex laboratory tests.

Trypanosoma Species in Small Nonflying Mammals in an Area With a Single Previous Chagas Disease Case

Trypanosomatids are hemoflagellate parasites that even though they have been increasingly studied, many aspects of their biology and taxonomy remain unknown. The aim of this study was to investigate the Trypanosoma sp. transmission cycle in nonflying small mammals in an area where a case of acute Chagas disease occurred in Mangaratiba municipality, Rio de Janeiro state. Three expeditions were conducted in the area: the first in 2012, soon after the human case, and two others in 2015. Sylvatic mammals were captured and submitted to blood collection for trypanosomatid parasitological and serological exams. Dogs from the surrounding areas where the sylvatic mammals were captured were also tested for T. cruzi infection. DNA samples were extracted from blood clots and positive hemocultures, submitted to polymerase chain reaction targeting SSU rDNA and gGAPDH genes, sequenced and phylogenetic analysed. Twenty-one wild mammals were captured in 2012, mainly rodents, and 17 mammals, mainly marsupials, were captured in the two expeditions conducted in 2015. Only four rodents demonstrated borderline serological T. cruzi test (IFAT), two in 2012 and two in 2015. Trypanosoma janseni was the main Trypanosoma species identified, and isolates were obtained solely from Didelphis aurita. In addition to biological differences, molecular differences are suggestive of genetic diversity in this flagellate species. Trypanosoma sp. DID was identified in blood clots from D. aurita in single and mixed infections with T. janseni. Concerning dogs, 12 presented mostly borderline serological titers for T. cruzi and no positive hemoculture. In blood clots from 11 dogs, T. cruzi DNA was detected and characterized as TcI (n = 9) or TcII (n = 2). Infections by Trypanosoma rangeli lineage E (n = 2) and, for the first time, Trypanosoma caninum, Trypanosoma dionisii, and Crithidia mellificae (n = 1 each) were also detected in dogs. We concluded that despite the low mammalian species richness and degraded environment, a high Trypanosoma species richness species was being transmitted with the predominance of T. janseni and not T. cruzi, as would be expected in a locality of an acute case of Chagas disease.

Seroprevalence and detection of Trypanosoma cruzi in dogs living in a non-endemic area for Chagas disease in the legal Amazon region, Brazil

Trypanosoma cruzi, the etiological agent for Chagas disease, is widely distributed in the Americas. Its hosts are humans and wild and domestic mammals, and its vectors are triatomine insects. Studies have indicated that domestic dogs are sentinel animals in the epidemiology of Chagas disease in endemic regions, including states in the Legal Amazon region of Brazil. In São Luís, the capital of Maranhão, a non-endemic state, the existence of a domestic cycle involving domestic rats has been proven, along with a wild cycle maintained by didelphids. However, no studies on T. cruzi infection in domestic animals in this locality have been conducted. The aim of this study was to investigate occurrence of T. cruzi in dogs living in the Itaqui Bacanga district of São Luís, Maranhão, by means of serological and molecular tests. Blood samples were obtained from 330 dogs and structured epidemiological questionnaires were applied to their keepers. These samples were used in the indirect immunofluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). Fisher's exact test was used for statistical calculations with the aim of identifying risk factors. Out of the 330 animals, 105 (31.8%) were reactive in IFAT, 46 (13.0%) in ELISA and 20 (6.0%) in both serological tests. The results were not significant (p > 0.05) when submitted to statistical analysis for the studied variables. From PCR, 58 samples (17.5%) were found to be positive and, of these, one (0.3%) showed similarity to T. cruzi after sequencing. These data demonstrate that dogs were exposed to and infected by T. cruzi. Thus, they can be considered sentinel animals for Chagas disease in the locality studied, which signals that there is a need for epidemiological surveillance actions.

Environmental influence on <em>Triatoma vitticeps</em> occurrence and <em>Trypanosoma cruzi</em> infection in the Atlantic Forest of south-eastern Brazil

Trypanosoma cruzi requires a triatomine insect vector for its life cycle, which can be complex in different enzootic scenarios, one of which is the unique transmission network in the Atlantic Forest of south-eastern Brazil. In Espírito Santo (ES) State, highly infected Triatoma vitticeps are frequently reported invading domiciles. However, triatomines were not found colonizing residences and mammals in the surrounding areas did not present T. cruzi infection. To date, the biotic and abiotic variables that modulate T. vitticeps occurrence and T. cruzi infection in ES State are still unknown. The aim of this study was to identify the environmental variables that modulate their occurrence. Local thematic maps were generated for two response variables: T. vitticeps occurrence and T. cruzi infection. The following explanatory variables were tested: climate (temperature, relative air humidity and rainfall), altitude elevation, mammalian species richness as well as soil and vegetation types. Spatiotemporal distribution patterns and correlation levels between response and explanatory variables were assessed through spatial statistics and map algebra modelling. The central and southern mesoregions presented higher T. vitticeps and T. cruzi distributions and can be considered transmission hotspots. The explanatory variables that can explain these phenomena were relative air humidity, average temperature, soil type, altitude elevation and mammalian species richness. Algebra map modelling demonstrated that central and southern mesoregions presented the environmental conditions needed for T. vitticeps occurrence and T. cruzi infection. The consideration of environmental variables is essential for understanding the T. cruzi transmission cycle. Cartographic and statistical methodologies used in parasitology have been demonstrated to be reliable and enlightening tools that should be incorporated routinely to expand the understanding of vector-borne parasite transmission.

The potential risk of enzootic Trypanosoma cruzi transmission inside four training and re-training military battalions (BITER) in Colombia

BACKGROUND

Colombia's National Army is one of the largest military institutions in the country based on the number of serving members and its presence throughout the country. There have been reports of cases of acute or chronic cases of Chagas disease among active military personnel. These may be the result of military-associated activities performed in jungles and other endemic areas or the consequence of exposure to Trypanosoma cruzi inside military establishments/facilities located in endemic areas. The aim of the present study was to describe the circulation of T. cruzi inside facilities housing four training and re-training battalions [Battalions of Instruction, Training en Re-training (BITERs)] located in municipalities with historical reports of triatomine bugs and Chagas disease cases. An entomological and faunal survey of domestic and sylvatic environments was conducted inside each of these military facilities.

METHODS

Infection in working and stray dogs present in each BITER location was determined using serological and molecular tools, and T. cruzi in mammal and triatomine bug samples was determined by PCR assay. The PCR products of the vertebrate 12S rRNA gene were also obtained and subjected to Sanger sequencing to identify blood-feeding sources. Finally, we performed a geospatial analysis to evaluate the coexistence of infected triatomines and mammals with the military personal inside of each BITER installation.

RESULTS

In total, 86 specimens were collected: 82 Rhodnius pallescens, two Rhodnius prolixus, one Triatoma dimidiata and one Triatoma maculata. The overall T. cruzi infection rate for R. pallescens and R. prolixus was 56.1 and 100% respectively, while T. dimidiata and T. maculata were not infected. Eight feeding sources were found for the infected triatomines, with opossum and humans being the most frequent sources of feeding (85.7%). Infection was most common in the common opossum Didelphis marsupialis, with infection levels of 77.7%. Sylvatic TcI was the most frequent genotype, found in 80% of triatomines and 75% of D. marsupialis. Of the samples collected from dogs (n = 52), five (9.6%; 95% confidence interval: 3.20-21.03) were seropositive based on two independent tests. Four of these dogs were creole and one was a working dog. The spatial analysis revealed a sympatry between infected vectors and mammals with the military population.

CONCLUSIONS

We have shown a potential risk of spillover of sylvatic T. cruzi transmission to humans by oral and vectorial transmission in two BITER installations in Colombia. The results indicate that installations where 100,000 active military personnel carry out training activities should be prioritized for epidemiological surveillance of Chagas disease.

Epidemiology, Biodiversity, and Technological Trajectories in the Brazilian Amazon: From Malaria to COVID-19

The Amazon biome is under severe threat due to increasing deforestation rates and loss of biodiversity and ecosystem services while sustaining a high burden of neglected tropical diseases. Approximately two thirds of this biome are located within Brazilian territory. There, socio-economic and environmental landscape transformations are linked to the regional agrarian economy dynamics, which has developed into six techno-productive trajectories (TTs). These TTs are the product of the historical interaction between Peasant and Farmer and Rancher practices, technologies and rationalities. This article investigates the distribution of the dominant Brazilian Amazon TTs and their association with environmental degradation and vulnerability to neglected tropical diseases. The goal is to provide a framework for the joint debate of the local economic, environmental and health dimensions. We calculated the dominant TT for each municipality in 2017. Peasant trajectories (TT1, TT2, and TT3) are dominant in ca. fifty percent of the Amazon territory, mostly concentrated in areas covered by continuous forest where malaria is an important morbidity and mortality cause. Cattle raising trajectories are associated with higher deforestation rates. Meanwhile, Farmer and Rancher economies are becoming dominant trajectories, comprising large scale cattle and grain production. These trajectories are associated with rapid biodiversity loss and a high prevalence of neglected tropical diseases, such as leishmaniasis, Aedes-borne diseases and Chagas disease. Overall, these results defy simplistic views that the dominant development trajectory for the Amazon will optimize economic, health and environmental indicators. This approach lays the groundwork for a more integrated narrative consistent with the economic history of the Brazilian Amazon.

Trypanosoma rangeli Genetic, Mammalian Hosts, and Geographical Diversity from Five Brazilian Biomes

Trypanosoma rangeli is a generalist hemoflagellate that infects mammals and is transmitted by triatomines around Latin America. Due to its high genetic diversity, it can be classified into two to five lineages. In Brazil, its distribution outside the Amazon region is virtually unknown, and knowledge on the ecology of its lineages and on host species diversity requires further investigation. Here, we analyzed 57 T. rangeli samples obtained from hemocultures and blood clots of 1392 mammals captured in different Brazilian biomes. The samples were subjected to small subunit (SSU) rDNA amplification and sequencing to confirm T. rangeli infection. Phylogenetic inferences and haplotype networks were reconstructed to classify T. rangeli lineages and to infer the genetic diversity of the samples. The results obtained in our study highlighted both the mammalian host range and distribution of T. rangeli in Brazil: infection was observed in five new species (Procyon cancrivorous, Priodontes maximum, Alouatta belzebul, Sapajus libidinosus, and Trinomys dimidiatus), and transmission was observed in the Caatinga biome. The coati (Nasua nasua) and capuchin monkey (S. libidinosus) are the key hosts of T. rangeli. We identified all four T. rangeli lineages previously reported in Brazil (A, B, D, and E) and possibly two new genotypes.

Deforestation effects on Attalea palms and their resident Rhodnius, vectors of Chagas disease, in eastern Amazonia

Attalea palms provide primary habitat to Rhodnius spp., vectors of Trypanosoma cruzi. Flying from palms, these blood-sucking bugs often invade houses and can infect people directly or via food contamination. Chagas disease (CD) risk may therefore increase when Attalea palms thrive near houses. For example, Attalea dominate many deforested landscapes of eastern Amazonia, where acute-CD outbreaks are disturbingly frequent. Despite this possible link between deforestation and CD risk, the population-level responses of Amazonian Attalea and their resident Rhodnius to anthropogenic landscape disturbance remain largely uncharted. We studied adult Attalea palms in old-growth forest (OGF), young secondary forest (YSF), and cattle pasture (CP) in two localities of eastern Amazonia. We recorded 1856 Attalea along 10 transects (153.6 ha), and detected infestation by Rhodnius spp. in 18 of 280 systematically-sampled palms (33 bugs caught). Distance-sampling models suggest that, relative to OGF, adult Attalea density declined by 70-80% in CP and then recovered in YSF. Site-occupancy models estimate a strong positive effect of deforestation on palm-infestation odds (βCP-infestation = 4.82±1.14 SE), with a moderate decline in recovering YSF (βYSF-infestation = 2.66±1.10 SE). Similarly, N-mixture models suggest that, relative to OGF, mean vector density sharply increased in CP palms (βCP-density = 3.20±0.62 SE) and then tapered in YSF (βYSF-density = 1.61±0.76 SE). Together, these results indicate that disturbed landscapes may support between ~2.5 (YSF) and ~5.1 (CP) times more Attalea-dwelling Rhodnius spp. per unit area than OGF. We provide evidence that deforestation may favor palm-dwelling CD vectors in eastern Amazonia. Importantly, our landscape-disturbance effect estimates explicitly take account of (i) imperfect palm and bug detection and (ii) the uncertainties about infestation and vector density arising from sparse bug data. These results suggest that incorporating landscape-disturbance metrics into the spatial stratification of transmission risk could help enhance CD surveillance and prevention in Amazonia.

Triatomine home invasions in active foci of Chagas disease in Abaetetuba, Pará, Brazil

BACKGROUND

Chagas disease is a parasitic infection with high re-emergence rates in some Amazon regions. The main vectors of Trypanosoma cruzi are haematophagous insects, the triatomines. Only a few reports are available about the occurrence of these wild vectors and their contact with the inhabitants of the riverside regions of the Amazon. This study describes the unusual behaviour of the triatomines that have invaded the homes of the residents of Abaetetuba, the city that has the second highest number of cases of Chagas disease.

METHODS

Two cross-sectional studies were conducted using sero-epidemiological surveys of the inhabitants of Abaetetuba with registered triatomine home invasions. The frequencies of the variables of interest were analysed using Epi Info version 7.2.

RESULTS

In 2014 and 2017, 145 persons registered home invasions of triatomines in their domiciles and 16.55% reported having been bitten by insects. The environmental features described indicated potential conditions for the persistence of the parasite's life cycle. Of the enrolled inhabitants, 0.47% were positive for immunoglobulin G anti-T. cruzi antibodies.

CONCLUSIONS

Home invasions of triatomines were confirmed in two periods, with a description of unusual behaviour for the genus Rhodnius. The use of serological surveillance in human populations at risk of this occurrence may constitute a new tool for the early detection of silent infections.

Host infection and community composition predict vector burden

Lyme disease is the most prevalent vector-borne disease in the United States, yet critical gaps remain in our understanding of tick and host interactions that shape disease dynamics. Rodents such as deer mice (Peromyscus spp.) and dusky-footed woodrats (Neotoma fuscipes) are key reservoirs for Borrelia burgdorferi, the etiological bacterium of Lyme disease, and can vary greatly in abundance between habitats. The aggregation of Ixodes pacificus, the western black-legged tick, on rodent hosts is often assumed to be constant across various habitats and not dependent on the rodent or predator communities; however, this is rarely tested. The factors that determine tick burdens on key reservoir hosts are important in estimating Lyme disease risk because larger tick burdens can amplify pathogen transmission. This study is the first to empirically measure I. pacificus larval burdens on competent reservoir hosts as a function of community factors such as rodent diversity, predator diversity, and questing tick abundance. Rodents were live trapped at oak woodland sites to collect tick burdens and tissue samples to test for infection with Borrelia burgdorferi sensu lato. We found that N. fuscipes tick burdens were negatively correlated with predator diversity, but positively correlated with questing I. pacificus larvae. In addition, rodent hosts that were infected with B. burgdorferi sensu lato tend to have higher burdens of larval ticks. These results demonstrate that tick burdens can be shaped by variability between individuals, species, and the broader host community with consequences for transmission and prevalence of tick-borne pathogens.

Risk factors for triatominae infestation in a municipality of Colombia

BACKGROUND

Identifying risk factors for Triatominae infestation is essential for the development of vector control interventions.

METHODS

To determine the intra- and peridomiciliary risk factors associated with triatomine infestation, a cross-sectional analytical study was carried out with random cluster sampling in two stages, which included the identification of risk factors by survey and direct observation, as well as the search and capture of triatomines. The detection of trypanosomes in triatomines was carried out by observing the rectal content and then by conventional polymerase chain reaction (PCR).

RESULTS

In 21 of the 207 houses inspected, 13 specimens of R. colombiensis and 19 specimens of P. geniculatus were found. Entomological indices included: dispersion 36%, infestation 10%, infection 65%, colonization 4.7%, density 15%, and concentration 152%. An association was found between the presence of Triatominae and the existence of branches and fissures in the floors, as well as with the presence of accumulated objects and with knowledge about Chagas disease. The risk of having triatomines in urban homes is 5.7 times higher than the risk in rural areas [confidence interval (CI) 0.508-67.567]; 6.6 times in houses with cracked soil (CI 0.555-81.994), 6 times in houses located near caneys (CI 0.820-44.781), and 6.16 times with accumulated objects (CI 1.542-39.238).

CONCLUSION

Chagas disease is a complex problem that requires control based on the vector's elimination or surveillance, which implies identifying species and their distribution, generating alerts, knowledge, and awareness in the population. It is necessary to intensify surveillance activities for the event, especially in changing aspects of Chagas diseases' transmission dynamics, such as urbanization and the type of housing associated with the vector's presence.

Wild and Domestic Canids and Their Interactions in the Transmission Cycles of Trypanosoma Cruzi and Leishmania spp. in an Area of the Brazilian Cerrado

Trypanosoma cruzi and Leishmania spp. are parasites that infect multiple hosts including canids, considered bioaccumulators of parasites. Deforestation in the Cerrado biome has resulted in the exposure of wild canids to anthropized areas, where they may establish ecological and epidemiological relationships with domestic dogs. We evaluated the infection by trypanosomatids in canids from a Cerrado agroecosystem between 2013 and 2017. Samples of wild canids (blood, bone marrow and skin) and dogs (blood) were collected for parasitological, serological and molecular diagnosis. A total of 414 samples from wild (n = 131) and domestic (n = 283) canids were collected, including recaptures. We obtained five positive hemocultures from Lycalopex vetulus (n = 2), Cerdocyon thous (n = 1) and dogs (n = 2), all characterized as T. cruzi TcIII/V (18S rDNA) and TcIII/V/VI (gGAPDH); one positive skin fragment for Leishmania sp. (C. thous), one positive skin culture (Chrysocyon brachyurus) and one positive fresh blood examination from a dog. Infection by T. cruzi and Leishmania spp. was serologically confirmed in 18% and 4% of the canids, respectively. Active transmission was attested by seroconversion events and occurred despite the low rate of positive parasitological assays. Wild and domestic canids infected by both parasites were detected sharing the same areas, pointing to a possible spillover of parasites among them.

Trypanosomes of vectors and domestic dogs in Trypanosoma cruzi transmission areas from Brazilian southwestern amazon: New mammalian host for Trypanosoma janseni

Trypanosoma cruzi is a widespread protozoan in Latin America causing Chagas disease in humans and able to infect several other mammal species. The objective of this study was to investigate the T. cruzi infection in triatomine fauna as well as in dogs from distinct areas of Acre, western Brazilian Amazonia, which recently reported acute cases of human CD as well as an area that have not notify this disease recently. Triatomines were collected and the intestinal contents were evaluated for the presence of trypanosomatids by optical microscopy and polymerase chain reaction (PCR) targeting the mini-exon gene. Blood smear, hemoculture, PCR and serology were performed in the studied mammals. Fecal content of four triatomines were positive (11.6%) in the fresh examination. Molecular analysis identified Trypanosoma cruzi TCI in two specimens. Blood samples from 90 dogs were obtained. Trypanosoma sp. was observed in six blood smears (6/83, 7.22%). Seropositivity for T. cruzi was 8/89 (8.98). One dog's hemoculture was obtained and characterized as T. rangeli. PCR reactions in blood clots resulted in one positive dog (1/75, 1.3%) infected by T. janseni, providing a new mammalian host for a recently described Trypanosoma species. The results demonstrate the low exposition and prevalence for T. cruzi suggesting that dogs are not important to T. cruzi transmission cycle in the studied áreas.

Triatoma brasiliensis Neiva, 1911 and Triatoma pseudomaculata Corrêa and Espínola, 1964 (Hemiptera, Reduviidae, Triatominae) in rural communities in Northeast Brazil

Chagas disease is an important endemic morbidity in Latin America affecting millions of people in the American continent. It is caused by the protozoan Trypanosoma cruzi, and transmitted through the feces of the insect vector belonging to the subfamily Triatominae. The present conducted an entomological survey of triatomines and analyzed entomological indicators, such as the rate of infestation, colonization, triatomine density and natural infection in rural communities in the municipality of Campinas do Piaui, Piaui State, in the Northeast region of Brazil. Data on the search of triatomines performed in 167 domiciliary units (DUs), harvested during the period of February to July 2019, in 12 rural communities were analyzed. The capture of triatomines occurred in all studied communities, being 76 the number of positive DUs, of the 167 surveyed, presenting a global rate of infestation of 45.51%. Two triatomines species were collected: Triatoma brasiliensis (98.49%) and T. pseudomaculata (1.51%), the first was found in the domiciliary and peridomiciliary areas, while the second was captured only in peridomiciliary areas. The index of colonization was 17.1%. Natural infection was observed only in 5.44% of T. brasiliensis samples. The entomological survey was conducted in rural communities, showingthe risk of transmission of Chagas disease to the local population, requiring continuous entomological surveillance and vector control.

Trypanosoma cruzi infection in domestic and synanthropic mammals such as potential risk of sylvatic transmission in a rural area from north of Antioquia, Colombia

In Colombia, dogs and opossum are the most important mammals in domestic and sylvatic T. cruzi transmission. However, the role of both species has not been evaluated in areas where both species converge in the peridomestic area. To evaluate the infection status of domestic and wild mammals in peridomestic habitats of Puerto Valdivia, Antioquia Department. The infection of domestic dogs and small wild mammals was performed by hemoculture, molecular and serological methods. Additionally, the infection in children under 15 years old and triatomine searches was carried out. We found that 16.07% and 34% dogs, and 59.1% and 61.1% Didelphis marsupialis were found positive by molecular and serological methods respectively. Moreover, in 25% and 75% of the infected dogs were detected TcI_Dom and TcI sylvatic, respectively, while all the D. marsupialis were infected with TcI. Six Rattus rattus and three Proechimys semispinosus were captured but without T. cruzi infection. Finally, none of the 82 children were positive and no triatomine bugs were captured. D. marsupialis and domestics dogs have an important role in the transmission of T. cruzi suggesting a potential risk in T. cruzi transitions areas.

Eco-epidemiological study reveals the importance of Triatoma dimidiata in the Trypanosoma cruzi transmission, in a municipality certified without transmission by Rhodnius prolixus in Colombia

Boyaca department is an endemic area for Chagas disease in Colombia, where 24 of its municipalities have been certified by the PAHO with interruption of Trypanosoma cruzi transmission by R. prolixus. However, the presence of secondary vectors, represent a risk of parasite transmission for citizens and a challenge for the health care institutions. The aim of this work was to investigate eco-epidemiological features of Chagas disease in the municipality of Socota (Boyaca), in order to improve control and surveillance strategies. To understand the transmission dynamics of T. cruzi in this area, we designed a comprehensive, multi-faceted study including: (i) entomological survey in five villages (La Vega, Comaita, Chusvita, Guaquira and Pueblo Nuevo), (ii) blood meal source determination, (iii) T. cruzi infection rate in collected triatomines, (iv) identification of circulating T. cruzi genotypes, (v) serological determination of T. cruzi infection in domestic dogs; and (vi) evaluation of infection in synanthropic mammals. A total of 90 T. dimidiata were collected, of which 73.3% (66/90) and 24.4% (22/90) were collected inside dwellings and peridomestic areas, respectively, while the rest (2/90) in Chusvita Elementary School. T. cruzi infection was evidenced in 40% (36/90) of triatomine bugs using PCR analyses, in which only DTU I was found, and TcI _Dom was the most distributed. Blood-meal analysis showed that T. dimidiata only fed of humans. Seroprevalence in domestic dogs was 4.6% (3/66), while that two Didelphis marsupialis captured showed no infection. In conclusion, the high dispersion and colonization of T. dimidiata shown in this municipality, along the high rate of T. cruzi (TcI) infection and its anthropophilic behavior constitute a risk situation for Chagas disease transmission in this municipality certified without R. prolixus. The epidemiological implications of these findings are herein discussed.

Understanding the oral transmission of Trypanosoma cruzi as a veterinary and medical foodborne zoonosis

Chagas disease is a neglected tropical disease transmitted by the protozoan Trypanosoma cruzi that lately has been highlighted because several outbreaks attributed to oral transmission of the parasite have occurred. These outbreaks are characterized by high mortality rates and massive infections that cannot be related to other types of transmission such as the vectorial route. Oral transmission of Chagas disease has been reported in Brazil, Colombia, Venezuela, Bolivia, Ecuador, Argentina and French Guiana, most of them are massive oral outbreaks caused by the ingestion of beverages and food contaminated with triatomine feces or parasites' reservoirs secretions and considered since 2012 as a foodborne disease. In this review, we present the current status and all available data regarding oral transmission of Chagas disease, highlighting its relevance as a veterinary and medical foodborne zoonosis.

Epidemiological and clinical characteristics of Trypanosoma cruzi infection in dogs (Canis lupus familiaris) from a Chagas Disease-Endemic Urban Area in Colombia

In the last few years, an unusual increase in the number of acute Chagas disease outbreaks, presumably due to oral transmission, has been reported in urban areas in Santander, Colombia. Given the importance of dogs (Canis lupus familiaris) as reservoir hosts and sentinels of T. cruzi infection across different regions of America, we carried out a serological and molecular survey on T. cruzi infection in 215 dogs from the metropolitan area of Bucaramanga, Santander. Serological detection was carried out using enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence antibody test (IFAT), and indirect hemagglutination assay (IHA), while molecular detection was done using a nested PCR (nPCR), targeting the microsatellite region of T. cruzi nuclear DNA. Animals were defined as seropositive when at least two of the three serological tests were positive, and only these animals were evaluated with the nPCR. To discriminate DTU TcI from other DTUs, a multiplex PCR was performed in the T. cruzi-positive samples. Additionally, clinical and hematological traits were evaluated in these hosts. The dog sera showed a seropositivity rate of 27.9 % (60/215), of which 43.3 % (26/60) were positive for nPCR. Statistical analysis indicated that T. cruzi seropositive in dogs was associated with specific socioeconomic sectors and a lack of garbage collection in these municipalities. Hematological analyses showed that T. cruzi infection was associated with anemia and platelet alterations but not with alterations of aspartate aminotransferase (ASAT) and creatine kinase myocardial band (CK-MB). The high seroprevalence of infection and active circulation of T. cruzi I (TcI) in dogs reflect the risk of infection to humans in this area, which should be taken into consideration when Chagas disease control programs are implemented. In addition, T. cruzi infection may take a toll on dog health, which should be considered during dog care and management.

Landmarks of the Knowledge and Trypanosoma cruzi Biology in the Wild Environment

Trypanosomatids are ancient parasitic eukaryotes that still maintain prokaryotic characteristics. Trypanosoma cruzi, a primarily wild mammal parasite, infected humans already long before European colonization of the Americas. T. cruzi heterogeneity remains an unsolved question, and until now, it has still not been possible to associate T. cruzi genotypes with any biological or epidemiological feature. One of the first biochemical attempts to cluster the T. cruzi subpopulations recognized three main subpopulations (zymodemes) that have been associated with the transmission cycles in the wild (Z1; Z3) and in the domestic environment (Z2). The description of wild mammal species harboring Z2 two decades later challenged this assemblage attempt. Currently, the genotypes of T. cruzi are assembled in seven discrete typing units (DTUs). The biology of T. cruzi still shows novelties such as the description of epimastigotes multiplying and differentiating to metacyclic trypomastigotes in the lumen of the scent glands of Didelphis spp. and the capacity of the true meiosis in parallel to clonal reproduction. The study of the transmission cycle among wild animals has broken paradigms and raised new questions: (i) the interaction of the T. cruzi DTUs with each of its mammalian host species displays peculiarities; (ii) the impact of mixed genotypes and species on the transmissibility of one or another species or on pathogenesis is still unknown; (iii) independent T. cruzi transmission cycles may occur in the same forest fragment; (iv) the capacity to act as a reservoir depends on the peculiarities of the host species and the parasite genotype; and (v) faunistic composition is a defining trait of the T. cruzi transmission cycle profile. The development of models of environmental variables that determine the spatial distribution of the elements that make up T. cruzi transmission by spatial analysis, followed by map algebra and networking, are the next steps toward interpreting and dealing with the new profile of Chagas disease with its many peculiarities. There is no way to solve this neglected disease once and for all if not through a multidisciplinary look that takes into account all kinds of human and animal activities in parallel to environmental variations.

Towards common ground in the biodiversity-disease debate

The disease ecology community has struggled to come to consensus on whether biodiversity reduces or increases infectious disease risk, a question that directly affects policy decisions for biodiversity conservation and public health. Here, we summarize the primary points of contention regarding biodiversity–disease relationships and suggest that vector-borne, generalist wildlife and zoonotic pathogens are the types of parasites most likely to be affected by changes to biodiversity. One synthesis on this topic revealed a positive correlation between biodiversity and human disease burden across countries, but as biodiversity changed over time within these countries, this correlation became weaker and more variable. Another synthesis—a meta-analysis of generally smaller-scale experimental and field studies—revealed a negative correlation between biodiversity and infectious diseases (a dilution effect) in various host taxa. These results raise the question of whether biodiversity–disease relationships are more negative at smaller spatial scales. If so, biodiversity conservation at the appropriate scales might prevent wildlife and zoonotic diseases from increasing in prevalence or becoming problematic (general proactive approaches). Further, protecting natural areas from human incursion should reduce zoonotic disease spillover. By contrast, for some infectious diseases, managing particular species or habitats and targeted biomedical approaches (targeted reactive approaches) might outperform biodiversity conservation as a tool for disease control. Importantly, biodiversity conservation and management need to be considered alongside other disease management options. These suggested guiding principles should provide common ground that can enhance scientific and policy clarity for those interested in simultaneously improving wildlife and human health.

There has been intense debate as to whether biodiversity increases or reduces the risk of infectious disease. This Review is the result of researchers from both sides of the debate attempting to reach a consensus.

Performance of recombinant chimeric proteins in the serological diagnosis of Trypanosoma cruzi infection in dogs

BACKGROUND

Dogs are considered sentinels in areas of Trypanosoma cruzi transmission risk to humans. ELISA is generally the method of choice for diagnosing T. cruzi exposure in dogs, but its performance substantially depends on the antigenic matrix employed. In previous studies, our group has developed four chimeric antigens (IBMP-8.1, 8.2, 8.3, and 8.4) and evaluated their potential for diagnosing T. cruzi exposure in humans. For human sera, these chimeric antigens presented superior diagnostic performances as compared to commercial tests available in Brazil, Spain, and Argentina. Therefore, in this study we have evaluated the potential of these antigenic proteins for detection of anti-T. cruzi IgG antibodies in dog sera.

METHODOLOGY/PRINCIPAL FINDINGS

The IBMP-ELISA assays were optimized by checkerboard titration. Subsequently, the diagnostic potential was validated through analysis of ROC curves and the performance of the tests was determined using double entry tables. Cross-reactivity was also evaluated for babesiosis, ehrlichiosis, dirofilariosis, anaplasmosis, and visceral leishmaniasis. Best performance was shown by IBMP-8.3 and IBMP-8.4, although all four antigens demonstrated a high diagnostic performance with 46 positive and 149 negative samples tested. IBMP-8.3 demonstrated 100% sensitivity, followed by IBMP-8.4 (96.7-100%), IBMP-8.2 (73.3-87.5%), and IBMP-8.1 (50-100%). The highest specificities were achieved with IBMP-8.2 (100%) and IBMP-8.4 (100%), followed by IBMP-8.3 (96.7-97.5%) and IBMP 8.1 (89.1-100%).

CONCLUSIONS/SIGNIFICANCE

The use of chimeric antigenic matrices in immunoassays for anti-T. cruzi IgG antibody detection in sera of infected dogs was shown to be a promising tool for veterinary diagnosis and epidemiological studies. The chimeric antigens used in this work allowed also to overcome the common hurdles related to serodiagnosis of T. cruzi infection, especially regarding variation of efficiency parameters according to different strains and cross-reactivity with other infectious diseases.

A review of regulation ecosystem services and disservices from faunal populations and potential impacts of agriculturalisation on their provision, globally

Land use and cover change (LUCC) is the main cause of natural ecosystem degradation and biodiversity loss and can cause a decrease in ecosystem service provision. Animal populations are providers of some key regulation services: pollination, pest and disease control and seed dispersal, the so-called faunal ecosystem services (FES). Here we aim to give an overview on the current and future status of regulation FES in response to change from original habitat to agricultural land globally. FES are much more tightly linked to wildlife populations and biodiversity than are most ecosystem services, whose determinants are largely climatic and related to vegetation structure. Degradation of ecosystems by land use change thus has much more potential to affect FES. In this scoping review, we summarise the main findings showing the importance of animal populations as FES providers and as a source of ecosystem disservices; underlying causes of agriculturalisation impacts on FES and the potential condition of FES under future LUCC in relation to the expected demand for FES globally. Overall, studies support a positive relationship between FES provision and animal species richness and abundance. Agriculturalisation has negative effects on FES providers due to landscape homogenisation, habitat fragmentation and loss, microclimatic changes and development of population imbalance, causing species and population losses of key fauna, reducing services whilst enhancing disservices. Since evidence suggests an increase in FES demand worldwide is required to support increased farming, it is imperative to improve the understanding of agriculturalisation on FES supply and distribution. Spatial conservation prioritisation must factor in faunal ecosystem functions as the most biodiversity-relevant of all ecosystem services and that which most closely links sites of service provision of conservation value with nearby sites of service use to provide ecosystem services of agricultural and economic value.

Trypanosoma cruzi transmission in the wild and its most important reservoir hosts in Brazil

Trypanosoma cruzi (Kinetoplastea: Trypanosomatidae) infects all tissues of its hosts, which along with humans, include hundreds of mammalian species in the Americas. The epidemiology of T. cruzi has been changing in that currently the majority of the cases and/or outbreaks of Chagas disease occur by the ingestion of comestibles contaminated by T. cruzi metacyclic forms. These cases/outbreaks occur in distinct regional scenarios, mainly in the Amazon biome and are related to the local interaction mode of humans with their surroundings, as well as with the overall local ecological peculiarities. As trypanosomiasis caused by T. cruzi is primarily a zoonosis, understanding the variables that influences its transmission in the wild as well as the role played by the extant fauna in the maintenance of the parasite, is critical in establishing control measures. Here, we present the results of our studies of T. cruzi infection of free ranging wild mammalian fauna in the five biomes of Brazil, a country of continental dimensions. From 1992 up to 2017, we examined a total of 6587 free-ranging non-volant wild mammal specimens. Our studies found that 17% of mammals were seropositive and 8% of all animals displayed positive hemocultures indicative of high parasitemia and, consequently, of infectivity potential. We observed that opossums, mainly Philander spp. and Didelphis spp., the coati Nasua nasua, the capuchin monkey Sapajus libidinosus and the golden lion tamarin Leontopithecus rosalia, were mammal taxa that demonstrated higher rates of positive hemocultures. Additionally, Didelphis spp. demonstrated to be a competent bioaccumulator of TcI diversity. Chiroptera were distinguished for hosting the greatest diversity of species and genotypes of Trypanosoma spp. Additionally the observation of the higher host range of some Trypanosoma spp., shows the need to reassess the ecology of representatives of the taxon. Altogether, our results showed that each locality, may display distinct enzootiological and epidemiological scenarios that must be taken into account when it comes to establishing control and/or clarification campaigns of the local population.

Dissecting the phyloepidemiology of Trypanosoma cruzi I (TcI) in Brazil by the use of high resolution genetic markers

BACKGROUND

Trypanosoma cruzi, the causal agent of Chagas disease, is monophyletic but genetically heterogeneous. It is currently represented by six genetic lineages (Discrete Typing Units, DTUs) designated TcI-TcVI. TcI is the most geographically widespread and genetically heterogeneous lineage, this as is evidenced by a wide range of genetic markers applied to isolates spanning a vast geographic range in Latin America.

METHODOLOGY/PRINCIPAL FINDINGS

In total, 78 TcI isolated from hosts and vectors distributed in 5 different biomes of Brazil, were analyzed using 6 nuclear housekeeping genes, 25 microsatellite loci and one mitochondrial marker. Nuclear markers reveal substantial genetic diversity, significant gene flow between biomes, incongruence in phylogenies, and haplotypic analysis indicative of intra-DTU genetic exchange. Phylogenetic reconstructions based on mitochondrial and nuclear loci were incongruent, and consistent with introgression. Structure analysis of microsatellite data reveals that, amongst biomes, the Amazon is the most genetically diverse and experiences the lowest level of gene flow. Investigation of population structure based on the host species/genus, indicated that Didelphis marsupialis might play a role as the main disperser of TcI.

CONCLUSIONS/SIGNIFICANCE

The present work considers a large TcI sample from different hosts and vectors spanning multiple ecologically diverse biomes in Brazil. Importantly, we combine fast and slow evolving markers to contribute to the epizootiological understanding of TcI in five distinct Brazilian biomes. This constitutes the first instance in which MLST analysis was combined with the use of MLMT and maxicircle markers to evaluate the genetic diversity of TcI isolates in Brazil. Our results demonstrate the existence of substantial genetic diversity and the occurrence of introgression events. We provide evidence of genetic exchange in TcI isolates from Brazil and of the relative isolation of TcI in the Amazon biome. We observe the absence of strict associations with TcI genotypes to geographic areas and/or host species.

Conservation of biodiversity as a strategy for improving human health and well-being

The Earth's ecosystems have been altered by anthropogenic processes, including land use, harvesting populations, species introductions and climate change. These anthropogenic processes greatly alter plant and animal communities, thereby changing transmission of the zoonotic pathogens they carry. Biodiversity conservation may be a potential win-win strategy for maintaining ecosystem health and protecting public health, yet the causal evidence to support this strategy is limited. Evaluating conservation as a viable public health intervention requires answering four questions: (i) Is there a general and causal relationship between biodiversity and pathogen transmission, and if so, which direction is it in? (ii) Does increased pathogen diversity with increased host biodiversity result in an increase in total disease burden? (iii) Do the net benefits of biodiversity conservation to human well-being outweigh the benefits that biodiversity-degrading activities, such as agriculture and resource utilization, provide? (iv) Are biodiversity conservation interventions cost-effective when compared to other options employed in standard public health approaches? Here, we summarize current knowledge on biodiversity-zoonotic disease relationships and outline a research plan to address the gaps in our understanding for each of these four questions. Developing practical and self-sustaining biodiversity conservation interventions will require significant investment in disease ecology research to determine when and where they will be effective.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.

Molecular Epidemiology of Trypanosomatids and Trypanosoma cruzi in Primates from Peru

We determined the prevalence rate and risk of infection of Trypanosoma cruzi and other trypanosomatids in Peruvian non-human primates (NHPs) in the wild (n = 126) and in different captive conditions (n = 183). Blood samples were collected on filter paper, FTA cards, or EDTA tubes and tested using a nested PCR protocol targeting the 24Sα rRNA gene. Main risk factors associated with trypanosomatid and T. cruzi infection were genus and the human-animal context (wild vs captive animals). Wild NHPs had higher prevalence of both trypanosomatids (64.3 vs 27.9%, P < 0.001) and T. cruzi (8.7 vs 3.3%, P = 0.057), compared to captive NHPs, suggesting that parasite transmission in NHPs occurs more actively in the sylvatic cycle. In terms of primate family, Pitheciidae had the highest trypanosomatid prevalence (20/22, 90.9%) and Cebidae had the highest T. cruzi prevalence (15/117, 12.8%). T. cruzi and trypanosomatids are common in Peruvian NHPs and could pose a health risk to human and animals that has not been properly studied.

High Trypanosoma spp. diversity is maintained by bats and triatomines in Espírito Santo state, Brazil

The aim of this study was to reevaluate the ecology of an area in the Atlantic Forest, southeast Brazil, where Chagas disease (CD) has been found to occur. In a previous study, immediately after the occurrence of a CD case, we did not observe any sylvatic small mammals or dogs with Trypanosoma cruzi cruzi infections, but Triatoma vitticeps presented high T. c. cruzi infection rates. In this study, we investigated bats together with non-volant mammals, dogs, and triatomines to explore other possible T. c. cruzi reservoirs/hosts in the area. Seventy-three non-volant mammals and 186 bats were captured at three sites within the Guarapari municipality, Espírito Santo state. Rio da Prata and Amarelos sites exhibited greater richness in terms of non-volant mammals and bats species, respectively. The marsupial Metachirus nudicaudatus, the rodent Trinomys paratus, and the bats Artibeus lituratus and Carollia perspicillata were the most frequently captured species. As determined by positive hemocultures, only two non-volant mammals were found to be infected by Trypanosoma species: Monodelphis americana, which was infected by T. cascavelli, T. dionisii and Trypanosoma sp., and Callithrix geoffroyi, which was infected by T. minasense. Bats presented T. c. cruzi TcI and TcIII/V, T. c. marinkellei, T. dionisii, T. rangeli B and D, and Trypanosoma sp. infections. Seven dogs were infected with T. cruzi based only on serological exams. The triatomines T. vitticeps and Panstrongylus geniculatus were found to be infected by trypanosomes via microscopy. According to molecular characterization, T. vitticeps specimens were infected with T. c. cruzi TcI, TcII, TcIII/V, and TcIV, T. c. marinkellei and T. dionisii. We observed high trypanosome diversity in a small and fragmented region of the Atlantic Forest. This diversity was primarily maintained by bats and T. vitticeps. Our findings show that the host specificity of the Trypanosoma genus should be thoroughly reviewed. In addition, our data show that CD cases can occur without an enzootic cycle near residential areas.

Prevalence of Trypanosoma cruzi and Other Trypanosomatids in Frequently-Hunted Wild Mammals from the Peruvian Amazon

To better understand the ecology of Trypanosoma cruzi in the northeastern Peruvian Amazon, we evaluated the prevalence of T. cruzi and other trypanosomatids in four orders of wild mammals hunted and consumed by inhabitants of three remote indigenous communities in the Peruvian Amazon. Of 300 wild mammals sampled, 115 (38.3%) were infected with trypanosomatids and 15 (5.0%) with T. cruzi. The prevalence of T. cruzi within each species was as follows: large rodents (Cuniculus paca, 5.5%; Dasyprocta spp., 2.6%), edentates (Dasypus novemcinctus, 4.2%), and carnivores with higher prevalence (Nasua nasua, 18.8%). The high prevalence of T. cruzi and other trypanosomatids in frequently hunted wild mammals suggests a sizeable T. cruzi sylvatic reservoir in remote Amazonian locations.

Drivers of house invasion by sylvatic Chagas disease vectors in the Amazon-Cerrado transition: A multi-year, state-wide assessment of municipality-aggregated surveillance data

Background

Insecticide spraying efficiently controls house infestation by triatomine bugs, the vectors of Trypanosoma cruzi. The strategy, however, is ineffective against sylvatic triatomines, which can transmit Chagas disease by invading (without colonizing) man-made structures. Despite growing awareness of the relevance of these transmission dynamics, the drivers of house invasion by sylvatic triatomines remain poorly understood.

Methods/Findings

About 12,000 sylvatic triatomines were caught during routine surveillance in houses of Tocantins state, Brazil, in 2005–2013. Using negative binomial regression, information-theoretic model evaluation/averaging, and external model validation, we investigated the effects of regional (Amazon/Cerrado), landscape (preservation/disturbance), and climate covariates (temperature, rainfall) on the municipality-aggregated numbers of house-invading Rhodnius pictipes, R. robustus, R. neglectus, and Panstrongylus geniculatus. House invasion by R. pictipes and R. robustus was overall more frequent in the Amazon biome, tended to increase in municipalities with more well-preserved land, and decreased in rainier municipalities. Across species, invasion decreased with higher landscape-disturbance levels and in hotter-day municipalities. Invasion by R. neglectus and P. geniculatus increased somewhat with more land at intermediate disturbance and peaked in average-rainfall municipalities. Temperature effects were more pronounced on P. geniculatus than on Rhodnius spp.

Conclusions

We report widespread, frequent house invasion by sylvatic triatomines in the Amazon–Cerrado transition. Our analyses indicate that readily available environmental metrics may help predict the risk of contact between sylvatic triatomines and humans at coarse geographic scales, and hint at specific hypotheses about climate and deforestation effects on those vectors–with some taxon-specific responses and some seemingly general trends. Thus, our focal species appear to be quite sensitive to higher temperatures, and might be less common in more heavily-disturbed than in better-preserved environments. This study illustrates, in sum, how entomological routine-surveillance data can be efficiently used for Chagas disease risk prediction and stratification when house-colonizing vectors are absent.

Triatomine bugs are the vectors of Chagas disease, still a key public health concern in the Americas. Insecticide spraying efficiently controls house infestation by triatomines, but is useless against sylvatic bugs–which can transmit the disease by simply invading human residences. Although this behavior is common, the drivers of house invasion by wild triatomines remain poorly understood. Using municipality-aggregated data from routine surveillance, we investigated whether and how some major environmental factors affect house invasion by four triatomine species across the transition between Amazon rainforests and Cerrado savannahs in Brazil. We found that house invasion (i) is widespread, (ii) varies by region for some species, (iii) is overall less frequent in areas with higher levels of landscape disturbance, and (iv) is less common in hotter and in rainier sites. Although the effects of landscape disturbance and climate differed somewhat among bug species, the general approach we describe here may help advance Chagas disease risk assessment when house-colonizing vectors are absent.

Identification of novel mammalian hosts and Brazilian biome geographic distribution of Trypanosoma cruzi TcIII and TcIV

Trypanosoma cruzi is a parasitic protozoan responsible for Chagas disease. Seven different Discrete Typing Units (DTUs) of T. cruzi are currently identified in nature: TcI-TcVI, and TcBat whose distribution patterns in nature, hosts/reservoirs and eco-epidemiological importance are still little known. Here, we present novel data on the geographic distribution and diversity of mammalian hosts and vectors of T. cruzi DTUs TcIII and TcIV. In this study, we analyzed 61 T. cruzi isolates obtained from 18 species of mammals (five orders) and two Hemiptera genera. Samples were collected from five Brazilian biomes (Pantanal, Caatinga, Cerrado, Atlantic Rainforest, and Amazon) previously characterized as Z3 or mixed infection (TcI-Z3) by mini-exon gene PCR. To identify TcIII and TcIV genotypes, we applied restriction fragment length polymorphism analysis to the PCR-amplified histone 3 gene. DTUs TcIII and TcIV were identified in single and mixed infections from wide dispersion throughout five Brazilian biomes studied, with TcIV being the most common. Pantanal was the biome that displayed the largest number of samples characterized as TcIII and TcIV in single and mixed infections, followed by Atlantic Rainforest and Amazon. Species from the Didelphimorphia order displayed the highest frequency of infection and were found in all five biomes. We report, for the first time, the infection of a species of the Artiodactyla order by DTU TcIII. In addition, we describe new host species: five mammals (marsupials and rodents) and two genera of Hemiptera. Our data indicate that DTUs TcIII and TcIV are more widespread and infect a larger number of mammalian species than previously thought. In addition, they are transmitted in restricted foci and cycles, but in different microhabitats and areas with distinct ecological profiles. Finally, we show that DTUs TcIII and TcIV do not present any specific association with biomes or host species.

Prevalence of Trypanosoma cruzi infection in dogs and small mammals in Nuevo León, Mexico

Chagas disease, caused by the protozoan Trypanosoma cruzi, is an important public health concern in areas extending from South America northward into the southern United States of America. Although this hemoflagellate has many wild and domestic mammalians reported as reservoir hosts, studies on this subject are scarce in Nuevo León state, a region located in northeastern Mexico. This cross-sectional study showed that the general prevalence of T. cruzi infection in Nuevo León state was 14.5% (35/241), this percentage matching the ones determined by PCR and traditional diagnostics. Localities and infected mammals did not significantly differ (χ²=6.098, p=0.192); however the number of infected animals was highly correlated with mammalian species (p=0.009). Striped skunks (Mephitis mephitis) were found to be the most infected overall (11/34, 32.3%), while dogs (Canis familiaris) had the lowest prevalence. In conclusion, although the prevalence of T. cruzi infection in small mammals was lower in Nuevo León than in other states of Mexico, our results provide new locality records, including striped skunks, opossums (Didelphis marsupialis) and dogs, and extend the recorded area to woodrats (Neotoma micropus).

Canine Macrophage DH82 Cell Line As a Model to Study Susceptibility to Trypanosoma cruzi Infection

Trypanosoma cruzi is an obligatory intracellular protozoan parasite, and it is the etiological agent of Chagas' disease that is endemic in the Americas. In addition to humans, a wide spectrum of mammals can be infected by T. cruzi, including dogs. Dogs develop acute and chronic disease, similar to human infection. T. cruzi can infect almost all cell types and after cell invasion, the metacyclics trypomastigotes localize in the cytoplasm, where they transform into amastigotes, the replicative form of T. cruzi in mammals. After amastigote multiplication and differentiation, parasites lyse host cells and spread through the body by blood circulation. In this work, we evaluated the in vitro ability of T. cruzi to infect a canine macrophage cell line DH82 compared with RAW264.7, a murine tissue culture macrophage. Our results have shown that the T. cruzi is able to infect, replicate and differentiate in DH82 cell line. We observed that following treatment with LPS and IFN-γ DH82 cells were more resistant to infection and that resistance was not related reactive oxygen species production in our system. In this study, we also found that DH82 cells became more susceptible to T. cruzi infection when cocultured with apoptotic cells. The analysis of cytokine production has showed elevated levels of the TGF-β, IL-10, and TNF-α produced by T. cruzi-infected canine macrophages. Additionally, we demonstrated a reduced expression of the MHC class II and CD80 by infected DH82 cell line.

Molecular and serological detection of Trypanosoma cruzi in dogs (Canis lupus familiaris) suggests potential transmission risk in areas of recent acute Chagas disease outbreaks in Colombia

Chagas disease is a zoonotic infection widely distributed in tropical and subtropical regions of America, including more than 50% of the Colombian territory. In the last years, an increase of outbreaks of acute Chagas disease has been observed in the east of the country due to environmental changes and mammal movements toward human settlements. Given the importance of dogs (Canis lupus familiaris) as reservoir hosts and sentinels of Trypanosoma cruzi infection across different regions of America, in this study we reported a serological and molecular detection of T. cruzi infection in 242 dogs from an endemic area of Meta department (East of Colombia), with recent emergence of acute Chagas disease outbreaks. The distribution of T. cruzi infection in dogs was not homogeneous, ranging from 0-41.4% and 0-5.1% in different sampling sectors, through serological (ELISA/IFAT) and molecular methods (conventional and real time PCR), respectively. Statistical analysis indicated that dog infection was associated with specific sampling sectors. Our results show a moderate seroprevalence of infection and active circulation of T. cruzi in dogs from this zone, which suggest areas with potential risk of infection to human that must be taken into consideration when Chagas disease control programs need to be implemented.

Modeling the effects of palm-house proximity on the theoretical risk of Chagas disease transmission in a rural locality of the Orinoco basin, Colombia

Background

Chagas disease is a major public health concern in Latin America and it is transmitted by insects of the subfamily Triatominae, including Rhodnius spp. Since palm trees are ubiquitous in Colombia and a habitat for Rhodnius spp., the presence of palms near villages could increase contact rates between vectors and humans. Therefore, knowing whether a relationship exists between the proximity of palms to villages and the abundance and distribution of vectors therein, may be critical for Chagas disease prevention programs. Adapting a mathematical model for R. prolixus population dynamics in a small village, we model the implications of changing distances between palms and dwellings, to the risk of Chagas disease infection.

Methods

We implemented a mathematical model that reflects R. prolixus population dynamics in a small village located in the department of Casanare (Colombia) to study the role of palm-house proximity. We varied the distance between palms and houses by monitoring the network global efficiency metric. We constructed 1,000 hypothetical villages varying distances and each one was run 100 times.

Results

According to the model, as palm-house proximity increases, houses were more likely to be visited by triatomine bugs. The number of bugs per unit time increased progressively in a non-linear fashion with high variability. We stress the importance of village configuration on the model output.

Conclusions

From a theoretical perspective, palm-house proximity may have a positive effect on the incidence of Chagas disease. The model predicts a 1% increase in new human cases per year when houses and palms are brought closer by 75%.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1884-8) contains supplementary material, which is available to authorized users.

Lineage-specific serology confirms Brazilian Atlantic forest lion tamarins, Leontopithecus chrysomelas and Leontopithecus rosalia, as reservoir hosts of Trypanosoma cruzi II (TcII)

Background

Trypanosoma cruzi, the agent of Chagas disease in humans, has a vast reservoir of mammalian hosts in the Americas, and is classified into six genetic lineages, TcI-TcVI, with a possible seventh, TcBat. Elucidating enzootic cycles of the different lineages is important for understanding the ecology of this parasite, the emergence of new outbreaks of Chagas disease and for guiding control strategies. Direct lineage identification by genotyping is hampered by limitations of parasite isolation and culture. An indirect method is to identify lineage-specific serological reactions in infected individuals; here we describe its application with sylvatic Brazilian primates.

Methods

Synthetic peptides representing lineage-specific epitopes of the T. cruzi surface protein TSSA were used in ELISA with sera from Atlantic Forest Leontopithecus chrysomelas (golden-headed lion tamarin), L. rosalia (golden lion tamarin), Amazonian Sapajus libidinosus (black-striped capuchin) and Alouatta belzebul (red-handed howler monkey).

Results

The epitope common to lineages TcII, TcV and TcVI was recognised by sera from 15 of 26 L. chrysomelas and 8 of 13 L. rosalia. For 12 of these serologically identified TcII infections, the identity of the lineage infection was confirmed by genotyping T. cruzi isolates. Of the TcII/TcV/TcVI positive sera 12 of the 15 L. chrysomelas and 2 of the 8 L. rosalia also reacted with the specific epitope restricted to TcV and TcVI. Sera from one of six S. libidinous recognised the TcIV/TcIII epitopes.

Conclusions

This lineage-specific serological surveillance has verified that Atlantic Forest primates are reservoir hosts of at least TcII, and probably TcV and TcVI, commonly associated with severe Chagas disease in the southern cone region of South America. With appropriate reagents, this novel methodology is readily applicable to a wide range of mammal species and reservoir host discovery.

Cutaneous leishmaniasis prevalence and morbidity based on environmental factors in Ilam, Iran: Spatial analysis and land use regression models

The aim of this study was to investigate the impact of the environmental factors on cutaneous leishmaniasis (CL) prevalence and morbidity in Ilam province, western Iran, as a known endemic area for this disease. Accurate locations of 3237 CL patients diagnosed from 2013 to 2015, their demographic information, and data of 17 potentially predictive environmental variables (PPEVs) were prepared to be used in Geographic Information System (GIS) and Land-Use Regression (LUR) analysis. The prevalence, risk, and predictive risk maps were provided using Inverse Distance Weighting (IDW) model in GIS software. Regression analysis was used to determine how environmental variables affect on CL prevalence. All maps and regression models were developed based on the annual and three-year average of the CL prevalence. The results showed that there was statistically significant relationship (P value≤0.05) between CL prevalence and 11 (64%) PPEVs which were elevation, population, rainfall, temperature, urban land use, poorland, dry farming, inceptisol and aridisol soils, and forest and irrigated lands. The highest probability of the CL prevalence was predicted in the west of the study area and frontier with Iraq. An inverse relationship was found between CL prevalence and environmental factors, including elevation, covering soil, rainfall, agricultural irrigation, and elevation while this relation was positive for temperature, urban land use, and population density. Environmental factors were found to be an important predictive variables for CL prevalence and should be considered in management strategies for CL control.

Trypanosoma cruzi diversity in infected dogs from areas of the north coast of Chile

As part of a multi-site research program on the eco-epidemiology and control of Chagas disease in northern Chile, we sought to identify the Trypanosoma cruzi discrete typing units (DTUs) infecting rural and peridomestic dogs, using direct methods without grown of the parasite in the laboratory and thus to assess the use of this species as a sentinel of the disease in well-defined endemic areas of T. cruzi in Chile. Infected dogs (35) from three villages were included in the study. The studied villages were Caleta Río Seco and Caleta San Marcos, both in the Tarapacá Region, and La Serena in the Coquimbo Region. These villages were selected based on previous evidence of Mepraia infection reports of the Chilean Ministry of Health. Amplicons from nested-PCR positive samples were used as targets to determine the infective T. cruzi DTUs circulating in blood using PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). Results of hybridization with dog samples from Caleta Rio Seco showed single infections in 2 out of 16 and mixed infections in 14 out of 16. TcVI was the most frequent DTU found in this area. A highlight is that for the first time the presence of TcIII is reported in this area. Samples from Caleta San Marcos showed single infections in 5 out of 9 and mixed infections in 4 out of 9. TcVI was the most frequent DTU found in this area. Samples from La Serena showed single infections in 5 out of 10 and mixed infections in 2 out of 10; we were unable to genotype the other 3 samples. Our results indicate that infection by T. cruzi DTUs in dogs is not homogeneously distributed but rather specific to each region of our country, as demonstrated by the differences in the T. cruzi DTU distribution in some localities.

Ecological scenario and Trypanosoma cruzi DTU characterization of a fatal acute Chagas disease case transmitted orally (Espírito Santo state, Brazil)

BACKGROUND

Trypanosoma cruzi infection via oral route results in outbreaks or cases of acute Chagas disease (ACD) in different Brazilian regions and poses a novel epidemiological scenario. In the Espírito Santo state (southeastern Brazil), a fatal case of a patient with ACD led us to investigate the enzootic scenario to avoid the development of new cases. At the studied locality, Triatoma vitticeps exhibited high T. cruzi infection rates and frequently invaded residences.

METHODS

Sylvatic and domestic mammals in the Rio da Prata locality, where the ACD case occurred, and in four surrounding areas (Baia Nova, Buenos Aires, Santa Rita and Todos os Santos) were examined and underwent parasitological and serological tests. Triatomines were collected for a fecal material exam, culturing and mini-exon gene molecular characterization, followed by RFLP-PCR of H3/Alul. Paraffin-embedded cardiac tissue of a patient was washed with xylene to remove paraffin and DNA was extracted using the phenol-chloroform method. For genotype characterization, PCR was performed to amplify the 1f8, GPI and 18S rRNA genes. In the case of V7V8 SSU rRNA, the PCR products were molecularly cloned. PCR products were sequenced and compared to sequences in GenBank. Phylogenetic analysis using maximum likelihood method with 1000 bootstrap replicates was performed.

RESULTS

None of the animals showed positive hemocultures. Three rodents and two dogs showed signs of infection, as inferred from borderline serological titers. T. vitticeps was the only triatomine species identified and showed T. cruzi infection by DTUs TcI and TcIV. The analysis of cardiac tissue DNA showed mixed infection by T. cruzi (DTUs I, II, III and IV) and Trypanosoma dionisii.

CONCLUSIONS

Each case or outbreak of ACD should be analyzed as a particular epidemiological occurrence. The results indicated that mixed infections in humans may play a role in pathogenicity and may be more common than is currently recognized. Direct molecular characterization from biological samples is essential because this procedure avoids parasite selection. T. dionisii may under certain and unknown circumstances infect humans. The distribution of T. cruzi DTUS TcIII and TcIV in Brazilian biomes is broader than has been assumed to date.

A comparative study of Trypanosoma cruzi infection in sylvatic mammals from a protected and a disturbed area in the Argentine Chaco

Understanding the complex epidemiology of Trypanosoma cruzi transmission cycles requires comparative studies in widely different environments. We assessed the occurrence of T. cruzi infection in sylvatic mammals, their infectiousness to the vector, and parasite genotypes in a protected area of the Argentine Chaco, and compared them with information obtained similarly in a nearby disturbed area. A total of 278 mammals from >23 species in the protected area were diagnosed for T. cruzi infection using xenodiagnosis, kDNA-PCR and nuclear satellite DNA-PCR (SAT) from blood samples. The relative abundance and species composition differed substantially between areas. Didelphis albiventris opossums were less abundant in the protected area; had a significantly lower body mass index, and a stage structure biased toward earlier stages. The capture of armadillos was lower in the protected area. The composite prevalence of T. cruzi infection across host species was significantly lower in the protected area (11.1%) than in the disturbed area (22.1%), and heterogeneous across species groups. The prevalence of infection in D. albiventris and Thylamys pusilla opossums was significantly lower in the protected area (nil for D. albiventris), whereas infection in sigmodontine rodents was three times higher in the protected area (17.5 versus 5.7%). Parasite isolates from the two xenodiagnosis-positive mammals (1 Dasypus novemcinctus and 1 Conepatus chinga) were typed as TcIII; both specimens were highly infectious to Triatoma infestans. Fat-tailed opossums, bats and rodents were kDNA-PCR-positive and xenodiagnosis-negative. Desmodus rotundus and Myotis bats were found infected with T. cruzi for the first time in the Gran Chaco.

Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas

The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species.