Copaifera spp. oleoresins control Trypanosoma cruzi infection in human trophoblast cells (BeWo) and placental explants

Congenital Chagas disease (CCD) is a worldwide neglected problem with significant treatment limitations. This study aimed to evaluate the potential of Copaifera spp. oleoresins (ORs) against Trypanosoma cruzi infection in trophoblast cells (BeWo lineage) and human chorionic villous explants (HCVE). The cytotoxicity of ORs was investigated using LDH and MTT assays. T. cruzi (Y strain) proliferation, invasion and reversibility were assessed in OR-treated BeWo cells, and proliferation was evaluated in OR-treated HCVE. The ultrastructure of T. cruzi trypomastigotes and amastigotes treated with ORs were analyzed by scanning and transmission electronic microscopy. ROS production in infected and treated BeWo cells and cytokines in BeWo and HCVE were measured. The ORs irreversibly decreased T. cruzi invasion, proliferation and release in BeWo cells by up to 70 %, 82 % and 80 %, respectively, and reduced parasite load in HCVE by up to 80 %. Significant structural changes in treated parasites were observed. ORs showed antioxidant capacity in BeWo cells, reducing ROS production induced by T. cruzi infection. Also, T. cruzi infection modulated the cytokine profile in both BeWo cells and HCVE; however, treatment with ORs upregulated cytokines decreased by T. cruzi infection in BeWo cells, while downregulated cytokines increased by the T. cruzi infection in HCVE. In conclusion, non-cytotoxic concentrations of Copaifera ORs demonstrated promising potential for controlling T. cruzi infection in models of the human maternal-fetal interface.

Prevention of congenital chagas disease by trypanocide treatment in women of reproductive age: A meta-analysis of observational studies

BACKGROUND

Maternal-foetal transmission of Chagas disease (CD) affects newborns worldwide. Although Benznidazole and Nifurtimox therapies are the standard treatments, their use during pregnancy is contra-indicated. The effectiveness of trypanocidal medications in preventing congenital Chagas Disease (cCD) in the offsprings of women diagnosed with CD was highly suggested by other studies.

METHODS

We performed a systematic review and meta-analysis of studies evaluating the effectiveness of treatment for CD in women of childbearing age and reporting frequencies of cCD in their children. PubMed, Scopus, Web of Science, Cochrane Library, and LILACS databases were systematically searched. Statistical analysis was performed using Rstudio 4.2 using DerSimonian and Laird random-effects models. Heterogeneity was examined with the Cochran Q test and I2 statistics. A p-value of <0.05 was considered statistically significant.

RESULTS

Six studies were included, comprising 744 children, of whom 286 (38.4%) were born from women previously treated with Benznidazole or Nifurtimox, trypanocidal agents. The primary outcome of the proportion of children who were seropositive for cCD, confirmed by serology, was signigicantly lower among women who were previously treated with no congenital transmission registered (OR 0.05; 95% Cl 0.01-0.27; p = 0.000432; I2 = 0%). In women previously treated with trypanocidal drugs, the pooled prevalence of cCD was 0.0% (95% Cl 0-0.91%; I2 = 0%), our meta-analysis confirms the excellent effectiveness of this treatment. The prevalence of adverse events in women previously treated with antitrypanocidal therapies was 14.01% (95% CI 1.87-26.14%; I2 = 80%), Benznidazole had a higher incidence of side effects than Nifurtimox (76% vs 24%).

CONCLUSION

The use of trypanocidal therapy in women at reproductive age with CD is an effective strategy for the prevention of cCD, with a complete elimination of congenital transmission of Trypanosoma cruzi in treated vs untreated infected women.

Novel 3D human trophoblast culture to explore T. cruzi infection in the placenta

Introduction

Human trophoblastic cell lines, such as BeWo, are commonly used in 2D models to study placental Trypanosoma cruzi infections. However, these models do not accurately represent natural infections. Three-dimensional (3D) microtissue cultures offer a more physiologically relevant in vitro model, mimicking tissue microarchitecture and providing an environment closer to natural infections. These 3D cultures exhibit functions such as cell proliferation, differentiation, morphogenesis, and gene expression that resemble in vivo conditions.

Methods

We developed a 3D culture model using the human trophoblastic cell line BeWo and nonadherent agarose molds from the MicroTissues® 3D Petri Dish® system. Both small (12-256) and large (12-81) models were tested with varying initial cell numbers. We measured the diameter of the 3D cultures and evaluated cell viability using Trypan Blue dye. Trophoblast functionality was assessed by measuring β-hCG production via ELISA. Cell fusion was evaluated using confocal microscopy, with Phalloidin or ZO-1 marking cell edges and DAPI staining nuclei. T. cruzi infection was assessed by microscopy and quantitative PCR, targeting the EF1-α gene for T. cruzi and GAPDH for BeWo cells, using three parasite strains: VD (isolated from a congenital Chagas disease infant and classified as Tc VI), and K98 and Pan4 (unrelated to congenital infection and classified as Tc I).

Results

Seeding 1000 BeWo cells per microwell in the large model resulted in comparable cellular viability to 2D cultures, with a theoretical diameter of 408.68 ± 12.65 μm observed at 5 days. Functionality, assessed through β-hCG production, exceeded levels in 2D cultures at both 3 and 5 days. T. cruzi infection was confirmed by qPCR and microscopy, showing parasite presence inside the cells for all three tested strains. The distribution and progression of the infection varied with each strain.

Discussion

This innovative 3D model offers a simple yet effective approach for generating viable and functional cultures susceptible to T. cruzi infection, presenting significant potential for studying the placental microenvironment.

Trypanosoma cruzi Isolates Naturally Adapted to Congenital Transmission Display a Unique Strategy of Transplacental Passage

Chagas disease is mainly transmitted by vertical transmission (VT) in nonendemic areas and in endemic areas where vector control programs have been successful. For the present study, we isolated natural Trypanosoma cruzi strains vertically transmitted through three generations and proceeded to study their molecular mechanism of VT using mice. No parasitemia was detected in immunocompetent mice, but the parasites were able to induce an immune response and colonize different organs. VT experiments revealed that infection with different strains did not affect mating, pregnancy, or resorption, but despite low parasitemia, VT strains reached the placenta and resulted in higher vertical transmission rates than strains of either moderate or high virulence. While the virulent strain modulated more than 2,500 placental genes, VT strains modulated 150, and only 29 genes are shared between them. VT strains downregulated genes associated with cell division and replication and upregulated immunomodulatory genes, leading to anti-inflammatory responses and tolerance. The virulent strain stimulated a strong proinflammatory immune response, and this molecular footprint correlated with histopathological analyses. We describe a unique placental response regarding the passage of T. cruzi VT isolates across the maternal-fetal interphase, challenging the current knowledge derived mainly from studies of laboratory-adapted or highly virulent strains. IMPORTANCE The main findings of this study are that we determined that there are Trypanosoma cruzi strains adapted to transplacental transmission and completely different from the commonly used laboratory reference strains. This implies a specific strategy for the vertical transmission of Chagas disease. It is impressive that the strains specialized for vertical transmission modify the gene expression of the placenta in a totally different way than the reference strains. In addition, we describe isolates of T. cruzi that cannot be transmitted transplacentally. Taken together, these results open up new insights into the molecular mechanisms of this insect vector-independent transmission form.

Chagas disease in Oklahoma

Chagas disease, caused by infection with the protozoan Trypanosoma cruzi, is one of the leading public health problems in the Western Hemisphere. The parasite is mainly transmitted by contact with infected insect vectors but other forms of transmission are important in endemic areas. In the United States, while the disease is largely restricted to immigrants from endemic countries in Latin America, there is some risk of local acquisition. T. cruzi circulates in a sylvatic cycle between mammals and local triatomine insects in the southern half of the country, where human residents may be at risk for incidental infection. There are several reported cases of locally-acquired Chagas disease in the United States, but there is a paucity of information in Oklahoma. We present a brief summary of the available data of Chagas disease in Oklahoma to raise awareness and serve as a foundation for future research.

Estimation of the morbidity and mortality of congenital Chagas disease: A systematic review and meta-analysis

Chagas disease is caused by the parasite Trypanosoma cruzi which can be transmitted from mother to baby during pregnancy. There is no consensus on the proportion of infected infants with clinical signs of congenital Chagas disease (cCD). The objective of this systematic review is to determine the burden of cCD. Articles from journal inception to 2020 reporting morbidity and mortality associated with cCD were retrieved from academic search databases. Observational studies, randomized-control trials, and studies of babies diagnosed with cCD were included. Studies were excluded if they were case reports or series, without original data, case-control without cCD incidence estimates, and/or did not report number of participants. Two reviewers screened articles for inclusion. To determine pooled proportion of infants with cCD with clinical signs, individual clinical signs, and case-fatality, random effects meta-analysis was performed. We identified 4,531 records and reviewed 4,301, including 47 articles in the narrative summary and analysis. Twenty-eight percent of cCD infants showed clinical signs (95% confidence interval (CI) = 19.0%, 38.5%) and 2.2% of infants died (95% CI = 1.3%, 3.5%). The proportion of infected infants with hepatosplenomegaly was 12.5%, preterm birth 6.0%, low birth weight 5.8%, anemia 4.9%, and jaundice 4.7%. Although most studies did not include a comparison group of non-infected infants, the proportion of infants with cCD with clinical signs at birth are comparable to those with congenital toxoplasmosis (10.0%-30.0%) and congenital cytomegalovirus (10.0%-15.0%). We conclude that cCD burden appears significant, but more studies comparing infected mother-infant dyads to non-infected ones are needed to determine an association of this burden to cCD.

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.

Trypanosoma cruzi seroprevalence and associated factors in women in Casanare-Colombia

Chagas disease is caused by the parasite Trypanosoma cruzi and transmitted mainly by triatomines and from mothers to children. In Colombia, this disease is a public health problem and due to its high endemicity and vertical transmission, women are susceptible populations that must be evaluated. Our objective was to determinate the Trypanosoma cruzi seroprevalence and factors associated with women in Pore (Municipality), Casanare, Colombia. Cross-sectional study. A sample of 230 healthy volunteer women, 15 years or older, without previous diagnosis of Chagas disease was taken; the serological analysis was done using the Chagas ELISA IgG and IgM and indirect Hemagglutination (HAI) technique. In addition, a survey was applied to each participant in order to explore the presence of factors that could be associated with a positive test result. The seropostitivity found in Pore Casanare's women was 16.9% (39/230, 95% CI 12.1-21.7), additionally it was found that rural origin, the coexistence with animals, especially chickens, age, low level schooling and housing material are factors associated with T. cruzi infection in this population. The results of this study indicate the importance of conducting extensive seroepidemiological studies in populations of endemic areas, due to the difficulty in detecting cases in the acute phase; therefore, screening allows the establishment of a follow-up and treatment time line that contributes to the interruption of the transmission vertical.

Epidemiology of congenital Chagas disease 6 years after implementation of a public health surveillance system, Catalonia, 2010 to 2015

Background

Chagas disease is endemic in Latin America and affects 8 million people worldwide. In 2010, Catalonia introduced systematic public health surveillance to detect and treat congenital Chagas disease.

Aim

The objective was to evaluate the health outcomes of the congenital Chagas disease screening programme during the first 6 years (2010–2015) after its introduction in Catalonia.

Methods

In a surveillance system, we screened pregnant women and newborns and other children of positive mothers, and treated Chagas-positive newborns and children. Diagnosis was confirmed for pregnant women and children with two positive serological tests and for newborns with microhaematocrit and/or PCR at birth or serology at age 9 months.

Results

From 2010 to 2015, the estimated screening coverage rate increased from 68.4% to 88.6%. In this period, 33,469 pregnant women were tested for Trypanosoma cruzi and 937 positive cases were diagnosed. The overall prevalence was 2.8 cases per 100 pregnancies per year (15.8 in Bolivian women). We followed 82.8% of newborns until serological testing at age 9–12 months and 28 were diagnosed with Chagas disease (congenital transmission rate: 4.17%). Of 518 siblings, 178 (34.3%) were tested and 14 (7.8%) were positive for T. cruzi. Having other children with Chagas disease and the heart clinical form of Chagas disease were maternal risk factors associated with congenital T. cruzi infection (p < 0.05).

Conclusion

The increased screening coverage rate indicates consolidation of the programme in Catalonia. The rate of Chagas disease congenital transmission in Catalonia is in accordance with the range in non-endemic countries.

Seroprevalence of Trypanosoma cruzi Infection in Pregnant Women Suggests a High Risk for Congenital Transmission in Central Veracruz, Mexico

PURPOSE

The state of Veracruz, Mexico, is a well-recognized endemic region for Chagas disease, but congenital transmission has not been extensively studied. We estimated here the prevalence and the risk of congenital transmission of Trypanosoma cruzi in pregnant women from 27 municipalities of central Veracruz.

METHODS

528 sera from pregnant women were analyzed by ELISA and IFA assays for the detection of IgG antibodies against T. cruzi.

RESULTS

The presence of anti-T. cruzi antibodies was identified in women from 17 municipalities, obtaining an overall seroprevalence of 17.0%. A higher seropositivity was observed in the municipalities of Orizaba (25.2%), Nogales (13.6%), and Río Blanco (10.5%). The results suggest that there is a high risk of congenital transmission of T. cruzi in the region.

CONCLUSION

There are currently limited actions for the surveillance and control of congenital transmission of Chagas disease in Veracruz.

Epidemiology and pathogenesis of maternal-fetal transmission of Trypanosoma cruzi and a case for vaccine development against congenital Chagas disease

Trypanos o ma cruzi (T. cruzi or Tc) is the causative agent of Chagas disease (CD). It is common for patients to suffer from non-specific symptoms or be clinically asymptomatic with acute and chronic conditions acquired through various routes of transmission. The expecting women and their fetuses are vulnerable to congenital transmission of Tc. Pregnant women face formidable health challenges because the frontline antiparasitic drugs, benznidazole and nifurtimox, are contraindicated during pregnancy. However, it is worthwhile to highlight that newborns can be cured if they are diagnosed and given treatment in a timely manner. In this review, we discuss the pathogenesis of maternal-fetal transmission of Tc and provide a justification for the investment in the development of vaccines against congenital CD.

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.

Trypomastigote Excretory Secretory Antigen Blot Is Associated With Trypanosoma cruzi Load and Detects Congenital T. cruzi Infection in Neonates, Using Anti-Shed Acute Phase Antigen Immunoglobulin M

Background

Congenital Trypanosoma cruzi infection accounts for an estimated 22% of new cases of Chagas disease in Latin America. However, neonatal diagnosis is challenging, as 9-month follow-up for immunoglobulin G testing is poor, quantitative polymerase chain reaction (qPCR) analysis is not routinely performed, and the micromethod misses ≥40% of congenital infections.

Methods

Biorepository samples from new mothers and their infants from Piura, Peru, (an area of nonendemicity), and Santa Cruz, Bolivia (an area of endemicity) were accessed. Infant specimens were assessed using the micromethod, qPCR analysis, and a trypomastigote excretory secretory antigen (TESA) blot for detection of immunoglobulin M (IgM)-specific shed acute phase antigen (SAPA) bands, using qPCR as the gold standard.

Results

When compared to qPCR, IgM TESA blot was both sensitive and specific for congenital Chagas disease diagnosis. Cumulative sensitivity (whether only 4 bands or all 6 bands were present) was 80% (95% confidence interval [CI], 59%-92%). Specificity was 94% (95% CI, 92%-96%) in the area of endemicity and 100% in the area of nonendemicity. SAPA bands occurred sequentially and in pairs, and parasite loads correlated highly with the number of SAPA bands present. The micromethod detected infection in fewer than half of infected infants.

Conclusions

The IgM TESA blot for detection of SAPA bands is rapid, relatively inexpensive, and more sensitive than the micromethod and may be a useful point-of-care test for detection of congenital T. cruzi infection.

Evaluation and Management of Congenital Chagas Disease in the United States

Chagas disease is underappreciated as a health concern in the United States. Approximately 40 000 women of childbearing age living in the United States have chronic Chagas disease. Most of them are unaware that they have an infection that is transmissible to their offspring. The estimated US maternal-to-infant transmission rate of Trypanosoma cruzi is 1% to 5%. Ten percent to 40% of neonates with congenital T cruzi infection have clinical signs consistent with a congenital infection but no findings are unique to Chagas disease. If left untreated, 20% to 40% of infants with Chagas disease will later develop potentially fatal cardiac manifestations. Molecular testing can confirm the diagnosis in neonates. Treatment is well tolerated in infancy and usually results in cure. Screening of at-risk women during pregnancy can identify maternal infection and allow early assessment and treatment for congenital T cruzi infection.

Evolution of incidence and geographical distribution of Chagas disease in Mexico during a decade (2007-2016)

Chagas disease, whose aetiological agent is the protozoan Trypanosoma cruzi, mainly occurs in Latin America. In order to know the epidemiology and the geographical distribution of this disease in Mexico, the present work analyses the national surveillance data (10 years) for Chagas disease issued by the General Directorate of Epidemiology (GDE). An ecological analysis of Chagas disease (2007–2016) was performed in the annual reports issued by the GDE in Mexico. The cases and incidence were classified by year, state, age group, gender and seasons. A national distribution map showing Chagas disease incidence was generated. An increase of new cases was identified throughout the country (rates from 0.37 to 0.81 per 100 000 inhabitants). Of the total cases accumulated (7388), the major cases were attributed to the states of Veracruz, Chiapas, Quintana Roo, Oaxaca, Morelos and Yucatán. The analysis per age groups and gender revealed that, in most age groups, the incidence was higher in the male population. The most number of cases was identified in spring and summer; a direct relationship between the environmental temperature increase and the number of new cases was identified. The analysis showed that the rate of Chagas disease increased presumably due to state programmes; the search for new cases has expanded and we speculate that the disease is associated with occupational activities. These results summarise and recall how important it is to implement the monitoring of Chagas disease mainly in south states of the Mexican Republic in order to implement strategies to control this disease.

Dynamics of T Cells Repertoire During Trypanosoma cruzi Infection and its Post-Treatment Modulation

Chagas disease courses with different clinical phases and has a variable clinical presentation and progression. The acute infection phase mostly exhibits a non-specific symptomatology. In the absence of treatment, the acute phase is followed by a chronic phase, which is initially asymptomatic. This chronic asymptomatic phase of the disease is characterized by a fragile balance between the host's immune response and the parasite replication. The loss of this balance is crucial for the progression of the sickness. The virulence and tropism of the T. cruzi infecting strain together to the inflammation processes in the cardiac tissue are the main factors for the establishment and severity of the cardiomyopathy. The efficacy of treatment in chronic Chagas disease patients is controversial. However, several studies carried out in chronic patients demonstrated that antiparasitic treatment reduces parasite load in the bloodstream and leads to an improvement in the immune response against the Trypanosoma cruzi parasite. The present review is mainly focused on the cellular patterns associated to the clinical status and the evolution of the disease in chronic patients, as well as the effectiveness of the treatment related to T. cruzi infection control. Therefore, an emphasis is placed on the dynamics of specific-antigens T cell subpopulations, their memory and activation phenotypes, their functionality and their contribution to pathogenesis or disease control, as well as their association with risk of congenital transmission of the parasite.

Toward Improving Early Diagnosis of Congenital Chagas Disease in an Endemic Setting

Background

Congenital Trypanosoma cruzi transmission is now estimated to account for 22% of new infections, representing a significant public health problem across Latin America and internationally. Treatment during infancy is highly efficacious and well tolerated, but current assays for early detection fail to detect >50% of infected neonates, and 9-month follow-up is low.

Methods

Women who presented for delivery at 2 urban hospitals in Santa Cruz Department, Bolivia, were screened by rapid test. Specimens from infants of infected women were tested by microscopy (micromethod), quantitative PCR (qPCR), and immunoglobulin (Ig)M trypomastigote excreted-secreted antigen (TESA)-blots at birth and 1 month and by IgG serology at 6 and 9 months.

Results

Among 487 infants of 476 seropositive women, congenital T. cruzi infection was detected in 38 infants of 35 mothers (7.8%). In cord blood, qPCR, TESA-blot, and micromethod sensitivities/specificities were 68.6%/99.1%, 58.3%/99.1%, and 16.7%/100%, respectively. When birth and 1-month results were combined, cumulative sensitivities reached 84.2%, 73.7%, and 34.2%, respectively. Low birthweight and/or respiratory distress were reported in 11 (29%) infected infants. Infants with clinical signs had higher parasite loads and were significantly more likely to be detected by micromethod.

Conclusions

The proportion of T. cruzi-infected infants with clinical signs has fallen since the 1990s, but symptomatic congenital Chagas disease still represents a significant, albeit challenging to detect, public health problem. Molecular methods could facilitate earlier diagnosis and circumvent loss to follow-up but remain logistically and economically prohibitive for routine screening in resource-limited settings.

Survey of Pediatric Infectious Diseases Society Members About Congenital Chagas Disease

Participants in a survey about congenital Chagas disease, distributed electronically to Pediatric Infectious Diseases Society members, perceived having limited knowledge about congenital Trypanosoma cruzi infection. Most rarely or never consider the diagnosis in infants born to parents from Latin America. Improved awareness of congenital Chagas disease and assessment of at-risk infants is needed.

Towards a New Strategy for Diagnosis of Congenital Trypanosoma cruzi Infection

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

Interdisciplinary approach at the primary healthcare level for Bolivian immigrants with Chagas disease in the city of São Paulo

Background/Methods

In a pioneering cross-sectional study among Bolivian immigrants in the city of São Paulo, Brazil, the epidemiological profile, clinical manifestations and morbidity of Chagas disease were described. The feasibility of the management of Chagas disease at primary healthcare clinics using a biomedical and psychosocial interdisciplinary approach was also tested. Previously, a Trypanosoma cruzi (T. cruzi) infection rate of 4.4% among 633 immigrants was reported. The samples were screened using two commercial enzyme-linked immunoassay (ELISA) tests generated with epimastigote antigens, and those with discrepant or seropositive results were analyzed by confirmatory tests: indirect immunofluorescence (IFI), TESA-blot and a commercial recombinant ELISA. PCR and blood cultures were performed in seropositive patients.

Results

The majority of the 28 seropositive patients were women, of whom 88.89% were of child-bearing age. The predominant clinical forms of Chagas disease were the indeterminate and atypical cardiac forms. Less than 50% received the recommended antiparasitic treatment of benznidazole. An interdisciplinary team was centered on primary healthcare physicians who applied guidelines for the management of patients. Infectologists, cardiologists, pediatricians and other specialists acted as reference professionals. Confirmatory serology and molecular biology tests, as well as echocardiography, Holter and other tests, were performed for the assessment of affected organs in secondary healthcare centers. The published high performance of two commercial ELISA tests was not confirmed.

Conclusion

An interdisciplinary approach including antiparasitic treatment is feasible at the primary healthcare level for the management of Chagas disease in Bolivian immigrants. The itinerant feature of immigration was associated with a lack of adherence to antiparasitic treatment and was considered a main challenge for the clinical management of this population. This approach is recommended for management of the infected population in endemic and nonendemic areas, although different strategies are needed depending on the severity of the disease and the structure of the healthcare system.

Chagas disease affects approximately 6 million Latin American people. It is considered a neglected tropical disease since it mainly affects vulnerable, poverty-stricken people. Public health policies and investments in research on new treatment and control instruments have not been prioritized. In fact, disease urbanization occurred in Latin America in the 80s, and an estimated 15 million people moved from disease-endemic areas to nonendemic areas. Estimations have indicated that 2.9% of immigrants were infected by T. cruzi in 15 European countries, and more than 300,000 infected immigrants resided in the USA. In São Paulo, the estimated number of Bolivian immigrants exceeds 300,000. This study revealed the presence of mild clinical manifestations in predominantly young infected individuals, including reproductive-age women. For the first time, the feasibility of managing chronic Chagas disease at primary healthcare level centers with a biomedical and psychosocial interdisciplinary approach has been reported in the National Public Health System of Brazil. Additionally, the utilized commercial tests did not confirm the previously expected performance for diagnosis of infection. Finally, the itinerant characteristics of the Bolivian immigrant population was reported as a main factor underlying the lack of adherence to antiparasitic treatment and a main challenge for complete clinical management.

Trypanosoma cruzi seroprevalence in pregnant women and screening by PCR and microhaematocrit in newborns from Guanajuato, Mexico

Chagas disease is caused by an infection with the protozoan hemoflagellate Trypanosoma cruzi, and it is a major endemic health problem in Latin America. The congenital route is one of the main non-vectorial pathways of transmission, which can arise either in the chronic or acute phase of maternal infection. Serological screening of T. cruzi infection was performed in 520 pregnant women and newborns at the Hospital General Regional de León, Guanajuato, Mexico, between 2014 and 2015. Anti-T. cruzi antibodies were detected in 20 mothers (4%) by ELISA and HIA with four PCR-positive newborn cases. Risk factors were identified according to an epidemiological survey, and the most significant (P<0.050) factors associated with T. cruzi infection were the building materials of dwellings, the presence of pets and dwellings located in rural areas. This study constitutes the first systematic study on congenital Chagas disease and the epidemiological risk factors in Guanajuato. Our results represent the probability of an incidence of 770 cases per 100,000 births during a period of 12 months, with a vertical transmission rate by 0.8%, which highlights the necessity to establish reliable serological and PCR tests in pregnant women to prevent vertical transmission. However, it is also important to follow-up the newborns from seropositive mothers for one year, which is necessary, as many children yielded negative results.

Prevalence of Trypanosoma cruzi infection among Bolivian immigrants in the city of São Paulo, Brazil

With the urbanisation of the population in developing countries and the process of globalisation, Chagas has become an emerging disease in the urban areas of endemic and non-endemic countries. In 2006, it was estimated that the prevalence of Chagas disease among the general Bolivian population was 6.8%. The aim of the present study was to determine the prevalence of Trypanosoma cruzi infection among Bolivian immigrants living in São Paulo, Brazil. This study had a sample of 633 volunteers who were randomly selected from the clientele of primary care units located in the central districts of São Paulo, Brazil. Infection was detected by two different ELISA assays with epimastigote antigens, followed by an immunoblot with trypomastigote antigens as a confirmatory test. The prevalence of the infection was 4.4%. Risk factors independently associated with the infection were: a history of rural jobs in Bolivia, knowledge of the vector involved in transmission, and having relatives with Chagas disease. Brazil has successfully eliminated household vector transmission of T. cruzi, as well as its transmission by blood transfusion. The arrival of infected immigrants represents an additional challenge to primary care clinics to manage chronic Chagas disease, its vertical transmission, and the blood derivatives and organ transplant programs.

Diagnosis of Congenital Chagas Disease Using an Iron Superoxide Dismutase Excreted as Antigen, in Mothers and Their Children During the First Year of Life

BACKGROUND

Chagas disease caused by Trypanosoma cruzi is endemic in Latin America. Human infection is mainly spread by Triatominae insects. Other forms of transmission are congenital, blood transfusion and organ transplantation.

METHODS

Anti-T. cruzi antibodies were determined by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) in 155 serum samples from mothers and their babies. Indirect immunofluorescence (IFA) and a commercial test were used to validate efficacy of a specific ELISA-iron-excreted superoxide dismutase assay. Sera from babies were collected at 6 and 12 months, whereas maternal samples were obtained after delivery. Calostrum and umbilical cord samples were simultaneously obtained.

RESULTS

Anti-T. cruzi antibodies were detected in 8 (5.16%) mothers by ELISA-WB, in 7 (4.51%) using IFA and in 1 (0.64%) by a commercial kit. Nine (5.80%) 6-month-old children were positive by ELISA-WB and 7 (4.51%) by IFA; negative results were obtained when the commercial kit was used. At 12 month of age, 15 (9.67%) children were positive by ELISA-WB, 13 (8.38%) by IFA and 1 (0.64%) by the commercial test. Antibodies were detected in 4 mothers whose children were serologically negative. Four other mothers and their children were positive, but only one of them had detected antibodies in umbilical cord up to 12 months, thus assuming vertical transmission.

CONCLUSIONS

The use of iron-excreted superoxide dismutase as antigen in serologic tests for detection of T. cruzi yielded promising results as diagnostic procedure.

IgG Autoantibodies Induced by T. cruzi During Pregnancy: Correlation with Gravidity Complications and Early Outcome Assessment of the Newborns

Objective The aim of the present research was to evaluate the correlation of vertically transmitted IgG antibodies induced by T. cruzi and newborn early outcome assessment, mainly birth weight and gestational age. Methods We performed a cross-sectional study with 183 pregnant women (64 with asymptomatic Chagas disease) and their newborns. Both were subjected to complete clinical examination. Peripheral parasitemia was assessed in mother and neonates by parasite detection through microscopic examination of the buffycoat from mother's peripheral and cord blood. Antibodies induced by T. cruzi, such as anti-FRA, anti-B13, anti-p2β and anti-T. cruzi were assessed by immunoassay. Birth weight, general condition evaluation by APGAR Score and gestational age by Capurro Score, were determined in newborns. Results The rate of stillbirth background and pregnancy-induced hypertension were higher in patients with Chagas disease (p = 0.01 and p = 0.02, respectively). Parasitemia was detectable in 17 mothers and 4 newborns. The newborns of mothers with detectable parasitemia presented decreased gestational age (p = 0.006) and body weight (p = 0.04). Mostly all the mothers with Chagas disease and all their newborns have positive values of antibodies induced by T. cruzi; however, only anti-p2β showed to be related to the presence of complication during pregnancy (OR 2.35, p = 0.036), and to low birth weight (OR 1.55, p = 0.02). Conclusions Low birth weight and decreased postnatal estimation of maturity were related to detectable parasitemia in the mother. Also, vertical transmission of T. cruzi-induced autoantibodies might have clinical implication in newborns given the negative association between anti-p2β values and weight.

Benznidazole Extended-Release Tablets for Improved Treatment of Chagas Disease: Preclinical Pharmacokinetic Study

Benznidazole (BNZ) is the first-line drug for the treatment of Chagas disease. The drug is available in the form of immediate-release tablets for 100-mg (adult) and 12.5-mg (pediatric) doses. The drug is administered two or three times daily for 60 days. The high frequency of daily administrations and the long period of treatment are factors that significantly contribute to the abandonment of therapy, affecting therapeutic success. Accordingly, this study aimed to evaluate the preclinical pharmacokinetics of BNZ administered as extended-release tablets (200-mg dose) formulated with different types of polymers (hydroxypropyl methylcellulose K4M and K100M), compared to the tablets currently available. The studies were conducted with rabbits, and BNZ quantification was performed in plasma and urine by ultraperformance liquid chromatography methods previously validated. The bioavailability of BNZ was adequate in the administration of extended-release tablets; however, with the administration of the pediatric tablet, the bioavailability was lower than with other tablets, which showed that the clinical use of this formulation should be monitored. The pharmacokinetic parameters demonstrated that the extended-release tablets prolonged drug release from the pharmaceutical matrix and provided an increase in the maintenance of the drug concentrationin vivo, which would allow the frequency of administration to be reduced. Thus, a relative bioavailability study in humans will be planned for implementation of a new product for the treatment of Chagas disease.

Congenital Chagas disease as an ecological model of interactions between Trypanosoma cruzi parasites, pregnant women, placenta and fetuses

The aim of this paper is to discuss the main ecological interactions between the parasite Trypanosoma cruzi and its hosts, the mother and the fetus, leading to the transmission and development of congenital Chagas disease. One or several infecting strains of T. cruzi (with specific features) interact with: (i) the immune system of a pregnant woman whom responses depend on genetic and environmental factors, (ii) the placenta harboring its own defenses, and, finally, (iii) the fetal immune system displaying responses also susceptible to be modulated by maternal and environmental factors, as well as his own genetic background which is different from her mother. The severity of congenital Chagas disease depends on the magnitude of such final responses. The paper is mainly based on human data, but integrates also complementary observations obtained in experimental infections. It also focuses on important gaps in our knowledge of this congenital infection, such as the role of parasite diversity vs host genetic factors, as well as that of the maternal and placental microbiomes and the microbiome acquisition by infant in the control of infection. Investigations on these topics are needed in order to improve the programs aiming to diagnose, manage and control congenital Chagas disease.

The importance of the multidisciplinary approach to deal with the new epidemiological scenario of Chagas disease (global health)

There are currently two major factors that have modified the epidemiology of Chagas disease in the last decades: climate change and migration flows. In this new scenario, there are new challenges to control and prevent Trypanosoma cruzi infection in endemic countries, such as the control of a wider distribution of triatomine vectors or the reinforcement of vertical transmission programs. In non-endemic areas, few countries are aware of the emergence of this new disease and have established changes in their health systems. To address this new public health challenge, the priorities should be control programs to avoid new cases of T. cruzi infection acquired through vertical transmission, blood transfusion or organ transplant. In both, endemic and non-endemic areas, the international community and all the actors involved in Chagas disease must join efforts mainly in two directions: better management of the infection in affected individuals and more research to cover the knowledge gap mainly in physiopathology, diagnosis and treatment.

Between a bug and a hard place: Trypanosoma cruzi genetic diversity and the clinical outcomes of Chagas disease

Over the last 30 years, concomitant with successful transnational disease control programs across Latin America, Chagas disease has expanded from a neglected, endemic parasitic infection of the rural poor to an urbanized chronic disease, and now a potentially emergent global health problem. Trypanosoma cruzi infection has a highly variable clinical course, ranging from complete absence of symptoms to severe and often fatal cardiovascular and/or gastrointestinal manifestations. To date, few correlates of clinical disease progression have been identified. Elucidating a putative role for T. cruzi strain diversity in Chagas disease pathogenesis is complicated by the scarcity of parasites in clinical specimens and the limitations of our contemporary genotyping techniques. This article systematically reviews the historical literature, given our current understanding of parasite genetic diversity, to evaluate the evidence for any association between T. cruzi genotype and chronic clinical outcome, risk of congenital transmission or reactivation and orally transmitted outbreaks.

Perinatal Screening for Chagas Disease in Southern Texas

Perinatal screening for Trypanosoma cruzi in a cohort of 4000 predominantly Hispanic women in southern Texas revealed that Chagas disease occurs with sufficient frequency (0.25%) that targeted perinatal screening should be considered to identify infected mothers and infants at risk for congenital infection.

[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.

Use of a novel chagas urine nanoparticle test (chunap) for diagnosis of congenital chagas disease

Background

Detection of congenital T. cruzi transmission is considered one of the pillars of control programs of Chagas disease. Congenital transmission accounts for 25% of new infections with an estimated 15,000 infected infants per year. Current programs to detect congenital Chagas disease in Latin America utilize microscopy early in life and serology after 6 months. These programs suffer from low sensitivity by microscopy and high loss to follow-up later in infancy. We developed a Chagas urine nanoparticle test (Chunap) to concentrate, preserve and detect T. cruzi antigens in urine for early, non-invasive diagnosis of congenital Chagas disease.

Methodology/Principal Findings

This is a proof-of-concept study of Chunap for the early diagnosis of congenital Chagas disease. Poly N-isopropylacrylamide nano-particles functionalized with trypan blue were synthesized by precipitation polymerization and characterized with photon correlation spectroscopy. We evaluated the ability of the nanoparticles to capture, concentrate and preserve T. cruzi antigens. Urine samples from congenitally infected and uninfected infants were then concentrated using these nanoparticles. The antigens were eluted and detected by Western Blot using a monoclonal antibody against T. cruzi lipophosphoglycan. The nanoparticles concentrate T. cruzi antigens by 100 fold (western blot detection limit decreased from 50 ng/ml to 0.5 ng/ml). The sensitivity of Chunap in a single specimen at one month of age was 91.3% (21/23, 95% CI: 71.92%–98.68%), comparable to PCR in two specimens at 0 and 1 month (91.3%) and significantly higher than microscopy in two specimens (34.8%, 95% CI: 16.42%–57.26%). Chunap specificity was 96.5% (71/74 endemic, 12/12 non-endemic specimens). Particle-sequestered T. cruzi antigens were protected from trypsin digestion.

Conclusion/Significance

Chunap has the potential to be developed into a simple and sensitive test for the early diagnosis of congenital Chagas disease.

Congenital Chagas disease is one of the main pillars for the control of Chagas disease because 25% of new infections occur by this route. Conventional diagnosis of congenital Chagas disease is based on microscopy at birth and serology at 9 months. However microscopy misses many infections and many at-risk infants fail to complete serology at six to nine months. We have developed a Chagas urine nanoparticle test (Chunap) for concentration and detection of T. cruzi antigens. Chunap was evaluated in urine samples of 1-month old children. At this age children have the highest levels of parasitemia and therefore also excrete the highest levels of antigen. Parents prefer a urine test to having their baby's blood drawn. Chunap diagnosed congenital infection in a single urine sample as well as PCR in two blood samples. This study also shows that hydrogel/trypan blue particles used in our test efficiently capture, concentrate and protect urinary T. cruzi antigens from enzymatic degradation. Chunap allows for the early diagnosis of congenital Chagas disease, and with appropriate adaptation, may allow early point-of-care intervention.

Field evaluation of the InBios Chagas detect plus rapid test in serum and whole-blood specimens in Bolivia

Trypanosoma cruzi causes Chagas disease, which affects an estimated 7 million to 8 million people. Chagas disease is endemic throughout Latin America, with the highest prevalence in Bolivia. Conventional diagnosis requires a well-equipped laboratory with experienced personnel. We evaluated the Chagas Detect Plus (CDP) (InBios, Seattle, WA), a rapid immunochromatographic assay for IgG antibodies to T. cruzi. CDP performance was compared to infection status based on results obtained by indirect hemagglutination assay, immunofluorescent-antibody test, and enzyme-linked immunosorbent assay. Confirmed infection required positive results by at least 2 conventional assays. We used specimens from adults of both sexes in a general hospital in the city of Santa Cruz and from pregnant women in a hospital and children in villages in the Bolivian Chaco, an area of hyperendemicity. CDP was performed in paired whole-blood and serum specimens from 385 individuals in the two hospital studies and in 200 serum specimens from the community study. CDP showed sensitivities/specificities of 96.2% (95% confidence interval, 92.7 to 98.4)/98.8% (95.9 to 99.9) in whole blood and 99.3% (97.5 to 99.9)/96.9% (94.2 to 98.6) in serum, with no differences by sex, age group, or study site. CDP showed excellent sensitivity and specificity in our study population, comparable to those of conventional serology. The test is reliable for field surveys, requires no laboratory equipment, and performed well in serum and whole blood. The CDP could also be used for accurate maternal screening to identify neonates at risk of congenital transmission. CDP performance data in diverse geographic areas are needed to strengthen the evidence base for its use.

Mother-to-child transmission of congenital Chagas disease, Japan

We report a patient with congenital Chagas disease in Japan. This report reemphasizes the role of neglected and emerging tropical diseases in the era of globalization. It also indicates the need for increased vigilance for detecting Chagas disease in non-disease-endemic countries.

Chagas' disease: pregnancy and congenital transmission

Chagas disease is a chronic infection that kills approximately 12,000 people a year. Mass migration of chronically infected and asymptomatic persons has caused globalization of Chagas disease and has made nonvectorial infection, including vertical and blood-borne transmission, more of a threat to human communities than vectorial infection. To control transmission, it is essential to test all pregnant women living in endemic countries and all pregnant women having migrated from, or having lived in, endemic countries. All children born to seropositive mothers should be tested not only within the first month of life but also at ~6 months and ~12 months of age. The diagnosis is made by identification of the parasite in blood before the age of 6 months and by identification of the parasite in blood and/or positive serology after 10 months of age. Follow up for a year is essential as a significant proportion of cases are initially negative and are only detected at a later stage. If the condition is diagnosed and treated early, the clinical response is excellent and the majority of cases are cured.

Prevalence of Chagas disease in pregnant women and congenital transmission of Trypanosoma cruzi in Brazil: a systematic review and meta-analysis

OBJECTIVE

To estimate the prevalence of Chagas disease in pregnant women and the risk of congenital transmission of Trypanosoma cruzi infection in Brazil, through a systematic review and meta-analysis.

METHODS

We searched electronic databases, grey literature and reference lists of included publications to identify epidemiological studies on the prevalence of Chagas disease in pregnant women and on the congenital transmission rate of T. cruzi infection in Brazil published between January 1980 and June 2013. Pooled estimates and 95% confidence intervals (95% CIs) were calculated using fixed- and random-effects models.

RESULTS

Sixteen articles were included - 12 studies on the prevalence of Chagas disease in pregnant women (549,359 pregnant women) and nine on congenital transmission rates (1687 children born to infected mothers). Prevalence of Chagas disease in pregnant women ranged from 0.1% to 8.5%, and congenital transmission rates from 0% to 5.2%. The pooled prevalence of Chagas disease among pregnant women across studies was 1.1% (95% CI: 0.6-2.0); the pooled congenital transmission rate was 1.7% (95% CI: 0.9-3.1). In 2010, 34,629 pregnant women were estimated to be infected with T. cruzi, and 312-1073 children born (mean: 589 cases) with congenital infection.

CONCLUSION

Congenital Chagas disease is a neglected public health problem in Brazil. Systematic congenital Chagas disease control programs through routine prenatal screening for T. cruzi should be widely implemented in Brazil's endemic areas, to identify infected pregnant women and newborns at risk of congenital infection.

Chagas disease and breast-feeding

Mothers with this disease should continue breast-feeding unless they are experiencing the acute phase, reactivated disease, or bleeding nipples.

Chagas disease (infection by the protozoan Trypanosoma cruzi) is a major parasitic disease of the Americas and one of the main neglected tropical diseases. Although various routes of transmission sre recognized, the risk for transmission of the infection through breast-feeding has not clearly been established. We reviewed the literature on transmission of T. cruzi through breast-feeding to provide breast-feeding mothers with Chagas disease with medical guidance. Although data from animal studies and human studies are scarce, we do not recommend that mothers with Chagas disease discontinue breast-feeding, unless they are experiencing the acute phase of the disease, reactivated disease resulting from immunosuppression, or bleeding nipples. In these cases, thermal treatment of milk before feeding the infant may be considered.

[Paediatric Chagas in a non-endemic area]

INTRODUCTION

Immigration has introduced new diseases into Spanish society, one of which is Chagas disease. Young women of childbearing age and children infected with Trypanosoma cruzi from endemic areas are at risk of developing the disease years later, and pregnant women can transmit the infection through the placenta.

METHODS

Serological screening for anti-T.cruzi antibodies was performed on all immigrant children coming from a Chagas endemic area and seen in our Pathology Unit between 2003 and 2008, as well as on newborns of T.cruzi positive infected pregnant women coming from Latin America. Two ELISA tests were used (bioelisa Chagas Biokit® with recombinant antigens, and an 'in house' ELISA with crude antigen). Patients with sufficient sample were also screened by nested PCR (TCZ3/Z4).

RESULTS

A total of 202 children, aged 1 day to 14 years old were included in the study, of whom 22 (10.8%) were diagnosed with asymptomatic infection, 5 of which were congenital as they were born in this country. All infected patients received treatment with benznidazole, with three of them currently with a serologically negative result after treatment.

CONCLUSION

Chagas disease is a new imported paediatric disease that can affect children from endemic countries, but can also be acquired in our country by vertical transmission. Therefore, we believe that it is essential to perform serological screening on all children and pregnant women in the prenatal care from endemic areas, and provide specific treatment for those infected patients, given the good results observed in the paediatric population.

Chagas disease (American trypanosomiasis) in Mexico: an update

Chagas disease is a parasitic infection caused by the protozoan Trypanosoma cruzi, a flagellated organism that is transmitted mainly to humans through the infected feces of triatomine kissing bugs (vector transmission in endemic areas) or by transfusion of infected blood, donations of infected organ, or transmission from an infected mother to her child at birth. Chagas disease was first described in 1909 by the Brazilian physician Carlos Chagas, and due to the parasite's distribution throughout North, Central and South America, the disease is commonly known as American trypanosomiasis. However, this disease is now present in non-endemic countries such as Canada, the United States of America, and several countries in Europe (principally Spain). Moreover, Chagas disease was recently designated by the World Health Organization as one of the main neglected tropical diseases. The aim of this review is to summarize the research efforts recently described in studies conducted in Mexico on Chagas disease. In this country, there are no existing vector control programs. In addition, there is no consensus on the diagnostic methods for acute and chronic Chagas disease in maternity wards and blood banks, and trypanocidal therapy is not administered to chronic patients. The actual prevalence of the disease is unknown because no official reporting of cases is performed. Therefore, the number of people infected by different routes of transmission (vector, congenital, blood transfusion, organ transplantation, or oral) is unknown. We believe that by promoting education about Chagas disease in schools starting at the basic elementary level and including reinforcement at higher education levels will ensure that the Mexican population would be aware of this health problem and that the control measures adopted will have more acceptance and success. We hope that this review sensitizes the relevant authorities and that the appropriate measures to reduce the risk of infection by T. cruzi are undertaken to provide the Mexican people a better quality of life.

Dried blood as an alternative to plasma or serum for Trypanosoma cruzi IgG detection in screening programs

Trypanosoma cruzi serological screening is recommended for people potentially exposed to this parasite in countries where Trypanosoma cruzi is endemic and those where it is not endemic. Blood samples on filter paper may be a practical alternative to plasma/serum for antibody detection. Using the Architect Chagas assay, we detected the presence of IgG against T. cruzi in matched serum and dried blood spots (DBS) collected from 147 patients residing in Madrid, Spain, who had potential previous exposure to T. cruzi. The κ statistic for the DBS/serum proportion of agreement for the detection of antibodies against T. cruzi was 0.803, considering an S/CO (assay result unit; chemiluminescent signal from the sample [S] divided by the mean chemiluminescent signal for the three calibrators used in the test [CO]) cutoff value of ≥1.00. The relative sensitivity of the Architect test using DBS increased from 95.2% to 98.8% when the cutoff was lowered from ≥1.00 to ≥0.88, while the relative specificity decreased from 84.1% to 71.6%. Overall, the median S/CO values for DBS were significantly lower than those for serum (2.6 versus 6.5; P < 0.001). Discrepancies that occurred with the use of DBS included 10 false positives (with low S/CO values in 9 cases [median, 2.13]) and 4 false negatives, with mean S/CO values of 0.905 (gray zone). Using DBS plus a highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) may be a simple and reliable method for detecting IgG against T. cruzi when blood sampling by venipuncture is not feasible. This method may also reduce the false-negative rates observed with some rapid diagnostic tests. The lower relative sensitivity compared to the reference method may be increased by lowering the optical density threshold.

Childhood parasitic infections endemic to the United States

Endemic parasitic infections in the United States are more frequent than is commonly perceived. Intestinal parasitic infection with Cryptosporidium, Dientamoeba, and Giardia occurs most often in children in northern states during the summer months. Zoonotic Toxocara and Toxoplasma parasitic infections are more frequent in southern states, in African Americans, and in populations with lower socioeconomic status. Approximately 300, 000 people in the United States have Trypanosoma cruzi infection. Local, vector-borne transmission of T cruzi and Leishmania infections has been documented in southern states. Parasitic diseases endemic to the United States are not uncommon but are understudied.

Detection of soluble antigen and DNA of Trypanosoma cruzi in urine is independent of renal injury in the guinea pig model

The diagnosis of Chagas disease in humans is generally limited to the detection of specific antibodies. Detection of T. cruzi antigens in urine has been reported previously, but is not used in the diagnosis. In this study, soluble T. cruzi antigens and DNA were detected in urine samples and were associated with kidney injury and systemic detection of the parasite. We used 72 guinea pigs infected with T. cruzi Y strain and 18 non-infected guinea pigs. Blood, kidney, heart and urine samples were collected during the acute phase and chronic phase. Urine samples were concentrated by ultrafiltration. Antigens were detected by Western Blot using a polyclonal antibody against trypomastigote excretory-secretory antigen (TESA). T. cruzi DNA was detected by PCR using primers 121/122 and TcZ1/TcZ2. Levels of T. cruzi DNA in blood, heart and kidney were determined by quantitative PCR. T. cruzi antigens (75 kDa, 80 kDa, 120 kDa, 150 kDa) were detected in the acute phase (67.5%) and the chronic phase (45%). Parasite DNA in urine was detected only in the acute phase (45%). Kidney injury was characterized by high levels of proteinuria, kidney injury molecule-1 (KIM-1) and urea, and some histopathological changes such as inflammation, necrosis, fibrosis and scarce parasites. The detection of antigens and DNA in urine was associated with the presence of parasite DNA in blood and heart and with high levels of parasite DNA in blood, but not with the presence of parasite in kidney or kidney injury. These results suggest that the detection of T. cruzi in urine could be improved to be a valuable method for the diagnosis of Chagas disease, particularly in congenital Chagas disease and in immunocompromised patients.