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IntroductionChagas disease is caused by the protozoan parasite Trypanosoma cruzi, and it is the most important neglected tropical disease in the Americas. Two drugs are available to treat the infection, but their efficacy in the chronic stage of the disease, when most cases are diagnosed, is reduced. Their tolerability is also hindered by common adverse effects, making the development of safer and efficacious alternatives a pressing need. T. cruzi is unable to synthesize purines de novo, relying on a purine salvage pathway to acquire these from its host, making it an attractive target for the development of new drugs. MethodsWe evaluated the anti-parasitic activity of 23 purine analogs with different substitutions in the complementary chains of their purine rings. We sequentially screened the compounds' capacity to inhibit parasite growth, their toxicity in Vero and HepG2 cells, and their specific capacity to inhibit the development of amastigotes. We then used in-silico docking to identify their likely targets.ResultsEight compounds showed specific anti-parasitic activity, with IC50 values ranging from 2.42 to 8.16 μM. Adenine phosphoribosyl transferase, and hypoxanthine-guanine phosphoribosyl transferase, are their most likely targets. DiscussionOur results illustrate the potential role of the purine salvage pathway as a target route for the development of alternative treatments against T. cruzi infection, highlithing the apparent importance of specific substitutions, like the presence of benzene groups in the C8 position of the purine ring, consistently associated with a high and specific anti-parasitic activity.

Abstract Background Chagas disease is a neglected zoonosis caused by the parasite Trypanosoma cruzi. It affects over six million people, mostly in Latin America. Drugs available to treat T. cruzi infection have associated toxicity and questionable efficacy at the chronic stage. Hence, the discovery of more effective and safer drugs is an unmet medical need. For this, natural products represent a pool of unique chemical diversity that can serve as excellent templates for the synthesis of active molecules. Methods A collection of 79 extracts of Amaryllidaceae plants were screened against T. cruzi. Active extracts against the parasite were progressed through two cell toxicity assays based on Vero and HepG2 cells to determine their selectivity profile and discard those toxic to host cells. Anti-T. cruzi-specific extracts were further qualified by an anti-amastigote stage assay. Results Two extracts, respectively from Crinum erubescens and Rhodophiala andicola, were identified as highly active and specific against T. cruzi and its mammalian replicative form. Conclusions The results retrieved in this study encourage further exploration of the chemical content of these extracts in search of new anti-T. cruzi drug development starting points. Graphic abstract

Abstract Introduction In the current mobility and globalization context, there is a growing need to identify potential changes on the pattern of diseases in the European Union (EU)/European Economic Area (EEA) and provide accurate diagnosis and treatment for the population. The pattern of rare communicable diseases that can affect people returning to EU/EEA from travel abroad, visiting EU/EEA or establishing in the EU/EEA is of special relevance. The objective of this manuscript is to give an overview about the EURaDMoG study and discuss the feasibility of establishing a European network on rare communicable diseases and other rare conditions linked to mobility and globalization. Methods We undertook a three-steps process where we first conducted a narrative review to estimate the prevalence and incidence and to list rare communicable and non-communicable diseases linked to mobility and globalization in the EU/EEA; second, we organized an international consultation workshop with experts in the diseases previously selected; and finally, the feasibility study analysed how successful a European expert network on rare diseases linked to mobility and globalization focused on health care provision would be, accounting for different operational and also sustainability criteria. Results First, considering the areas or topics that the network should cover, it was concluded that communicable and non-communicable rare diseases linked to mobility and globalization should be differentiated. Second, since all non-communicable rare diseases linked to mobility and globalization identified are already covered by different European Reference Networks (ERNs), there is no need for them to be included in a new European network. Three scenarios were considered for establishing a potential European network for rare communicable diseases linked to Mobility and Globalisation with a focus on Health Care provision: 1) To maintain the current situation “Status Quo” scenario; 2) to create a specific European expert network (EEN) on rare communicable diseases linked to mobility and globalisation; 3) to develop a new ERN on communicable rare diseases linked to mobility and globalisation. Conclusions Since the focus is the provision of health care, an ERN could have the potential to better boost the quality of care being facilitated by technological tools and online platforms that permit the safe and ethically acceptable exchange of data. However, this potential new network should not eclipse current existing networks and they should be complementary.

Chagas disease is emerging in countries to which it is not endemic. Biomarkers for earlier therapeutic response assessment in patients with chronic Chagas disease are needed. We profiled plasma-derived extracellular vesicles from a heart transplant patient with chronic Chagas disease and showed the potential of this approach for discovering such biomarkers.

Abstract Background Chagas disease, caused by the protozoan Trypanosoma cruzi, is a neglected disease that affects ~7 million people worldwide. Development of new drugs to treat the infection remains a priority since those currently available have frequent side effects and limited efficacy at the chronic stage. Natural products provide a pool of diversity structures to lead the chemical synthesis of novel molecules for this purpose. Herein we analyzed the anti-T. cruzi activity of nine alkaloids derived from plants of the family Amaryllidaceae. Methods The activity of each alkaloid was assessed by means of an anti-T. cruzi phenotypic assay. We further evaluated the compounds that inhibited parasite growth on two distinct cytotoxicity assays to discard those that were toxic to host cells and assure parasite selectivity. Results We identified a single compound (hippeastrine) that was selectively active against the parasite yielding selectivity indexes of 12.7 and 35.2 against Vero and HepG2 cells, respectively. Moreover, it showed specific activity against the amastigote stage (IC50 = 3.31 μM). Conclusions Results reported here suggest that natural products are an interesting source of new compounds for the development of drugs against Chagas disease.

Background Most people with chronic Chagas disease do not receive specific care and therefore are undiagnosed and do not receive accurate treatment. This manuscript discusses and evaluates a collaborative strategy to improve access to healthcare for patients with Chagas in Bolivia, a country with the highest prevalence of Chagas in the world. Methods With the aim of reinforcing the Chagas National Programme, the Bolivian Chagas Platform was born in 2009. The first stage of the project was to implement a vertical pilot program in order to introduce and consolidate a consensual protocol-based healthcare, working in seven centers (Chagas Platform Centers). From 2015 on the model was extended to 52 primary healthcare centers, through decentralized, horizontal scaling-up. To evaluate the strategy, we have used the WHO ExpandNet program. Results The strategy has significantly increased the number of patients cared for, with 181,397 people at risk of having T. cruzi infection tested and 57,871 (31·9%) new diagnostics performed. In those with treatment criteria, 79·2% completed the treatment. The program has also trained a significant number of health personnel through the specific Chagas guidelines (67% of healthcare workers in the intervention area). Conclusions After being recognized by the Chagas National Programme as a healthcare model aligned with national laws and priorities, the Bolivian platform of Chagas as an innovation, includes attributes that they have made it possible to expand the strategy at the national level and could also be adapted in other countries. Author summary The Bolivian Chagas Platform was born in 2009 to promote comprehensive care for Chagas disease (CD), a neglected tropical disease that affects more than a million people in Bolivia. A two-phase strategy was designed to introduce protocol-based healthcare in Bolivia through prevention, case-management, healthcare professionals training, and community activities. From an initial seven centers in the vertical phase (Chagas Platform centers), 52 healthcare primary healthcare centers adopted CD protocolized care in a second phase (Chagas Healthcare Network) through decentralized, horizontal scaling-up. 181,397 people at risk of having T. cruzi infection were tested (15%), 57,871 (31.9%) tested positive, and 18,582 (32.1%) were treated. Sixty-seven percent of healthcare workers were trained. Adequate domestic financial and human resources were ensured at the end of the scaling-up. Translational research and training activities improved evidence-based decision-making in clinical management. The Bolivian Chagas Platform as innovation, included attributes that enabled scaling-up at national and international level.

Introduction Chagas disease (CD) affects ~7 million people worldwide. Benznidazole (BZN) and nifurtimox (NFX) are the only approved drugs for CD chemotherapy. Although both drugs are highly effective in acute and paediatric infections, their efficacy in adults with chronic CD (CCD) is lower and variable. Moreover, the high incidence of adverse events (AEs) with both drugs has hampered their widespread use. Trials in CCD adults showed that quantitative PCR (qPCR) assays remain negative for 12 months after standard-of-care (SoC) BZN treatment in ~80% patients. BZN pharmacokinetic data and the nonsynchronous nature of the proliferative mammal-dwelling parasite stage suggested that a lower BZN/NFX dosing frequency, combined with standard or extended treatment duration, might have the same or better efficacy than either drug SoC, with fewer AEs.Methods and analysis New ThErapies and Biomarkers for ChagaS infEctiOn (TESEO) is an open-label, randomised, prospective, phase-2 clinical trial, with six treatment arms (75 patients/arm, 450 patients). Primary objectives are to compare the safety and efficacy of two new proposed chemotherapy regimens of BZN and NFX in adults with CCD with the current SoC for BZN and NFX, evaluated by qPCR and biomarkers for 36 months posttreatment and correlated with CD conventional serology. Recruitment of patients was initiated on 18 December 2019 and on 20 May 2021, 450 patients (study goal) were randomised among the six treatment arms. The treatment phase was finalised on 18 August 2021. Secondary objectives include evaluation of population pharmacokinetics of both drugs in all treatment arms, the incidence of AEs, and parasite genotyping.Ethics and dissemination The TESEO study was approved by the National Institutes of Health (NIH), U.S. Food and Drug Administration (FDA), federal regulatory agency of the Plurinational State of Bolivia and the Ethics Committees of the participating institutions. The results will be disseminated via publications in peer-reviewed journals, conferences and reports to the NIH, FDA and participating institutions.Trial registration number NCT03981523.

Mounting a balanced and robust humoral immune response is of utmost importance for reducing the infectivity of Trypanosoma cruzi. While the role of such a response in controlling the infection is well known, there is a lack of tools that can be used to quickly evaluate it. We developed a serum parasite inhibition assay (to evaluate changes in the parasite infection after exposing infective T. cruzi trypomastigotes to serum samples from infected patients). It is based on Vero cells as the hosts and the Tulahuen β-galactosidase parasite strain, genetically engineered to be quantifiable by spectrophotometry. In parallel, we developed an in-house ELISA to correlate the anti-T. cruzi antibody titres of the clinical samples with their observed anti-parasitic effect in the serum parasite inhibition assay. Serum samples from chronically T. cruzi-infected patients significantly inhibited parasite invasion in a titre-dependant manner, regardless of the patient’s clinical status, compared to samples from the non-infected controls. In addition, there was a clear correlation between the reactivity of the samples to the whole-parasite lysates by ELISA and the inhibitory effect. The results of this work confirm the previously described anti-parasitic effect of the serum of individuals exposed to T. cruzi and present a framework for its large-scale evaluation in further studies. The serum parasite inhibition assay represents a reproducible way to evaluate the intensity and anti-parasitic effect of humoral responses against T. cruzi, which could be applied to the evaluation of candidate antigens/epitopes in the design of Chagas disease vaccine candidates.

ObjectiveChagas disease (CD) globalization facilitated the co-infection with Human Immunodeficiency Virus (HIV) in endemic and non-endemic areas. Considering the underestimation of Trypanosoma cruzi (T. cruzi)-HIV co-infection and the risk of life-threatening Chagas Disease Reactivation (CDR), this study aimed to analyze the major co-infection clinical characteristics and its mortality rates.MethodsThis is a cross-sectional retrospective multicenter study of patients with CD confirmed by two serological or one parasitological tests, and HIV infection confirmed by immunoblot. CDR was diagnosed by direct microscopy with detection of trypomastigote forms in the blood or other biological fluids and/or amastigote forms in inflammatory lesions.ResultsOut of 241 patients with co-infection, 86.7% were from Brazil, 47.5% had ConclusionThis study showed major features on T. cruzi-HIV co-infection and highlighted the prognostic role of CD4+ cells for reactivation and mortality. Since lethality was high in meningoencephalitis and all untreated patients died shortly after the diagnosis, early diagnosis, immediate antiparasitic treatment, patient follow-up and epidemiological surveillance are essentials in T. cruzi/HIV co-infection and CDR managements.

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

ObjectiveDesign and build a strategy construction and evaluation software system to help stakeholders to develop viable strategies to expand (and adapt) the Chagas Platform healthcare model through the primary healthcare system in Bolivia.MethodsThe software was built based on a ranking of medical Interventions and Actions (needed to support Interventions' implementation) needed for comprehensive management of Chagas Disease in Bolivia. The ranking was performed using a Multi Criteria Decision Analysis (MCDA) methodology adapted to the WHO's building blocks framework. Data regarding the criteria and the rankings was obtained through surveys and interviews with health care professionals working on Chagas disease. The Analytical Hierarchy Process was used to construct the decision criteria weights. Data Envelopment Analysis was used to identify the Interventions that lay on the efficiency frontier of outcomes and the complexity of associated Actions. These techniques were combined with integer programing tools using the open-source software R to build a decision-making tool to assess the outcomes and complexity of any combination of Interventions and Actions. This model and tool were applied to data concerning the care of Chagas disease in Bolivia collected through surveys of experts. The tool works by loading the data from each specific context.ResultsThe initial set of Interventions and Actions recommended after analysis of the survey data was further refined through face-to-face interviews with field experts in Bolivia, resulting in a strategy of 18 Interventions and 15 Actions. Within the WHO model the Leadership and Governance building block came up as the one needing more support with Actions such as the inclusion of Chagas into Annual Municipal Operational Plans by appointing local and provincial coordinators.ConclusionThis project established the suitability of the model for constructing healthcare strategies. The model could be developed further resulting in a decision-making tool for program managers in a wide range of healthcare related issues, including neglected and/ or prevalent diseases. The tool has the potential to be used at different stages of decision making by diverse stakeholders in order to coordinate activities needed to address a health problem.

Background The best strategy for controlling morbidity due to imported strongyloidiasis in migrants is unclear. We evaluate the cost-effectiveness of six possible interventions.Methods We developed a stochastic Markov chain model. The target population was adult migrants from endemic countries to the European Union; the time horizon, a lifetime and the perspective, that of the health system. Average and incremental cost-effectiveness ratios (ACER and ICER) were calculated as 2016 EUR/life-year gained (LYG). Health interventions compared were: base case (no programme), primary care-based presumptive treatment (PCPresTr), primary care-based serological screening and treatment (PCSerTr), hospital-based presumptive treatment (HospPresTr), hospital-based serological screening and treatment (HospSerTr), hospital-based presumptive treatment of immunosuppressed (HospPresTrim) and hospital-based serological screening and treatment of the immunosuppressed (HospSerTrim). The willingness to pay threshold (WTP) was €32 126.95/LYG.Results The base case model yielded a loss of 2 486 708.24 life-years and cost EUR 3 238 393. Other interventions showed the following: PCPresTr: 2 488 095.47 life-years (Δ1 387.23LYG), cost: EUR 8 194 563; ACER: EUR 3573/LYG; PCSerTr: 2 488 085.8 life-years (Δ1377.57LYG), cost: EUR 207 679 077, ACER: EUR 148 407/LYG; HospPresTr: 2 488 046.17 life-years (Δ1337.92LYG), cost: EUR 14 559 575; ACER: EUR 8462/LYG; HospSerTr: 2 488 024.33 life-years (Δ1316.08LYG); cost: EUR 207 734 073; ACER: EUR 155 382/LYG; HospPresTrim: 2 488 093.93 life-years, cost: EUR 1 105 483; ACER: EUR −1539/LYG (cost savings); HospSerTrim: 2 488 073.8 life-years (Δ1365.55LYG), cost: EUR 4 274 239; ACER: EUR 759/LYG. One-way and probabilistic sensitivity analyses were undertaken; HospPresTrim remained below WTP for all parameters’ ranges and iterations.Conclusion Presumptively treating all immunosuppressed migrants from areas with endemic Strongyloides would generate cost savings to the health system.

BackgroundDespite of a high disease burden, mainly in Latin America, Chagas disease (CD) is underdiagnosed and undertreated. Rapid diagnostic tests (RDTs) might improve the access to diagnosis. The aim of this study is to review the accuracy of commercially available RDTs used in field conditions for the diagnosis of chronic CD in populations at risk, in endemic and non-endemic countries.Methods/principal findingsWe undertook a comprehensive search of the following databases: PubMed, SCOPUS, LILACS (last up-date on the 01st July, 2017), without language or date limits. Non-electronic sources have been also searched. This review included clinical studies with cohort recruitment of individuals at risk of T. cruzi exposure, without age limits; adequate reference standards for the diagnosis of CD. We excluded case-control studies and those testing RDTs during acute CD. Data on test accuracies were pooled through a bivariate random-effects model. Only one index test was evaluated separately. Geographical area, commercial brand, disease prevalence, study size, and risk of bias were explored as possible source of heterogeneity. Values of sensitivity and specificity were computed to obtain summary positive/negative likelihood ratios, and summary diagnostic odds ratio. Ten studies were included on six different immunochromatographic RDTs. The pooled sensitivity and specificity of the RDTs resulted 96.6% (95% CI 91.3-98.7%) and 99.3% (95% CI 98.4-99.7%), respectively. Test accuracy was particularly good in endemic areas (98.07%/99.03% of sensitivity/specificity, respectively). One test (Stat-Pak) showed an overall sensitivity of 97% (95% CI 87.6-99.3) and specificity of 99.4% (95% CI 98.6-99.8).Conclusions/significanceRDTs demonstrated to be sufficiently accurate to recommend their use for screening in endemic areas, even as stand-alone tests. This approach might increase the accessibility to the diagnosis. However, an additional confirmatory test in case of positive result remains a prudent approach.

Background: Chagas disease (CD) is endemic in Latin America and particularly common in Bolivia, but there is little information on the characteristics of chronic digestive involvement. Objectives: To determine the prevalence and characterize digestive manifestations in chronic CD patients in Cochabamba, Bolivia. Methods: Eighty-five T. cruzi-seropositive individuals with or without digestive symptoms (G1 group), and fifteen T. cruzi-seronegative patients with similar digestive symptoms to those seen in CD (G2 group) were included in the study. All patients underwent a detailed history including past medical history, epidemiological information, hygiene and dietary habits, a complete physical examination, two serological tests for T. cruzi, video endoscopy, barium swallow, and barium enema. Findings: We observed digestive manifestations in T. cruzi seropositive and seronegative patients. Colonic manifestations were detected in both groups, highlighting the relevance of other confounder factors in the region. Constipation was present in 52.9% of G1 patients, 62.4% presented two or more upper digestive tract symptoms, and 5.9% of them presented esophageal manifestations. Helicobacter pylori infection was detected in 58.8% of G1 patients, and all patients presented gastritis on endoscopy. Conclusions: Prevalence of digestive involvement in CD patients is higher than expected. However, digestive symptoms are not always caused by T. cruzi infection and require differential diagnoses.

Malaria and Chagas disease, caused by Plasmodium spp. and Trypanosoma cruzi parasites, remain important global health problems. Available treatments for those diseases present several limitations, such as lack of efficacy, toxic side effects, and drug resistance. Thus, new drugs are urgently needed. The discovery of new drugs may be benefited by considering the significant biological differences between hosts and parasites. One of the most striking differences is found in the purine metabolism, because most of the parasites are incapable of de novo purine biosynthesis. Herein, we have analyzed the in vitro anti-P. falciparum and anti-T. cruzi activity of a collection of 81 purine derivatives and pyrimidine analogs. We firstly used a primary screening at three fixed concentrations (100, 10, and 1 µM) and progressed those compounds that kept the growth of the parasites < 30% at 100 µM to dose–response assays. Then, we performed two different cytotoxicity assays on Vero cells and human HepG2 cells. Finally, compounds specifically active against T. cruzi were tested against intracellular amastigote forms. Purines 33 (IC50 = 19.19 µM) and 76 (IC50 = 18.27 µM) were the most potent against P. falciparum. On the other hand, 6D (IC50 = 3.78 µM) and 34 (IC50 = 4.24 µM) were identified as hit purines against T. cruzi amastigotes. Moreover, an in silico docking study revealed that P. falciparum and T. cruzi hypoxanthine guanine phosphoribosyltransferase enzymes could be the potential targets of those compounds. Our study identified two novel, purine-based chemotypes that could be further optimized to generate potent and diversified anti-parasitic drugs against both parasites.

Chagas disease, caused by the parasite Trypanosoma cruzi (T. cruzi), affects more than six million people worldwide, with its greatest burden in Latin America. Available treatments present frequent toxicity and variable efficacy at the chronic phase of the infection, when the disease is usually diagnosed. Hence, development of new therapeutic strategies is urgent. Repositioning of licensed drugs stands as an attractive fast-track low-cost approach for the identification of safer and more effective chemotherapies. With this purpose we screened 32 licensed drugs for different indications against T. cruzi. We used a primary in vitro assay of Vero cells infection by T. cruzi. Five drugs showed potent activity rates against it (IC50 < 4 µmol L−1), which were also specific (selectivity index >15) with respect to host cells. T. cruzi inhibitory activity of four of them was confirmed by a secondary anti-parasitic assay based on NIH-3T3 cells. Then, we assessed toxicity to human HepG2 cells and anti-amastigote specific activity of those drugs progressed. Ultimately, atovaquone-proguanil, miltefosine, and verapamil were tested in a mouse model of acute T. cruzi infection. Miltefosine performance in vitro and in vivo encourages further investigating its use against T. cruzi.

The definition of a biomarker provided by the World Health Organization is any substance, structure, or process that can be measured in the body, or its products and influence, or predict the incidence or outcome of disease. Currently, the lack of prognosis and progression markers for chronic Chagas disease has posed limitations for testing new drugs to treat this neglected disease. Several molecules and techniques to detect biomarkers in Trypanosoma cruzi-infected patients have been proposed to assess whether specific treatment with benznidazole or nifurtimox is effective. Isolated proteins or protein groups from different T. cruzi stages and parasite-derived glycoproteins and synthetic neoglycoconjugates have been demonstrated to be useful for this purpose, as have nucleic acid amplification techniques. The amplification of T. cruzi DNA using the real-time polymerase chain reaction method is the leading test for assessing responses to treatment in a short period of time. Biochemical biomarkers have been tested early after specific treatment. Cytokines and surface markers represent promising molecules for the characterisation of host cellular responses, but need to be further assessed.

We evaluate the association between Trypanosoma cruzi infection and strongyloidiasis in a cohort of Latin American (LA) migrants screened for both infections in a non-endemic setting.Case-control study including LA individuals who were systematically screened for T. cruzi infection and strongyloidiasis between January 2013 and April 2015. Individuals were included as cases if they had a positive serological result for Strongyloides stercoralis. Controls were randomly selected from the cohort of individuals screened for T. cruzi infection that tested negative for S. stercoralis serology. The association between T. cruzi infection and strongyloidiasis was evaluated by logistic regression models.During the study period, 361 individuals were screened for both infections. 52 (14.4%) individuals had a positive serological result for strongyloidiasis (cases) and 104 participants with negative results were randomly selected as controls. 76 (48.7%) indiviuals had a positive serological result for T. cruzi. Factors associated with a positive T. cruzi serology were Bolivian origin (94.7% vs 78.7%; p = 0.003), coming from a rural area (90.8% vs 68.7%; p = 0.001), having lived in an adobe house (88.2% vs 70%; p = 0.006) and a referred contact with triatomine bugs (86.7% vs 63.3%; p = 0.001). There were more patients with a positive S. stercoralis serology among those who were infected with T. cruzi (42.1% vs 25%; p = 0.023). Epidemiological variables were not associated with a positive strongyloidiasis serology. T. cruzi infection was more frequent among those with strongyloidiasis (61.5% vs 42.3%; p = 0.023). In multivariate analysis, T. cruzi infection was associated with a two-fold increase in the odds of strongyloidiasis (OR 2.23; 95% CI 1.07-4.64; p = 0.030).T. cruzi infection was associated with strongyloidiasis in LA migrants attending a tropical diseases unit even after adjusting for epidemiological variables. These findings should encourage physicians in non-endemic settings to implement a systematic screening for both infections in LA individuals.

BACKGROUND:Bolivia has the highest prevalence of Chagas disease (CD) in the world (6.1%), with more than 607,186 people with Trypanosoma cruzi infection, most of them adults. In Bolivia CD has been declared a national priority. In 2009, the Chagas National Program (ChNP) had neither a protocol nor a clear directive for diagnosis and treatment of adults. Although programs had been implemented for congenital transmission and for acute cases, adults remained uncovered. Moreover, health professionals were not aware of treatment recommendations aimed at this population, and research on CD was limited; it was difficult to increase awareness of the disease, understand the challenges it presented, and adapt strategies to cope with it. Simultaneously, migratory flows that led Bolivian patients with CD to Spain and other European countries forced medical staff to look for solutions to an emerging problem. INTERVENTION:In this context, thanks to a Spanish international cooperation collaboration, the Bolivian platform for the comprehensive care of adults with CD was created in 2009. Based on the establishment of a vertical care system under the umbrella of ChNP general guidelines, six centres specialized in CD management were established in different epidemiological contexts. A common database, standardized clinical forms, a and a protocolized attention to adults patients, together with training activities for health professionals were essential for the model success. With the collaboration and knowledge transfer activities between endemic and non-endemic countries, the platform aims to provide care, train health professionals, and create the basis for a future expansion to the National Health System of a proven model of care for adults with CD. RESULTS:From 2010 to 2015, a total of 26,227 patients were attended by the Platform, 69% (18,316) were diagnosed with T. cruzi, 8,567 initiated anti-parasitic treatment, more than 1,616 health professionals were trained, and more than ten research projects developed. The project helped to increase the number of adults with CD diagnosed and treated, produce evidence-based clinical practice guidelines, and bring about changes in policy that will increase access to comprehensive care among adults with CD. The ChNP is now studying the Platform's health care model to adapt and implement it nationwide. CONCLUSIONS:This strategy provides a solution to unmet demands in the care of patients with CD, improving access to diagnosis and treatment. Further scaling up of diagnosis and treatment will be based on the expansion of the model of care to the NHS structures. Its sustainability will be ensured as it will build on existing local resources in Bolivia. Still human trained resources are scarce and the high staff turnover in Bolivia is a limitation of the model. Nevertheless, in a preliminary two-years-experience of scaling up this model, this limitations have been locally solved together with the health local authorities.

Chagas disease is caused by the parasite Trypanosoma cruzi. It affects several million people, mainly in Latin America, and severe cardiac and/or digestive complications occur in ~30% of the chronically infected patients. Disease acute stage is mostly asymptomatic and infection goes undiagnosed. In the chronic phase direct parasite detection is hampered due to its concealed presence and diagnosis is achieved by serological methods, like ELISA or indirect hemagglutination assays. Agreement in at least two tests must be obtained due to parasite wide antigenic variability. These techniques require equipped labs and trained personnel and are not available in distant regions. As a result, many infected people often remain undiagnosed until it is too late, as the two available chemotherapies show diminished efficacy in the advanced chronic stage. Easy-to-use rapid diagnostic tests have been developed to be implemented in remote areas as an alternative to conventional tests. They do not need electricity, nor cold chain, they can return results within an hour and some even work with whole blood as sample, like Chagas Stat-Pak (ChemBio Inc.) and Chagas Detect Plus (InBIOS Inc.). Nonetheless, in order to qualify a rapidly diagnosed positive patient for treatment, conventional serological confirmation is obligatory, which might risk its start. In this study two rapid tests based on distinct antigen sets were used in parallel as a way to obtain a fast and conclusive Chagas disease diagnosis using whole blood samples. Chagas Stat-Pak and Chagas Detect Plus were validated by comparison with three conventional tests yielding 100% sensitivity and 99.3% specificity over 342 patients seeking Chagas disease diagnosis in a reference centre in Sucre (Bolivia). Combined used of RDTs in distant regions could substitute laborious conventional serology, allowing immediate treatment and favouring better adhesion to it.

The disappearance of lytic, protective antibodies (Abs) from the serum of patients with Chagas disease is accepted as a reliable indicator of parasitological cure. The efficiency of a chemiluminescent enzyme-linked immunosorbent assay based on a purified, trypomastigote-derived glycosylphosphatidylinositol-anchored mucin antigen for the serologic detection of lytic Abs against Trypanosoma cruzi was evaluated in a nonendemic setting using a panel of 92 positive and 58 negative human sera. The technique proved to be highly sensitive {100%; 95% confidence interval (CI) = 96-100} and specific (98.3%; 95% CI = 90.7-99.7), with a kappa score of 0.99. Therefore, this assay can be used to detect active T. cruzi infection and to monitor trypanosomicidal treatment.

Thromboembolic events were described in patients with Chagas disease without cardiomyopathy. We aim to confirm if there is a hypercoagulable state in these patients and to determine if there is an early normalization of hemostasis factors after antiparasitic treatment. Ninety-nine individuals from Chagas disease-endemic areas were classified in two groups: G1, with T.cruzi infection (n = 56); G2, healthy individuals (n = 43). Twenty-four hemostasis factors were measured at baseline. G1 patients treated with benznidazole were followed for 36 months, recording clinical parameters and performance of conventional serology, chemiluminescent enzyme-linked immunosorbent assay (trypomastigote-derived glycosylphosphatidylinositol-anchored mucins), quantitative polymerase chain reaction, and hemostasis tests every 6-month visits. Prothrombin fragment 1+2 (F1+2) and endogenous thrombin potential (ETP) were abnormally expressed in 77% and 50% of infected patients at baseline but returned to and remained at normal levels shortly after treatment in 76% and 96% of cases, respectively. Plasmin-antiplasmin complexes (PAP) were altered before treatment in 32% of G1 patients but normalized in 94% of cases several months after treatment. None of the patients with normal F1+2 values during follow-up had a positive qRT-PCR result, but 3/24 patients (13%) with normal ETP values did. In a percentage of chronic T. cruzi infected patients treated with benznidazole, altered coagulation markers returned into normal levels. F1+2, ETP and PAP could be useful markers for assessing sustained response to benznidazole.

BACKGROUND:Few studies have assessed the burden of Chagas disease in non-endemic countries and most of them are based on prevalence estimates from Latin American (LA) countries that likely differ from the prevalence in migrants living in Europe. The aim of this study was to systematically review the existing data informing current understanding of the prevalence of Chagas disease in LA migrants living in European countries. METHODS:We conducted a systematic review and meta-analysis of studies reporting prevalence of Chagas disease in European countries belonging to the European Union (EU) before 2004 in accordance with the MOOSE guidelines and based on the database sources MEDLINE and Global Health. No restrictions were placed on study date, study design or language of publication. The pooled prevalence was estimated using random effect models based on DerSimonian & Laird method. RESULTS:We identified 18 studies conducted in five European countries. The random effect pooled prevalence was 4.2% (95%CI:2.2-6.7%); and the heterogeneity of Chagas disease prevalence among studies was high (I2 = 97%,p

Digestive damage due to Chagas disease (CD) occurs in 15-20% of patients diagnosed as a result of peristaltic dysfunction in some endemic areas. The symptoms of chronic digestive CD are non-specific, and there are numerous confounders. Diagnosis of CD may easily be missed if symptoms are not evaluated by a well trained physician. Regular tests, as barium contrast examinations, probably lack the necessary sensitivity to detect early digestive damage.71 individuals with T. cruzi infection (G1) and 18 without (G2) coming from Latin American countries were analyzed. They were asked for clinical and epidemiological data, changes in dietary habits, and history targeting digestive and cardiac CD symptoms. Serological tests for T. cruzi, barium swallow, barium enema, an urea breath test, and esophageal manometry were requested for all patients.G1 and G2 patients did not show differences in lifestyle and past history. Fifteen (21.1%) of G1 had digestive involvement. Following Rezende criteria, esophagopathy was observed in 8 patients in G1 (11.3%) and in none of those in G2. Manometry disorders were recorded in 34 G1 patients and in six in G2. Isolated hypotensive lower esophageal sphincter (LES) was found in sixteen G1 patients (23.9%) and four G2 patients (28.8%). Achalasia was observed in two G1 patients. Among G1 patients, ineffective esophageal motility was seen in six (five with symptoms), diffuse esophageal spasm in two (one with dysphagia and regurgitation), and nutcracker esophagus in three (all with symptoms). There were six patients with hypertonic upper esophageal sphincter (UES) among G1. Following Ximenes criteria, megacolon was found in ten G1 patients (13.9%), and in none of the G2 patients.The prevalence of digestive chronic CD in our series was 21.1%. Dysphagia is a non-pathognomonic symptom of CD, but a good marker of early esophageal involvement. Manometry could be a useful diagnostic test in selected cases, mainly in patients with T. cruzi infection and dysphagia in whose situation barium swallow does not evidence alterations. Constipation is a common but non-specific symptom that can be easily managed. Testing for CD is mandatory in a patient from Latin America with constipation or dysphagia, and if diagnosis is confirmed, megacolon and esophageal involvement should be investigated.

Immunosuppression, which has become an increasingly relevant clinical condition in the last 50 years, modifies the natural history of Trypanosoma cruzi infection in most patients with Chagas disease. The main goal in this setting is to prevent the consequences of reactivation of T. cruzi infection by close monitoring. We analyze the relationship between Chagas disease and three immunosuppressant conditions, including a description of clinical cases seen at our center, a brief review of the literature, and recommendations for the management of these patients based on our experience and on the data in the literature. T. cruzi infection is considered an opportunistic parasitic infection indicative of AIDS, and clinical manifestations of reactivation are more severe than in acute Chagas disease. Parasitemia is the most important defining feature of reactivation. Treatment with benznidazole and/or nifurtimox is strongly recommended in such cases. It seems reasonable to administer trypanocidal treatment only to asymptomatic immunosuppressed patients with detectable parasitemia, and/or patients with clinically defined reactivation. Specific treatment for Chagas disease does not appear to be related to a higher incidence of neoplasms, and a direct role of T. cruzi in the etiology of neoplastic disease has not been confirmed. Systemic immunosuppressive diseases or immunosuppressants can modify the natural course of T. cruzi infection. Immunosuppressive doses of corticosteroids have not been associated with higher rates of reactivation of Chagas disease. Despite a lack of evidence-based data, treatment with benznidazole or nifurtimox should be initiated before immunosuppression where possible to reduce the risk of reactivation. Timely antiparasitic treatment with benznidazole and nifurtimox (or with posaconazole in cases of therapeutic failure) has proven to be highly effective in preventing Chagas disease reactivation, even if such treatment has not been formally incorporated into management protocols for immunosuppressed patients. International consensus guidelines based on expert opinion would greatly contribute to standardizing the management of immunosuppressed patients with Chagas disease.