Mother-to-child Chagas disease transmission: The challenge of detection and prevention in areas without the risk of vectorial transmission.

Chagas disease (CD) is caused by the parasite Trypanosoma cruzi. Although it is endemic in many Latin American (LA) countries, mother-to-child transmission has caused it to expand to other countries and continents. In places where vector transmission is controlled or absent, the epidemiological importance of T. cruzi transmission of the infected mother to her child during pregnancy or childbirth (i.e., perinatal CD) increases. In countries where CD is not endemic, CD screening should be performed in pregnant or fertile women who are native to LA countries or whose mothers are native to LA countries. Diagnosis is established by detecting anti-T. cruzi IgG antibodies in a serum or plasma sample. Antiparasitic treatment cannot be offered during pregnancy, and since the majority of infected newborns are asymptomatic at birth, a diagnosis is made by direct observation or concentration (microhematocrit) or by using molecular testing techniques. Once the infected child receives a diagnosis, it is essential to offer treatment (benznidazole/nifurtimox) as soon as possible, with good tolerance and effectiveness in the first year of life. Even if the diagnosis is negative at birth, the newborn must be followed up for at least the first 9 months of life.

Potencial transmisión congénita de la enfermedad de Chagas en la segunda generación de jóvenes embarazadas que asistieron a su control prenatal en el departamento de Cordillera, Paraguay

Trypanosoma cruzi es el agente causal de la enfermedad de Chagas. En Paraguay se estima que existen 165.000 personas infectadas y actualmente la principal vía de transmisión es la congénita, con una prevalencia del 5% y con alrededor de 400 niños infectados nacidos por año. El departamento de Cordillera es área endémica de la Región Oriental del país, donde se implementó el Programa de Control Prenatal de Chagas en el año 1995. El objetivo de este estudio fue inferir sobre la potencial transmisión congénita de la enfermedad de Chagas en jóvenes embarazadas de segunda generación de Cordillera que asistieron a su control prenatal en el período 2010-2012, 15 años después de la implementación del Programa de Control Prenatal. De 9.588 embarazadas; 482 fueron seropositivas (5%); 2,74% en el grupo de 12 a 19 años, 4,93% de 20 a 30 años, 8,03% de 31 a 40 años y 16,11% de 41 a 48 años. Para estimar el origen de la transmisión congénita de segunda generación se tuvo en cuenta a las 72 seropositivas de 12 a 19 años y según la base de datos de las respectivas madres 61 eran seropositivas. Con esta información se estima que la transmisión a embarazadas de segunda generación de 12 a 19 años fue congénita en un 85% indicando una transmisión congénita muy significativa en la población de estudio. Esta información ayudaría al Programa Nacional de Chagas en el fortalecimiento del control de la transmisión congénita de la enfermedad de Chagas en el país.

Trypanosoma cruzi is the causative agent of Chagas disease. In Paraguay, it is estimated that 165,000 people are infected and currently the main route of transmission is the congenital one, with a prevalence of 5% and about 400 infected children are born per year. The Department of Cordillera is an endemic area of the Eastern Region of the country, where the Chagas Prenatal Control Program was implemented in 1995. The aim of this study was to infer the potential congenital transmission of Chagas disease towards second generation pregnant women from the Department of Cordillera who attended their prenatal control in the period 2010-2012, 15 years after the implementation of the Prenatal Control Program. Of 9,588 pregnant women; 482 were seropositive (5%); 2.74% in the group aged 12 to 19 years, 4.93% aged 20 to 30 years, 8.03% aged 31 to 40 years, and 16.11% aged 41 to 48 years. To estimate the origin of second generation congenital transmission, the 72 seropositive women aged 12 to 19 years were taken into account and according to the database of their respective mothers, 61 mothers of the 72 were seropositive. With this información, it can be estimated that 85% of the transmission to second generation pregnant women aged 12 to 19 years was congenital showing a very significant congenital transmission in the study population. This information could help the National Chagas Program in strengthening the control of congenital transmission of Chagas disease in the country.

The transcriptome landscape of 3D-cultured placental trophoblasts reveals activation of TLR2 and TLR3/7 in response to low Trypanosoma cruzi parasite exposure.

Vertical transmission of Trypanosoma cruzi (T. cruzi) become a globalized health problem accounting for 22% of new cases of Chagas disease (CD). Congenital infection is now considered the main route of CD spread in non-endemic countries where no routine disease testing of pregnant women is implemented. The main mechanisms that lead to fetal infection by T. cruzi remain poorly understood. Mother-to-child transmission may occur when bloodstream trypomastigotes interact with the syncytiotrophoblasts (SYNs) that cover the placenta chorionic villi. These highly specialized cells function as a physical barrier and modulate immune responses against pathogen infections. To model the human placenta environment, we have previously used a three-dimensional (3D) cell culture system of SYNs that exhibits differentiation characteristics comparable to placental trophoblasts. Further, we have shown that 3D-grown SYNs are highly resistant to T. cruzi infection. In this work, we used RNA sequencing and whole transcriptome analysis to explore the immunological signatures that drive SYNs' infection control. We found that the largest category of differentially expressed genes (DEGs) are associated with inflammation and innate immunity functions. Quantitative RT-PCR evaluation of selected DEGs, together with detection of cytokines and chemokines in SYNs culture supernatants, confirmed the transcriptome data. Several genes implicated in the Toll-like receptors signaling pathways were upregulated in 3D-grown SYNs. In fact, TLR2 blockade and TLR3/7 knockdown stimulated T. cruzi growth, suggesting that these molecules play a significant role in the host cell response to infection. Ingenuity Pathway Analysis of DEGs predicted the activation of canonical pathways such as S100 protein family, pathogen induced cytokine storm, wound healing, HIF1α signaling and phagosome formation after T. cruzi exposure. Our findings indicate that SYNs resist infection by eliciting a constitutive pro-inflammatory response and modulating multiple defense mechanisms that interfere with the parasite's intracellular life cycle, contributing to parasite killing and infection control.

Knowledge Production on Congenital Chagas Disease across Time, Borders and Disciplines: A Comprehensive Scoping Review.

Congenital transmission is a key route of Trypanosoma cruzi infection in Latin America and globally, contributing significantly to the burden of Chagas disease. The interruption of transmission from mother to child has recently become a focus issue. However, the research landscape on congenital Chagas disease remains largely unexplored. The purpose of this scoping review is to assess the production of knowledge on congenital Chagas disease (CCD), aiming to identify research trends and potential gaps. Our initial hypothesis was that the CCD literature overly represents the medical sciences and that there is a need for socio-cultural research on the subject. We conducted a systematic search of publications focusing on congenital Chagas disease in six languages (English, Spanish, Portuguese, French, German and Italian). This comprehensive literature search identified 876 studies that met the inclusion criteria, out of a total of 8893 sources. The relevant literature was analyzed by language, year of publication, discipline, source type and research location. The main outcome of this study has been to prove our hypothesis that there is a scarcity of knowledge produced within the non-biomedical sciences on CCD. This underscores the need for further exploration into the social and structural issues surrounding this disease. Visually clear data concerning congenital Chagas disease produced by this study can contribute to hone in future research efforts and support funding applications. Additionally, this article provides a reference list that other researchers can consult for their own studies.

Monocytes from Uninfected Neonates Born to Trypanosoma cruzi-Infected Mothers Display Upregulated Capacity to Produce TNF-α and to Control Infection in Association with Maternally Transferred Antibodies.

Activated monocytes/macrophages that produce inflammatory cytokines and nitric oxide are crucial for controlling Trypanosoma cruzi infection. We previously showed that uninfected newborns from T. cruzi infected mothers (M+B- newborns) were sensitized to produce higher levels of inflammatory cytokines than newborns from uninfected mothers (M-B- newborns), suggesting that their monocytes were more activated. Thus, we wondered whether these cells might help limit congenital infection. We investigated this possibility by studying the activation status of M+B- cord blood monocytes and their ability to control T. cruzi in vitro infection. We showed that M+B- monocytes have an upregulated capacity to produce the inflammatory cytokine TNF-α and a better ability to control T. cruzi infection than M-B- monocytes. Our study also showed that T. cruzi-specific Abs transferred from the mother play a dual role by favoring trypomastigote entry into M+B- monocytes and inhibiting intracellular amastigote multiplication. These results support the possibility that some M+B- fetuses may eliminate the parasite transmitted in utero from their mothers, thus being uninfected at birth.

Amplicon Sequencing Reveals Complex Infection in Infants Congenitally Infected With Trypanosoma Cruzi and Informs the Dynamics of Parasite Transmission.

Congenital transmission of Trypanosoma cruzi is an important source of new Chagas infections worldwide. The mechanisms of congenital transmission remain poorly understood, but there is evidence that parasite factors are involved. Investigating changes in parasite strain diversity during transmission could provide insight into the parasite factors that influence the process. Here we use amplicon sequencing of a single copy T. cruzi gene to evaluate the diversity of infection in clinical samples from Chagas positive mothers and their infected infants. Several infants and mothers were infected with multiple parasite strains, mostly of the same TcV lineage, and parasite strain diversity was higher in infants than mothers. Two parasite haplotypes were detected exclusively in infant samples, while one haplotype was never found in infants. Together, these data suggest multiple parasites initiate a congenital infection and that parasite factors influence the probability of vertical transmission.

Family cluster of Chagas disease among Bolivian immigrants in Italy: High rate of maternal-fetal transmission.

BACKGROUND: Chagas disease (CD) or American trypanosomiasis is a neglected anthropozoonosis caused by Trypanosoma cruzi that affects 6-8 million people worldwide (mainly in Latin America), 30-40% of whom develop cardiac or digestive complications. Once confined to endemic areas of Latin America, CD has more recently become a global disease as a result of migration flows from endemic to non-endemic regions, particularly in northern America and Europe. Congenital transmission is a particular challenge as it may be sustained for multiple generations and perpetuate the infection even in non-endemic countries. METHODS: Subjects were identified during a cross-sectional survey of CD among Latin American people living in Milan, Italy. Serology was carried out using tests based on either a lysate and a recombinant antigen of Trypanosoma cruzi. They were also tested by a conventional Polymerase Chain Reaction (PCR) targeting the 330 bp variable region of the T. cruzi kinetoplast minicircle genome and a commercial real-time PCR. RESULTS: We here describe a Bolivian family cluster with seven affected people with at least two autochthonous congenital T. cruzi infection which was identified during the course of a CD screening programme. We also review the epidemiology, diagnosis and control of congenital CD, with particular emphasis on the challenges facing the control and management of such a complex and still largely hidden disease. CONCLUSIONS: Our experience confirms the need to screen for CD all family members once a case is diagnosed and shows the possible high rate of congenital CD also in non-endemic areas.

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.

Chagas Disease in Pregnant Women from Endemic Regions Attending the Hospital General de Mexico, Mexico City.

Trypanosoma cruzi infection leads to Chagas disease (CD), a neglected tropical infection of significant public health importance in South and Central America and other, non-endemic, countries. Pregnant women and their children are of particular importance to screen as T. cruzi can be transmitted vertically. The objective of this study was to screen for T. cruzi infection among pregnant women from endemic areas seen at the Hospital General de Mexico for prenatal care, so that they and their children may be quickly connected to CD treatment. Pregnant women were recruited through the hospital prenatal clinic and screened for T. cruzi infection using a series of serological and molecular tests. Of 150 screened patients, mean age 26.8 (SD 6.4), 30 (20.0%) were positive by at least one diagnostic test. Of these, only nine (6%) were positive as determined by PCR. Diagnosis of chronic CD is difficult in endemic places like Mexico due to the limitations of current commercially available diagnostic tests. Further evaluation of diagnostic performance of various assays could improve current CD diagnostic algorithms and proper care management in these regions. Genetic variability in the parasite may also play a role in the differing assay performances seen in this study, and this may be a valuable avenue of further research.

Chagas disease affects the human placental barrier's turnover dynamics during pregnancy

BACKGROUND Trypanosoma cruzi crosses the placental barrier and produces the congenital transmission of Chagas disease (CD). Structural alterations of the chorionic villi by this parasite have been described in vitro, but little is known about trophoblast turnover in placentas from women with CD. OBJECTIVE To analyze the proliferation and fusion processes in placentas from women with CD. METHODS Archived human term placenta paraffin-embedded blocks were used, from women with CD (CDP), and no pathology (NP). Immunohistochemistry tests were performed for Ki67 to calculate the proliferation index (PI) of cytotrophoblast (CTB) and Syncytin-1, a fusion marker of syncytiotrophoblast (STB). Hematoxylin/Eosin stained sections were employed to analyze STB percentages, STB detachment areas and syncytial knots quantity. Non parametric Student's t-tests were performed (p < 0.05). RESULTS Syncytial knots and STB detachment significantly increased in placental villi from the CDP group. STB percentage was significantly lower in the CDP group as well as the PI and Syncytin-1 expression significantly decreased in these placentas, compared with control (NP). CONCLUSION Dynamic of trophoblast turnover is altered in placentas from women with CD. These changes may lead into a gap in the placental barrier possibly allowing the parasite entry into the chorionic villi.

Recognition and screening for Chagas disease in the USA.

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is a public health concern, mainly among countries in South and Central America. However, despite the large number of immigrants from endemic countries living in the USA, awareness of CD is poor in the medical community, and therefore it is significantly underdiagnosed. To avoid the catastrophic cardiac complications of CD and to prevent maternal-fetal transmission, widespread educational programs highlighting the need for diagnosis are urgently needed.

Diagnostico de Chagas Congénito en el Hospital de Niños "Sor María Ludovica" / Diagnosis of Congenital Chagas in the Children's Hospital "Sor María Ludovica"

Introducción:La transmisión congénita de Trypanosoma cruzi constituye, en la actualidad, la vía que genera mayor cantidad de nuevos casos de infección aguda. El diagnóstico y tratamiento temprano aseguran una elevada probabilidad de cura parasitológica. El objetivo del trabajo fue evaluar el seguimiento de potenciales casos de Chagas Congénito, estimar la tasa de transmisión materno-fetal y la capacidad diagnóstica del microhematocrito. Materiales y métodos: Se realizó un estudio descriptivo transversal sobre hijos de mujeres con Chagas, que concurrieron al Laboratorio Central del H.I.A.E.P. Sor María Ludovica durante abril 2013-febrero 2019. Los niños fueron estudiados por microhematocrito y pruebas serológicas. Los resultados se obtuvieron del Sistema Informático de Laboratorio de Wiener®. Resultados: En el período de tiempo evaluado, fueron estudiados por microhematocrito un total de 268 niños (edad promedio= 2,35 meses), obteniéndose 16 resultados positivos. De los 252 niños con microhematocrito negativo, 58 fueron seguidos por pruebas serológicas hasta el año de vida, obteniéndose 3 resultados positivos. Se evidenció una pérdida de seguimiento serológico del 77%. La tasa de transmisión congénita estimada fue del 6,9% y el porcentaje de detección diagnóstica de la técnica directa, del 84,2%. Conclusión: La búsqueda de infección congénita en hijos de mujeres con Chagas, y su seguimiento hasta el año de vida, resulta esencial para lograr la detección y tratamiento temprano de nuevos casos. Sin embargo, la pérdida de seguimiento de potenciales casos de Chagas Congénito resulta alarmante. Esto enfatiza la necesidad de plantear estrategias sólidas para mejorar la aplicación del algoritmo diagnóstico

Introduction:Congenital Trypanosoma cruzi transmission is currently the route that generates the largest number of new cases of acute infection. Early diagnosis and treatment ensure a high probability of parasitological cure. The aim of this article was to evaluate the follow-up of possible cases of Congenital Chagas, to estimate the maternal-fetal transmission rate and the diagnostic capacity of microhematocrit. Materials and methods: A cross-sectional descriptive study was carried out on children born from Chagasic women, who attended the Central Laboratory of the H.I.A.E.P Sor María Ludovica during April 2013-February 2019. The children were studied by microhematocrit and serological tests. The results were obtained from the Wiener® Laboratory Information System. Results: In the evaluated time period, a total of 268 children (mean age = 2.35 months) were studied by microhematocrit, obtaining 16 positive results. Among the 252 children with negative microhematocrit, 58 were followed by serological tests up to one year of life, obtaining 3 positive results. A 77% loss of serological follow-up was evidenced. The estimated congenital transmission rate was 6.9% and the percentage of diagnostic detection of the direct technique was 84.2%. Conclusion: The search for congenital infection in children born from Chagasic women, and its follow-up until one year of life, is essential to achieve the early detection and treatment of new cases. However, the loss of follow-up of potential cases of Congenital Chagas is alarming. This emphasizes the need to propose solid strategies to improve the application of the diagnostic algorithm

Prospective multicenter evaluation of real time PCR Kit prototype for early diagnosis of congenital Chagas disease.

BACKGROUND: Current algorithm for Congenital Chagas Disease (cCD) diagnosis is unsatisfactory due to low sensitivity of the parasitological methods. Moreover, loss to follow-up precludes final serodiagnosis after nine months of life in many cases. A duplex TaqMan qPCR kit for Trypanosoma cruzi DNA amplification was prospectively evaluated in umbilical cord (UCB) and peripheral venous blood (PVB) of infants born to CD mothers at endemic and non-endemic sites of Argentina. METHODS: We enrolled and followed-up 370 infants; qPCR was compared to gold-standard cCD diagnosis following studies of diagnostic accuracy guidelines. FINDINGS: Fourteen infants (3·78%) had cCD. The qPCR sensitivity and specificity were higher in PVB (72·73%, 99·15% respectively) than in UCB (66·67%, 96·3%). Positive and negative predictive values were 80 and 98·73% and 50 and 98·11% for PVB and UCB, respectively. The Areas under the Curve (AUC) of ROC analysis for qPCR and micromethod (MM) were 0·81 and 0·67 in UCB and 0·86 and 0·68 in PVB, respectively. Parasitic loads ranged from 37·5 to 23,709 parasite equivalents/mL. Discrete typing Unit Tc V was identified in five cCD patients and in six other cCD cases no distinction among Tc II, Tc V or Tc VI was achieved. INTERPRETATION: This first prospective field study demonstrated that qPCR was more sensitive than MM for early cCD detection and more accurate in PVB than in UCB. Its use, as an auxiliary diagnostic tool to MM will provide more accurate records on cCD incidence. FUNDING: FITS SALUD 001-CHAGAS (FONARSEC, MINCyT, Argentina) to the Public-Private Consortium (INGEBI-CONICET, INP-ANLIS MALBRAN and Wiener Laboratories); ERANET-LAC-HD 328 to AGS and PICT 2015-0074 (FONCYT, MinCyT) to AGS and FA.

Evaluation of the Performance of the Loopamp Trypanosoma cruzi Detection Kit for the Diagnosis of Chagas Disease in an Area Where It Is Not Endemic, Spain.

In Spain, PCR is the tool of choice for the diagnosis of congenital Chagas disease (CD) and serology for diagnosing chronic CD. A loop-mediated isothermal amplification test for Trypanosoma cruzi DNA detection showed good analytical performance and ease of use. We aimed to evaluate the performance of the Loopamp Trypanosoma cruzi detection kit (Eiken Chemical Co. Ltd., Japan) (Tcruzi-LAMP) for congenital and chronic CD diagnosis using well-characterized samples. We included samples from 39 congenital and 174 chronic CD cases and from 48 uninfected children born to infected mothers and 34 nonchagasic individuals. The sensitivity, specificity, and accuracy of Tcruzi-LAMP were estimated using standard case definitions for congenital CD (positive result by parasitological or PCR tests or serology after 9 months of age) and chronic CD (positive serology by at least two tests). The Tcruzi-LAMP results were read by visual examination and a real-time fluorimeter. For congenital CD, Tcruzi-LAMP sensitivity was 97% for both types of reading; specificity was 92% by visual examination and 94% by fluorimeter. For chronic CD, sensitivity was 47% and specificity 100%. The accuracy in congenital CD was >94% versus 56% in chronic CD. The agreement of Tcruzi-LAMP with PCR tests was better in congenital CD (kappa, 0.86 to 0.91) than in chronic CD (kappa, 0.67 to 0.83). The Loopamp Trypanosoma cruzi detection kit showed good performance for the diagnosis of congenital CD. Tcruzi-LAMP, like PCR, can be useful for the screening and early diagnosis of congenital infection.

Risk Factors for Maternal Chagas Disease and Vertical Transmission in a Bolivian Hospital.

BACKGROUND: Vertical transmission of Trypanosoma cruzi infection accounts for a growing proportion of new cases of Chagas disease. Better risk stratification is needed to predict which women are more likely to transmit the infection. METHODS: This study enrolled women and their infants at the Percy Boland Women's Hospital in Santa Cruz, Bolivia. Pregnant women were screened for Chagas disease by rapid test and received confirmatory serology. Infants of seropositive mothers underwent diagnostic testing with quantitative polymerase chain reaction (qPCR). RESULTS: Among 5828 enrolled women, 1271 (21.8%) screened positive for Chagas disease. Older maternal age, family history of Chagas disease, home conditions, lower educational level, and history of living in a rural area were significantly associated with higher adjusted odds of maternal infection. Of the 1325 infants of seropositive mothers, 65 infants (4.9%) were diagnosed with congenital Chagas disease. Protective factors against transmission included cesarean delivery (adjusted odds ratio [aOR]: .60; 95% confidence interval [CI]: .36-.99) and family history of Chagas disease (aOR: .58; 95% CI: .34-.99). Twins were significantly more likely to be congenitally infected than singleton births (OR: 3.32; 95% CI: 1.60-6.90). Among congenitally infected infants, 32.3% had low birth weight, and 30.8% required hospitalization after birth. CONCLUSIONS: Although improved access to screening and qPCR increased the number of infants diagnosed with congenital Chagas disease, many infants remain undiagnosed. A better understanding of risk factors and improved access to highly sensitive and specific diagnostic techniques for congenital Chagas disease may help improve regional initiatives to reduce disease burden.

The Immunoglobulin M-Shed Acute Phase Antigen (SAPA)-test for the Early Diagnosis of Congenital Chagas Disease in the Time of the Elimination Goal of Mother-to-Child Transmission.

BACKGROUND: Diagnosis of congenital Chagas disease (CChD) in most endemic areas is based on low-sensitive microscopy at birth and 9-month immunoglobulin G (IgG), which has poor adherence. We aim to evaluate the accuracy of the Immunoglobulin M (IgM)-Shed Acute Phase Antigen (SAPA) test in the diagnosis of CChD at birth. METHODS: Two cohort studies (training and validation cohorts) were conducted in 3 hospitals in the department of Santa Cruz, Bolivia. Pregnant women were screened for Chagas disease, and all infants born to seropositive mothers were followed for up to 9 months to diagnose CChD. A composite reference standard was used to determine congenital infection and was based on the parallel use of microscopy, quantitative polymerase chain reaction (qPCR), and IgM-trypomastigote excreted-secreted antigen (TESA) blot at birth and/or 1 month, and/or the detection of anti-Trypanosoma cruzi IgG at 6 or 9 months. The diagnostic accuracy of the IgM-SAPA test was calculated at birth against the composite reference standard. RESULTS: Adherence to the 6- or 9-month follow-up ranged from 25.3% to 59.7%. Most cases of CChD (training and validation cohort: 76.5% and 83.7%, respectively) were detected during the first month of life using the combination of microscopy, qPCR, and/or IgM-TESA blot. Results from the validation cohort showed that when only 1 infant sample obtained at birth was evaluated, the qPCR and the IgM-SAPA test have similar accuracy (sensitivity: range, 79.1%-97.1% and 76.7%-94.3%, respectively, and specificity: 99.5% and 92.6%, respectively). CONCLUSIONS: The IgM-SAPA test has the potential to be implemented as an early diagnostic tool in areas that currently rely only on microscopy.

Aleatory Trypanosoma cruzi Vertical Transmission in Chiapas, Mexico: A Case Report.

Congenital Chagas disease is considered a form of dispersion of Trypanosoma cruzi related to human migration from endemic, often rural to previously non-endemic urban areas. This fact increases the Chagas disease establishment risk inside of family members by vertical transmission pathway. Congenital Chagas disease cases in newborns could not identified by the health professional even in endemic regions. Here we present the first family cluster of Chagas disease cases from Chiapas: one of the most important endemic areas in South of Mexico, where vertical T. cruzi transmission incidence rate is ranged between 2% to 22% revealing an important public health problem. Two cases inside a family from Chiapas, México with positive antibodies against T. cruzi detected by ELISA are presented; one of them got the infection through vertical pathway. We think that congenital Chagas disease should not be ignored in a newborn born from an asymptomatic Chagas disease mother, who may transmit the parasite infection randomly.

Higher congenital transmission rate of Trypanosoma cruzi associated with family history of congenital transmission

Abstract INTRODUCTION: Congenital transmission (CT) of Trypanosoma cruzi has led to globalization of Chagas disease and its growing relevance as a public health problem. Although the occurrence of CT has been associated with several factors, its mechanisms are still unknown. This study aimed to analyze the geographical and familiar variables of mothers and their association with CT of Chagas disease in a population living in non-endemic areas of Argentina for the last decades. METHODS: We developed a retrospective cohort study in a sample of 2120 mother-child pairs who attended three reference centers in the cities of Buenos Aires, Santa Fe, and Salta between 2002 and 2015. RESULTS: The highest CT rates were observed in children born to Argentinean mothers (10.7%) and in children born to mothers from Buenos Aires (11.7%). Considering the areas of origin of the mothers, those from areas of null-low risk for vector-borne infection had higher CT rates than those from areas of medium-high risk (11.1% vs 8.2%). We also observed a significant intra-familiar "cluster effect," with CT rates of 35.9% in children with an infected sibling, compared to 8.2% in children without infected siblings (RR=4.4 95% CI 2.3-8.4). CONCLUSIONS: The associations observed suggest a higher CT rate in children born to mothers who acquired the infection congenitally, with familiar antecedents, and from areas without the presence of vectors. These observations are considered new epidemiological evidence about Chagas disease in a contemporary urban population, which may contribute to the study of CT and may also be an interesting finding for healthcare professionals.

Investigation of Chagas disease within the same family: case study / Investigação da doença de Chagas em um mesmo núcleo familiar: estudo de caso

ABSTRACT Chagas disease (CD) is a neglected endemic disease. Its classic form of transmission occurs through hematophagous triatomine insects. Its classic form of transmission occurs through hematophagous triatomine insects. There are cases of the disease in non-endemic regions that occur through alternative transmissions, as this possibility also exists. The aim of this study was to report a case among members of a same family (born and resident in Taquarituba, São Paulo, Brazil) diagnosed with CD. The family matriarch lived in a mud house in the countryside and reported contact with the triatomine during childhood. Two grown-up children are also seroreactive; both reported not having contact with the insect as children. Medical record analyzes and new laboratory tests were performed. Clinical history and recent tests have confirmed positivity for CD in the matriarch and her grown-up children. Parasitological techniques have shown negative results, evidencing that they are in the chronic form of the disease. Congenital transmission may have occurred between them, as well as the possibility of vector transmission by secondary species cannot be ruled out, since the patients come from a municipality considered endemic for CD in the past.

RESUMEN La enfermedadde Chagas (EC) es una infección endémica que ha sido descuidada. Su forma clásica de transmisión ocurre mediante insectos triatominos hematófagos. Hay casos de la enfermedad en regiones no endémicas que ocurrieron por vías alternativas de transmisión, puesto que también hay esa posibilidad. El objetivo de este estudio fue reportar un caso de miembros de una misma familia diagnosticados con EC. La matriarca de la familia vivía en una casa hecha de barro en la zona ruraly reportó contacto con el triatomino en su infancia. Dos hijosson también sero-reactivos, pero no reportaron contacto con el insecto cuando eran ninos. Se hicieron análisis de historial médico y nuevaspruebas de laboratorio. El histórico clínico y laspruebas recientes confirmaran la positividad para EC, tanto en la madre como en los hijos. Las técnicasparasitológicas demostraron resultados negativos, comprobando la forma crónica de la enfermedad. Transmisión congénitapuede haber ocurrido entre ellos, así como no se puede descartar la posibilidad de ocurrencia de transmisión vectorial por especies secundarias, ya que los pacientes proceden de un municipio que fue considerado endémico para EC en el pasado.

RESUMO A doença de Chagas (DC) é uma enfermidade endêmica negligenciada. Sua forma clássica de transmissão ocorre por meio de insetos triatomíneos hematófagos. Há casos da doença em regiões não endêmicas ocorridos por transmissões alternativas, uma vez que também existe essa possibilidade. O objetivo deste estudo foi relatar um caso de membros da mesma família (natural e residente em Taquarituba, São Paulo, Brasil) diagnosticados com DC. A matriarca da família morava em uma casa de barro na zona rural e relatou contato com o triatomíneo na infância. Dois filhos também são sororreagentes; ambos relataram não terem tido contato com o inseto quando crianças. Análises de prontuário e novos testes laboratoriais foram feitos. O histórico clínico e os recentes exames confirmaram a positividade para DC, tanto na mãe quanto nos filhos. As técnicas parasitológicas demonstraram resultados negativos, constatando forma crônica da doença. Transmissão congênita pode ter ocorrido entre eles, assim como também não se pode descartar a possibilidade de ocorrência de transmissão vetorial por espécies secundárias, visto que os pacientes são oriundos de um município considerado endêmico para DC no passado.

Congenital Transmission of Trypanosoma cruzi: A Review About the Interactions Between the Parasite, the Placenta, the Maternal and the Fetal/Neonatal Immune Responses.

Chagas disease (CD), caused by the protozoan parasite Trypanosoma cruzi, is considered a neglected tropical disease by the World Health Organization. Congenital transmission of CD is an increasingly relevant public health problem. It progressively becomes the main transmission route over others and can occur in both endemic and non-endemic countries. Though most congenitally infected newborns are asymptomatic at birth, they display higher frequencies of prematurity, low birth weight, and lower Apgar scores compared to uninfected ones, and some suffer from severe symptoms. If not diagnosed and treated, infected newborns are at risk of developing disabling and life-threatening chronic pathologies later in life. The success or failure of congenital transmission depends on interactions between the parasite, the placenta, the mother, and the fetus. We review and discuss here the current knowledge about these parameters, including parasite virulence factors such as exovesicles, placental tropism, potential placental defense mechanisms, the placental transcriptome of infected women, gene polymorphism, and the maternal and fetal/neonatal immune responses, that might modulate the risk of T. cruzi congenital transmission.