Epidemiological modeling of Trypanosoma cruzi : Low stercorarian transmission and failure of host adaptive immunity explain the frequency of mixed infections in humans

by Nicol ás Tomasini, Paula Gabriela Ragone, Sébastien Gourbière, Juan Pablo Aparicio, Patricio Diosque People living in areas with active vector-borne transmission of Chagas disease have multiple contacts with its causative agent,Trypanosoma cruzi. Reinfections byT.cruzi are possible at least in animal models leading to lower or even hardly detectable parasitaemia. In humans, although reinfections are thought to have major public health implications by increasing the risk of chronic manifestations of the disease, there is little quantitative knowledge about their frequency and the timing of parasite re-inoculation in the course of the disease. Here, we implemented stochastic agent-based models i) to estimate the rate of re-inoculation in humans and ii) to assess how frequent are reinfections during the acute and chronic stages of the disease according to alternative hypotheses on the adaptive immune response following a primary infection. By using a hybrid genetic algorithm, the models were fitted to epidemiological data of Argentinean rural villages where mixed infections by different genotypes ofT.cruzi reach 56% in humans. To explain this percentage, the best model predicted 0.032 (0.008 –0.042) annual reinfections per individual with 98.4% of them occurring in the chronic phase. In addition, the parasite escapes to the adaptive immune response mounted after the primary infection in at least 20% of the events of re-inoculation. With these low a...
Source: PLoS Computational Biology - Category: Biology Authors: Source Type: research

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Authors: Norman FF, Comeche B, Chamorro S, López-Vélez R Abstract Introduction: Recent increases in population movements have created novel health challenges in many areas of the World, and health policies have been adapted accordingly in several countries. However, screening guidelines for infectious diseases are not standardized and generally do not include comprehensive screening for parasitic infections.Areas covered: Malaria, Chagas disease, leishmaniasis, amebiasis, filariases, strongyloidiasis and schistosomiasis are reviewed, focusing on the challenges posed for their diagnosis and management ...
Source: Expert Review of Anti-Infective Therapy - Category: Infectious Diseases Tags: Expert Rev Anti Infect Ther Source Type: research
Publication date: Available online 3 January 2020Source: Biochimica et Biophysica Acta (BBA) - Molecular Basis of DiseaseAuthor(s): Augusto E. Bivona, Andrés Sánchez Alberti, Natacha Cerny, Sebastián N. Trinitario, Emilio L. MalchiodiAbstractChagas disease is currently endemic to 21 Latin-American countries and has also become a global concern because of globalization and mass migration of chronically infected individuals. Prophylactic and therapeutic vaccination might contribute to control the infection and the pathology, as complement of other strategies such as vector control and chemotherapy. Ideal...
Source: Biochimica et Biophysica Acta (BBA) Molecular Basis of Disease - Category: Molecular Biology Source Type: research
buquerque S Abstract Chagas disease is a tropical illness caused by the protozoan Trypanosoma cruzi. The disease affects populations of the Americas and has been spread to other continents due to the migration process. The disease is partially controlled by two drugs, Benznidazole and Nifurtimox. These molecules are active in the acute phase of the infection but are usually ineffective during the symptomatic chronic phase. Several research groups have developed novel candidates to control Chagas disease; however, no novel commercial formulation is available. In this article, we described the anti-T. cruzi effects ...
Source: Biomed Res - Category: Research Authors: Tags: Biomed Res Int Source Type: research
CONCLUSIONS: Chagas disease affected mostly women, with the indeterminate chronic form of the disease.
Source: Revista da Sociedade Brasileira de Medicina Tropical - Category: Tropical Medicine Source Type: research
CONCLUSIONS: These data contribute to a better understanding of the distribution of T. cruzi infection in the Northeastern region of Brazil. Preventive measures based on vector control should be implemented in the study ar ea in order to reduce the burden this neglected tropical disease.
Source: Revista da Sociedade Brasileira de Medicina Tropical - Category: Tropical Medicine Source Type: research
Trypanosoma cruzi is the causative agent of Chagas disease, which is endemic to subtropical and tropical Americas. The disease treatment remains partially ineffective, involving therapies directed to the parasite...
Source: Parasites and Vectors - Category: Microbiology Authors: Tags: Research Source Type: research
Abstract Chagas disease (CD), caused by Trypanosoma cruzi, is the main parasitic disease in the Western Hemisphere, with an increasing number of cases, especially in non-endemic regions. The disease is characterized by cardiomegaly and mega viscera, nevertheless, the clinical outcome is hard to predict, underscoring the need for further research into the pathophysiology of CD. Even though most basic and translational research involving CD is performed using in vivo models, in vitro models arise as an ethical, rapidly evolving, and physiologically relevant alternative for CD research. In the present review, we disc...
Source: Acta Tropica - Category: Infectious Diseases Authors: Tags: Acta Trop Source Type: research
Mepraia gajardoi and Mepraia spinolai are endemic triatomine vector species of Trypanosoma cruzi, a parasite that causes Chagas disease. These vectors inhabit arid, semiarid and Mediterranean areas of Chile. Mepr...
Source: Parasites and Vectors - Category: Microbiology Authors: Tags: Research Source Type: research
ppi A Abstract The protozoan Trypanosoma cruzi is the causative agent of Chagas' disease, endemic in Latin America but present worldwide. Research efforts have focused on the examination of immune mechanisms that mediate host protection as well as immunopathology during this parasitic infection. The study of CD8+ T cell immunity emerges as a key aspect given the critical importance of parasite-specific CD8+ T cells for host resistance throughout the infection. In recent years, new research has shed light on novel pathways that modulate the induction, maintenance, and regulation of CD8+ T cell respon...
Source: Trends in Parasitology - Category: Parasitology Authors: Tags: Trends Parasitol Source Type: research
Authors: Kim YH, Yang Z, Lee J, Ahn HJ, Chong CK, Maricondi W, Dias RF, Nam HW Abstract Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and is endemic in many Latin American countries. Diagnosis is based on serologic testing and the WHO recommends two or more serological tests for confirmation. Acidic ribosomal P protein of T. cruzi showed strong reactivity against positive sera of patients, and we cloned the protein after fragmenting it to enhance its antigenicity and solubility. Twelve positive sera of Chagas disease patients were reacted with the fragmented ribosomal P protein using western...
Source: Korean Journal of Parasitology - Category: Parasitology Tags: Korean J Parasitol Source Type: research
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