Challenges in the management of Chagas disease in Latin-American migrants in Europe

Chagas disease

Chagas disease persists as a global public health problem due to the high morbidity and mortality burden. Despite the possibility of a cure and advances in transmission control, epidemiological transformations, such as urbanisation and globalisation, and the emerging importance of oral and vertical transmission mean that Chagas disease should be considered an emerging disease, with new cases occurring worldwide. Important barriers to diagnosis, treatment, and care remain, resulting in repressed numbers of reported cases, which in turn leads to inadequate public policies. The validation of new diagnostic tools and treatment options is needed, as existing tools pose serious limitations to access to health care. Integrated models of surveillance, with community and intersectional participation, embedded in the concept of One Health, are essential for control. In addition, mitigation strategies for the main social determinants of health, including difficulties imposed by migration, are important to improve access to comprehensive health care in a globalised scenario.

Exploring Peripheral Blood-Derived Extracellular Vesicles as Biomarkers: Implications for Chronic Chagas Disease with Viral Infection or Transplantation

Extracellular vesicles (EVs) are lipid bilayer envelopes that encapsulate cell-specific cargo, rendering them promising biomarkers for diverse diseases. Chagas disease, caused by the parasite Trypanosoma cruzi, poses a significant global health burden, transcending its initial epicenter in Latin America to affect individuals in Europe, Asia, and North America. In this study, we aimed to characterize circulating EVs derived from patients with chronic Chagas disease (CCD) experiencing a reactivation of acute symptoms. Blood samples collected in EDTA were processed to isolate plasma and subsequently subjected to ultracentrifugation for particle isolation and purification. The EVs were characterized using a nanoparticle tracking analysis and enzyme-linked immunosorbent assay (ELISA). Our findings revealed distinctive differences in the size, concentration, and composition of EVs between immunosuppressed patients and those with CCD. Importantly, these EVs play a critical role in the pathophysiology of Chagas disease and demonstrate significant potential as biomarkers in the chronic phase of the disease. Overall, our findings support the potential utility of the CL-ELISA assay as a specific sensitive tool for detecting circulating EVs in chronic Chagasic patients, particularly those with recurrent infection following an immunosuppressive treatment or with concurrent HIV and Chagas disease. Further investigations are warranted to identify and validate the specific antigens or biomarkers responsible for the observed reactivity in these patient groups, which may have implications for diagnosis, the monitoring of treatment, and prognosis.

Lychnopholide loaded in surface modified polylactide nanocapsules (LYC-PLA-PEG-NC) cure mice infected by Trypanosoma cruzi strain a prototype of resistance to benznidazole and nifurtimox: First insights of its mechanism of action

Chagas disease (CD) remains neglected and causes high morbidity and mortality. The great difficulty is the lack of effective treatment. The current drugs cause side effects and have limited therapeutic efficacy in the chronic phase. This study aims to fulfil some gaps in studies of the natural substance lychnopholide nanoencapsulated LYC-PLA-PEG-NC (LYC-NC) and free (Free-LYC): the activity in epimastigotes and amastigotes to determine its selectivity index (SI), the therapeutic efficacy in mice infected with Colombian Trypanosoma cruzi strain and insight of the mechanism of LYC-NC action on T. cruzi. The SI was obtained by calculation of the ratio between the IC50 value toward H9c2 cells divided by the IC50 value in the anti-T. cruzi test. Infected Swiss mice were treated with 2 and 12 mg/kg/day via intravenous and oral, respectively, and the therapeutic efficacy was determined. The IC50 of LYC-NC and Free-LYC for epimastigotes of T. cruzi were similar. Both were active against amastigotes in cell culture, particularly Free-LYC. The SI of LYC-NC and Free-LYC were 45.38 and 32.11, respectively. LYC-NC 2 and 12 mg/kg/day cured parasitologically, 62.5% and 80% of the animals, respectively, infected with a strain resistant to treatment. The fluorescent NC was distributed in the cardiomyocyte cytoplasm, infected or not, and interacted with the trypomastigotes. Together, these results represent advances in demonstrating LYC as a potent new therapeutic option for treating CD.

Pentoxifylline reduces inflammation and prevents myocardial perfusion derangements in experimental chronic Chagas' cardiomyopathy

BACKGROUND

Myocardial perfusion defect (MPD) is common in chronic Chagas cardiomyopathy (CCC) and is associated with inflammation and development of left ventricular systolic dysfunction. We tested the hypothesis that pentoxifylline (PTX) could reduce inflammation and prevent the development of MPD in a model of CCC in hamsters.

METHODS AND RESULTS

We investigated with echocardiogram and rest myocardial perfusion scintigraphy at baseline (6-months after T. cruzi infection/saline) and post-treatment (after additional 2-months of PTX/saline administration), female Syrian hamsters assigned to 3 groups: T. cruzi-infected animals treated with PTX (CH + PTX) or saline (CH + SLN); and uninfected control animals (CO). At the baseline, all groups showed similar left ventricular ejection fraction (LVEF) and MPD areas. At post-treatment evaluation, there was a significant increase of MPD in CH + SLN group (0.8 ± 1.6 to 9.4 ± 9.7%), but not in CH + PTX (1.9 ± 3.0% to 2.7 ± 2.7%) that exhibited MPD area similar to CO (0.0 ± 0.0% to 0.0 ± 0.0%). The LVEF decreased in both infected groups. Histological analysis showed a reduced inflammatory infiltrate in CH + PTX group (395.7 ± 88.3 cell/mm2), as compared to CH + SLN (515.1 ± 133.0 cell/mm2), but larger than CO (193.0 ± 25.7 cell/mm2). The fibrosis and TNF-α expression was higher in both infected groups.

CONCLUSIONS

The prolonged use of PTX is associated with positive effects, including prevention of MPD development and reduction of inflammation in the chronic hamster model of CCC.

Novel diamides inspired by protein kinase inhibitors as anti-Trypanosoma cruzi agents: in vitro and in vivo evaluations

Background: Chagas disease is a life-threatening illness caused by Trypanosoma cruzi. The involvement of serine-/arginine-rich protein kinase in the T. cruzi life cycle is significant. Aims: To synthesize, characterize and evaluate the trypanocidal activity of diamides inspired by kinase inhibitor, SRPIN340. Material & Methods: Synthesis using a three-step process and characterization by infrared, nuclear magnetic resonance and high-resolution mass spectrometry were conducted. The selectivity index was obtained by the ratio of CC50/IC50 in two in vitro models. The most active compound, 3j, was evaluated using in vitro cytokine assays and assessing in vivo trypanocidal activity. Results: 3j activity in the macrophage J774 lineage showed an anti-inflammatory profile, and mice showed significantly reduced parasitemia and morbidity at low compound dosages. Conclusion: Novel diamide is active against T. cruzi in vitro and in vivo.

Further Investigations of Nitroheterocyclic Compounds as Potential Antikinetoplastid Drug Candidates

Due to the lack of specific vaccines, management of the trypanosomatid-caused neglected tropical diseases (sleeping sickness, Chagas disease and leishmaniasis) relies exclusively on pharmacological treatments. Current drugs against them are scarce, old and exhibit disadvantages, such as adverse effects, parenteral administration, chemical instability and high costs which are often unaffordable for endemic low-income countries. Discoveries of new pharmacological entities for the treatment of these diseases are scarce, since most of the big pharmaceutical companies find this market unattractive. In order to fill the pipeline of compounds and replace existing ones, highly translatable drug screening platforms have been developed in the last two decades. Thousands of molecules have been tested, including nitroheterocyclic compounds, such as benznidazole and nifurtimox, which had already provided potent and effective effects against Chagas disease. More recently, fexinidazole has been added as a new drug against African trypanosomiasis. Despite the success of nitroheterocycles, they had been discarded from drug discovery campaigns due to their mutagenic potential, but now they represent a promising source of inspiration for oral drugs that can replace those currently on the market. The examples provided by the trypanocidal activity of fexinidazole and the promising efficacy of the derivative DNDi-0690 against leishmaniasis seem to open a new window of opportunity for these compounds that were discovered in the 1960s. In this review, we show the current uses of nitroheterocycles and the novel derived molecules that are being synthesized against these neglected diseases.

Cannabis sativa: A look at protozoa, helminths, insect vectors, and pests

Active principles extracted from plants, such as essential oils, have been commonly described in the literature as therapeutic targets for numerous pathological conditions. Cannabis sativa, which has an ancient and peculiar history, has been used for various purposes, from recreational to compounds of pharmacotherapeutic and industrial importance, such as pesticides based on this plant. It is a plant that contains approximately 500 described cannabinoid compounds and is the target of in vitro and in vivo studies at different locations. This review clarifies the role of cannabinoid compounds in parasitic infections caused by helminths and protozoa. In addition, this study briefly presented the use of C. sativa constituents in the formulation of pesticides for vector control, as the latter topic is justified by the economic burden faced by several regions where vector-borne diseases are a troubling reality. Studies involving cannabis compounds with pesticidal potential should be encouraged, especially those that evaluate their effectiveness against the different life cycles of insects, seeking to interrupt vector proliferation after egg laying. Actions aimed at the management and cultivation of plant species with ecologically correct pharmacotherapeutic and pesticide potentials are becoming urgent.

Diagnostic pathways of Chagas disease in Spain: a qualitative study

BACKGROUND

Due to the mobility of the population in recent years and the spread of Chagas disease (CD) to non-endemic regions, early diagnosis and treatment of CD has become increasingly relevant in non-endemic countries. In order for screening to be effective, health system accessibility must be taken into consideration. This study uses Tanahashi's Health Service Coverage model to gain a deeper understanding of the main diagnostic pathways for Chagas disease in a non-endemic country and the barriers and bottlenecks present in each pathway.

METHODS

This study used a qualitative design with a phenomenological approach. Twenty-one interviews, two focus group sessions, and two triangular group sessions were conducted between 2015 and 2018 with 37 Bolivian men and women diagnosed with CD in Madrid, Spain. A topic guide was designed to ensure that the interviewers obtained the data concerning knowledge of CD (transmission, symptoms, and treatment), attitudes towards CD, and health behaviour (practices in relation to CD). All interviews, focus groups and triangular groups were recorded and transcribed. A thematic, inductive analysis based on Grounded Theory was performed by two researchers.

RESULTS

Three main pathways to CD diagnosis were identified: 1) pregnancy or blood/organ donation, with no bottlenecks in effective coverage; 2) an individual actively seeking CD testing, with bottlenecks relating to administrative, physical, and time-related accessibility, and effectiveness based on the healthcare professional's knowledge of CD; 3) an individual not actively seeking CD testing, who expresses psychological discomfort or embarrassment about visiting a physician, with a low perception of risk, afraid of stigma, and testing positive, and with little confidence in physicians' knowledge of CD.

CONCLUSIONS

Existing bottlenecks in the three main diagnostic pathways for CD are less prevalent during pregnancy and blood donation, but are more prevalent in individuals who do not voluntarily seek serological testing for CD. Future screening protocols will need to take these bottlenecks into consideration to achieve effective coverage.

Analysis of the Chagas disease situation in Japan: a cross sectional study and cost-effectiveness analysis of a Chagas disease screening program

BACKGROUND

Japan is estimated to host 3000 cases of Chagas disease (CD). However, there are no epidemiological data and policies for prevention and care. We aimed to analyze the current situation of CD in Japan and identify possible barriers to seeking care.

METHODS

This cross-sectional study included Latin American (LA) migrants living in Japan from March 2019 to October 2020. We obtained blood samples to identify participants infected with Trypanosoma cruzi, and data about sociodemographic information, CD risk factors, and barriers to access to the Japanese national health care system (JNHS). We used the observed prevalence to calculate the cost-effectiveness analysis of the screening of CD in the JNHS.

FINDINGS

The study included 428 participants, most of them were from Brazil, Bolivia and Peru. The observed prevalence was 1.6% (expected prevalence= 0.75%) and 5.3% among Bolivians. Factors associated with seropositivity were being born in Bolivia, having previously taken a CD test, witnessing the triatome bug at home, and having a relative with CD. The screening model was more cost-effective than the non-screening model from a health care perspective (ICER=200,320 JPY). Factors associated with access to JNHS were being female, length of stay in Japan, Japanese communication skills, source of information, and satisfaction about the JNHS.

INTERPRETATION

Screening of asymptomatic adults at risk of CD may be a cost-effective strategy in Japan. However, its implementation should consider the barriers that affect LA migrants in access to the JNHS.

FUNDING

Nagasaki University and Infectious Diseases Japanese Association.

Knowledge, attitudes, behaviors, and serological status related to Chagas disease among Latin American migrants in Germany: A cross-sectional study in six German cities

Background

Little is known about knowledge, attitudes and behaviors concerning Chagas disease (CD) among Latin American migrants in Germany to inform public health decision making.

Methods

A cross-sectional, questionnaire-based study was conducted between March 2014 and October 2019 among Latin American migrants in six cities in Germany to obtain information on migration history, socioeconomic and insurance status, knowledge about CD, potential risk factors for Trypanosoma cruzi infection, and willingness to donate blood or organs.

Results

168 participants completed the questionnaire. The four countries with the highest proportion of participants contributing to the study population were Colombia, Mexico, Peru and Ecuador. Before migrating to Europe, the majority of the study population resided in an urban setting in houses made of stone or concrete, had higher academic education and was integrated into the German healthcare and healthcare insurance system. The majority of all study participants were also willing to donate blood and organs and a quarter of them had donated blood previously. However, many participants lacked basic knowledge about symptoms and modes of transmission of Chagas disease. One out of 56 serologic tests (1.8%) performed was positive. The seropositive female participant born in Argentina had a negative PCR test and no signs of cardiac or other organ involvement.

Conclusions

The study population does not reflect the population structure at risk for T. cruzi infection in endemic countries. Most participants had a low risk profile for infection with T. cruzi. Although the sample size was small and sampling was not representative of all persons at risk in Germany, the seroprevalence found was similar to studies previously conducted in Europe. As no systematic screening for T. cruzi in Latin American blood and organ donors as well as in women of child-bearing age of Latin American origin is implemented in Germany, a risk of occasional transmission of T. cruzi remains.

Chagas Heart Disease: Beyond a Single Complication, from Asymptomatic Disease to Heart Failure

Chagas cardiomyopathy (CC), caused by the protozoan Trypanosoma cruzi, is an important cause of cardiovascular morbidity and mortality in developing countries. It is estimated that 6 to 7 million people worldwide are infected, and it is predicted that it will be responsible for 200,000 deaths by 2025. The World Health Organization (WHO) considers Chagas disease (CD) as a Neglected Tropical Disease (NTD), which must be acknowledged and detected in time, as it remains a clinical and diagnostic challenge in both endemic and non-endemic regions and at different levels of care. The literature on CC was analyzed by searching different databases (Medline, Cochrane Central, EMBASE, PubMed, Google Scholar, EBSCO) from 1968 until October 2022. Multicenter and bioinformatics trials, systematic and bibliographic reviews, international guidelines, and clinical cases were included. The reference lists of the included papers were checked. No linguistic restrictions or study designs were applied. This review is intended to address the current incidence and prevalence of CD and to identify the main pathogenic mechanisms, clinical presentation, and diagnosis of CC.

Diagnosis and Clinical Management of Chagas Disease: An Increasing Challenge in Non-Endemic Areas

Chagas disease (CD) is caused by the parasite Trypanosoma cruzi, and it is endemic in Central, South America, Mexico and the South of the United States. It is an important cause of early mortality and morbidity, and it is associated with poverty and stigma. A third of the cases evolve into chronic cardiomyopathy and gastrointestinal disease. The infection is transmitted vertically and by blood/organ donation and can reactivate with immunosuppression. Case identification requires awareness and screening programmes targeting the population at risk (women in reproductive age, donors, immunocompromised patients). Treatment with benznidazole or nifurtimox is most effective in the acute phase and prevents progression to chronic phase when given to children. Treating women antenatally reduces but does not eliminate vertical transmission. Treatment is poorly tolerated, contraindicated during pregnancy, and has little effect modifying the disease in the chronic phase. Screening is easily performed with serology. Migration has brought the disease outside of the endemic countries, where the transmission continues vertically and via blood and tissue/organ donations. There are more than 32 million migrants from Latin America living in non-endemic countries. However, the infection is massively underdiagnosed in this setting due to the lack of awareness by patients, health authorities and professionals. Blood and tissue donation screening policies have significantly reduced transmission in endemic countries but are not universally established in the non-endemic setting. Antenatal screening is not commonly done. Other challenges include difficulties accessing and retaining patients in the healthcare system and lack of specific funding for the interventions. Any strategy must be accompanied by education and awareness campaigns directed to patients, professionals and policy makers. The involvement of patients and their communities is central and key for success and must be sought early and actively. This review proposes strategies to address challenges faced by non-endemic countries.

Transfer of parasitology research to patents worldwide

Mankind has known about different parasitic diseases since ancient times. There is no doubt that parasites are the infectious agents that have caused the most deaths throughout history. But even today, parasitic diseases affect more than one billion people worldwide. In this paper, the relationship between articles published in the area of parasitology and international patents in this field from 1996 to 2019 was analyzed. For this purpose, Scopus has been used. This is a database developed by Elsevier, which, in addition to having numerous indexed journals and books, has developed SciVal, an analysis tool with which the publications that have been cited in the patents of the 5 largest patent offices in the world have been analyzed. The analysis has allowed us to study 2814 publications, to know their time trend, their Authors, Affiliations, and Countries, as well as the journals in which they have been published. Also, the topics and topic clusters related to parasitology that appear in publications cited in international patents have been known. Thus, the existence of six Topic Clusters that group 94% of all publications has been discovered. Of all of them, the Topic Cluster referring to malaria stands out above all others, with 968 articles (34% of the total), probably due to the fact that malaria continues to be, to this day, one of the great challenges for both industry and basic research throughout the world.

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.

The Importance of Screening for Chagas Disease Against the Backdrop of Changing Epidemiology in the USA

Purpose of Review

This review seeks to identify factors contributing to the changing epidemiology of Chagas disease in the United States of America (US). By showcasing screening programs for Chagas disease that currently exist in endemic and non-endemic settings, we make recommendations for expanding access to Chagas disease diagnosis and care in the US.

Recent Findings

Several factors including but not limited to increasing migration, climate change, rapid population growth, growing urbanization, changing transportation patterns, and rising poverty are thought to contribute to changes in the epidemiology of Chagas disease in the US. Outlined are some examples of successful screening programs for Chagas disease in other countries as well as in some areas of the US, notably those which focus on screening high-risk populations and are linked to affordable and effective treatment options.

Summary

Given concerns that Chagas disease prevalence and even risk of transmission may be increasing in the US, there is a need for improving detection and treatment of the disease. There are many successful screening programs in place that can be replicated and/or expanded upon in the US. Specifically, we propose integrating Chagas disease into relevant clinical guidelines, particularly in cardiology and obstetrics/gynecology, and using advocacy as a tool to raise awareness of Chagas disease.

Trypanocidal treatment of Chagas disease

Chagas disease is a neglected parasitosis caused by the protozoan parasite Trypanosoma cruzi. This infection is present in most Latin American countries, although, due to migratory movements, it is a growing cause for concern in non-endemic countries. The only two drugs currently available for its treatment-benznidazole and nifurtimox-were marketed 50 years ago. While they are very effective for acute and recent infection, and for the prevention of maternofoetal transmission, their efficacy declines in people who have chronic infection, especially those older than 18 years of age. In the presence of visceral involvement, parasiticidal treatment is of little or no value. The safety profile of both drugs is far from ideal, with frequent adverse events and high rates of drug discontinuation, mainly in adults. So far, new drugs and new strategies have not been shown to improve the results of the current nitroimidazoles, although the results are promising. In this review, we focus on the aspects that allow clinicians to make the best use of currently available drugs. In addition, we discuss new therapeutic options and ongoing research in the field.

Combined use of two rapid tests for the conclusive diagnosis of Chagas disease: a systematic scoping review

OBJECTIVE

The goal of this systematic scoping review is to collect and summarise scientific evidence regarding the validity of two simultaneous immunochromatographic tests for the conclusive diagnosis of Chagas disease. The research was informed by the following review questions: Will the use of two rapid tests be a valid method for the definitive diagnosis of Chagas disease when compared with conventional serological tests? In what type of population has the operation of two rapid tests been tried for the diagnosis of Chagas disease? What are the biomedical and public health advantages of the diagnostic method resulting from the combination of two rapid tests over the conventional serological method? Will it be a cost-benefit strategy for the diagnosis of Chagas with respect to conventional serological tests?

DESIGN

Systematic scoping review.

SETTING

A search of the published and unpublished literature in five databases was carried out, in order to identify, screen and select the studies included in this review.

RESULTS

468 studies were identified, of which 46 were screened with a full-text reading, and finally, three articles were included in the review. All studies were in endemic countries with adult and paediatric populations (n=1133) and, together, they evaluated four different rapid tests. The rapid tests showed good sensitivity (97.4%-100%) and specificity (96.1%-100%) for the diagnosis of Chagas when used in combination and compared with the reference tests.

CONCLUSIONS

The simultaneous use of at least two immunochromatographic rapid tests is a valid option for the definitive diagnosis of chronic Chagas in endemic rural areas, as long as there are studies that previously evaluate their performance on the areas of implementation. Therefore, this could be an alternative to the current diagnostic standard. However, additional studies are still needed in more countries in order to provide further evidence and to investigate the cost-benefit.

Clinical profile and mortality in patients with T. cruzi/HIV co-infection from the multicenter data base of the "Network for healthcare and study of Trypanosoma cruzi/HIV co-infection and other immunosuppression conditions"

OBJECTIVE

Chagas 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.

METHODS

This 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.

RESULTS

Out of 241 patients with co-infection, 86.7% were from Brazil, 47.5% had <200 CD4+ T cells/μL and median viral load was 17,000 copies/μL. Sixty CDR cases were observed. Death was more frequent in patients with reactivation and was mainly caused by CDR. Other causes of death unrelated to CDR were the manifestation of opportunistic infections in those with Acquired Immunodeficiency Syndrome. The time between the co-infection diagnosis to death was shorter in patients with CDR. Lower CD4+ cells count at co-infection diagnosis was independently associated with reactivation. Similarly, lower CD4+ cells numbers at co-infection diagnosis and male sex were associated with higher lethality in CDR. Additionally, CD4+ cells were lower in meningoencephalitis than in myocarditis and milder forms.

CONCLUSION

This 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.

The Association of Residence Permits on Utilization of Health Care Services by Migrant Workers in China

Due to the limitations in the verifiability of individual identity, migrant workers have encountered some obstacles in access to public health care services. Residence permits issued by the Chinese government are a solution to address the health care access inequality faced by migrant workers. In principle, migrant workers with residence permits have similar rights as urban locals. However, the validity of residence permits is still controversial. This study aimed to examine the impact of residence permits on public health care services. Data were taken from the China Migrants Dynamic Survey (CMDS). Our results showed that the utilization of health care services of migrant workers with residence permits was significantly better than others. However, although statistically significant, the substantive significance is modest. In addition, megacities had significant negative moderating effects between residence permits and health care services utilization. Our research results emphasized that reforms of the household registration system, taking the residence permit system as a breakthrough, cannot wholly address the health care access inequality in China. For developing countries with uneven regional development, the health care access inequality faced by migrant workers is a structural issue.

Oxidative stress implications for therapeutic vaccine development against Chagas disease

INTRODUCTION

Pathogenesis of Chagas disease (CD) caused by the protozoan parasite Trypanosoma cruzi (T. cruzi) involves chronic oxidative and inflammatory stress. In this review, we discuss the research efforts in therapeutic vaccine development to date and the potential challenges imposed by oxidative stress in achieving an efficient therapeutic vaccine against CD.

AREAS COVERED

This review covers the immune and nonimmune mechanisms of reactive oxygen species production and immune response patterns during T. cruzi infection in CD. A discussion on immunotherapy development efforts, the efficacy of antigen-based immune therapies against T. cruzi, and the role of antioxidants as adjuvants is discussed to provide promising insights to developing future treatment strategies against CD.

EXPERT OPINION

Administration of therapeutic vaccines can be a good option to confront persistent parasitemia in CD by achieving a rapid, short-lived stimulation of type 1 cell-mediated immunity. At the same time, adjunct therapies could play a critical role in the preservation of mitochondrial metabolism and cardiac muscle contractility in CD. We propose combined therapy with antigen-based vaccine and small molecules to control the pathological oxidative insult would be effective in the conservation of cardiac structure and function in CD.

Assessing the entomo-epidemiological situation of Chagas disease in rural communities in the state of Piauí, Brazilian semi-arid region

BACKGROUND

In northeastern Brazil, the wild nature of Trypanosoma cruzi vectors has challenged control actions. This study aims to describe the entomological and epidemiological scenario of Chagas disease in rural communities in the state of Piauí.

METHODS

A cross-sectional study (n=683 individuals/244 dwellings) was carried out to obtain serum samples, sociodemographic data and intra- and peridomestic triatomines.

RESULTS

The overall seroprevalence rate was 8.1%, with no positive tests among subjects <30 y of age. Prevalence rates reached 34.3% and 39.1% among subjects 61-75 and >75 y of age, respectively; 1474 triatomines were collected, of which 90.3% were found in peridomiciliary structures and 9.7% inside houses; 87.2% were classified as Triatoma brasiliensis. T. cruzi infection rates in insects were 0.5% by light microscopy and 0.9% by culture in NNN/LIT medium. Five cultivated isolates were submitted to molecular genotyping, three of which were identified as T. cruzi I and two as T. cruzi II.

CONCLUSIONS

Although no vector transmission currently occurs, prevalence rates are high in adults and the elderly. This disease should be targeted by primary healthcare providers. Insect surveillance and control activities should not be discontinued in an environment favourable to the perpetuation of house colonization by triatomines.

Do the new triatomine species pose new challenges or strategies for monitoring Chagas disease? An overview from 1979-2021

Chagas disease persists as one of the most important, and yet most neglected, diseases in the world, and several changes in its epidemiological aspects have been recorded since its discovery. Currently, some of the most relevant changes are related to: (i) the reduction in the incidence of the endemic due to the control of the most important vectors, Triatoma infestans and Rhodnius prolixus, in many countries; (ii) the migration of human populations spreading cases of the disease throughout the world, from endemic to non-endemic areas, transforming Chagas disease into a global threat; and (iii) new acute cases and deaths caused by oral transmission, especially in the north of Brazil. Despite the reduction in the number of cases, new challenges need to be responded to, including monitoring and control activities aiming to prevent house infestation by the secondary vectors from occurring. In 1979, Lent & Wygodzinsky(1) published the most complete review of the subfamily Triatominae, encompassing 111 recognised species in the taxon. Forty-two years later, 46 new species and one subspecies have been described or revalidated. Here we summarise the new species and contextualise them regarding their ecology, epidemiologic importance, and the obstacles they pose to the control of Chagas disease around the world.

6-Methyl-7-Aryl-7-Deazapurine Nucleosides as Anti-Trypanosoma cruzi Agents: Structure-Activity Relationship and in vivo Efficacy

Chagas disease is a tropical infectious disease resulting in progressive organ-damage and currently lacks efficient treatment and vaccine options. The causative pathogen, Trypanosoma cruzi, requires uptake and processing of preformed purines from the host because it cannot synthesize these de novo, instigating the evaluation of modified purine nucleosides as potential trypanocides. By modifying the pyrimidine part of a previously identified 7-aryl-7-deazapurine nucleoside, we found that substitution of a 6-methyl for a 6-amino group allows retaining T. cruzi amastigote growth inhibitory activity but confers improved selectivity towards mammalian cells. By keeping the 6-methyl group unaltered, and introducing different 7-aryl groups, we identified several analogues with sub-micromolar antitrypanosomal activity. The 7-(4-chlorophenyl) analogue 14, which was stable in microsomes, was evaluated in an acute mouse model. Oral administration of 25 mg/kg b.i.d. suppressed peak parasitemia and protected mice from infection-related mortality, gave similar reductions as the reference drug of blood parasite loads determined by qPCR, but as benznidazole failed to induce sterile cure in the short time period of drug exposure (5 days).

Antimicrobial Activity of Chitosan Oligosaccharides with Special Attention to Antiparasitic Potential

The global rise of infectious disease outbreaks and the progression of microbial resistance reinforce the importance of researching new biomolecules. Obtained from the hydrolysis of chitosan, chitooligosaccharides (COSs) have demonstrated several biological properties, including antimicrobial, and greater advantage over chitosan due to their higher solubility and lower viscosity. Despite the evidence of the biotechnological potential of COSs, their effects on trypanosomatids are still scarce. The objectives of this study were the enzymatic production, characterization, and in vitro evaluation of the cytotoxic, antibacterial, antifungal, and antiparasitic effects of COSs. NMR and mass spectrometry analyses indicated the presence of a mixture with 81% deacetylated COS and acetylated hexamers. COSs demonstrated no evidence of cytotoxicity upon 2 mg/mL. In addition, COSs showed interesting activity against bacteria and yeasts and a time-dependent parasitic inhibition. Scanning electron microscopy images indicated a parasite aggregation ability of COSs. Thus, the broad biological effect of COSs makes them a promising molecule for the biomedical industry.

Novel N,N-di-alkylnaphthoimidazolium derivative of β-lapachone impaired Trypanosoma cruzi mitochondrial electron transport system

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease, a neglected tropical disease that is endemic in Latin America and spreading worldwide due to globalization. The current treatments are based on benznidazole and nifurtimox; however, these drugs have important limitations and limited efficacy during the chronic phase, reinforcing the necessity of an alternative chemotherapy. For the last 30 years, our group has been evaluating the biological activity of naphthoquinones and derivatives on T. cruzi, and of the compounds tested, N1, N2 and N3 were found to be the most active in vitro. Here, we show the synthesis of a novel β-lapachone-derived naphthoimidazolium named N4 and assess its activity on T. cruzi stages and the mechanism of action. The new compound was very active on all parasite stages (IC₅₀/24 h in the range of 0.8-7.9 μM) and had a selectivity index of 5.4. Mechanistic analyses reveal that mitochondrial ROS production begins after short treatment starts and primarily affects the activity of complexes II-III. After 24 h treatment, a partial restoration of mitochondrial physiology (normal complexes II-III and IV activities and controlled H₂O₂ release) was observed; however, an extensive injury in its morphology was still detected. During treatment with N4, we also observed that trypanothione reductase activity increased in a time-dependent manner and concomitant with increased oxidative stress. Molecular docking calculations indicated the ubiquinone binding site of succinate dehydrogenase as an important interaction point with N4, as with the FMN binding site of dihydroorotate dehydrogenase. The results presented here may be a good starting point for the development of alternative treatments for Chagas disease and for understanding the mechanism of naphthoimidazoles in T. cruzi.

Should obstetricians working in non-endemic countries care about emerging tropical diseases?

Due to migration and international travels, obstetricians are increasingly faced with a globalized obstetric setting and should adapt their daily clinical and diagnostic approach to the modifications of tropical and subtropical infections epidemiology. This paper is focused on five emerging infectious diseases, namely Chagas disease, HTLV-1 infection, malaria, schistosomiasis and Zika virus infection, having a high prevalence in migrant populations and which can affect international travelers. These diseases frequently pass unrecognized since they are characterized by few or no symptoms during pregnancy, however they may cause a relevant maternal, fetal and neonatal impact. Specific and reliable diagnostic and treatment options are available but are rarely used during routine obstetrical practice.

Describing nearly two decades of Chagas disease in Germany and the lessons learned: a retrospective study on screening, detection, diagnosis, and treatment of Trypanosoma cruzi infection from 2000 - 2018

Background

The highly complex and largely neglected Chagas disease (CD) has become a global health problem due to population movements between Latin America and non-endemic countries, as well as non-vectorial transmission routes. Data on CD testing and treatment from routine patient care in Germany of almost two decades was collected and analysed.

Methods

German laboratories offering diagnostics for chronic Trypanosoma cruzi (T. cruzi) infection in routine patient care were identified. All retrievable data on tests performed during the years of 2000–2018 were analysed. Additional clinical information regarding patients diagnosed with CD was collected through questionnaires.

Results

Five German laboratories with diagnostics for T. cruzi infection in routine patient care were identified. Centres in Hamburg and Munich offered two independent serological tests to confirm the CD diagnosis, as recommended by WHO during the entire time period 2000–2018. Overall, a total of n = 10,728 independent tests involving n = 5991 individuals were identified with a progressive increase in testing rates over time, only n = 130 (16.0%) of the tested individuals with known nationality came from CD endemic countries. Of all test units conducted at the included institutes, a total of n = 347/10,728 (3.2%) tests on CD were positive, of which n = 200/347 (57.6%) were ELISA, n = 133/347 (38.3%) IFT, n = 10/347 (2.9%) PCR, and n = 4/347 (1.2%) RDT. Of the n = 5991 individuals only n = 81 (1.4%) with chronic infection were identified, n = 52 females and n = 28 males. Additional clinical information could only be collected from n = 47.

Conclusion

The results of this study give insight into the deployment of screening, detection, diagnosis, and treatment of T. cruzi over the last two decades in Germany and existing deficits therein; the creation of guidelines for Germany could be a step forward to improve the existing gaps.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05600-8.

Starvation and pH stress conditions induced mitochondrial dysfunction, ROS production and autophagy in Trypanosoma cruzi epimastigotes

Chagas disease is a neglected illness endemic in Latin America that mainly affects rural populations. The etiological agent of Chagas disease is the protozoan Trypanosoma cruzi, which has three different parasite stages and a dixenous life cycle that includes colonization of the vertebrate and invertebrate hosts. During its life cycle, T. cruzi is subjected to stress conditions, including variations in nutrient availability and pH, which impact parasite survival and differentiation. The plasticity of mitochondrial function in trypanosomatids has been defined as mitochondrial activity related to substrate availability. Thus, mitochondrial remodeling and autophagy, which is a constitutive cellular process of turnover and recycling of cellular components, may constitute a response to the nutritional and pH stress in the host. To assess these processes, epimastigotes were subjected to acidic, alkaline, and nutritional stress conditions, and mitochondrial function and its influence on the autophagic process were evaluated. Our data demonstrated that the three stress conditions affected the mitochondrial structure, inducing organelle swelling and impaired oxidative phosphorylation. Stressed epimastigotes produced increased ROS levels and overexpressed antioxidant enzymes. The stress conditions resulted in an increase in the number of autophagosomes and exacerbated the expression of different autophagy-related genes (Atgs). A correlation between mitochondrial dysfunction and autophagic phenotypes was also observed. After 24 h, acid stress and nutritional deprivation induced metacyclogenesis phenotypes (mitochondrial remodeling and autophagy). On the other hand, alkaline stress was transient due to insect blood feeding and culminated in an increase in autophagic flux as a survival mechanism.

Anthropological study on Chagas Disease: Sociocultural construction of illness and embodiment of health barriers in Bolivian migrants in Rome, Italy

INTRODUCTION

Chagas Disease (CD) is endemic in many Latin-American countries, Bolivia in particular. It is now spreading in Italy as a host country for transcontinental migrants and becoming an emerging health problem. This anthropological action-research, as part of a wider medical project on Neglected Tropical Diseases, has the purpose of analyzing the sociocultural construction of CD and its representation in Bolivian people living in Rome as well as barriers, such as the stigma about the illness, to access the National Health Service for those potentially affected.

METHODS

The ethnographic study was carried out from 2016 to 2018 by a medical anthropologist at the National Institute for Health, Migration and Poverty (INMP) on 72 Bolivian migrants (47 women and 25 men) living in Rome. The study was carried out through: a territorial mapping of Bolivian networks and communities aimed at recruiting people, participant observation, and application of semi-structured and unstructured interviews. The interviews were hold in Spanish and proposed to all participants before or during medical examination, or during events organized by the Bolivian community in Rome. The interview consisted of 16 items and covered four macro areas: personal and migration history, health status, access to the Italian National Health Service and knowledge about CD; plus 5 items for those who received a diagnosis of Chagas Disease in Italy.

RESULTS

The sociocultural construction and the deep stigma about the illness built by participants and their families could hinder both diagnosis and treatment. Institutional barriers also contributed to reduce adherence to screening tests: often, opening hours of the outpatient clinic were incompatible with participants' precarious employments. To guarantee participant's access to public health services and their adherence to the diagnostic protocol, we implemented a profound revision of our cultural and institutional approach to them.

CONCLUSIONS

The analysis evidenced the limitations of the conventional approach applied by the Italian National Health Service to this migrant community, such as the absence of socio-cultural and linguistics competences that can help understanding patients' perception and representation of the illness. The multidisciplinary approach instead-with clinicians using the ethnographic results to adjust their work to the participants' needs-was a successful attempt to ensure therapeutic alliance.

Comparative evaluation of community interventions for the immigrant population of Latin American origin at risk for Chagas disease in the city of Barcelona

Introduction

Chagas disease presents bio-psycho-social and cultural determinants for infected patients, their family members, close friends, and society. For this reason, diagnosis and treatment require an active approach and an integral focus, so that we can prevent the disease from creating stigma and exclusion, as is actively promoting access to diagnosis, medical attention and social integration

Methodology

The study was conducted in the Metropolitan Area of Barcelona (Catalonia, Spain) from 2004 to 2017. After an increased detection rates of CHD in our region, the process of construction of community strategies started (2004–2013). Different community interventions with informational, educational, and communication components were designed, developed, implemented, and evaluated. The results of the evaluation helped to determine which intervention should be prioritized: 1) workshop; 2) community event; 3) in situ screening. Afterwards, those strategies were implemented (2014–2017).

Results

Each of the three strategies resulted in a different level of coverage, or number of people reached. The in situ screening interventions reached the highest coverage (956 persons, 58.98%).Clear differences exist (p-value<0.001) between the three strategies regarding the percentage of screenings and diagnoses carried out. The largest number was in the in situ screening intervention, with a total of 830 persons screened despite the greatest number of diagnoses was among the workshop participants (33 persons, 20.75% of those screened). The prevalence of infection found is similar among the three strategies, ranging from 16.63% to 22.32% of the screened patients (p-value = 0.325).

Conclusions

The results of the study show that community interventions seem to be necessary to improve access to diagnosis and treatment of CHD in the area of Barcelona. They also show which strategy is the most appropriate based on the detected needs of the community, the proposed objectives of the intervention, and the given socio-temporal context.

Trypanocidal treatment of Chagas disease

Chagas disease is a neglected parasitosis caused by the protozoan parasite Trypanosoma cruzi. This infection is present in most Latin American countries, although, due to migratory movements, it is a growing cause for concern in non-endemic countries. The only two drugs currently available for its treatment-benznidazole and nifurtimox-were marketed 50 years ago. While they are very effective for acute and recent infection, and for the prevention of maternofoetal transmission, their efficacy declines in people who have chronic infection, especially those older than 18 years of age. In the presence of visceral involvement, parasiticidal treatment is of little or no value. The safety profile of both drugs is far from ideal, with frequent adverse events and high rates of drug discontinuation, mainly in adults. So far, new drugs and new strategies have not been shown to improve the results of the current nitroimidazoles, although the results are promising. In this review, we focus on the aspects that allow clinicians to make the best use of currently available drugs. In addition, we discuss new therapeutic options and ongoing research in the field.

The Clinical and Parasitologic Follow-up of Trypanosoma cruzi-infected Children in a Nonendemic Country

BACKGROUND

Chagas disease has become a global health problem, with the pediatric population being especially vulnerable. Our aim was to describe the clinical-epidemiologic aspects of disease in this population, as well as tolerance and adherence to treatment and the subsequent evolution of the disease.

METHODS

A prospective study involving 949 children 0-14 years of age screened from 2007 to 2018. Diagnosis was performed by polymerase chain reaction and/or microhematocrit in <1-year-old children or serology in those ≥1 year of age. After diagnosis, children were examined for the clinical manifestation of Chagas disease and were treated with benznidazole. Treatment response was monitored by polymerase chain reaction and serology.

RESULTS

Forty children were infected (4.2% of the population screened). Twelve children were diagnosed during the acute phase (≤1-year-old), 3 of whom were symptomatic, and 28 (4- to 14-year-olds) were in the chronic phase: 18 in the indeterminate phase and 10 presented cardiac and/or digestive involvement. Regarding treatment, 10 (25.6%) children had side effects (6 mild, 2 moderate and 2 severe reactions), leading to treatment interruption in 3 of them. No side effects were detected in ≤1-year-old children (P < 0.05). Cure was confirmed in 29.4% of the children during follow-up, and the age of the children at treatment (≤1 year) was clearly associated with the effectiveness of treatment (P < 0.05).

CONCLUSIONS

Effectiveness and safety of treatment were optimum in ≤1-year-old children. Increased side effects, cardiac and/or digestive disorder incidence and lower treatment effectiveness were detected in older children, highlighting the need for early screening.

The current drug discovery landscape for trypanosomiasis and leishmaniasis: Challenges and strategies to identify drug targets

Human trypanosomiasis and leishmaniasis are vector-borne neglected tropical diseases caused by infection with the protozoan parasites Trypanosoma spp. and Leishmania spp., respectively. Once restricted to endemic areas, these diseases are now distributed worldwide due to human migration, climate change, and anthropogenic disturbance, causing significant health and economic burden globally. The current chemotherapy used to treat these diseases has limited efficacy, and drug resistance is spreading. Hence, new drugs are urgently needed. Phenotypic compound screenings have prevailed as the leading method to discover new drug candidates against these diseases. However, the publication of the complete genome sequences of multiple strains, advances in the application of CRISPR/Cas9 technology, and in vivo bioluminescence-based imaging have set the stage for advancing target-based drug discovery. This review analyses the limitations of the narrow pool of available drugs presently used for treating these diseases. It describes the current drug-based clinical trials highlighting the most promising leads. Furthermore, the review presents a focused discussion on the most important biological and pharmacological challenges that target-based drug discovery programs must overcome to advance drug candidates. Finally, it examines the advantages and limitations of modern research tools designed to identify and validate essential genes as drug targets, including genomic editing applications and in vivo imaging.

Screening Marine Natural Products for New Drug Leads against Trypanosomatids and Malaria

Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.

Factors associated with Chagas screening among immigrants from an endemic country in Madrid, Spain

INTRODUCTION

Approximately 120,000 people live with Chagas disease in Europe, 43% of whom are living in Spain. Early diagnosis and treatment are critical to improve outcomes for those living with Chagas, and also for the prevention of ongoing transmission. The decision to be tested for Chagas is affected by a range of factors. Studies have highlighted the need to consider the wider social determinants of healthcare seeking behaviour related to Chagas. In Madrid, 44% of Bolivians undergo Chagas screening, which is a higher rate than other European regions, but studies concerning the factors which determine testing have not been performed. This study aimed to assess, for a first time, the factors associated with screening for Chagas among Bolivians living in Madrid trying to help in developing strategies and health recommendations.

METHODS

This was a cross-sectional survey about knowledge of Chagas and practices of Bolivians living in Madrid, Spain. A structured questionnaire was administered to 376 participants regarding Chagas health-seeking behaviour. Determinants were assessed by multiple logistic regressions adjusted by sex.

RESULTS

After adjusting for others variables and sex, the factors shown to be associated with Chagas screening were to have between 35 and 54 years of age; coming from a department with high prevalence of Chagas (OR 2.17 95% CI 0.99-4.76); received information about Chagas in Spain (OR 2.44 95% CI 1.32-4.51); and received any advice to do the test, especially if the advice came from a professional.

CONCLUSIONS

Health authorities should coordinate and promote strategies addressed to diagnose and treat Chagas taking into account all factors associated with screening. Our study suggests that professional advice appears to be the cornerstone to encourage Bolivians to undergo Chagas screening in Madrid. It is time to change the burden of the decision of being screened from the patient to the doctor. Being diagnosed for Chagas needs to become an institutional strategy.

Update on the major imported protozoan infections in travelers and migrants

Globalization has contributed to the emergence of specific parasitic diseases in novel geographical areas, and in these regions, these infections in travelers and immigrants may cause a considerable burden of disease. Timely diagnosis and treatment of protozoan infections to decrease mortality and prevent associated complications are essential. In this respect, the increased availability of specific DNA-detection procedures has improved the diagnosis of many imported parasitic infections. Travelers and immigrants with associated comorbidities or immunosuppression may pose a special challenge regarding management. An updated review of the main protozoan infections in mobile populations (malaria, Chagas disease, leishmaniasis, enteric protozoan infections) is provided, focusing on the changing epidemiology of these diseases, recent developments in diagnosis and management and the possibility of local transmission of imported infections.

Usefulness of real-time PCR during follow-up of patients treated with Benznidazole for chronic Chagas disease: Experience in two referral centers in Barcelona

BACKGROUND

Antitrypanosomal treatment with Benznidazole (BZ) or Nifurtimox may be recommended for patients with chronic Chagas disease (CD) to reduce the onset or progression of symptoms. However, such treatment has limited efficacy and high level of toxic effects. In addition, the current cure biomarker (serology conversion) precludes any treatment assessment unless a prolonged follow-up is arranged. PCR is thus the most useful, alternative surrogate marker for evaluating responses to treatment. The aim of this study is to describe the usefulness of real-time PCR in monitoring BZ treatment within a large cohort of chronic CD cases in Barcelona.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 370 chronic CD patients were monitored with real-time PCR post-BZ treatment. The median follow-up was 4 years (IQR 2.2-5.3y), with a median of 3 clinical visits (IQR 2-4). Only 8 patients (2.2%) presented with at least one incident of positive real-time PCR after treatment and were therefore considered as treatment failure. Four of those failure patients had completed full course treatment, whereas the remaining cases had defaulted with a statistical difference between both groups (p = 0.02). Half of the failure patients had undergone less than 4 years of follow-up monitoring all presented with parasitemia before treatment.

CONCLUSIONS/SIGNIFICANCE

BZ treatment failure was highly infrequent in our cohort. BZ discontinuation was a risk factor for positive real-time PCR results during clinical follow-up. Regular testing with real-time PCR during follow-up allows for early detection of treatment failure in patients with chronic CD.

Overcoming challenges in the diagnosis and treatment of parasitic infectious diseases in migrants

Introduction: Recent increases in population movements have created novel health challenges in many areas of the World, and health policies have been adapted accordingly in several countries. However, screening guidelines for infectious diseases are not standardized and generally do not include comprehensive screening for parasitic infections.Areas covered: Malaria, Chagas disease, leishmaniasis, amebiasis, filariases, strongyloidiasis, and schistosomiasis are reviewed, focusing on the challenges posed for their diagnosis and management in vulnerable populations such as migrants. The methodology included literature searches in public databases such as PubMed.gov and Google Scholar and search of the US National Library of Medicine online database of privately and publicly funded clinical studies (ClinicalTrials.gov) until November 2019.Expert opinion: Parasitic infections which may remain asymptomatic for prolonged periods, leading to chronic infection and complications, and/or may be transmitted in non-endemic areas are ideal candidates for screening. Proposed strategies to improve diagnosis in vulnerable groups such as migrants include facilitating access to healthcare in a multi-dimensional manner considering location, individual characteristics, and timing. Limitations and availability of specific diagnostic techniques should be addressed and focus on drug and vaccine development for these neglected infections should be prioritized through collaborative initiatives with public disclosure of results.

The role of the first level of health care in the approach to Chagas disease in a non-endemic country

BACKGROUND

Chagas disease has crossed South America's borders and in recent years has spread to regions that were not previously affected. Early diagnosis and treatment of Chagas disease improves the clinical prognosis and prevents vertical transmission. Taking into account the lack of evidence of how primary care services manage Chagas disease in a non-endemic country, this study assessed Chagas disease knowledge, attitudes and practices among primary health care professionals.

METHODS AND PRINCIPAL FINDINGS

Between 2017 and 2019, eight focus groups were formed with 41 family physicians and 40 nurses from healthcare centers in Madrid, Spain, and 70 field notes were collected during non-participant observation. The family physicians and nurses showed a lack of general knowledge about Chagas disease, and they did not identify the country of origin to request the blood test. The family physicians and nurses thought that the population did not talk broadly about Chagas disease because of the stigma or shame. The role of nurses was more focused on vaccination status and chronic disease follow-up, and family physicians assumed a facilitating role to send patients to different hospital facilities. Communication between primary care professionals and the hospital is a barrier frequently experienced by family physicians.

CONCLUSIONS

The diagnosis of CD in non-endemic countries continues being an important challenge for health systems. The results obtained with the study of the knowledge, attitudes and practices at primary care through a qualitative approach allows to obtain evidence that could help to develop strategies for the screening of CD in a protocolized way in order to avoid that the diagnosis depends exclusively on the request of the patient.

Congenital Chagas Disease in the Ecuadorian Amazon: Maternal Screening at Delivery and Evaluation of Risk Factors Associated with Vector Exposure

Congenital infection with Trypanosoma cruzi remains a major route for Chagas disease transmission in endemic and non-endemic regions. We evaluated an intervention strategy aimed to detect congenital Chagas disease cases at a major hospital in the Ecuadorian Amazon via cord blood analysis at the time of delivery. All women giving birth at the hospital during the study period (191) were invited to participate. Among them, two (1.0%) did not adjust to the inclusion criteria and four (2.1%) declined to participate in the study, showing the intervention had good acceptability among the mothers. It was possible to obtain cord blood samples during 146 of the deliveries, and only one woman was found to be seropositive, without evidence of transmission to the newborn at delivery or 8 months later. In addition, sociodemographic and economic characterization of the study population revealed that few women had previous knowledge about Chagas disease (16.1%) whereas more than half (62.5%) recognized the vector. Recognizing the vector and having seen it indoors were associated with women from rural families, involved in agriculture, and hunting in the forest. Interestingly, most women (87.3%) reported having easy access to Ecuador's national health system, suggesting serological screening during prenatal visits would be of value in this province. With a proper prenatal screening system in place, cord blood screening would allow for timely detection of T. cruzi infection in newborns from both seropositive women and the minority (2.1%) of women who do not comply with prenatal care visits.

Chagas disease: comments on the 2018 PAHO Guidelines for diagnosis and management

BACKGROUND

Chagas disease, or American trypanosomiasis, is a protozoan infectious disease endemic throughout most of the Americas, caused by the trypanosome, Trypanosoma cruzi, and mainly transmitted to humans by reduviid or kissing bugs. Some progress has been achieved in control of the disease mainly in endemic areas, but migration flows have acted as drivers for the emergence of the disease mainly in non-endemic areas of Europe and North America. Most imported cases of Chagas disease in Europe are reported in migrants from highly endemic areas of countries such as Bolivia and Paraguay, and reports of Chagas disease in travellers are extremely rare.

METHODS

Pan American Health Organization (PAHO) recently updated their guidelines on the diagnosis and management of Chagas. These guidelines and their applicability to migrants and travellers are reviewed.

RESULTS

PAHO recommends the use of two serological tests for diagnosis of chronic infection (allowing for the use of a single sensitive test followed by confirmation in special settings such as the screening of potential blood donors). The indication for specific trypanocidal treatment of acute infections, children and women of child-bearing age remains as before, with either benznidazole or nifurtimox being the treatment of choice. For chronic infection with/without organ damage, treatment recommendations are less well defined. Although treatment is generally not recommended in patients with visceral involvement, decisions regarding treatment need to be tailored to the individual. Either benznidazole or nifurtimox may be used for initial treatment.

CONCLUSIONS

The recent PAHO Guidelines provide a framework to aid the diagnosis and management of this infection, but several aspects such as the underdiagnosis of infections, the multidisciplinary approach to patient management, the investigation of novel biomarkers of disease progression/response to treatment and the development of new treatment strategies are areas which should be further strengthened.

Chagas and health promotion: dialogue inspired by the Curitiba Statement

With the objective of providing an insightful analysis of Chagas disease in the world, the authors share their collective reflections about the current situation of this public health problem in: rural environments of Latin America; urban environments of endemic and non-endemic areas everywhere; and, at a global level. A perspective based on the 'Democracy and Health Promotion' axis allowed the development of an innovative update about Chagas disease as a model of a complex socio-environmental health problem, with a key set of elements that goes beyond biomedical aspects. The authors created a dialogue between the fundamental elements of the Curitiba Statement on Health Promotion and Equity and crucial aspects of a reflection on the reality of Chagas disease today that at the same time challenges the different actors involved. With that reference, the call to promote a 'critical analysis of viabilities and opportunities for action, considering the potentialities and barriers imposed by the complexity of social movements in the present context of recedes and the loss of rights' was emphasized repeatedly. Finally, on the occasion of the recent creation of the Technical Group on Information, Education and Communication to control Chagas disease, WHO Department of Control of Neglected Tropical Diseases, the authors share reflections to propose an inclusive and transformative approach of health promotion-what we hope is a new horizon for people affected, directly and indirectly, by Chagas disease.

Chagas screening and treatment among Bolivians living in Madrid, Spain: The need for an official protocol

Background

It is estimated that around 52,000 people live with Chagas in Spain, but only 10% have been diagnosed. Migrants from Bolivia bear the burden of Chagas infection in Spain. However, little is known about their current management of Chagas diagnosis and treatment patterns. This study aimed to assess the Chagas related disease perception and health behaviour of Bolivians living in Madrid.

Methods and principal findings

For a first time, a cross-sectional survey about Chagas’ knowledges and practices was carried out in Madrid, Spain. A total of 376 Bolivians were interviewed about their Chagas health-seeking behaviour. Differences between men and women were assessed Most of Bolivians living in Madrid have access to the public health services. 44% of Bolivians included in the survey had a Chagas screening test done. However, while women did their test for Chagas mostly at hospital (59.2%), men also used the community campaigns (17.5%) and blood banks (14.3%). The prevalence reported among Bolivians tested was 27.7%. Unfortunately, more than half of those reporting a positive test for Chagas did not begin or completed treatment. Only 45.7% of positives reported having had their children tested for Chagas.

Conclusions

Despite the increase in the number of Chagas diagnoses done in Madrid, the number of Bolivians who tested positive and then started or completed treatment remains very low. The fact that most Bolivians’ access to the health system is through the primary healthcare services should be considered for improving management of cases and follow-up of treatment adherence. Local and national protocol establishing guidelines for the screening and treatment of Chagas disease would help improving case detection and management at all levels of the healthcare system.

Infectious diseases at different stages of migration: an expert review

BACKGROUND

Human migration is increasing in magnitude and scope. The majority of migrants arriving in high-income countries originate from countries with a high prevalence of infectious diseases. The risk and burden of infectious diseases are not equally distributed among migrant groups and vary with migration stage.

METHODS

A broad literature review was conducted on the drivers for infectious diseases and associated health outcomes among migrants across different stages of migration. The aim was to provide practitioners with an overview of the key infectious disease risks at each stage to guide health promotion strategies.

RESULTS

A complex interaction of factors leads to infectious diseases and associated poor health outcomes among migrants. The most important drivers are the epidemiology of infectious diseases in their countries of origin, the circumstances and conditions of the migration journey and barriers accessing healthcare post-arrival. During the recent large waves of forced migration into Europe, the primary health concerns on arrival were psychological, traumatic and chronic non-communicable diseases. In the early settlement period, crowded and unhygienic living conditions in reception camps facilitated outbreaks of respiratory, gastrointestinal, skin infections and vaccine preventable diseases. After re-settlement, undetected and untreated latent infections due to tuberculosis, viral hepatitis, HIV, chronic helminthiasis and Chagas' disease led to poor health outcomes. Migrants are disproportionally affected by preventable travel-related diseases such as malaria, typhoid and hepatitis due to poor uptake of pre-travel prophylaxis and vaccination. Infectious diseases among migrants can be decreased at all migration stages with health promotion strategies adapted to their specific needs and delivered in a linguistically and culturally sensitive manner.

CONCLUSIONS

Tailored health promotion and screening approaches and accessible and responsive health systems, regardless of legal status, will be needed at all migration stages to limit the burden and transmission of infectious diseases in the migrant population.

Potential Utility of Protein Targets of Cysteine-S-Nitrosylation in Identifying Clinical Disease Status in Human Chagas Disease

Trypanosoma cruzi (Tc) infection causes Chagas disease (ChD) presented by dilated cardiomyopathy and heart failure. During infection, oxidative and nitrosative stresses are elicited by the immune cells for control the pathogen; however, excess nitric oxide and superoxide production can result in cysteine S-nitrosylation (SNO) of host proteins that affects cellular homeostasis and may contribute to disease development. To identify the proteins with changes in SNO modification levels as a hallmark of ChD, we obtained peripheral blood mononuclear cells (PBMC) from seronegative, normal healthy (NH, n = 30) subjects, and from seropositive clinically asymptomatic (ChD CA, n = 25) or clinically symptomatic (ChD CS, n = 28) ChD patients. All samples were treated (Asc+) or not-treated (Asc⁻) with ascorbate (reduces nitrosylated thiols), labeled with the thiol-labeling BODIPY FL-maleimide dye, resolved by two-dimensional electrophoresis (total 166 gels), and the protein spots that yielded significant differences in abundance or SNO level at p-value of ≤ 0.05_{t−test/Welch/BH} were identified by MALDI-TOF/TOF MS or OrbiTrap LC-MS/MS. Targeted analysis of a new cohort of PBMC samples (n = 10–14/group) was conducted to verify the differential abundance/SNO levels of two of the proteins in ChD (vs. NH) subjects. The multivariate adaptive regression splines (MARS) modeling, comparing differences in relative SNO level (Asc⁻/Asc+ ratio) of the protein spots between any two groups yielded SNO biomarkers that exhibited ≥90% prediction success in classifying ChD CA (582-KRT1 and 884-TPM3) and ChD CS (426-PNP, 582-KRT1, 486-ALB, 662-ACTB) patients from NH controls. Ingenuity Pathway Analysis (IPA) of the SNO proteome dataset normalized to changes in protein abundance suggested the proteins belonging to the signaling networks of cell death and the recruitment and migration of immune cells were most affected in ChD CA and ChD CS (vs. NH) subjects. We propose that SNO modification of the select panel of proteins identified in this study have the potential to identify ChD severity in seropositive individuals exposed to Tc infection.

Differential infectivity of two Trypanosoma cruzi strains in placental cells and tissue

Congenital Chagas disease, caused by Trypanosoma cruzi (T. cruzi), has become epidemiologically relevant. The probability of congenital transmission depends on the maternal and developing fetal/newborn immune responses, placental factors and importantly, the virulence of the parasite. It has been proposed, that different genotypes of T. cruzi and their associated pathogenicity, virulence and tissue tropism may play an important role in congenital infection. Since there is no laboratory or animal model that recapitulates the complexities of vertical transmission in humans, here we studied parasite infectivity in human placental explants (HPE) as well as in the human trophoblast-derived cell line BeWo of the Y(DTU II) and the VD (TcVI) T. cruzi strains; the latter was isolated from a human case of congenital infection. Our results show that the VD strain is more infective and pathogenic than the Y strain, as demonstrated by qPCR and cell counting as well as by histopathological analysis. The present study constitutes the first approach to study the relationship between parasite two parasite strains from different genotypes and the infection efficiency in human placenta.

Scientometrics analysis of research activity and collaboration patterns in Chagas cardiomyopathy

Background

Chagas cardiomyopathy is a serious and common complication of Chagas disease.

Methods

Through bibliometric and Social Network Analysis, we examined patterns of research on Chagas cardiomyopathy, identifying the main countries, authors, research clusters, and topics addressed; and measuring the contribution of different countries.

Results

We found 1932 documents on Chagas cardiomyopathy in the MEDLINE database. The most common document type was ‘journal article’, accounting for 79.6% of the total (n = 1538), followed by ‘review’ (n = 217, 11.2%). The number of published records increased from 156 in 1980–1984 to 311 in 2010–2014. Only 2.5% were clinical trials. Brazil and the USA dominated the research, participating in 53.1% and 25.7%, respectively, of the documents. Other Latin American countries where Chagas is endemic contributed less, with Bolivia, where Chagas disease is most prevalent, producing only 1.8% of the papers. We observed a high rate of domestic collaboration (83.1% of the documents published in 2010–2016) and a lower but significant rate of international collaboration (32.5% in the same time period). Although clinical research dominated overall, the USA, Mexico and several countries in Europe produced a considerable body of basic research on animal models. We identified four main research clusters, focused on heart failure and dysfunction (physical symptoms, imaging techniques, treatment), and on myocarditis and parasitemia in animal models.

Conclusions

Research on Chagas cardiomyopathy increased over the study period. There were more clinical than basic studies, though very few of the documents were clinical trials. Brazil and the USA are currently leading the research on this subject, while some highly endemic countries, such as Bolivia, have contributed very little. Different approaches could help to redress this imbalance: encouraging researchers to conduct more clinical trials, launching international collaborations to help endemic countries contribute more, and strengthening links between basic and clinical research.

Scientific production on Chagas cardiomyopathy has grown considerably since the turn of the 21st century, probably reflecting the increased incidence of Chagas disease in non-endemic areas like the USA and Europe. Brazil and the USA dominate the research, but we found a very small proportion of clinical trials on Chagas cardiomyopathy and a low scientific production in several endemic countries with a high prevalence of the disease such as Colombia, Chile, Mexico and Bolivia. We observed a polarity between endemic and non-endemic countries where clinical research and basic research predominate, respectively. Different approaches could help to redress the observed imbalance of research on Chagas cardiomyopathy: encouraging researchers to conduct more clinical trials, launching international collaborations to help endemic countries contribute more, and strengthening links between basic and clinical research. It is crucial to foster translational research in order to link basic knowledge on the physiology of the disease with clinical applications in diagnosis and treatment.