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Dai X, Wu X, Jiang J, Rong L. Modeling the impact of non-human host predation on the transmission of Chagas disease. Math Biosci 2024; 374:109230. [PMID: 38851529 DOI: 10.1016/j.mbs.2024.109230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 05/07/2024] [Accepted: 06/04/2024] [Indexed: 06/10/2024]
Abstract
In addition to the traditional transmission route via the biting-and-defecating process, non-human host predation of triatomines is recognized as another significant avenue for Chagas disease transmission. In this paper, we develop an eco-epidemiological model to investigate the impact of predation on the disease's spread. Two critical thresholds, Rvp (the basic reproduction number of triatomines) and R0p (the basic reproduction number of the Chagas parasite), are derived to delineate the model's dynamics. Through the construction of appropriate Lyapunov functions and the application of the Bendixson-Dulac theorem, the global asymptotic stabilities of the equilibria are fully established. The vector-free equilibrium E0 is globally stable when Rvp<1. E1, the disease-free equilibrium, is globally stable when Rvp>1 and R0p<1, while the endemic equilibrium E∗ is globally stable when both Rvp>1 and R0p>1. Numerical simulations highlight that the degree of host predation on triatomines, influenced by non-human hosts activities, can variably increase or decrease the Chagas disease transmission risk. Specifically, low or high levels of host predation can reduce R0p to below unity, while intermediate levels may increase the infected host populations, albeit with a reduction in R0p. These findings highlight the role played by non-human hosts and offer crucial insights for the prevention and control of Chagas disease.
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Affiliation(s)
- Xuan Dai
- School of Science, Shanghai Maritime University, Shanghai, 201306, PR China
| | - Xiaotian Wu
- School of Science, Shanghai Maritime University, Shanghai, 201306, PR China.
| | - Jiao Jiang
- School of Science, Shanghai Maritime University, Shanghai, 201306, PR China
| | - Libin Rong
- Department of Mathematics, University of Florida, Gainesville, FL 32611, USA.
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Fiatsonu E, Busselman RE, Hamer GL, Hamer SA, Ndeffo-Mbah ML. Effectiveness of fluralaner treatment regimens for the control of canine Chagas disease: A mathematical modeling study. PLoS Negl Trop Dis 2023; 17:e0011084. [PMID: 36693084 PMCID: PMC9897538 DOI: 10.1371/journal.pntd.0011084] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 02/03/2023] [Accepted: 01/09/2023] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Canine Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and transmitted by insect triatomine vectors known as kissing bugs. The agent can cause cardiac damage and long-term heart disease and death in humans, dogs, and other mammals. In laboratory settings, treatment of dogs with systemic insecticides has been shown to be highly efficacious at killing triatomines that feed on treated dogs. METHOD We developed compartmental vector-host models of T. cruzi transmission between the triatomine and dog population accounting for the impact of seasonality and triatomine migration on disease transmission dynamics. We considered a single vector-host model without seasonality, and model with seasonality, and a spatially coupled model. We used the models to evaluate the effectiveness of the insecticide fluralaner with different durations of treatment regimens for reducing T. cruzi infection in different transmission settings. RESULTS In low and medium transmission settings, our model showed a marginal difference between the 3-month and 6-month regimens for reducing T. cruzi infection among dogs. The difference increases in the presence of seasonality and triatomine migration from a sylvatic transmission setting. In high transmission settings, the 3-month regimen was substantially more effective in reducing T. cruzi infections in dogs than the other regimens. Our model showed that increased migration rate reduces fluralaner effectiveness in all treatment regimens, but the relative reduction in effectiveness is minimal during the first years of treatment. However, if an additional 10% or more of triatomines killed by dog treatment were eaten by dogs, treatment could increase T. cruzi infections in the dog population at least during the first year of treatment. CONCLUSION Our analysis shows that treating all peridomestic dogs every three to six months for at least five years could be an effective measure to reduce T. cruzi infections in dogs and triatomines in peridomestic transmission settings. However, further studies at the local scale are needed to better understand the potential impact of routine use of fluralaner treatment on increasing dogs' consumption of dead triatomines.
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Affiliation(s)
- Edem Fiatsonu
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Rachel E. Busselman
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Gabriel L. Hamer
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Sarah A. Hamer
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Martial L. Ndeffo-Mbah
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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Oliveira MM, Bonturi CR, Salu BR, Oliva MLV, Mortara RA, Orikaza CM. Modulation of STAT-1, STAT-3, and STAT-6 activities in THP-1 derived macrophages infected with two Trypanosoma cruzi strains. Front Immunol 2022; 13:1038332. [PMID: 36389843 PMCID: PMC9643828 DOI: 10.3389/fimmu.2022.1038332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/04/2022] [Indexed: 12/03/2022] Open
Abstract
Trypanosoma cruzi is the causative protozoan of Chagas’ Disease, a neglected tropical disease that affects 6−7 million people worldwide. Interaction of the parasite with the host immune system is a key factor in disease progression and chronic symptoms. Although the human immune system is capable of controlling the disease, the parasite has numerous evasion mechanisms that aim to maintain intracellular persistence and survival. Due to the pronounced genetic variability of T. cruzi, co-infections or mixed infections with more than one parasite strain have been reported in the literature. The intermodulation in such cases is unclear. This study aimed to evaluate the co-infection of T. cruzi strains G and CL compared to their individual infections in human macrophages derived from THP-1 cells activated by classical or alternative pathways. Flow cytometry analysis demonstrated that trypomastigotes were more infective than extracellular amastigotes (EAs) and that strain G could infect more macrophages than strain CL. Classically activated macrophages showed lower number of infected cells and IL-4-stimulated cells displayed increased CL-infected macrophages. However, co-infection was a rare event. CL EAs decreased the production of reactive oxygen species (ROS), whereas G trypomastigotes displayed increased ROS detection in classically activated cells. Co-infection did not affect ROS production. Monoinfection by strain G or CL mainly induced an anti-inflammatory cytokine profile by decreasing inflammatory cytokines (IFN-γ, TNF-α, IL-1β) and/or increasing IL-4, IL-10, and TGF-β. Co-infection led to a predominant inflammatory milieu, with reduced IL-10 and TGF-β, and/or promotion of IFN-γ and IL-1β release. Infection by strain G reduced activation of intracellular signal transducer and activator of transcription (STAT) factors. In EAs, monoinfections impaired STAT-1 activity and promoted phosphorylation of STAT-3, both changes may prolong cell survival. Coinfected macrophages displayed pronounced activation of all STATs examined. These activations likely promoted parasite persistence and survival of infected cells. The collective results demonstrate that although macrophages respond to both strains, T. cruzi can modulate the intracellular environment, inducing different responses depending on the strain, parasite infective form, and co-infection or monoinfection. The modulation influences parasite persistence and survival of infected cells.
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Affiliation(s)
- Melissa Martins Oliveira
- ¹Microbiology, Immunology and Parasitology Department, Escola Paulista de Medicina, Federal University of São Paulo - UNIFESP, São Paulo, Brazil
| | - Camila Ramalho Bonturi
- ²Biochemistry Department, Escola Paulista de Medicina, Federal University of São Paulo - UNIFESP, São Paulo, Brazil
| | - Bruno Ramos Salu
- ²Biochemistry Department, Escola Paulista de Medicina, Federal University of São Paulo - UNIFESP, São Paulo, Brazil
| | - Maria Luiza Vilela Oliva
- ²Biochemistry Department, Escola Paulista de Medicina, Federal University of São Paulo - UNIFESP, São Paulo, Brazil
| | - Renato Arruda Mortara
- ¹Microbiology, Immunology and Parasitology Department, Escola Paulista de Medicina, Federal University of São Paulo - UNIFESP, São Paulo, Brazil
| | - Cristina Mary Orikaza
- ¹Microbiology, Immunology and Parasitology Department, Escola Paulista de Medicina, Federal University of São Paulo - UNIFESP, São Paulo, Brazil
- *Correspondence: Cristina Mary Orikaza,
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Olivo Freites C, Sy H, Gharamti A, Higuita NIA, Franco-Paredes C, Suárez JA, Henao-Martínez AF. Chronic Chagas Disease-the Potential Role of Reinfections in Cardiomyopathy Pathogenesis. Curr Heart Fail Rep 2022; 19:279-289. [PMID: 35951245 DOI: 10.1007/s11897-022-00568-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/11/2022] [Indexed: 10/15/2022]
Abstract
PURPOSE OF THE REVIEW Chagas disease is a neglected anthropozoonosis of global importance with significant cardiovascular-associated mortality. This review focuses on the Trypanosoma cruzi reinfections' role in chronic Chagas cardiomyopathy pathogenesis. We discuss and summarize the available data related to pathology, pathogenesis, diagnosis, and treatment of reinfections. RECENT FINDINGS Reinfections influence the genetic and regional diversity of T. cruzi, tissue tropism, modulation of the host's immune system response, clinical manifestations, the risk for congenital infections, differences in diagnostics performances, response to antiparasitic therapy, and the natural history of the disease. Animal models suggest that reinfections lead to worse outcomes and increased mortality, while other studies showed an association between reinfections and lower parasitemia levels and subsequent infection protection. In some regions, the human risk of reinfections is 14% at 5 years. Evidence has shown that higher anti-T. cruzi antibodies are correlated with an increased rate of cardiomyopathy and death, suggesting that a higher parasite exposure related to reinfections may lead to worse outcomes. Based on the existing literature, reinfections may play a role in developing and exacerbating chronic Chagas cardiomyopathy and are linked to worse outcomes. Control efforts should be redirected to interventions that address structural poverty for the successful and sustainable prevention of Chagas disease.
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Affiliation(s)
- Christian Olivo Freites
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Hendrik Sy
- Internal Medicine Department, Mount Sinai Health System, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Amal Gharamti
- Internal Medicine Department, Yale-Waterbury Hospital, Yale School of Medicine, New Haven, CT, USA
| | | | | | - José Antonio Suárez
- Clinical Research Department, Investigador SNI Senacyt Panamá, Instituto Conmemorativo Gorgas de Estudios de La Salud, Panamá City, Republic of Panama
| | - Andrés F Henao-Martínez
- Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Avenue, Mail Stop B168, Aurora, CO, USA.
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Chen L, Wu X, Xu Y, Rong L. Modelling the dynamics of Trypanosoma rangeli and triatomine bug with logistic growth of vector and systemic transmission. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:8452-8478. [PMID: 35801473 DOI: 10.3934/mbe.2022393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
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.
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Affiliation(s)
- Lin Chen
- Department of Mathematics, Hangzhou Normal University, Hangzhou 311121, China
| | - Xiaotian Wu
- College of Arts and Sciences, Shanghai Maritime University, Shanghai 201306, China
| | - Yancong Xu
- Department of Mathematics, Hangzhou Normal University, Hangzhou 311121, China
| | - Libin Rong
- Department of Mathematics, University of Florida, Gainesville 32611, USA
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6
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Dumonteil E, Herrera C. The Case for the Development of a Chagas Disease Vaccine: Why? How? When? Trop Med Infect Dis 2021; 6:tropicalmed6010016. [PMID: 33530605 PMCID: PMC7851737 DOI: 10.3390/tropicalmed6010016] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/06/2021] [Accepted: 01/19/2021] [Indexed: 11/16/2022] Open
Abstract
Chagas disease is a major neglected tropical disease, transmitted predominantly by triatomine insect vectors, but also through congenital and oral routes. While endemic in the Americas, it has turned into a global disease. Because of the current drug treatment limitations, a vaccine would represent a major advancement for better control of the disease. Here, we review some of the rationale, advances, and challenges for the ongoing development of a vaccine against Chagas disease. Recent pre-clinical studies in murine models have further expanded (i) the range of vaccine platforms and formulations tested; (ii) our understanding of the immune correlates for protection; and (iii) the extent of vaccine effects on cardiac function, beyond survival and parasite burden. We further discuss outstanding issues and opportunities to move Chagas disease development forward in the near future.
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Han CY, Issa H, Rychtář J, Taylor D, Umana N. A voluntary use of insecticide treated nets can stop the vector transmission of Chagas disease. PLoS Negl Trop Dis 2020; 14:e0008833. [PMID: 33141850 PMCID: PMC7671556 DOI: 10.1371/journal.pntd.0008833] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 11/17/2020] [Accepted: 09/24/2020] [Indexed: 11/19/2022] Open
Abstract
One of the stated goals of the London Declaration on Neglected Tropical Diseases is the interruption of domiciliary transmissions of Chagas disease in the region of the Americas. We used a game-theoretic approach to assess the voluntary use of insecticide treated nets (ITNs) in the prevention of the spread of infection through vector bites. Our results show that individuals behave rationally and weigh the risks of insect bites against the cost of the ITNs. The optimal voluntary use of ITNs results in predicted incidence rates that closely track the real incidence rates in Latin America. This means that ITNs are effective and could be used to control the spread of the disease by relying on individual decisions rather than centralized policies. Our model shows that to completely eradicate the vector transmission through the voluntary individual use of ITNs, the cost of ITNs should be as low as possible.
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Affiliation(s)
- Cheol Yong Han
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Habeeb Issa
- Department of Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jan Rychtář
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Dewey Taylor
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Nancy Umana
- Department of Biology, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Psychology, Virginia Commonwealth University, Richmond, Virginia, USA
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8
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Simoy MI, Aparicio JP. Ross-Macdonald models: Which one should we use? Acta Trop 2020; 207:105452. [PMID: 32302688 DOI: 10.1016/j.actatropica.2020.105452] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/07/2020] [Accepted: 03/16/2020] [Indexed: 11/19/2022]
Abstract
Ross-Macdonald models are the building blocks of most vector-borne disease models. Even for the same disease, different authors use different model formulations, but a study of the dynamical consequences of assuming different hypotheses is missing. In this work we present different formulations of the basic Ross-Macdonald model together with a careful discussion of the assumptions behind each model. The most general model presented is an agent based model for which arbitrary distributions for latency and infectious periods for both, host and vectors, is considered. At population level we also developed a deterministic Volterra integral equations model for which also arbitrary distributions in the waiting times are included. We compare the model solutions using different distributions for the infectious and latency periods using statistics, like the epidemic peak, or epidemic final size, to characterize the epidemic curves. The basic reproduction number (R0) for each formulation is computed and compared with empirical estimations obtained with the agent based models. The importance of considering realistic distributions for the latent and infectious periods is highlighted and discussed. We also show that seasonality is a key driver of vector-borne disease dynamics shaping the epidemic curve and its duration.
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Affiliation(s)
- Mario Ignacio Simoy
- Instituto de Investigaciones en Energía no Convencional (INENCO), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Av. Bolivia 5100, Salta 4400, Argentina; Instituto Multidisciplinario sobre Ecosistemas y Desarrollo Sustentable, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNICEN), Facultad de Ciencias Exactas, Paraje Arroyo Seco s/n, Tandil 7000, Argentina
| | - Juan Pablo Aparicio
- Instituto de Investigaciones en Energía no Convencional (INENCO), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Av. Bolivia 5100, Salta 4400, Argentina; Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, PO Box 871904 Tempe, AZ 85287-1904, USA.
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9
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Monje-Rumi MM, Floridia-Yapur N, Zago MP, Ragone PG, Pérez Brandán CM, Nuñez S, Barrientos N, Tomasini N, Diosque P. Potential association of Trypanosoma cruzi DTUs TcV and TcVI with the digestive form of Chagas disease. INFECTION GENETICS AND EVOLUTION 2020; 84:104329. [PMID: 32339759 DOI: 10.1016/j.meegid.2020.104329] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 11/28/2022]
Abstract
The relationship among genetic diversity of Trypanosoma cruzi and clinical forms of Chagas disease remain elusive. In order to assess the possible association between different T. cruzi Discrete Typing Units (DTUs) and the clinical pictures of the disease, 205 chronic patients from Salta province, Argentina, were analysed. One hundred and twenty-two of these patients were clinically categorized as: cardiac 38.5% (47/122), digestive 15% (18/122), cardio-digestive 16% (20/122) and asymptomatic 30% (37/122). From each patient, blood samples were taken for both, Polymerase Chain Reaction (PCR) targeting kDNA and blood culture analyses. The presence of T. cruzi kDNA was detected in 43% (88/205) of the patients. T. cruzi DTUs were identified in 74% (65/88) of the kDNA positive patients by PCR-hybridization using specific probes. We detected the presence of DTUs TcI, TcII, TcV and TcVI. Single infections (i.e. presence of only one DTU in the sample) were detected in 38.64% of the samples (34/88), while mixed infections were 35.23% (31/88). TcV was the most prevalent DTU (60.3%- 53/88). The association analyses showed, for the first time to the best of our knowledge, that TcV and TcVI were associated with the digestive form of Chagas Disease (Fisher p = .0001).
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Affiliation(s)
- M M Monje-Rumi
- Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina. Av. Bolivia, 5150 Salta, Argentina
| | - N Floridia-Yapur
- Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina. Av. Bolivia, 5150 Salta, Argentina
| | - M P Zago
- Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina. Av. Bolivia, 5150 Salta, Argentina
| | - P G Ragone
- Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina. Av. Bolivia, 5150 Salta, Argentina
| | - C M Pérez Brandán
- Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina. Av. Bolivia, 5150 Salta, Argentina
| | - S Nuñez
- Servicio de Cardiología, Hospital San Bernardo, Av. José Tobias 69, Salta, Argentina
| | - N Barrientos
- Servicio de Cardiología, Hospital San Bernardo, Av. José Tobias 69, Salta, Argentina
| | - N Tomasini
- Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina. Av. Bolivia, 5150 Salta, Argentina
| | - P Diosque
- Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina. Av. Bolivia, 5150 Salta, Argentina.
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Modelling triatomine bug population and Trypanosoma rangeli transmission dynamics: Co-feeding, pathogenic effect and linkage with chagas disease. Math Biosci 2020; 324:108326. [PMID: 32092467 DOI: 10.1016/j.mbs.2020.108326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/18/2020] [Accepted: 02/18/2020] [Indexed: 11/21/2022]
Abstract
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 Rv (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 Rv>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.
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Detailed ecological associations of triatomines revealed by metabarcoding and next-generation sequencing: implications for triatomine behavior and Trypanosoma cruzi transmission cycles. Sci Rep 2018. [PMID: 29515202 PMCID: PMC5841364 DOI: 10.1038/s41598-018-22455-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Trypanosoma cruzi is the agent of Chagas disease, transmitted by hematophagous triatomine vectors. Establishing transmission cycles is key to understand the epidemiology of the disease, but integrative assessments of ecological interactions shaping parasite transmission are still limited. Current approaches also lack sensitivity to assess the full extent of this ecological diversity. Here we developed a metabarcoding approach based on next-generation sequencing to identify triatomine gut microbiome, vertebrate feeding hosts, and parasite diversity and their potential interactions. We detected a dynamic microbiome in Triatoma dimidiata, including 23 bacterial orders, which differed according to blood sources. Fourteen vertebrate species served as blood sources, corresponding to domestic, synantropic and sylvatic species, although four (human, dog, cow and mice) accounted for over 50% of blood sources. Importantly, bugs fed on multiple hosts, with up to 11 hosts identified per bug, indicating very frequent host-switching. A high clonal diversity of T. cruzi was detected, with up to 20 haplotypes per bug. This analysis provided much greater sensitivity to detect multiple blood meals and multiclonal infections with T. cruzi, which should be taken into account to develop transmission networks, and characterize the risk for human infection, eventually leading to a better control of disease transmission.
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Cevey ÁC, Mirkin GA, Donato M, Rada MJ, Penas FN, Gelpi RJ, Goren NB. Treatment with Fenofibrate plus a low dose of Benznidazole attenuates cardiac dysfunction in experimental Chagas disease. Int J Parasitol Drugs Drug Resist 2017; 7:378-387. [PMID: 29040909 PMCID: PMC5727348 DOI: 10.1016/j.ijpddr.2017.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/30/2017] [Accepted: 10/06/2017] [Indexed: 12/24/2022]
Abstract
Trypanosoma cruzi induces serious cardiac alterations during the chronic infection. Intense inflammatory response observed from the beginning of infection, is critical for the control of parasite proliferation and evolution of Chagas disease. Peroxisome proliferator-activated receptors (PPAR)-α, are known to modulate inflammation. In this study we investigated whether a PPAR-α agonist, Fenofibrate, improves cardiac function and inflammatory parameters in a murine model of T. cruzi infection. BALB/c mice were sequentially infected with two T. cruzi strains of different genetic background. Benznidazole, commonly used as trypanocidal drug, cleared parasites but did not preclude cardiac pathology, resembling what is found in human chronic chagasic cardiomyopathy. Fenofibrate treatment restored to normal values the ejection and shortening fractions, left ventricular end-diastolic, left ventricular end-systolic diameter, and isovolumic relaxation time. Moreover, it reduced cardiac inflammation and fibrosis, decreased the expression of pro-inflammatory (IL-6, TNF-α and NOS2) and heart remodeling mediators (MMP-9 and CTGF), and reduced serum creatine kinase activity. The fact that Fenofibrate partially inhibited NOS2 expression and NO release in the presence of a PPAR-α non-competitive inhibitor, suggested it also acted through PPAR-α-independent pathways. Since IκBα cytosolic degradation was inhibited by Fenofibrate, it can be concluded that the NFκB pathway has a role in its effects. Thus, we demonstrate that Fenofibrate acts through PPAR-α-dependent and -independent pathways. Our study shows that combined treatment with Fenofibrate plus Benznidazole is able both to reverse the cardiac dysfunction associated with the ongoing inflammatory response and fibrosis and to attain parasite clearance in an experimental model of Chagas disease.
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Affiliation(s)
- Ágata C Cevey
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Inmunología, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Buenos Aires, Argentina
| | - Gerardo A Mirkin
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Inmunología, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Buenos Aires, Argentina
| | - Martín Donato
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Patología, Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Medicina, Instituto de Fisiopatología Cardiovascular (INFICA), Buenos Aires, Argentina
| | - María J Rada
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Inmunología, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Buenos Aires, Argentina
| | - Federico N Penas
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Inmunología, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Buenos Aires, Argentina
| | - Ricardo J Gelpi
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Patología, Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Medicina, Instituto de Fisiopatología Cardiovascular (INFICA), Buenos Aires, Argentina
| | - Nora B Goren
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Inmunología, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Buenos Aires, Argentina; CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y SIDA (INBIRS), Buenos Aires, Argentina.
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