Congenitally transmitted Chagas disease in Canada: a family cluster

Severe Chagas disease in Ecuador: a countrywide geodemographic epidemiological analysis from 2011 to 2021

Background

Chagas disease is a neglected and often forgotten tropical disease caused by the Trypanosoma cruzi. This parasite can be transmitted through the direct contact of human skin with feces and urine of the triatomine insect. According to the World Health Organization (WHO), an estimated 6-7 million people are infected worldwide, killing at least 14,000 every year. The disease has been reported in 20 of the 24 provinces of Ecuador, with El Oro, Guayas, and Loja being the most affected.

Methodology

We analyzed the morbidity and mortality rates of severe Chagas disease in Ecuador on a nationwide, population-based level. Hospitalization cases and deaths were also examined based on altitude, including low (< 2,500 m) and high (> 2,500 m) altitudes, according to the International Society. Data was retrieved from the National Institute of Statistics and Census hospital admissions and in-hospital mortality databases from 2011 to 2021.

Results

A total of 118 patients have been hospitalized in Ecuador since 2011 due to Chagas disease. The overall in-hospital mortality rate was 69.4% (N = 82). Men have a higher incidence rate (4.8/1,000,000) than women, although women have a significantly higher mortality rate than men (6.9/1,000,000).

Conclusion

Chagas disease is a severe parasitic condition that primarily affects rural and poorer areas of Ecuador. Men are more likely to be infected due to differences in work and sociocultural activities. Using average elevation data, we conducted a geodemographic analysis to assess incidence rates by altitude. Our findings indicate that the disease is more common at low and moderate altitudes, but recent increases in cases at higher altitudes suggest that environmental changes, such as global warming, could be driving the proliferation of disease-carrying vectors in previously unaffected areas.

Modelling the dynamics of Trypanosoma rangeli and triatomine bug with logistic growth of vector and systemic transmission

In this paper, an insect-parasite-host model with logistic growth of triatomine bugs is formulated to study the transmission between hosts and vectors of the Chagas disease by using dynamical system approach. We derive the basic reproduction numbers for triatomine bugs and Trypanosoma rangeli as two thresholds. The local and global stability of the vector-free equilibrium, parasite-free equilibrium and parasite-positive equilibrium is investigated through the derived two thresholds. Forward bifurcation, saddle-node bifurcation and Hopf bifurcation are proved analytically and illustrated numerically. We show that the model can lose the stability of the vector-free equilibrium and exhibit a supercritical Hopf bifurcation, indicating the occurrence of a stable limit cycle. We also find it unlikely to have backward bifurcation and Bogdanov-Takens bifurcation of the parasite-positive equilibrium. However, the sustained oscillations of infected vector population suggest that Trypanosoma rangeli will persist in all the populations, posing a significant challenge for the prevention and control of Chagas disease.

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.

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

PURPOSE OF REVIEW

Lack of recognition of congenital Chagas disease in infants of mothers from endemic regions who are living in countries nonendemic for Trypanosoma cruzi infection suggests a high rate of underdiagnosis. Pregnancy is the optimal access point for identifying Chagas disease in at-risk mothers and their infants. In this review, we update progress toward implementation of pregnancy-based screening for congenital Chagas disease in nonendemic settings.

RECENT FINDINGS

International organizations have updated recommendations for diagnosis, treatment and prevention of congenital Chagas disease. Reports of successful implementation of pregnancy-based screening at some centers provide a model for optimizing diagnosis of congenital Chagas disease. Screening family members of index patients may identify additional T. cruzi-infected persons. Promising tests to augment current diagnostic modalities for maternal and congenital Chagas disease are in development. Universal or risk-based screening would be cost-effective. More healthcare providers are now aware that treatment of congenital Chagas disease is curative and are promoting efforts to make pregnancy-based screening for congenital Chagas disease a standard of care.

SUMMARY

Ongoing efforts to implement routine pregnancy-based screening for congenital Chagas disease in nonendemic regions will mutually benefit infants, their mothers and family members and can prevent potentially fatal Chagas cardiomyopathy.

A systematic review of historical and current trends in Chagas disease

Introduction

Chagas disease (CD) is caused by Trypanosoma cruzi. When acquired, the disease develops in stages. For diagnosis, laboratory confirmation is required, and an extensive assessment of the patient's health should be performed. Treatment consists of the administration of trypanocidal drugs, which may cause severe adverse effects. The objective of our systematic review was to analyze data contained in the CD published case reports to understand the challenges that patients and clinicians face worldwide.

Materials and methods

We performed a systematic review following the PRISMA guidance. PubMed database was explored using the terms 'American trypanosomiasis' or 'Chagas disease'. Results were limited to human case reports written in English or Spanish. A total of 258 reports (322 patients) were included in the analysis. Metadata was obtained from each article. Following this, it was analyzed to obtain descriptive measures.

Results

From the sample, 56.2% were males and 43.8% were females. Most cases were from endemic countries (85.4%). The most common clinical manifestations were fever during the acute stage (70.0%), dyspnea during the chronic stage in its cardiac form (53.7%), and constipation during the chronic stage in its digestive form (73.7%). Most patients were diagnosed in the chronic stage (72.0%). Treatment was administered in 56.2% of cases. The mortality rate for the acute stage cases was 24.4%, while for the chronic stage this was 28.4%.

Discussion

CD is a parasitic disease endemic to Latin America, with increasing importance due to human and vector migration. In this review, we report reasons for delays in diagnosis and treatment, and trends in medical practices. Community awareness must be increased to improve CD's diagnoses; health professionals should be appropriately trained to detect and treat infected individuals. Furthermore, public health policies are needed to increase the availability of screening and diagnostic tools, trypanocidal drugs, and, eventually, vaccines.

Modelling triatomine bug population and Trypanosoma rangeli transmission dynamics: Co-feeding, pathogenic effect and linkage with chagas disease

Trypanosoma rangeli (T. rangeli), a parasite, is not pathogenic to human but pathogenic to some vector species to induce the behavior changes of infected vectors and subsequently impact the transmission dynamics of other diseases such as Chagas disease which shares the same vector species. Here we develop a mathematical model and conduct qualitative analysis for the transmission dynamics of T. rangeli. We incorporate both systemic and co-feeding transmission routes, and account for the pathogenic effect using infection-induced fecundity and fertility change of the triatomine bugs. We derive two thresholds R_v (the triatomine bug basic reproduction number) and R₀ (the T. rangeli basic reproduction number) to delineate the dynamical behaviors of the ecological and epidemiological systems. We show that when R_v>1 and R₀>1, a unique parasite positive equilibrium E* appears. We find that E* can be unstable and periodic oscillations can be observed where the pathogenic effect plays a significant role. Implications of the qualitative analysis and numerical simulations suggest the need of an integrative vector-borne disease prevention and control strategy when multiple vector-borne diseases are transmitted by the same set of vector species.

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.