Chagasic cardiomyopathy in immigrants from Latin America to Spain

Genetic Ablation and Pharmacological Blockade of Bradykinin B1 Receptor Unveiled a Detrimental Role for the Kinin System in Chagas Disease Cardiomyopathy

Chagas disease, the parasitic infection caused by Trypanosoma cruzi, afflicts about 6 million people in Latin America. Here, we investigated the hypothesis that T. cruzi may fuel heart parasitism by activating B1R, a G protein-coupled (brady) kinin receptor whose expression is upregulated in inflamed tissues. Studies in WT and B1R^-/- mice showed that T. cruzi DNA levels (15 days post infection-dpi) were sharply reduced in the transgenic heart. FACS analysis revealed that frequencies of proinflammatory neutrophils and monocytes were diminished in B1R^-/- hearts whereas CK-MB activity (60 dpi) was exclusively detected in B1R^+/+ sera. Since chronic myocarditis and heart fibrosis (90 dpi) were markedly attenuated in the transgenic mice, we sought to determine whether a pharmacological blockade of the des-Arg⁹-bradykinin (DABK)/B1R pathway might alleviate chagasic cardiomyopathy. Using C57BL/6 mice acutely infected by a myotropic T. cruzi strain (Colombian), we found that daily treatment (15-60 dpi) with R-954 (B1R antagonist) reduced heart parasitism and blunted cardiac injury. Extending R-954 treatment to the chronic phase (120-160 dpi), we verified that B1R targeting (i) decreased mortality indexes, (ii) mitigated chronic myocarditis, and (iii) ameliorated heart conduction disturbances. Collectively, our study suggests that a pharmacological blockade of the proinflammatory KKS/DABK/B1R pathway is cardioprotective in acute and chronic Chagas disease.

Comparison of the Bacterial Gut Microbiome of North American Triatoma spp. With and Without Trypanosoma cruzi

Chagas disease, caused by the hemoflagellate protist Trypanosoma cruzi, affects nearly 6 million people worldwide, mainly in Latin America. Hematophagous triatomine insects (“kissing bugs”) are the primary vectors of T. cruzi throughout the Americas and feed on a variety of animals, including humans. Control of triatomines is central to the control of T. cruzi infection. Recent advances in mitigation of other insect-borne diseases via the manipulation of insect-associated bacteria as a way to halt or slow disease transmission has opened questions to the applicability of these methods to Chagas disease vectors. Few studies have examined the hindgut microbiome of triatomines found in North America. In the current study, two species of triatomines were collected across Texas, United States, screened for the presence of T. cruzi, and analyzed for the bacterial composition of their hindguts using a 16S rRNA gene-fragment metabarcoding approach. We compared diversity of microbial community profiles across 74 triatomine insects to address the hypothesis that the richness and abundance of bacterial groups differ by T. cruzi infection and strain type, blood meal engorgement status, insect species, sex, and collection location. The gut microbial community of individual triatomines was characterized by low intraindividual taxonomic diversity and high interindividual variation that was weakly predicted by triatomine species, and was not predicted by triatomine sex, collection location, T. cruzi infection status, or blood meal score. However, we did find bacterial groups enriched in T. cruzi-positive individuals, including Enterobacterales, and Petrimonas. Additionally, we detected Salmonella enterica subspecies diarizonae in three triatomine individuals; this species is commonly associated with reptiles and domesticated animals and is a pathogen of humans. These data suggest that Triatoma spp. in Texas have variable patterns of colonized and transient bacteria, and may aid in development of novel means to interfere with transmission of the Chagas disease parasite T. cruzi. Deeper understanding of the effects of parasite infection on diverse insect vector microbiomes may highlight disease transmission risk and facilitate discovery of possible intervention strategies for biological control of this emerging vector-borne disease of global health significance.

Usefulness of the ARCHITECT Chagas® assay as a single test for the diagnosis of chronic Chagas disease

OBJECTIVES

Imported Chagas disease (CD) is an emerging health problem in Europe due to immigration from endemic countries. Although WHO currently recommends two different serological methods to establish diagnosis, new tools like the ARCHITECT Chagas assay have potential for use as a single diagnostic test. Our objective was to determine an optimal signal-to-cut-off (S/CO) value for the ARCHITECT Chagas assay to diagnose CD with a single test.

METHODS

A retrospective study conducted at the 12 de Octubre University Hospital (Madrid, Spain). All patients with requests for Chagas screening between January 2014 and August 2017 were consecutively included. All samples were routinely tested with the ARCHITECT assay. Negative samples (S/CO < 0.8) required no further testing. Immunochromatographic testing (ICT) and/or indirect immunofluorescence (IFI) was used to confirm samples with S/CO ≥ 0.8. Receiver operator characteristic (ROC) curve analysis determined the ARCHITECT S/CO value that yielded 100% specificity and positive predictive value. SPSS software, version 22.0 was used for data analysis.

RESULTS

A total of 4153 samples were analysed; 361 (8.69%) gave a reactive ARCHITECT Chagas result. 261/361 (72.3%) were women; median age was 38 years old (2-79). 92.8% were Bolivian. A total of 307 (85.0%) were confirmed as cases of Chagas; 52 (14.4%) were not infected; two (0.6%) were not evaluable. Seroprevalence was 7.39%. An S/CO ≥ 3.80 yielded 100% specificity (95% confidence interval [CI], 0.93-1.00) and 100% positive predictive value (95% CI, 0.99-1.00).

CONCLUSIONS

Using S/CO ≥ 3.80, the ARCHITECT Chagas could be used as a single test for diagnosis of chronic CD in Bolivian immigrants. Patients with S/CO between 0.80 and 3.80 would require additional testing.

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.

[Estimating demand for anti-Chagas drugs: a contribution for access in Latin America]

OBJECTIVE

Describe a tool to estimate demand for benznidazole and nifurtimox to treat Chagas disease, and report on its implementation in a group of Latin American countries.

METHODS

The project was carried out in the following stages: 1) development of a tool to estimate demand, and definition of the evaluation and decision variables to estimate demand 2) data collection via a questionnaire completed by representatives of control programs, complemented with data from the literature; 3) presentation of the tool, followed by validation, and adaptation by representatives of the control programs in order to plan drug procurement for 2012 and 2013; and 4) further analysis of the obtained data, especially regarding benznidazole, and comparison of country estimates.

RESULTS

Fourteen endemic countries of Latin America took part in the third stage, and a consolidated estimate was made. The number of estimated treatments, based on the number of tablets per treatment established in the regimen of reference was: 867 in the group under 1 year of age; 2 042 835 in the group from 1 to 15 years old; 2 028 in the group from 15 to 20 years old; and 10 248 in adults over 20. This means that it is possible to provide benznidazole to less than 1% of people for whom treatment is indicated.

CONCLUSIONS

The development and systematic use of demand management tools can play a key role in helping to provide access to the anti-Chagas drugs. There is a significant gap between the projected demand for drugs and current estimates of prevalence rates.

Estimación de la demanda de medicamentos antichagásicos: una contribución para el acceso en América Latina

Objetivo.

Describir una herramienta de estimación de la demanda de benznidazol y nifurtimox para la enfermedad de Chagas y relatar su aplicación en un conjunto de países de América Latina.

Métodos.

El proyecto se desarrolló en las siguientes etapas: 1) elaboración de una herramienta y definición de las variables de evaluación y decisión para estimación de la demanda, 2) recolección de datos a partir de un cuestionario a representantes de programas de control, complementado con datos de la literatura, 3) presentación, validación y adaptación de la herramienta por representantes de los programas de control, con la intención de planificar la adquisición de medicamentos para los años de 2012 y 2013, y 4) análisis complementar de los datos obtenidos, en especial benznidazol, y comparación de las estimaciones de los países.

Resultados.

Catorce países endémicos de América Latina participaron de la tercera etapa, con definición de una estimación consolidada. El número de tratamientos estimados a partir del número de comprimidos por tratamiento establecido en el esquema de referencia resultó ser de 867 en menores de un año, 2 042 835 en el grupo de 1 a 15 años, 2 028 en el grupo de 15 a 20 años y de 10 248 en adultos mayores de 20 años. Este cuantitativo representa la posibilidad de tratar menos de 1% de las personas con indicación para tratamiento con benznidazol.

Conclusiones.

El desarrollo y el uso sistemático de herramientas de gestión de la demanda pueden jugar un papel clave en el apoyo al acceso a los medicamentos en la enfermedad de Chagas. Existe una brecha significativa entre las previsiones de demanda de medicamentos y estimaciones actuales de las tasas de prevalencia.

Chagas disease in solid organ and heart transplantation

PURPOSE OF REVIEW

The diagnosis and management of acute and chronic infections with the microorganism Trypanosoma cruzi, which causes Chagas disease, is important in solid organ transplantation in both endemic and nonendemic countries. In this review, we examine recently published data on the topic of Chagas disease in solid organ transplantation, with an emphasis on data relevant to heart transplantation.

RECENT FINDINGS

Most people with chronic T. cruzi infection have the intermediate form of disease, but approximately 2% of infected persons will progress to Chagas cardiomyopathy per year. The risk of T. cruzi transmission with liver or kidney transplantation appears to be substantially less than that with heart transplantation. For patients with Chagas cardiomyopathy undergoing heart transplant, a structured clinical and laboratory monitoring protocol is necessary to monitor for T. cruzi reactivation. Recent data indicate that laboratory monitoring of peripheral blood with polymerase chain reaction testing can identify reactivation prior to the occurrence of symptoms and allograft injury.

SUMMARY

Transplant clinicians should exercise vigilance in surveillance for Chagas disease in both organ donors and recipients. Although Chagas disease may seem uncommon, it is pervasive in endemic and several nonendemic countries, including the United States and Spain.

Ecoepidemiology, short history and control of Chagas disease in the endemic countries and the new challenge for non-endemic countries

Chagas disease is maintained in nature through the interchange of three cycles: the wild, peridomestic and domestic cycles. The wild cycle, which is enzootic, has existed for millions of years maintained between triatomines and wild mammals. Human infection was only detected in mummies from 4,000-9,000 years ago, before the discovery of the disease by Carlos Chagas in 1909. With the beginning of deforestation in the Americas, two-three centuries ago for the expansion of agriculture and livestock rearing, wild mammals, which had been the food source for triatomines, were removed and new food sources started to appear in peridomestic areas: chicken coops, corrals and pigsties. Some accidental human cases could also have occurred prior to the triatomines in peridomestic areas. Thus, triatomines progressively penetrated households and formed the domestic cycle of Chagas disease. A new epidemiological, economic and social problem has been created through the globalisation of Chagas disease, due to legal and illegal migration of individuals infected by Trypanosoma cruzi or presenting Chagas disease in its varied clinical forms, from endemic countries in Latin America to non-endemic countries in North America, Europe, Asia and Oceania, particularly to the United States of America and Spain. The main objective of the present paper was to present a general view of the interchanges between the wild, peridomestic and domestic cycles of the disease, the development of T. cruzi among triatomine, their domiciliation and control initiatives, the characteristics of the disease in countries in the Americas and the problem of migration to non-endemic countries.

Trypanosoma cruzi infection in Elche (Spain): comparison of the seroprevalence in immigrants from Paraguay and Bolivia

Chagas disease is a global public health problem due to the recent emigration of people from Latin America to other regions, including Europe. The aim of this study is to determine the prevalence of Trypanosoma cruzi infection among Paraguayans and Bolivians living in Elche (Spain), a city located in the Mediterranean Coast of Spain. A cross-sectional study was conducted. Capillary blood samples were obtained through a finger prick, and collected on filter paper. An enzyme-linked immunosorbent assay and indirect immunofluorescence tests were performed to search for anti-T. cruzi IgG antibodies in the filter papers. Thirteen out of 201 participants were infected with T. cruzi in this study, seven out of 73 Bolivians and six out of 128 Paraguayans, corresponding to seroprevalences of 9·59% (95%CI, 4·72-18·5%) and 4·69% (95%CI, 2·17-9·85%), respectively. Palpitation, chest pain, and migration from rural endemic areas were the most common clinical and epidemiological risk factors associated with T. cruzi infection detected in the Paraguayan group. This study highlights that Chagas disease is no longer limited to the Bolivian population living in Spain. It is important to note this wider prevalence and, therefore, not discount Paraguayans in the screening for Chagas disease in Spain. Indeed, this should be considered for all immigrants from Latin America.

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.

The receptor Slamf1 on the surface of myeloid lineage cells controls susceptibility to infection by Trypanosoma cruzi

Trypanosoma cruzi, the protozoan parasite responsible for Chagas' disease, causes severe myocarditis often resulting in death. Here, we report that Slamf1-/- mice, which lack the hematopoietic cell surface receptor Slamf1, are completely protected from an acute lethal parasite challenge. Cardiac damage was reduced in Slamf1-/- mice compared to wild type mice, infected with the same doses of parasites, as a result of a decrease of the number of parasites in the heart even the parasitemia was only marginally less. Both in vivo and in vitro experiments reveal that Slamf1-defIcient myeloid cells are impaired in their ability to replicate the parasite and show altered production of cytokines. Importantly, IFN-γ production in the heart of Slamf1 deficient mice was much lower than in the heart of wt mice even though the number of infiltrating dendritic cells, macrophages, CD4 and CD8 T lymphocytes were comparable. Administration of an anti-Slamf1 monoclonal antibody also reduced the number of parasites and IFN-γ in the heart. These observations not only explain the reduced susceptibility to in vivo infection by the parasite, but they also suggest human Slamf1 as a potential target for therapeutic target against T. cruzi infection.

Sensitivity and specificity of an operon immunochromatographic test in serum and whole-blood samples for the diagnosis of Trypanosoma cruzi infection in Spain, an area of nonendemicity

Trypanosoma cruzi infection is an imported parasitic disease in Spain, and the majority of infected individuals are in the chronic phase of the disease. This study evaluated the sensitivity and specificity of the Operon immunochromatographic test (ICT-Operon; Simple Stick Chagas and Simple Chagas WB [whole blood]; Operon S.A., Spain) for different biological samples. Well-characterized serum samples were obtained from chagasic patients (n = 63), nonchagasic individuals (n = 95), visceral leishmaniasis patients (n = 38), and malaria patients (n = 55). Noncharacterized specimens were obtained from Latin American immigrants and individuals at risk with a clinical and/or epidemiological background: these specimens were recovered serum or plasma samples (n = 450), whole peripheral blood (n = 94), and capillary blood (n = 282). The concordance of the results by enzyme-linked immunosorbent assay and indirect immunofluorescence test was considered to be the "gold standard" for diagnosis. Serum and plasma samples were analyzed by Stick Chagas, and whole blood was analyzed by Simple Chagas WB. The sensitivity and specificity of the ICT-Operon in well-characterized samples were 100% and 97.9%, respectively. No cross-reactivity was found with samples obtained from visceral leishmaniasis patients. In contrast, a false-positive result was obtained in 27.3% of samples from malaria patients. The sensitivities of the rapid test in noncharacterized serum or plasma, peripheral blood, and capillary blood samples were 100%, 92.1%, and 86.4%, respectively, while the specificities were 91.6%, 93.6%, and 95% in each case. ICT-Operon showed variable sensitivity, depending on the kind of sample, performing better when serum or plasma samples were used. It could therefore be used for serological screening combined with any other conventional test.

[A clinical and epidemiological study of the Trypanosoma cruzi infected population in the north metropolitan area of Barcelona]

BACKGROUND

As an inevitable consequence of Latin American immigration to Europe, Spain and other European countries, it is necessary to confront the approach to cases of Chagas infection/disease for which, epidemiologically, there are more questions than answers. This study has aimed to describe all the Chagas-infected population in the north metropolitan area of Barcelona (406,000 inhabitants).

PATIENTS AND METHODS

A prospective and multicentric study was performed in 3 hospitals and 1 International Health Unit. It included all patients with Trypanosoma cruzi positive serology, regardless of the requesting reason.Results The 139 diagnosed cases represent an annual incidence of: a) 0.68/10,000 inhabitants and, b) 73.2/10,000 immigrants coming from endemic zones. Of the patients, 80 (57.6%) had alterations in some complementary tests: cardiologic 62 (44.6%), digestive 38 (27.3%) and 20 (14.4%) both. According to the Brazilian Consensus of Chagas cardiomyopathy, they were classified as: 0=84 (60.4%); a=40 (28.7%); b1=4 (2.9%), b2=10 (7.2%) and c/d=1 (0.7%). Treatment with benznidazole (5mg/kg/24h for 60 days) was prescribed in 116 (83.4%) patients, 89 (76.7%) of whom completed it. Secondary effects were recorded in 56 (50.9%), which made it necessary to withdraw it in 21 (19.1%).

CONCLUSIONS

Fewer cases of Chagas infection/disease than expected have been diagnosed in the North Metropolitan area of Barcelona. The series contains a high number of patients and there may be an elevated number of immigrants from endemic zones who have the asymptomatic chronic stages of the infection and who were unaware of their condition.

Lack of association between blood-based detection of Trypanosoma cruzi DNA and cardiac involvement in a non-endemic area

Cases of chronic Chagas disease have been increasing in non-endemic areas due to the growth in immigration. This study examined the association between positive Trypanosoma cruzi-DNA detection in blood by PCR and presence of chagasic cardiac involvement in a cohort of immigrants in a European city. No association was found in this study between the positive T. cruzi blood PCR and cardiac involvement.

Gastro-intestinal Chagas disease in migrants to Spain: prevalence and methods for early diagnosis

Each year in Spain, the number of Latin American immigrants who present with chronic Trypanosoma cruzi infection increases. Although gastro-intestinal abnormalities are not as common as cardiomyopathy in such infection, they can still lead to an impaired quality of life. In a recent study based in Madrid, the frequencies of gastro-intestinal involvement in a cohort of Latin American immigrants infected with T. cruzi, and the role of early diagnostic techniques in the detection of such involvement, were explored. Between January 2003 and April 2009, all Latin Americans who attended the Tropical Medicine Unit of the Hospital Universitario Ramón y Cajal were tested for T. cruzi infection, in IFAT and ELISA. Each subject found both IFAT- and ELISA-positive was considered to be infected (chronically) and checked for symptoms indicative of Chagas disease. Each infected subject giving informed consent was investigated further, using an electrocardiogram, an echocardiogram and oesophageal manometry. Between January 2003 and June 2008, every infected subject who consented was also explored using a barium swallow and barium enema. After July 2008, however, only subjects showing oesophageal and/or colonic symptoms were investigated in this manner. Of the 248 patients found infected with T. cruzi, 118 underwent oesophageal manometry, 75 a barium enema and 48 a barium swallow. Thirteen (11%) showed evidence of oesophageal involvement (incomplete relaxation of the lower oesophageal sphincter; three cases) or bowel involvement (five cases of dolichosigma, three of dolichocolon and two of megacolon). Only six of these 13 had any gastro-intestinal symptoms (all six were suffering from constipation). None of the barium swallows revealed any pathology. It appears that oesophageal manometry can reveal mild abnormalities not detected by barium swallow, even in asymptomatic patients, while barium enemas are useful in the detection of colonic involvement.

Mapping of Chagas disease research: analysis of publications in the period between 1940 and 2009

INTRODUCTION

Publications are often used as a measure of success in research work. Chagas disease occurs in Central and Southern America. However, during the past years, the disease has been occurring outside Latin America due to migration from endemic zones. This article describes a bibliometric review of the literature on Chagas disease research indexed in PubMed during a 70-year period.

METHODS

Medline was used via the PubMed online service of the U.S. National Library of Medicine from 1940 to 2009. The search strategy was: Chagas disease [MeSH] OR Trypanosoma cruzi [MeSH].

RESULTS

A total of 13,989 references were retrieved. The number of publications increased steadily over time from 1,361 (1940-1969) to 5,430 (2000-2009) (coefficient of determination for linear fit, R²=0.910). Eight journals contained 25% of the Chagas disease literature. Of the publications, 64.2% came from endemic countries. Brazil was the predominant country (37%), followed by the United States (17.6%) and Argentina (14%). The ranking in production changed when the number of publications was normalized by estimated cases of Chagas disease (Panama and Uruguay), population (Argentina and Uruguay), and gross domestic product (Bolivia and Brazil).

CONCLUSIONS

Several Latin American countries, where the prevalence of T. cruzi infection was not very high, were the main producers of the Chagas disease literature, after adjusting for economic and population indexes. The countries with more estimated cases of Chagas disease produced less research on Chagas disease than some developed countries.

Neglected tropical diseases outside the tropics

Background

The neglected tropical diseases (NTDs) cause significant morbidity and mortality worldwide. Due to the growth in international travel and immigration, NTDs may be diagnosed in countries of the western world, but there has been no specific focus in the literature on imported NTDs.

Methods

Retrospective study of a cohort of immigrants and travelers diagnosed with one of the 13 core NTDs at a Tropical Medicine Referral Unit in Spain during the period April 1989-December 2007. Area of origin or travel was recorded and analyzed.

Results

There were 6168 patients (2634 immigrants, 3277 travelers and 257 VFR travelers) in the cohort. NTDs occurred more frequently in immigrants, followed by VFR travelers and then by other travelers (p<0.001 for trend). The main NTDs diagnosed in immigrants were onchocerciasis (n = 240, 9.1%) acquired mainly in sub-Saharan Africa, Chagas disease (n = 95, 3.6%) in immigrants from South America, and ascariasis (n = 86, 3.3%) found mainly in immigrants from sub-Saharan Africa. Most frequent NTDs in travelers were: schistosomiasis (n = 43, 1.3%), onchocerciasis (n = 17, 0.5%) and ascariasis (n = 16, 0.5%), and all were mainly acquired in sub-Saharan Africa. The main NTDs diagnosed in VFR travelers were onchocerciasis (n = 14, 5.4%), and schistosomiasis (n = 2, 0.8%).

Conclusions

The concept of imported NTDs is emerging as these infections acquire a more public profile. Specific issues such as the possibility of non-vectorial transmission outside endemic areas and how some eradication programmes in endemic countries may have an impact even in non-tropical western countries are addressed. Recognising NTDs even outside tropical settings would allow specific prevention and control measures to be implemented and may create unique opportunities for research in future.

Neglected Tropical Diseases (NTDs) have been targeted due to their prevalence and the burden of disease they cause globally, but there has been no significant focus in the literature on the subject of NTDs as a group in immigrants and travelers, and no specific studies on the emerging phenomenon of imported NTDs. We present the experience of a Tropical Medicine Unit in a major European city, over a 19-year period, describing and comparing NTDs diagnosed amongst immigrants, travelers and travelers visiting friends and relatives (VFRs). NTDs were diagnosed outside tropical areas and occurred more frequently in immigrants, followed by VFR travelers and then by other travelers. The main NTDs diagnosed in immigrants were onchocerciasis, Chagas disease and ascariasis; most frequent NTDs in travelers were schistosomiasis, onchocerciasis and ascariasis, and onchocerciasis and schistosomiasis in VFRs. Issues focusing on modes of transmission outside endemic areas and how eradication programs for some NTDs in endemic countries may have an impact in non-tropical Western countries by decreasing disease burden in immigrants, are addressed. Adherence to basic precautions such as safe consumption of food/water and protection against arthropod bites could help prevent many NTDs in travelers.

Chagas disease: a Latin American health problem becoming a world health problem

Political repression and/or economic stagnation stimulated the flow of migration from the 17 Latin American countries endemic for Chagas disease to developed countries. Because of this migration, Chagas disease, an autochthonous disease of the Continental Western Hemisphere is becoming a global health problem. In 2006, 3.8% of the 80,522 immigrants from those 17 countries to Australia were likely infected with Trypanosoma cruzi. In Canada in 2006, 3.5% of the 156,960 immigrants from Latin America whose country of origin was identified were estimated to have been infected. In Japan in 2007, there were 80,912 immigrants from Brazil, 15,281 from Peru, and 19,413 from other South American countries whose country of origin was not identified, a portion of whom may have been also infected. In 15 countries of Europe in 2005, excluding Spain, 2.9% of the 483,074 legal Latin American immigrants were estimated to be infected with T. cruzi. By 2008, Spain had received 1,678,711 immigrants from Latin American endemic countries; of these, 5.2% were potentially infected with T. cruzi and 17,390 may develop Chagas disease. Further, it was estimated that 24-92 newborns delivered by South American T. cruzi infected mothers in Spain may have been congenitally infected with T. cruzi in 2007. In the USA we estimated that 1.9% of approximately 13 million Latin American immigrants in 2000, and 2% of 17 million in 2007, were potentially infected with T. cruzi. Of these, 49,157 and 65,133 in 2000 and 2007 respectively, may have or may develop symptoms and signs of chronic Chagas disease. Governments should implement policies to prevent donations of blood and organs from T. cruzi infected donors. In addition, an infrastructure that assures detection and treatment of acute and chronic cases as well as congenital infection should be developed.

Validation of a rapid immunochromatographic assay for diagnosis of Trypanosoma cruzi infection among Latin-American Migrants in Geneva, Switzerland

Chagas' disease is a global public health problem due to the recent exchange of population between Latin America and other regions, including Europe. The recent development of rapid diagnostic tests (RDTs) for Trypanosoma cruzi infection may improve patient access to diagnosis and care worldwide. We evaluated the diagnostic accuracy of the Chagas Stat-Pak RDT in a cohort of undocumented Latin-American migrants living in Geneva, Switzerland. Study participants were enrolled in a primary health care center. The Chagas Stat-Pak test was performed independently on blood and serum samples. A combination of two commercialized enzyme-linked immunosorbent assay (ELISA)-based serological tests was used for comparison (reference standard). A total of 999 adults (median age, 36 years) were included in the study; the majority were women (83%) and originally from Bolivia (47%) or Brazil (25%). A total of 125 participants (12.5%) were diagnosed with T. cruzi infection; with the exception of three individuals, all individuals diagnosed with T. cruzi were originally from Bolivia. The sensitivity and specificity of the Chagas Stat-Pak test on blood samples were 95.2% (95% confidence interval [95% CI], 89.2% to 97.9%) and 99.9% (95% CI, 99.3% to 100%), respectively. When the test was performed on serum samples, the sensitivity was 96% (95% CI, 91% to 98.3%), and the specificity was 99.8% (95% CI, 99.2% to 99.9%). The concordance of test results for blood and serum samples was 99.7%. Both negative and positive predictive values were above 98%. The Chagas Stat-Pak is an accurate diagnostic test for T. cruzi infection among Latin-American migrants living in Europe. The mild deficit in sensitivity should be interpreted in light of its ease of use and capacity to provide immediate results, which allow more people at risk to have access to diagnosis and care both in countries where Chagas' disease is endemic and in countries where this disease is not endemic.

Imported infectious diseases in mobile populations, Spain

Health screening of immigrant populations is needed to ensure early diagnosis and treatment.

Migration has contributed to the emergence of certain infectious diseases. To determine which infectious diseases were most common among 2 mobile immigrant groups (sub-Saharan Africans and Latin Americans) in Spain, we analyzed health and demographic characteristics of 2,198 immigrants referred to the Tropical Medicine Unit of Ramón y Cajal Hospital over a 20-year period. The most frequent diagnoses were for latent tuberculosis (716 patients [32.6%]), filariasis (421 [19.2%]), hepatropic virus chronic infection (262 [19.2%]), intestinal parasites (242 [11.0%]), and malaria (212 [9.6%]). Health screening of immigrant populations is needed to ensure early diagnosis and treatment of potentially transmissible infections.

Prevalence, clinical staging and risk for blood-borne transmission of Chagas disease among Latin American migrants in Geneva, Switzerland

Background

Migration of Latin Americans to the USA, Canada and Europe has modified Chagas disease distribution, but data on imported cases and on risks of local transmission remain scarce. We assessed the prevalence and risk factors for Chagas disease, staged the disease and evaluated attitudes towards blood transfusion and organ transplant among Latin American migrants in Geneva, Switzerland.

Methodology/Principal Findings

This cross-sectional study included all consecutive Latin American migrants seeking medical care at a primary care facility or attending two Latino churches. After completing a questionnaire, they were screened for Chagas disease with two serological tests (Biomérieux ELISA cruzi; Biokit Bioelisa Chagas). Infected subjects underwent a complete medical work-up. Predictive factors for infection were assessed by univariate and multivariate logistic regression analysis.1012 persons (females: 83%; mean age: 37.2 [SD 11.3] years, Bolivians: 48% [n = 485]) were recruited. 96% had no residency permit. Chagas disease was diagnosed with two positive serological tests in 130 patients (12.8%; 95%CI 10.8%–14.9%), including 127 Bolivians (26.2%; 95%CI 22.3%–30.1%). All patients were in the chronic phase, including 11.3% with cardiac and 0.8% with digestive complications. Predictive factors for infection were Bolivian origin (OR 33.2; 95%CI 7.5–147.5), reported maternal infection with T. cruzi (OR 6.9; 95%CI 1.9–24.3), and age older than 35 years (OR 6.7; 95%CI 2.4–18.8). While 22 (16.9%) infected subjects had already donated blood, 24 (18.5%) and 34 (26.2%) considered donating blood and organs outside Latin America, respectively.

Conclusions

Chagas disease is highly prevalent among Bolivian migrants in Switzerland. Chronic cardiac and digestive complications were substantial. Screening of individuals at risk should be implemented in nonendemic countries and must include undocumented migrants.

Chagas disease, a parasitic disease caused by Trypanosoma cruzi, is a leading cause of cardiac and digestive tract disorders in Mexico, Central and South America. An increasing number of cases have recently been reported in North America and Europe due to international human migration, but data outside Latin America remains scarce. This study showed that Chagas disease is an emerging health problem in Switzerland, affecting a substantial proportion of Latin American migrants (13%). Persons at increased risk of infection were Bolivian, older than 35 years or had a mother infected with T. cruzi. Early signs of cardiac or digestive tract disease were found in one out of six infected patients. The risk of local transmission by blood transfusion or organ transplant was illustrated by the frequent willingness expressed by patients to donate blood or organs in Switzerland. The authors recommend the screening of persons at risk of infection and the diffusion of appropriate information to the medical community to increase awareness of this emerging health problem. Considering that affected persons frequently lack health insurance in Switzerland, a facilitated access to medical care is an important step towards better recognition and management of Chagas disease.

Use of benznidazole to treat chronic Chagas' disease: a systematic review with a meta-analysis

BACKGROUND AND OBJECTIVES

The recent significant increase in the number of immigrants entering the European Union from South and Central America means that chronic Chagas' disease is an increasingly frequent diagnosis among immigrants in Europe. Our objectives were to evaluate published evidence on the treatment of chronic Chagas' disease with benznidazole and on the potential benefits of this drug in the chronic phase of the disease.

METHODS

We performed a systematic review and meta-analysis by means of an electronic search of the published literature, with no language restrictions, until October 2008. We included studies on chronically infected patients of any age who were in the indeterminate phase or had visceral involvement and for whom treatment with benznidazole was compared with placebo or no treatment. The primary endpoint was response to therapy (whether serological, parasitological or clinical), as it was measured in each of the studies included. Clinical response to therapy was also analysed.

RESULTS

We identified 696 studies, from which we chose 9: 3 clinical trials and 6 observational studies. Compared with placebo or no treatment, benznidazole increases 18-fold the probability of a response to therapy [global odds ratio (OR), 18.8; 95% confidence interval (CI), 5.2-68.3]. This effect was mainly observed in clinical trials (OR, 70.8; 95% CI, 16-314), whereas in observational studies it was much less marked (OR, 7.8; 95% CI, 2.1-28.9), and even less so when only observational studies in adults were considered (OR, 6.3; 95% CI, 1.6-24.7). Patients treated with benznidazole had a significantly lower risk of clinical events (OR, 0.29; 95% CI, 0.16-0.53). Up to 18% of patients discontinued treatment due to toxicity (cutaneous reactions followed by gastrointestinal disturbances); this was less common in children than in adults.

CONCLUSIONS

Analysis of available information reveals that the efficacy of treatment in late chronic infection is doubtful. Although data generally point to a beneficial effect, this could be marginal. This uncertainty is largely the result of differences in the study populations, endpoints and follow-up periods, and the fact that almost all of the information on treatment in the late chronic phase comes from non-randomized studies.