Congenital Chagas disease: progress toward implementation of pregnancy-based screening

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.

Gastrointestinal Manifestations of Chagas Disease: A Systematic Review with Meta-Analysis

The aims of this study were to estimate the prevalence of gastrointestinal manifestations among individuals with positive serology for Chagas disease (ChD) and to describe the clinical gastrointestinal manifestations of the disease. A systematic review with meta-analysis was conducted based on the criteria and recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The PubMed, Scopus, Virtual Health Library, Web of Science, and Embase databases were used to search for evidence. Two reviewers independently selected eligible articles and extracted data. RStudio® software was used for the meta-analysis. For subgroup analysis, the studies were divided according to the origin of the individuals included: 1) individuals from health units were included in the health care service prevalence analysis, and 2) individuals from the general population were included in the population prevalence analysis. A total of 2,570 articles were identified, but after removal of duplicates and application of inclusion criteria, 24 articles were included and 21 were part of the meta-analysis. Most of the studies were conducted in Brazil. Radiological diagnosis was the most frequent method used to identify the gastrointestinal clinical form. The combined effect of meta-analysis studies showed a prevalence of gastrointestinal manifestations in individuals with ChD of 12% (95% CI, 8.0-17.0%). In subgroup analysis, the prevalence for studies involving health care services was 16% (95% CI, 11.0-23.0%), while the prevalence for population-based studies was 9% (95% CI, 5.0-15.0%). Megaesophagus and megacolon were the main forms of ChD presentation in the gastrointestinal form. The prevalence of gastrointestinal manifestations of ChD was 12%. Knowing the prevalence of ChD in its gastrointestinal form is an important step in planning health actions for these patients.

Chagas Disease in Europe

Chagas disease is currently present in many non-endemic countries and remains a neglected tropical disease globally. A review of the literature identified significant gaps and scarcity of updated information from European countries, with most studies reporting data from Spain and Italy. The index of underdiagnosis may be as high as 70%, affecting mainly females of child-bearing age. Standardized screening of fertile, non-pregnant, women from endemic countries and subsequent treatment is considered an essential strategy to control transmission and prevent new cases, yet no uniform legislation for screening risk groups exists. There is heterogeneity in Europe in terms of preventive strategies to avoid transfusion-related transmission of Chagas disease, not necessarily in line with the European directives, with some countries conducting systematic screening for T. cruzi infection in blood donors, whilst others rely on pre-transfusion questionnaires. The growing burden of the infection in resource-rich areas may provide an opportunity for progress in certain aspects of control and prevention. Options for improving screening strategies, management and linkage to care are reviewed.

Trypanosoma cruzi STIB980: A TcI Strain for Drug Discovery and Reverse Genetics

Since the first published genome sequence of Trypanosoma cruzi in 2005, there have been tremendous technological advances in genomics, reverse genetics, and assay development for this elusive pathogen. However, there is still an unmet need for new and better drugs to treat Chagas disease. Here, we introduce a T. cruzi assay strain that is useful for drug research and basic studies of host-pathogen interactions. T. cruzi STIB980 is a strain of discrete typing unit TcI that grows well in culture as axenic epimastigotes or intracellular amastigotes. We evaluated the optimal parameters for genetic transfection and constructed derivatives of T. cruzi STIB980 that express reporter genes for fluorescence- or bioluminescence-based drug efficacy testing, as well as a Cas9-expressing line for CRISPR/Cas9-mediated gene editing. The genome of T. cruzi STIB980 was sequenced by combining short-read Illumina with long-read Oxford Nanopore technologies. The latter served as the primary assembly and the former to correct mistakes. This resulted in a high-quality nuclear haplotype assembly of 28 Mb in 400 contigs, containing 10,043 open-reading frames with a median length of 1077 bp. We believe that T. cruzi STIB980 is a useful addition to the antichagasic toolbox and propose that it can serve as a DTU TcI reference strain for drug efficacy testing.

Our Current Understanding of Chagas Disease and Trypanosoma cruzi Infection in the State of Florida — an Update on Research in this Region of the USA

Purpose of Review

Chagas disease (CD) is a neglected tropical disease caused by the protozoan parasite, Trypanosoma cruzi. Parasite transmission primarily occurs through direct interaction with an infected triatomine insect vector (kissing bug), but other routes are known. We aim to review the literature and discuss the unique circumstances of CD in the US state of Florida.

Recent Findings

Florida is home to naturally occurring kissing bugs that are invading homes and harbor T. cruzi. The state is also home to a diverse population of immigrants from Chagas-endemic regions in Latin America. In the USA, Florida is the state with the third highest estimated burden of CD, although the true prevalence is unknown.

Summary

Chagas disease is a chronic infection that often remains silent for decades. Those who manifest chronic disease may eventually die from debilitating cardiac and/or gastrointestinal manifestations. Florida is an opportune region of the USA for the study of CD, due to the existence of endemic transmission cycles in addition to the burden among people born in Chagas-endemic regions.

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.

Screening for Chagas Disease during Pregnancy in the United States-A Literature Review

Obstetrician-gynecologists in the United States have little clinical experience with the epidemiology, pathophysiology, diagnosis, and treatment of Chagas disease. The number of US parturients born in Central and South America has continued to increase over the last 20 years, making US obstetricians more and more likely to care for Chagas-infected mothers who may never be identified until dealing with long-term consequences of the disease. A literature search demonstrates that few US obstetric care providers recognize the risk of vertical transmission for the neonate and the missed opportunity of infant treatment to decrease disease prevalence. Most women will be asymptomatic during pregnancy, as will their neonates, making routine laboratory screening a necessity for the identification of at-risk neonates. While the benefits of treating asymptomatic women identified in pregnancy are not as clear as the benefits for the infants, future health screenings for evidence of the progression of Chagas disease may be beneficial to these families. The literature suggests that screening for Chagas in pregnancy in the US can be done in a cost-effective way. When viewed through an equity lens, this condition disproportionately affects families of lower socioeconomic means. Improved education of healthcare providers and appropriate resources for diagnosis and treatment can improve this disparity in health outcomes.