Mario J Grijalva

Mario J Grijalva
Ohio University · Infectious and Tropical Disease Institute, Dept. Biomedical Sciences

Doctor of Philosophy

About

191
Publications
18,030
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2,354
Citations
Additional affiliations
May 1999 - September 2017
Ohio University
Position
  • Professor (Full)

Publications

Publications (191)
Article
Full-text available
The objective of this study was to evaluate the effectiveness of selective and community-wide house insecticide spraying in controlling triatomines in the subtropical areas of Loja Province, Ecuador. We designed a quasi-experimental pre-post-test without a control group to compare entomological levels before and after spraying. The baseline study w...
Article
Chagas disease is endemic in ~70% of Ecuador. Rhodnius ecuadoriensis and Triatoma carrioni (Hemiptera: Reduviidae) are the primary vectors of Chagas disease in Southern Ecuador. This study tested the effectiveness of selective deltamethrin application of Domiciliary Units (DUs) infested with triatomines, coupled with community education activities...
Article
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Background Access to professional health care providers in Loja Province, Ecuador can be difficult for many citizens. The Health Care Access Barrier Model (HCAB) was established to provide a framework for classification, analysis, and reporting of modifiable health care access barriers. This study uses the HCAB Model to identify barriers and themes...
Article
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Objective Chagas disease (CD) is caused by the protozoan parasite, Trypanosoma cruzi. It affects 6 to 8 million people worldwide and leads to approximately 50,000 deaths per year. In vitro and in vivo studies had demonstrated that Tripanosoma cruzi infection causes an imbalance in the hypothalamic-pituitary-adrenal (HPA) axis that is accompanied by...
Article
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Although vaccines have been developed to prevent COVID-19, vaccine hesitancy is a significant barrier for vaccination programs. Most research on COVID-19 vaccine hesitancy has blamed misinformation and misstated concerns about effectiveness, safety, and side effects of these vaccines. The preponderance of these studies has been performed in the Glo...
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Background: Recent studies in the United States have shown that between 56 to 74% are willing to receive the COVID-19 vaccine. A significant portion of the population should be vaccinated to avoid severe illness and prevent unnecessary deaths. We examined correlates of COVID-19 vaccine acceptance among a representative sample of adults residing in...
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Accurate prediction of vectors dispersal, as well as identification of adaptations that allow blood-feeding vectors to thrive in built environments, are a basis for effective disease control. Here we adopted a landscape genomics approach to assay gene flow, possible local adaptation, and drivers of population structure in Rhodnius ecuadoriensis , a...
Article
Most development communication scholarship uses adeficits-based approach to social change. The asset-based community development (ABCD) emphasizes identifying acommunity’s strengths to promote social change. We offer an asset mapping that uses participatory mural painting as its discovery method. As part of an ongoing engagement in rural Ecuador, w...
Article
Charitable organizations continue to increase in the United States. Procuring charitable donations and meeting fundraising goals can be challenging for new organizations. Mental representations, or construals of phenomena, often drive charitable behaviors, preferences, and choices. Healthy Homes for Healthy Living (HHHL) focuses on reconstructing h...
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Chagas disease, caused by the protozoan Trypanosoma cruzi, affects more than 6 million people worldwide. Following a mostly asymptomatic acute phase, the disease progresses to a long-lasting chronic phase throughout which life-threatening disorders to the heart and/or gastrointestinal tract will manifest in about 30% of those chronically infected....
Article
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Trypanosoma cruzi is the parasite responsible for Chagas disease (CD), that affects 6-8 million people worldwide. CD treatment is limited to two drugs (benznidazole and nifurtimox). Treatment is mostly effective during the acute phase of the disease (initial two months post-infection), while their efficacy during the chronic phase is controversial....
Article
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Background COVID-19 threatens health systems worldwide, but Venezuela’s system is particularly vulnerable. To prevent the spread of COVID-19, individuals must adopt preventive behaviors. However, to encourage behavior change, we must first understand current knowledge, attitudes, and practices (KAPs) that inform response to this health threat. Met...
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Trypanosoma cruzi, a zoonotic kinetoplastid protozoan parasite, is the causative agent of American trypanosomiasis (Chagas disease). Having a very plastic, repetitive and complex genome, the parasite displays a highly diverse repertoire of surface molecules, with pivotal roles in cell invasion, immune evasion and pathogenesis. Before 2016, the comp...
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Understanding the blood meal patterns of insects that are vectors of diseases is fundamental in unveiling transmission dynamics and developing strategies to impede or decrease human–vector contact. Chagas disease has a complex transmission cycle that implies interactions between vectors, parasites and vertebrate hosts. In Ecuador, limited data on h...
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Background Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses in pregnant women and their children. In Ecuador, the coverage of seasonal influenza vaccination in pregnant women is low. The aim of this study was to assess the knowledge, attitudes, and practices (KAP) of pregnant women toward in...
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This study employed Uses and Gratification Theory (UGT), Health Belief Model (HBM) and a mix of techniques to highlight the important role of social media in health communication. A total of 602 comments posted by YouTube users as they interacted with news items reporting on Chagas disease were thus analysed. A web-based software called Netlytic wa...
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Analysis of genetic polymorphism is a powerful tool for epidemiological surveillance and research. Powerful inference from pathogen genetic variation, however, is often restrained by limited access to representative target DNA, especially in the study of obligate parasitic species for which ex vivo culture is resource-intensive or bias-prone. Moder...
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Preventing the transmission of SARS-CoV-2 (causative agent for COVID-19) requires implementing contact and respiratory precautions. Modifying human behavior is challenging and requires understanding knowledge, attitudes, and practices (KAPs) regarding health threats. This study explored KAPs among people in Ecuador. A cross-sectional, internet-base...
Preprint
Full-text available
Background: Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses in pregnant women and their children. In Ecuador, the coverage of seasonal influenza vaccination in pregnant women is low. The aim of this study was to assess the knowledge, attitudes and practices of pregnant women toward influenz...
Article
Full-text available
Preventing the spread of COVID-19 requires the modification of behavior, including social distancing, mask-wearing, and regular handwashing. Modifying behavior requires understanding people's knowledge, attitudes, and practices (KAPs) regarding health threats. We explored KAPs among Colombians to examine whether KAPs affect adherence to recommended...
Preprint
Full-text available
Background: Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses in pregnant women and their children. In Ecuador, the coverage of seasonal influenza vaccination in pregnant women is low. The aim of this study was to assess the knowledge, attitudes and practices of pregnant women toward influenz...
Preprint
Full-text available
Background: Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses in pregnant women and their children. In Ecuador, the coverage of seasonal influenza vaccination in pregnant women is low. The aim of this study was to assess the knowledge, attitudes and practices (KAP) of pregnant women toward in...
Preprint
Full-text available
Background: Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses in pregnant women and their children. In Ecuador, the coverage of seasonal influenza vaccination in pregnant women is low. The aim of this study was to assess the knowledge, attitudes, and practices (KAP) of pregnant women toward i...
Article
Full-text available
Background: Trypanosoma cruzi, the causative agent of Chagas disease, and T. rangeli are kinetoplastid parasites endemic to Latin America. Although closely related to T. cruzi and capable of infecting humans, T. rangeli is non-pathogenic. Both parasite species are transmitted by triatomine bugs, and the presence of T. rangeli constitutes a confoun...
Article
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Background: Chagas disease is a parasitic infection transmitted by "kissing bugs" (Hemiptera: Reduviidae: Triatominae) that has a huge economic impact in Latin American countries. The vector species with the upmost epidemiological importance in Ecuador are Rhodnius ecuadoriensis (Lent & Leon, 1958) and Triatoma dimidiata (Latreille, 1811). However...
Article
Rhodnius ecuadoriensis is one of the most important vector species of Chagas disease in Ecuador. This species is distributed in the Central coast region and in the south Andean region, and an incipient speciation process between these geographical populations was previously proposed. The current population genetics study only focused on the Central...
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The lack of a test for the early assessment of treatment efficacy in Chagas disease hampers the daily clinical management of patients, as well as the implementation of clinical trials. It is, therefore, of great importance to develop reliable tests to monitor treatment response. Herein, we present a target product profile (TPP) for the development...
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Objectives: Chronic malnutrition and anemia are prevalent in developing countries. This research aimed to determine the prevalence of chronic malnutrition and anemia and their associated factors in children under five using a multi-causal model in a rural community in the coast of Ecuador. Methods: The study included 314 children under 5 years o...
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Chagas disease is a neglected tropical disease that disproportionately affects impoverished rural communities. Insecticide-based approaches are inconsistently performed and exorbitantly priced for the communities affected. The present study considers an alternative approach to primary prevention of Chagas disease using entertainment education. As p...
Article
The United Nations Millennium Development Goals and Sustainable Development Goals generally guide deployments of the term “development.” This understanding of development may contribute to the marginalization of local populations. We argue that communities can be better served if we listen to how they conceptualize and contextualize their definitio...
Preprint
Full-text available
Analysis of genetic polymorphism is a powerful tool for epidemiological surveillance and research. Powerful inference from pathogen genetic variation, however, is often restrained by limited access to representative target DNA, especially in the study of obligate parasitic species for which ex vivo culture is resource-intensive or bias-prone. Moder...
Article
Full-text available
Introduction Control of triatomine infestation is a key strategy for the prevention of Chagas disease (CD). To promote this strategy, it is important to know which antecedents to behavioral change are the best to emphasize when promoting prevention. Objective The aim of this study was to determine predictors for intention to prevent home infestati...
Article
In the past 5–10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela’s health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 an...
Article
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Insecticide spraying of housing units is an important control measure for vector-borne infections such as Chagas disease. However, some vectors may survive treatment, due to imperfect spraying by the operator or because they hide deep in the cracks or other places, and re-emerge in the same unit when the effect of the insecticide wears off. While s...
Article
When communicators use media and communication to address problems of development, we seek to assess whether those interventions are grounded in current development challenges and in patterns of media use. Additional challenges emerge, however, from patterns in media use between those used by development communication professionals and those that a...
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Rhodnius ecuadoriensis Lent & León (Hemiptera: Reduviidae) is a major Chagas disease (CD) vector in Ecuador, but little is known about its population genetic structure. We tested six Short Tandem Repeats (STRs) from R. pallescens Barber in wild and synanthropic R.ecuadoriensis populations. Two STRs were monomorphic, two yielded ambiguous alleles, a...
Article
Limited genetic data are currently available for three vectors of Chagas disease in Ecuador, Panstrongylus howardi, P. chinai, and P. rufotuberculatus. Previously regarded as mainly sylvatic, these species have been poorly studied. Recently, they have been more frequently reported in domiciles and peridomiciles and are now considered true secondary...
Article
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Genetic exchange enables parasites to rapidly transform disease phenotypes and exploit new host populations. Trypanosoma cruzi, the parasitic agent of Chagas disease and a public health concern throughout Latin America, has for decades been presumed to exchange genetic material rarely and without classic meiotic sex. We present compelling evidence...
Article
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Background: The mortality rate in children under 5 years old (U5MR) has decreased considerably in Ecuador in the last decade; however, thousands of children continue to die from causes related to poverty. A social program known as Bono de Desarrollo Humano (BDH) was created to guarantee a minimum level of consumption for families and to reduce chr...
Article
In rural Ecuador pregnant women face complex challenges navigating the terrain between traditional and biomedical maternal health care services. Semi-structured interviews were conducted in three rural communities in Southern Ecuador that have presented active Chagas disease transmission with women who were pregnant or have given birth within the l...
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The terms “health” and “well-being” are commonly used in health communication research. These terms, despite calls for a consensus definition, are rarely explicitly defined. We argue that, instead of imposing a universal definition of health or well-being, communities can be better served if we adopt a culture-centered approach (CCA) and listen to...
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Background Human transmission of Chagas disease (CD) most commonly occurs in domiciliary spaces where triatomines remain hidden to feed on blood sources during inhabitants’ sleep. Similar to other neglected tropical diseases (NTDs), sustainable control of CD requires attention to the structural conditions of life of populations at risk, in this cas...
Article
Full-text available
In the past 5–10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela’s health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 an...
Article
Full-text available
Chagas disease is caused by Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae). It is transmitted to humans primarily through contaminated feces of blood-sucking vectors of the subfamily Triatominae, known in Ecuador as 'chinchorros'. Some Triatominae species can adapt to domiciliary and peridomiciliary environments where T. cruzi can be transmit...
Article
Chagas disease is caused by Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae). It is transmitted to humans primarily through contaminated feces of blood-sucking vectors of the subfamily Triatominae, known in Ecuador as ‘chinchorros’. Some Triatominae species can adapt to domiciliary and peridomiciliary environments where T. cruzi can be transmit...
Preprint
Full-text available
Trypanosoma cruzi, causative agent of Chagas disease, and T. rangeli are kinetoplastid parasites endemic to Latin America. Although closely-related to T. cruzi and capable of infecting humans, T. rangeli is non-pathogenic. Both parasite species are transmitted by triatomine bugs, and the presence of T. rangeli constitutes a confounding factor in th...
Article
Full-text available
The seroprevalence and epidemiology of Bartonella bacilliformis infection in the Andean highlands of Ecuador is largely unknown. We conducted a sero-epidemiologic survey of 319 healthy children aged 1–15 years living in six rural, mountain communities in Loja Province, Ecuador. Blood was collected by finger stick onto filter paper and dried, and th...
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Abstract Background: The white-naped squirrel, Simosciurus nebouxii (previously known as Sciurus stramineus), has recently been identified as an important natural host for Trypanosoma cruzi in Ecuador. The nests of this species have been reported as having high infestation rates with the triatomine vector Rhodnius ecuadoriensis. The present study a...
Article
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BACKGROUND: Eggs have epidemiological and taxonomic importance in the subfamily Triatominae, which contains Chagas disease vectors. The metric properties (size and shape) of eggs are useful for distinguishing between close species, or different geographical populations of the same species. METHODS: We examined the effects of egg viability on its m...
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Background Chagas disease (CD) is a life-threatening illness caused by the protozoan parasite Trypanosoma cruzi, which is transmitted by triatomine bugs. Triatomine bugs inhabit poorly constructed homes that create multiple hiding spots for the bugs. Modifying the actual structure of a home, along with the homeowners’ practices, can reduce triatomi...
Article
Scholars and practitioners are increasingly turning to maps as tools for promoting health and development communication. These maps are often criticized for privileging the interests of the global North and for authorizing (neo)colonial approaches. The authors offer a case of community mapping incorporating asset-based community development that of...
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Background: Insufficient physical activity (PA) and excessive sedentary behavior (SB) are the main contributors to adolescent obesity. However, it is uncertain whether recent economic growth and urbanization in Ecuador are contributing to an obesogenic environment. This study assessed the relationships among fitness, PA, SB, and perceived social su...
Preprint
Full-text available
Genetic exchange and hybridization in parasitic organisms is fundamental to the exploitation of new hosts and host populations. Variable mating frequency often coincides with strong metapopulation structure, where patchy selection or demography may favor different reproductive modes. Evidence for genetic exchange in Trypanosoma cruzi over the last...