Guidelines on the treatment of chronic coinfection by Trypanosoma cruzi and HIV outside endemic areas

Outcomes of patients in Chagas disease of the central nervous system: a systematic review

Chagas disease is a parasitic infection caused by the protozoan Trypanosoma cruzi. One of the complications of the disease is the infection of the central nervous system (CNS), as it can result from either the acute phase or by reactivation during the chronic phase, exhibiting high mortality in immunocompromised patients. This systematic review aimed to determine clinical and paraclinical characteristics of patients with Chagas disease in the CNS. Articles were searched from PubMed, Scopus and LILACS until January 2023. From 2325 articles, 59 case reports and 13 case series of patients with Chagas in the CNS were retrieved from which 138 patients were identified. In this population, 77% of the patients were male, with a median age of 35 years old, from which most of them came from Argentina and Brazil. Most of the individuals were immunocompromised from which 89% were HIV-positive, and 54 patients had an average of 48 cells per mm3 CD4+ T cells. Motor deficits and seizures were the most common manifestation of CNS compromise. Furthermore, 90 patients had a documented CNS lesion by imaging from which 89% were supratentorial and 86% were in the anterior/middle cranial fossa. The overall mortality was of 74%. Among patients who were empirically treated with anti-toxoplasma drugs, 70% died. This review shows how Chagas disease in the CNS is a devastating complication requiring prompt diagnosis and treatment to improve patients’ outcomes.

Critical analysis of Chagas disease treatment in different countries

As a result of globalization and constant migratory flows, Chagas disease is now present in almost all continents. The management and treatment of the disease is often influenced by the economic and social context of the societies that host patients. In this manuscript, we aim to provide a comparative review of approaches to patients with Chagas disease in the Americas and Europe.

Parasitological, serological and molecular diagnosis of acute and chronic Chagas disease: from field to laboratory

There is no consensus on the diagnostic algorithms for many scenarios of Trypanosoma cruzi infection, which hinders the establishment of governmental guidelines in endemic and non-endemic countries. In the acute phase, parasitological methods are currently employed, and standardised surrogate molecular tests are being introduced to provide higher sensitivity and less operator-dependence. In the chronic phase, IgG-based serological assays are currently used, but if a single assay does not reach the required accuracy, PAHO/WHO recommends at least two immunological tests with different technical principles. Specific algorithms are applied to diagnose congenital infection, screen blood and organ donors or conduct epidemiological surveys. Detecting Chagas disease reactivation in immunosuppressed individuals is an area of increasing interest. Due to its neglect, enhancing access to diagnosis of patients at risk of suffering T. cruzi infection should be a priority at national and regional levels.

Screening for Chagas disease should be included in entry-to-care testing for at-risk people with HIV living in the United States

Chagas disease screening of at-risk populations is essential to identify infected individuals and facilitate timely treatment before end-organ damage occurs. Co-infected people with HIV (PWH) are at risk for dangerous sequelae, specifically Trypanosoma cruzi reactivation disease. Recently published national recommendations indicate that at-risk PWH, particularly those from endemic areas or born to women from endemic areas, should be screened via a sensitive anti-T. cruzi IgG assay. However, immunocompromised patients with negative serologic results may warrant further investigation. Reactivation should be suspected in at-risk, untreated PWH with low CD4 cell counts presenting with acute neurologic or cardiac symptoms; these patients should be promptly evaluated and treated. One pragmatic solution to improve Chagas disease screening among PWH and thereby reduce T. cruzi -related morbidity and mortality is to incorporate Chagas disease screening into the panel of tests routinely performed during the entry-to-care evaluation for at-risk PWH.

Roadblocks in Chagas disease care in endemic and nonendemic countries: Argentina, Colombia, Spain, and the United States. The NET-Heart project

Background

Chagas disease (CD) is endemic in Latin America; however, its spread to nontropical areas has raised global interest in this condition. Barriers in access to early diagnosis and treatment of both acute and chronic infection and their complications have led to an increasing disease burden outside of Latin America. Our goal was to identify those barriers and to perform an additional analysis of them based on the Inter American Society of Cardiology (SIAC) and the World Heart Federation (WHF) Chagas Roadmap, at a country level in Argentina, Colombia, Spain, and the United States, which serve as representatives of endemic and nonendemic countries.

Methodology and principal findings

This is a nonsystematic review of articles published in indexed journals from 1955 to 2021 and of gray literature (local health organizations guidelines, local policies, blogs, and media). We classified barriers to access care as (i) existing difficulties limiting healthcare access; (ii) lack of awareness about CD and its complications; (iii) poor transmission control (vectorial and nonvectorial); (iv) scarce availability of antitrypanosomal drugs; and (v) cultural beliefs and stigma. Region-specific barriers may limit the implementation of roadmaps and require the application of tailored strategies to improve access to appropriate care.

Conclusions

Multiple barriers negatively impact the prognosis of CD. Identification of these roadblocks both nationally and globally is important to guide development of appropriate policies and public health programs to reduce the global burden of this disease.

Chagas disease (CD) has been described as an epidemic in Latin America, but its geographical influence is global. One of the biggest challenges in providing care for patients with CD is to improve access to early diagnosis and treatment in order to avoid chronic cardiovascular and gastrointestinal complications. However, different roadblocks interfere with the optimal care of these patients, which facilitates disease progression. While some barriers to care are global in scope, there are additionally national and even local obstacles for patients with CD. Appropriate delineation of these barriers will allow for the development of targeted interventions to improve the outlook for CD patients in both endemic and nonendemic countries alike.

Deaths related to Chagas disease and HIV/AIDS coinfection in Brazil: a nationwide population-based analysis

BACKGROUND

Trypanosoma cruzi/HIV coinfection has been described as a relevant clinical event and an emerging public health problem. Here, we describe the epidemiological patterns of deaths related to Chagas disease and HIV/AIDS coinfection in Brazil from 2000 to 2019.

METHODS

We performed a nationwide population-based study using mortality data obtained from the Brazilian Mortality Information System. We included all deaths recorded in Brazil from 2000 to 2019 in which Chagas disease and HIV/AIDS were mentioned on the same death certificate, either as underlying or as associated causes of death.

RESULTS

Chagas disease and HIV/AIDS were mentioned on 196/22 663 092 death certificates. HIV/AIDS was the underlying cause in 58.2% (114/196) of deaths and Chagas disease in 33.2% (65/196). The average annual mortality rate was 0.05 deaths/1 000 000 inhabitants (95% CI 0.03 to 0.09). The highest death rates were found among males, those aged 60-69 y, Afro-Brazilians, those with 1-3 y of schooling/study and residents in Chagas disease-endemic regions/states. Respiratory, infectious/parasitic and cardiovascular diseases/disorders were the associated causes of death most commonly mentioned.

CONCLUSIONS

Mortality due to Chagas disease and HIV/AIDS coinfection may be largely underestimated in Brazil. Our data further reinforce the importance of screening for T. cruzi infection in HIV-infected patients from Chagas disease-endemic areas. Appropriate clinical management should be ensured for Chagas disease and HIV coinfected patients.

Chagas Disease in People with HIV: A Narrative Review

Many questions remain unanswered regarding the epidemiology, pathophysiology, diagnosis, treatment, and monitoring of Trypanosoma cruzi infection in people with HIV (PWH). The reported prevalence of T. cruzi infection in PWH living in endemic countries ranges from 1-28% and is likely similar in at-risk US populations. While classic cardiac and gastrointestinal presentations of chronic Chagas disease occur in PWH, PWH are additionally at risk for a severe and often fatal form of T. cruzi-mediated disease called reactivation disease. T. cruzi reactivation typically occurs in PWH with low CD4 counts and poor virologic control. National HIV guidelines in several endemic South American countries recommend that all PWH be screened for T. cruzi infection at the time of HIV diagnosis; however, this recommendation is not widely implemented. The early detection of T. cruzi infection in PWH is critical as the sequelae of Chagas disease, including T. cruzi reactivation, may be preventable through the restoration of robust cellular immunity via the initiation of antiretroviral therapy and the appropriate use of antitrypanosomal therapy.

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.

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.

WHF IASC Roadmap on Chagas Disease

Background

Chagas Disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi, with some of the most serious manifestations affecting the cardiovascular system. It is a chronic, stigmatizing condition, closely associated with poverty and affecting close to 6 million people globally. Although historically the disease was limited to endemic areas of Latin America recent years have seen an increasing global spread. In addition to the morbidity and mortality associated with the disease, the social and economic burdens on individuals and society are substantial. Often called the 'silent killer', Chagas disease is characterized by a long, asymptomatic phase in affected individuals. Approximately 30% then go on develop chronic Chagas cardiomyopathy and other serious cardiac complications such as stroke, rhythm disturbances and severe heart failure.

Methods

In a collaboration of the World Hearth Federation (WHF) and the Inter-American Society of Cardiology (IASC) a writing group consisting of 20 diverse experts on Chagas disease (CD) was convened. The group provided up to date expert knowledge based on their area of expertise. An extensive review of the literature describing obstacles to diagnosis and treatment of CD along with proposed solutions was conducted. A survey was sent to all WHF Members and, using snowball sampling to widen the consultation, to a variety of health care professionals working in the CD global health community. The results were analyzed, open comments were reviewed and consolidated, and the findings were incorporated into this document, thus ensuring a consensus representation.

Results

The WHF IASC Roadmap on Chagas Disease offers a comprehensive summary of current knowledge on prevention, diagnosis and management of the disease. In providing an analysis of 'roadblocks' in access to comprehensive care for Chagas disease patients, the document serves as a framework from which strategies for implementation such as national plans can be formulated. Several dimensions are considered in the analysis: healthcare system capabilities, governance, financing, community awareness and advocacy.

Conclusion

The WHF IASC Roadmap proposes strategies and evidence-based solutions for healthcare professionals, health authorities and governments to help overcome the barriers to comprehensive care for Chagas disease patients. This roadmap describes an ideal patient care pathway, and explores the roadblocks along the way, offering potential solutions based on available research and examples in practice. It represents a call to action to decision-makers and health care professionals to step up efforts to eradicate Chagas disease.

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.

Chagas Disease in the United States: a Public Health Approach

Trypanosoma cruzi is the etiological agent of Chagas disease, usually transmitted by triatomine vectors. An estimated 20 to 30% of infected individuals develop potentially lethal cardiac or gastrointestinal disease. Sylvatic transmission cycles exist in the southern United States, involving 11 triatomine vector species and infected mammals such as rodents, opossums, and dogs. Nevertheless, imported chronic T. cruzi infections in migrants from Latin America vastly outnumber locally acquired human cases. Benznidazole is now FDA approved, and clinical and public health efforts are under way by researchers and health departments in a number of states. Making progress will require efforts to improve awareness among providers and patients, data on diagnostic test performance and expanded availability of confirmatory testing, and evidence-based strategies to improve access to appropriate management of Chagas disease in the United States.

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.

Molecular diagnosis of Trypanosoma cruzi

Chagas disease, caused by the kinetoplastid protozoan Trypanosoma cruzi, affects millions of people, most of them neglected populations. The different phases of the disease, the transmission mode and the high genetic variability of the parasite determine that molecular detection methods display different degree of success. Molecular diagnostic tests may be employed during epidemiological surveys of transmission, for early diagnosis of congenital transmission and acute infections due to oral transmission, transfusion or transplantation routes, reactivation due to immunosuppression and monitoring of treatment response in chronically infected patients receiving trypanocidal chemotherapy. This manuscript summarizes the most widely used molecular tools to detect T. cruzi infection in different epidemiological and clinical scenarios.

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

Chagas disease is endemic in Latin America. Due to migration the infection has crossed borders and it is estimated that 68,000-120,000 people with Chagas disease are currently living in Europe and 30% of them may develop visceral involvement. However, up to 90% of Chagas disease cases in Europe remain undiagnosed. The challenges which have to be overcome in Chagas disease in non-endemic countries are focused on related downing barriers to health care access, and related to screening, diagnostic tools and therapeutic management. The aim of this review is to highlight how healthcare management for Latin American migrants with Chagas disease in Europe may be improved. Medical literature was searched using PubMed. No limits were placed with respect to the language or date of publication although most of the articles selected were articles published in the last five years. Chosen search terms were "Chagas disease" AND ("migrants" OR "screening" OR "transmission" OR "treatment"; OR "knowledge" OR "non-endemic countries"); migrants AND ("Public health" OR "Health Service Accessibility" OR "Delivery of Health care"); and "Congenital Chagas disease". Healthcare management of migrant populations with Chagas disease in Europe has to be improved: -Surveillance programmes are needed to measure the burden of the disease; -screening programmes are needed; -administrative and cultural barriers in the access to health care for migrants should be reduced; -education programmes on Chagas disease should be performed -research on new diagnostic tools and therapeutic options are required. This review highlights the needs of profound changes in the health care of Latin American migrants with Chagas disease in Europe.

Does my patient have chronic Chagas disease? Development and temporal validation of a diagnostic risk score

INTRODUCTION

With the globalization of Chagas disease, unexperienced health care providers may have difficulties in identifying which patients should be examined for this condition. This study aimed to develop and validate a diagnostic clinical prediction model for chronic Chagas disease.

METHODS

This diagnostic cohort study included consecutive volunteers suspected to have chronic Chagas disease. The clinical information was blindly compared to serological tests results, and a logistic regression model was fit and validated.

RESULTS

The development cohort included 602 patients, and the validation cohort included 138 patients. The Chagas disease prevalence was 19.9%. Sex, age, referral from blood bank, history of living in a rural area, recognizing the kissing bug, systemic hypertension, number of siblings with Chagas disease, number of relatives with a history of stroke, ECG with low voltage, anterosuperior divisional block, pathologic Q wave, right bundle branch block, and any kind of extrasystole were included in the final model. Calibration and discrimination in the development and validation cohorts (ROC AUC 0.904 and 0.912, respectively) were good. Sensitivity and specificity analyses showed that specificity reaches at least 95% above the predicted 43% risk, while sensitivity is at least 95% below the predicted 7% risk. Net benefit decision curves favor the model across all thresholds.

CONCLUSIONS

A nomogram and an online calculator (available at http://shiny.ipec.fiocruz.br:3838/pedrobrasil/chronic_chagas_disease_prediction/) were developed to aid in individual risk estimation.

Impact of Helminth Infection on the Clinical and Microbiological Presentation of Chagas Diseases in Chronically Infected Patients

BACKGROUND

Helminth infections are highly prevalent in tropical and subtropical countries, coexisting in Chagas disease endemic areas. Helminth infections in humans may modulate the host immune system, changing the Th1/Th2 polarization. This immunological disturbance could modify the immune response to other infections. The aim of this study is to evaluate the relationship between clinical, microbiological and epidemiological characteristics of Chagas disease patients, with the presence of helminth infection.

METHODS

A prospective observational study was conducted at Vall d'Hebron University Hospital (Barcelona, Spain). Inclusion criteria were: age over 18 years, diagnosis of Chagas disease, and not having received specific treatment for Chagas disease previously to the inclusion. The study protocol included Chagas disease assessment (cardiac and digestive evaluation, detection of T. cruzi DNA measured by PCR in peripheral blood), and helminth infection diagnosis (detection of IgG anti-Strongyloides stercoralis by ELISA, microscopic examination of stool samples from three different days, and specific faecal culture for S. stercoralis larvae).

RESULTS

Overall, 65 patients were included, median age was 38 years, 75.4% were women and most of them came from Bolivia. Cardiac and digestive involvement was present in 18.5% and 27.7% of patients respectively. T. cruzi PCR was positive in 28 (43.1%) patients. Helminth infection was diagnosed in 12 (18.5%) patients. No differences were observed in clinical and epidemiological characteristics between patients with and without helminth infection. Nevertheless, the proportion of patients with positive T. cruzi PCR was higher among patients with helminth infection compared with patients without helminth infection (75% vs 35.8%, p = 0.021).

CONCLUSIONS

We observed a high prevalence of S. stercoralis infection among chronic Chagas disease patients attended in our tropical medicine unit. Strongyloidiasis was associated with significantly higher proportion of positive T. cruzi RT-PCR determined in peripheral blood.

[Update Chagas disease]

The constant migration flows have favored the presence of people with Chagas disease in regions traditionally regarded as non-endemic, such as North America, Europe, Asia and Oceania. This has forced both health authorities and professionals to be updated in order to respond to such a demand for assistance. Recent years have led to significant progress in the field of diagnosis and treatment of Chagas disease, one of the most neglected tropical diseases. Recent clinical trials are providing new evidence that makes the management of these patients, a constant challenge for the professionals involved. Innovative diagnostic tools and therapeutic regimens, allow us to face the future of Chagas disease with optimism.

Reactivation of Chagas Disease: Implications for Global Health

Reactivation of Chagas Disease (CD) is a global public health issue. Reactivation of disease can affect the management of CD and its clinical outcome, adding pressure to global health systems because it exacerbates symptoms, leading to misdiagnosis and delays in the administration of correct treatments. Concurrent infections complicate the issue of reactivation, because there are various parasites and disease treatment regimens that are able to influence or suppress the immune system of the host, reactivating disease within infected individuals. The effect of delayed symptoms of chronic CD and the potential for disease reactivation are of great importance to nonendemic regions of the world, where knowledge about CD is lacking and the potential for vectorial transmission is not known.

Trypanocidal Activity of Long Chain Diamines and Aminoalcohols

Thirteen aminoalcohols and eight diamines were obtained and tested against Trypanosoma cruzi epimastigotes strains MG, JEM and CL-B5 clone. Some of them were equal or more potent (1.0–6.6 times) than the reference compound nifurtimox. From them, three aminoalcohols and two diamines were selected for amastigotes assays. Compound 5 was as potent as the reference drug nifurtimox against amastigotes of the CL-B5 strain (IC₅₀ = 0.6 µM), with a selectivity index of 54.

Immunosuppression and Chagas disease; experience from a non-endemic country

Reactivation of Chagas disease in the chronic phase may occur when immunosuppression is established, sometimes resulting in high parasitaemia and severe clinical manifestations such as meningitis and meningoencephalitis. Although this situation is being increasingly described, there is still scarce information. This retrospective observational study was performed in three Tropical Medicine Units of Barcelona (Spain) included in the International Health Programme of the Catalan Health Institute (PROSICS). The objective of the study was to describe epidemiological, clinical, microbiological, prognostic and therapeutic data from patients with Chagas disease and any kind of immunosuppressive condition attended in these three institutions from January 2007 to October 2014. From 1823 patients with Chagas disease attending these three centres during the study period, 38 (2%) had some kind of immunosuppressive condition: 12 patients had human immunodeficiency virus infection, 8 patients had neoplasia, 4 patients underwent organ transplantation and 14 patients had an autoimmune disease. Eight (21.1%) patients had cardiac involvement, and six (15.8%) patients had gastrointestinal involvement. Acute Trypanosoma cruzi infection was detected in two Spanish patients. Thirty-one (81.6%) patients received treatment with benznidazole, of whom 17 (54.8%) had some kind of adverse event. No patient had a severe manifestation or reactivation of Chagas disease. Patients with Chagas disease under immunosuppressive conditions are being increasingly described, especially in non-endemic countries. More information about this topic is required and international consensus in the diagnosis, treatment and follow up of these patients must be established to reduce the morbidity and mortality.

[Consensus document for the detection and management of Chagas disease in primary health care in a non-endemic areas]

Chagas disease is caused by the protozoan Trypanosoma cruzi. Although it is commonly transmitted by an insect vector in continental Latin-America, in recent decades, due migration, has been diagnosed in other countries such Spain, the European country with a largest immigrant population of Latin American. For a long time, the patient remains asymptomatic, but some years after this stage, the symptoms can be serious (dilated cardiomyopathy, megacolon, megaesophagus). In addition, detection in pregnant women has a high priority because of the route of vertical transmission. Several specific guidelines about Chagas disease has been developed on the Banks of blood, maternal hospitals, HIV co-infection, organ transplant. But due to the detection of lack of information to primary care professionals, we consider to will be useful this document written and agreed to by family phisicians, pediatricians and specialists in International Health.

Parasitic infections in travelers and immigrants: part I protozoa

ABSTRACT 

The growth in international commerce, travel and migration contribute to the global emergence of certain parasitic infections. Importation of vectors and food products may contribute to the emergence of protozoan infections in nonendemic countries. Infections such as malaria are potentially fatal, especially in nonimmune patients, and outcome depends largely on timely diagnosis and treatment. Diagnosis/management of imported parasitic infections may be complex especially as some patients may have underlying immunosuppressive conditions such as HIV infection. Major challenges concern the development of improved diagnostic techniques, safer/more effective drug therapies and identification of biological markers of progression and response to treatment. Imported parasitic diseases which may be transmitted vertically or through blood transfusion/organ donation could become a public health priority in the near future. Climate change may affect arthropod distribution and facilitate the spread of protozoan vector-borne diseases. The first part of this review focuses on protozoan infections in travelers and immigrants.

An approach to the management of Trypanosoma cruzi infection (Chagas' disease) in immunocompromised patients

The epidemiology of Chagas disease has changed in the last decades due to migration movements, population ageing and the emergence of new transmission routes. In endemic countries, health facilities and access to healthcare are improving and T. cruzi infected patients are also benefiting from medical advances. The HIV epidemic has spread to both endemic and non-endemic areas for T. cruzi, organ transplant rates have increased recently, especially in Latin America, and other medical conditions affecting the immune system are increasing their global burden. The natural course of Chagas disease is mainly determined by the host's cellular immune response. These conditions may therefore overlap with T. cruzi infection and alter the disease's natural history which may present with atypical clinical forms and a higher associated morbidity and mortality in immunocompromised patients. The present review aims to contribute to the management of immunosuppressed patients with T. cruzi infection.

Immunosuppression and Chagas disease: a management challenge

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

Chagas disease in non-endemic countries: epidemiology, clinical presentation and treatment

Imported Chagas disease (Trypanosoma cruzi infection) is increasingly recognized as an emerging problem in the USA and Europe due to immigration from Latin America. Most migrants from endemic countries will have been infected during childhood. Based on the natural history of the disease, up to 35 % of those infected may develop cardiac and/or gastrointestinal manifestations during the third or fourth decade of life. This disease was described more than 100 years ago, yet many challenges still remain such as the identification of risk factors for visceral involvement, effective treatment for chronic cases, and reliable markers of cure following treatment. Transmission of the infection may occur even in non-endemic areas through non-vectorial routes and many countries are therefore currently facing the challenge of this emerging public health problem.

Mortality Related to Chagas Disease and HIV/AIDS Coinfection in Brazil

Chagas disease in patients with HIV infection represents a potentially serious event with high case fatality rates. This study describes epidemiological and clinical aspects of deaths related to Chagas disease and HIV/AIDS coinfection in Brazil, 1999-2007. We performed a descriptive study based on mortality data from the nationwide Mortality Information System. Of a total of about 9 million deaths, Chagas disease and HIV/AIDS were mentioned in the same death certificate in 74 cases. AIDS was an underlying cause in 77.0% (57) and Chagas disease in 17.6% (13). Males (51.4%), white skin color (50%), age group 40-49 years (29.7%), and residents in the Southeast region (75.7%) were most common. Mean age at death was significantly lower in the coinfected (47.1 years [SD ± 14.6]), as compared to Chagas disease deaths (64.1 years [SD ± 14.7], P < 0.001). Considering the lack of data on morbidity related to Chagas disease and AIDS coinfection, the use of mortality data may be an appropriate sentinel approach to monitor the occurrence of this association. Due to the epidemiological transition in Brazil, chronic Chagas disease and HIV/AIDS coinfection will be further complicated and require the development of evidence-based preventive control measures.