Transcriptomic evidence of immune modulation in subjects with chronic Trypanosoma cruzi infection.

Chagas disease is a neglected tropical infection that affects millions of people. This study explores transcriptomic changes in T. cruzi-infected subjects before and after treatment. Using total RNA sequencing, gene transcription was analyzed in peripheral blood mononuclear cells from asymptomatic (n=19) and symptomatic (n=8) T. cruzi-infected individuals, and non-infected controls (n=15). Differential expression was compared across groups, and before/after treatment in infected subgroups. Untreated infection showed 12 upregulated and 206 downregulated genes in all T. cruzi-infected subjects, and 47 upregulated and 215 downregulated genes in the symptomatic group. Few differentially expressed genes were found after treatment and between the different infected groups. Gene set enrichment analysis highlighted immune-related pathways activated during infection, with therapy normalizing immune function. Changes in the kynurenine/tryptophan ratio, increased pre-treatment, suggested chronic immune fatigue, which was restored post-treatment. These differentially expressed genes offer insights for potential biomarkers and pathways associated with disease progression and treatment response.

A Smartphone App for Real-Time Assessment of Malaria Prophylaxis Adverse Events.

Background: Growth of international travel to malarial areas over the last decades has contributed to more travelers taking malaria prophylaxis. Travel-related symptoms may be wrongly attributed to malaria prophylaxis and hinder compliance. Here, we aimed to assess the frequency of real-time reporting of symptoms by travelers following malaria prophylaxis using a smartphone app. Method: Adult international travelers included in this single-center study (Barcelona, Spain) used the smartphone Trip Doctor® app developed by our group for real-time tracking of symptoms and adherence to prophylaxis. Results: Six hundred four (n = 604) international travelers were included in the study; 74.3% (449) used the app daily, and for one-quarter of travelers, malaria prophylaxis was prescribed. Participants from the prophylaxis group traveled more to Africa (86.7% vs. 4.3%; p < 0.01) and to high travel medical risk countries (60.8% vs. 18%; p < 0.01) and reported more immunosuppression (30.8% vs. 23.1% p < 0.01). Regarding symptoms, no significant intergroup differences were observed, and no relationship was found between the total number of malarial pills taken and reported symptoms. Conclusions: In our cohort, the number of symptoms due to malaria prophylaxis was not significantly higher than in participants for whom prophylaxis was not prescribed, and the overall proportion of symptoms is higher compared with other studies.

Worldwide Control and Management of Chagas Disease in a New Era of Globalization: a Close Look at Congenital Trypanosoma cruzi Infection.

Population movements have turned Chagas disease (CD) into a global public health problem. Despite the successful implementation of subregional initiatives to control vectorial and transfusional Trypanosoma cruzi transmission in Latin American settings where the disease is endemic, congenital CD (cCD) remains a significant challenge. In countries where the disease is not endemic, vertical transmission plays a key role in CD expansion and is the main focus of its control. Although several health organizations provide general protocols for cCD control, its management in each geopolitical region depends on local authorities, which has resulted in a multitude of approaches. The aims of this review are to (i) describe the current global situation in CD management, with emphasis on congenital infection, and (ii) summarize the spectrum of available strategies, both official and unofficial, for cCD prevention and control in countries of endemicity and nonendemicity. From an economic point of view, the early detection and treatment of cCD are cost-effective. However, in countries where the disease is not endemic, national health policies for cCD control are nonexistent, and official regional protocols are scarce and restricted to Europe. Countries of endemicity have more protocols in place, but the implementation of diagnostic methods is hampered by economic constraints. Moreover, most protocols in both countries where the disease is endemic and those where it is not endemic have yet to incorporate recently developed technologies. The wide methodological diversity in cCD diagnostic algorithms reflects the lack of a consensus. This review may represent a first step toward the development of a common strategy, which will require the collaboration of health organizations, governments, and experts in the field.

A Phase 2, Randomized, Multicenter, Placebo-Controlled, Proof-of-Concept Trial of Oral Fexinidazole in Adults With Chronic Indeterminate Chagas Disease.

BACKGROUND: Chagas disease (CD) has significant global health impact, but safe, effective treatments remain elusive. The nitroimidazole fexinidazole is a potential treatment. METHODS: This double-blind, randomized, placebo-controlled, dose-finding, proof-of-concept study was conducted in Bolivia. Adults with serologically confirmed chronic indeterminate CD and positive PCR were randomly assigned to 1 of 6 fexinidazole regimens (1200 or 1800 mg/day for 2, 4, or 8 weeks) or placebo. Target recruitment was 20 patients/arm. The primary endpoint was sustained parasitological clearance by serial negative qPCR from end of treatment (EOT) until 6 months follow-up in the intention-to-treat (ITT) population. Follow-up was extended to 12 months. RESULTS: Enrollment was interrupted after 4/47 patients presented with transient asymptomatic grade 3 and 4 neutropenia. Treatment of ongoing patients was stopped in all patients administered >2 weeks. A total of 40 patients received treatment with fexinidazole from 3 days to 8 weeks. Delayed-onset neutropenia (n = 8) and increased liver enzymes (n = 8) were found in fexinidazole patients vs none in the placebo arm. In the ITT analysis, sustained parasitological clearance from EOT to 12 months follow-up varied between 66.7% (1200 mg-2 week) and 100.0% (1800 mg-2 week). Rapid, sustained clearance of parasitemia was observed in all treated patients with available data, but not in any patients in the placebo group, at 12 months (P = .0056). Further exploratory exposure-response analysis suggested low dosages of fexinidazole may be safe and effective. CONCLUSIONS: Further evaluation is needed to establish fexinidazole's minimum effective dosage and risk-benefit relationship. Results suggest potential for effective treatment regimens <10 days. CLINICAL TRIALS REGISTRATION: NCT02498782.

Feminist contributions on sexual experiences of women with serious mental illness: a literature review.

This paper aims to explore the contributions of research that include gender perspective in analysing the sexual experiences of women diagnosed with serious mental illness and to identify any barriers and systems that impede sexual fulfilment. We have developed a qualitative literature review using the PRISMA statement. The databases SCOPUS, WOS and PsychINFO were used in this review. Studies were included if they were published up to March 15, 2022, and only studies in English were included. An initial database search was preformed; upon screening for eligibility, there remained 16 studies that explored the sexual experiences of women with diagnoses of serious mental illness. The studies were analysed by a thematic synthesis. Data was coded line-by-line which generated descriptive themes, resulting in four synthesised findings. The four synthesised findings that derived from the reviewed studies were stigma and subjectivity, the experience of interpersonal relationships, the socialisation of women and the effects of psychiatric hegemony. A feminist perspective highlights the interrelationship between gender and stigma as it relates to serious mental illness and sexuality. A feminist perspective and an intersectional approach should be adopted at the intersubjective and structural level to account for the complexity of human experience and to subvert the heteropatriarchal system.

A Branched and Double Alpha-Gal-Bearing Synthetic Neoglycoprotein as a Biomarker for Chagas Disease.

Chagas disease (CD) is caused by the parasite Trypanosoma cruzi and affects 6-7 million people worldwide. The diagnosis is still challenging, due to extensive parasite diversity encompassing seven genotypes (TcI-VI and Tcbat) with diverse ecoepidemiological, biological, and pathological traits. Chemotherapeutic intervention is usually effective but associated with severe adverse events. The development of safer, more effective therapies is hampered by the lack of biomarker(s) (BMKs) for the early assessment of therapeutic outcomes. The mammal-dwelling trypomastigote parasite stage expresses glycosylphosphatidylinositol-anchored mucins (tGPI-MUC), whose O-glycans are mostly branched with terminal, nonreducing α-galactopyranosyl (α-Gal) glycotopes. These are absent in humans, and thus highly immunogenic and inducers of specific CD anti-α-Gal antibodies. In search for α-Gal-based BMKs, here we describe the synthesis of neoglycoprotein NGP11b, comprised of a carrier protein decorated with the branched trisaccharide Galα(1,2)[Galα(1,6)]Galß. 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.

Anti-Trypanosoma cruzi Activity of Metabolism Modifier Compounds.

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and affects over 6 million people worldwide. Development of new drugs to treat this disease remains a priority since those currently available have variable efficacy and frequent adverse effects, especially during the long regimens required for treating the chronic stage of the disease. T. cruzi modulates the host cell-metabolism to accommodate the cell cytosol into a favorable growth environment and acquire nutrients for its multiplication. In this study we evaluated the specific anti-T. cruzi activity of nine bio-energetic modulator compounds. Notably, we identified that 17-DMAG, which targets the ATP-binding site of heat shock protein 90 (Hsp90), has a very high (sub-micromolar range) selective inhibition of the parasite growth. This inhibitory effect was also highly potent (IC50 = 0.27 µmol L-1) against the amastigote intracellular replicative stage of the parasite. Moreover, molecular docking results suggest that 17-DMAG may bind T. cruzi Hsp90 homologue Hsp83 with good affinity. Evaluation in a mouse model of chronic T. cruzi infection did not show parasite growth inhibition, highlighting the difficulties encountered when going from in vitro assays onto preclinical drug developmental stages.

Plasma-Derived Extracellular Vesicles as Potential Biomarkers in Heart Transplant Patient with Chronic Chagas Disease.

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.

Towards a New Strategy for Diagnosis of Congenital Trypanosoma cruzi Infection.

The immigration of Latin American women of childbearing age has spread the congenital transmission of Chagas disease to areas of nonendemicity, and the disease is now a worldwide problem. Some European health authorities have implemented screening programs to prevent vertical transmission, but the lack of a uniform protocol calls for the urgent establishment of a new strategy common to all laboratories. Our aims were to (i) analyze the trend of passive IgG antibodies in the newborn by means of five serological tests for the diagnosis and follow-up of congenital Trypanosoma cruzi infection, (ii) assess the utility of these techniques for diagnosing a congenital transmission, and (iii) propose a strategy for a prompt, efficient, and cost-effective diagnosis of T. cruzi infection. In noninfected newborns, a continuous decreasing trend of passive IgG antibodies was observed, but none of the serological assays seroreverted in any the infants before 12 months. From 12 months onwards, serological tests achieved negative results in all the samples analyzed, with the exception of the highly sensitive chemiluminescent microparticle immunoassay (CMIA). In contrast, in congenitally infected infants, the antibody decline was detected only after treatment initiation. In order to improve the diagnosis of congenital T. cruzi infection, we propose a new strategy involving fewer tests that allows significant cost savings. The protocol could start 1 month after birth with a parasitological test and/or a PCR. If negative, a serological test would be carried out at 9 months, which if positive, would be followed by another at around 12 months for confirmation.

Biomarkers of therapeutic responses in chronic Chagas disease: state of the art and future perspectives.

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.

Challenges and advancements in the development of vaccines and therapies against Chagas disease.

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, presents a substantial global health burden, affecting millions of individuals worldwide and posing a continual risk of infection. Despite the high mortality and morbidity rates, effective vaccines to prevent infection by the parasite remain elusive, and the drugs currently available are suboptimal. Understanding the intricate dynamics of parasite-host interactions and the resulting immune responses, which contribute to both protection and pathology, is crucial for the development of effective vaccines and therapies against Chagas disease. In this Series paper, we discuss the challenges associated with discovering and translating prophylactic and therapeutic strategies from the laboratory bench to clinical application. We highlight ongoing efforts in vaccine and new drug development, with a focus on more advanced candidates for vaccines and drugs. We also discuss potential solutions, emphasising the importance of collaborative research efforts, sustained funding, and a comprehensive understanding of host-parasite interactions and immunopathology to advance the development of new vaccines and therapies against Chagas disease.

Living labs for migrant health research: the challenge of cocreating research with migrant population and policy makers.

The need for the public to take an active role in scientific research is becoming increasingly important, particularly in health-related research. However, the coexistence and alignment of scientific and citizen interests, needs, knowledge and timing is not straightforward, especially when involving migrant populations. To conduct impactful research, it becomes also essential to consider the perspectives of policymakers, thereby adding a layer of complexity to the processes.In this article we address the experience of a living lab created in a research institution and supported by the city council and a local foundation, in which we developed three experiences of patient and public involvement (PPI): (1) accessing to comprehensive care for people at risk of Chagas disease; (2) strategies towards improving access and quality of mental healthcare services in migrants; (3) promoting healthy and safe school environments in vulnerable urban settings.These three challenges provided an opportunity to delve into diverse strategies for involving key stakeholders, including migrant populations, expert researchers and political actors in health research. This article offers insights into the successes, challenges, and valuable lessons learnt from these endeavours, providing a vision that can be beneficial for future initiatives. Each living lab experience crafted its unique governance system and agenda tailored to specific challenge scenarios, giving rise to diverse methods and study designs.We have found that the management of the cocreation of the research question and the institutional support are key to building robust PPI processes with migrant groups.

How do we classify organ involvement in Chagas disease? A systematic review of organ involvement since 1909, Highlighting the urgent need for a universal classification system in Chronic Chagas disease.

Chagas disease (CD) is recognized as one of the 20 neglected tropical diseases by the World Health Organization (WHO), posing a significant global health challenge. The objective of this work was to conduct a systematic methodology review to explore the different classifications used to describe the presence and degree of organ involvement in patients with CD since the disease's description in 1909. We searched relevant electronic medical databases from their inception dates to July 2023. We also delved into historical variations and revisions of each classification, the necessary diagnostic methods, their prognostic value, and their uptake. Our study underscores the conspicuous absence of a universally accepted CD classification system for cardiac and digestive involvement, both in the context of clinical trials and within current clinical guidelines. This endeavour will facilitate cross-population comparisons if clinical manifestations and complementary test results are available for each patient, constituting a pivotal stride toward identifying precise prognoses and establishing a minimum data set requisite for a fitting CD classification, tailored to the test availability in both endemic and non-endemic regions.

Quality assurance of serologic testing for Chagas disease in a primary care setting of rural Paraguay.

The diagnosis of Chagas disease mostly relies on the use of multiple serologic tests that are often unavailable in many of the remote settings where the disease is highly prevalent. In the Teniente Irala Fernández Municipality, in central Paraguay, efforts have been made to increase the diagnostic capabilities of specific rural health centres, but no quality assurance of the results produced has been performed. We comparatively analysed the results obtained with 300 samples tested using a commercial rapid diagnostic test (RDT) and enzyme linked immunosorbent assays (ELISA) at the laboratory of the Teniente Irala Fernández Health Center (CSTIF) with those generated upon repeating the tests at an independent well-equipped research laboratory (CEDIC). A subgroup of 52 samples were further tested at Paraguay's Central Public Health Laboratory (LCSP) by means of a different technique to evaluate the diagnostic performance of the tests carried out at CSTIF. We observed an excellent agreement between the ELISA results obtained at CSTIF and CEDIC (kappa coefficients between 0.85 and 0.93 for every kit evaluated), and an overall good performance of the tests carried out at CSTIF. However, the sensitivity of one kit was lower at CSTIF (81.3 %) than at CEDIC (100 %). The individual use of an RDT to detect the infection at CSTIF showed a similar sensitivity to that obtained combining it to an ELISA test (92.3% vs 88.5, p = 1). Nonetheless, the generalizability of this result is yet limited and will require of further studies.

Evaluation of the accuracy of a multi-infection screening test based on a multiplex immunoassay targeting imported diseases common in migrant populations.

BACKGROUND: We aimed to evaluate the performance of a novel multiplex serological assay, able to simultaneously detect IgG of six infections, as a screening tool for imported diseases in migrants. METHODS: Six panels of 40 (n = 240) anonymized serum samples with confirmed infections were used as positive controls to assess the multiplex assay's sensitivity. One panel of 40 sera from non-infected subjects was used to estimate the seropositivity cutoffs, and 32 non-infected sera were used as negative controls to estimate each serology's sensitivity and specificity. The multi-infection screening test was validated in a prospective cohort of 48 migrants from endemic areas. The sensitivity of the Luminex assay was calculated as the proportion of positive results over all positive samples identified by reference tests. The specificity was calculated using 32 negative samples. Uncertainty was quantified with 95 % confidence intervals using receiver operating characteristic analyses. RESULTS: The sensitivity/specificity were 100 %/100 % for HIV (gp41 antigen), 97.5 %/100 % for Hepatitis B virus (HBV-core antigen), 100 %/100 % for Hepatitis C virus (HCV-core antigen), 92.5 %/90.6 % for strongyloidiasis [31-kDa recombinant antigen (NIE)], 97.5 %/100 % for schistosomiasis (combined serpin Schistosoma mansoni and S.haematobium antigens) and 95 %/90.6 % for Chagas disease [combined Trypanosoma cruzi kinetoplastid membrane protein-11 (KMP11) and paraflagellar rod proteins 2 (PFR2) antigens]. In the migrant cohort, antibody response to the combination of the T.cruzi antigens correctly identified 100 % individuals, whereas HBV-core antigen correctly identified 91.7 % and Strongyloides-NIE antigen 86.4 %. CONCLUSIONS: We developed a new, robust and accurate 8-plex Luminex assay that could facilitate the implementation of screening programmes targeting migrant populations.

Evaluation and validation of a PrintrLab-based LAMP assay to identify Trypanosoma cruzi in newborns in Bolivia: a proof-of-concept study.

BACKGROUND: Vertical transmission of Trypanosoma cruzi represents approximately 20% of new Chagas disease cases. Early detection and treatment for women of childbearing age and newborns is a public health priority, but the lack of a simple and reliable diagnostic test remains a major barrier. We aimed to evaluate the performance of a point-of-care loop-mediated isothermal amplification (LAMP) assay for the detection of T cruzi. METHODS: In this proof-of-concept study, we coupled a low-cost 3D printer repurposed for sample preparation and amplification (PrintrLab) to the Eiken T cruzi-LAMP prototype to detect vertically transmitted T cruzi, which we compared with standardised PCR and with the gold-standard algorithm (microscopy at birth and 2 months and serological study several months later). We screened pregnant women from two hospitals in the Bolivian Gran Chaco province, and those who were seropositive for T cruzi were offered the opportunity for their newborns to be enrolled in the study. Newborns were tested by microscopy, LAMP, and PCR at birth and 2 months, and by serology at 8 months. FINDINGS: Between April 23 and Nov 17, 2018, 986 mothers were screened, among whom 276 were seropositive for T cruzi (28·0% prevalence, 95% CI 25·6-31·2). In total, 224 infants born to 221 seropositive mothers completed 8 months of follow-up. Congenital transmission was detected in nine of the 224 newborns (4·0% prevalence, 1·9-7·5) by direct microscopy observation, and 14 more cases were diagnosed serologically (6·3%, 3·6-10·3), accounting for an overall vertical transmission rate of 10·3% (6·6-15·0; 23 of 224). All microscopy-positive newborns were positive by PrintrLab-LAMP and by PCR, while these techniques respectively detected four and five extra positive cases among the remaining 215 microscopy-negative newborns. INTERPRETATION: The PrintrLab-LAMP yielded a higher sensitivity than microscopy-based analysis. Considering the simpler use and expected lower cost of LAMP compared with PCR, our findings encourage its evaluation in a larger study over a wider geographical area. FUNDING: Inter-American Development Bank.

Efficacy and safety of fexinidazole for treatment of chronic indeterminate Chagas disease (FEXI-12): a multicentre, randomised, double-blind, phase 2 trial.

BACKGROUND: More than six million people worldwide, particularly in vulnerable communities in Latin America, are infected with Trypanosoma cruzi, the causative agent of Chagas disease. Only a small portion have access to diagnosis and treatment. Both drugs used to treat this chronic, neglected infection, benznidazole and nifurtimox, were developed more than 50 years ago, and adverse drug reactions during treatment pose a major barrier, causing 20% of patients to discontinue therapy. Fexinidazole proved efficacious in an earlier, interrupted clinical trial, but the doses evaluated were not well tolerated. The present study evaluated fexinidazole at lower doses and for shorter treatment durations. METHODS: In this randomised, double-blind, phase 2 trial, we included adult patients (18-60 years old) with confirmed T cruzi infection by serology and PCR and without signs of organ involvement. We evaluated three regimens of fexinidazole-600 mg once daily for 10 days (6·0 g total dose), 1200 mg daily for 3 days (3·6 g), and 600 mg daily for 3 days followed by 1200 mg daily for 4 days (6·6 g)-and compared them with a historical placebo control group (n=47). The primary endpoint was sustained negative results by PCR at end of treatment and on each visit up to four months of follow-up. This study is registered with ClinicalTrials.gov, NCT03587766, and EudraCT, 2016-004905-15. FINDINGS: Between Oct 16, 2017, and Aug 7, 2018, we enrolled 45 patients (n=15 for each group), of whom 43 completed the study. Eight (19%) of 43 fexinidazole-treated patients reached the primary endpoint, compared with six (13%) of 46 in the historical control group. Mean parasite load decreased sharply following treatment but rebounded beginning 10 weeks after treatment. Five participants had seven grade 3 adverse events: carpal tunnel, sciatica, device infection, pneumonia, staphylococcal infection, and joint and device dislocation. Two participants discontinued treatment due to adverse events unrelated to fexinidazole. INTERPRETATION: The fexinidazole regimens in this study had an acceptable safety profile but did not prove effective against T cruzi infection. Development of fexinidazole monotherapy for treating T cruzi infection has been stopped. FUNDING: The Drugs for Neglected Diseases initiative.

A standardized clinical database for research in Chagas disease: The NHEPACHA network.

The NHEPACHA Iberoamerican Network, founded on the initiative of a group of researchers from Latin American countries and Spain, aims to establish a research framework for Chagas disease that encompasses diagnosis and treatment. For this purpose, the network has created a questionnaire to gather relevant data on epidemiological, clinical, diagnostic, and therapeutic aspects of the disease. This questionnaire was developed based on a consensus of expert members of the network, with the intention of collecting high-quality standardized data, which can be used interchangeably by the different research centers that make up the NHEPACHA network. Furthermore, the network intends to offer a clinical protocol that can be embraced by other researchers, facilitating comparability among published studies, as well as the development of therapeutic response and progression markers.

A guide for the generation of repositories of clinical samples for research on Chagas disease.

Chagas disease, caused by the parasite Trypanosoma cruzi, affects over 6 million people, mainly in Latin America. Two different clinical phases, acute and chronic, are recognised. Currently, 2 anti-parasitic drugs are available to treat the disease (nifurtimox and benznidazole), but diagnostic methods require of a relatively complex infrastructure and trained personnel, limiting its widespread use in endemic areas, and the access of patients to treatment. New diagnostic methods, such as rapid tests (RDTs) to diagnose chronic Chagas disease, or loop-mediated isothermal amplification (LAMP), to detect acute infections, represent valuable alternatives, but the parasite's remarkable genetic diversity might make its implementation difficult. Furthermore, determining the efficacy of Chagas disease treatment is complicated, given the slow reversion of serological anti-T. cruzi antibody reactivity, which may even take decades to occur. New biomarkers to evaluate early therapeutic efficacy, as well as diagnostic tests able to detect the wide variety of circulating genotypes, are therefore, urgently required. To carry out studies that address these needs, high-quality and traceable samples from T. cruzi-infected individuals with different geographical backgrounds, along with associated clinical and epidemiological data, are necessary. This work describes the framework for the creation of such repositories, following standardised and uniform protocols, and considering the ethical, technical, and logistic aspects of the process. The manual can be adapted according to the resources of each laboratory, to guarantee that samples are obtained in a reproducible way, favouring the exchange of data among different work groups, and their generalizable evaluation and analysis. The main objective of this is to accelerate the development of new diagnostic methods and the identification of biomarkers for Chagas disease.

Benznidazole-related adverse drug reactions and their relationship to serum drug concentrations in patients with chronic chagas disease.

For treating Chagas disease (CD), a current worldwide health problem, only benznidazole and nifurtimox have been approved to be used. In both cases, unwanted drug-related adverse events (ADRs) are frequent when these drugs are used in adults in the chronic stage. The main objective of this study was to establish benznidazole ADRs and their relationship to serum concentrations in patients with chronic Trypanosoma cruzi infection in order to perform more accurate dosages to minimize ADRs. A total of 54 patients were recruited over 12 months. Of these 54 patients, 53 (98%) experienced at least one ADR during follow-up, and the overall average ADR incidence was 2.4 episodes/patient/month. Benznidazole treatment was discontinued in 11 patients, 7 among them due to severe adverse effects. The mean duration of treatment before withdrawal was 11 days. Benznidazole serum concentrations were recorded on days 15, 30, 45, and 60 of follow-up and evaluated according to clinical and epidemiological variables and ADR severity. No relationship was found between the benznidazole serum concentration and the ADRs. The mean (standard deviation) trough serum benznidazole concentrations (all below 20 mcg/ml) on days 15, 30, 45, and 60 were 6.4 (1.9), 6.1 (1.8), 6.2 (2.2), and 5.7 (1.7) µg/ml, respectively. Benznidazole serum concentrations do not appear to be related to the appearance of serious ADRs. Further, well-controlled studies are necessary to establish the optimal regimen for benznidazole in adults with chronic CD.