Mario J. Grijalva

Ohio University

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Jaime A. Costales

Pontificia Universidad Católica del Ecuador

Anita G. Villacís

Pontificia Universidad Católica del Ecuador

Sofía Ocaña-Mayorga

Pontificia Universidad Católica del Ecuador

Benjamin R. Bates

Ohio University

César A. Yumiseva

Pontificia Universidad Católica del Ecuador

Martin Llewellyn

University of Glasgow

Ana L. Moncayo

Pontificia Universidad Católica del Ecuador

Esteban G. Baus

Pontificia Universidad Católica del Ecuador

Philipp Schwabl

Harvard University

Claudia Nieto-Sánchez

Instituut voor Tropische Geneeskunde

Cooperative Institutions

Ohio University

Pontificia Universidad Católica del Ecuador

Centers for Disease Control and Prevention

Central University of Venezuela

London School of Hygiene & Tropical Medicine

Fundação Oswaldo Cruz

University of Glasgow

Universitat de Barcelona

Institut de Recherche pour le Développement

University of London

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Human Blood Meals in Sylvatic Triatomines Challenges Domestic-Centered Strategies for Prevention of Trypanosoma cruzi Transmission in Ecuador

American Journal of Tropical Medicine and Hygiene (2021)

Sofía Ocaña-Mayorga Juan José Bustillos Anita G. Villacís Ana L. Moncayo César A. Yumiseva

Transmission risk of Chagas disease has been associated with human-vector contacts and triatomines colonizing dwellings, but alternative scenarios, independent of domestic colonization, are poorly documented. In the present work, we estimated the frequency of human blood meals in triatomines from domicile, peridomicile, and sylvatic environments in two endemic regions in Ecuador. Blood meal origins were identified by sequencing a cytb gene fragment. Human blood meals were detected in 42% of the triatomines among 416 analyzed, including 48% of sylvatic triatomines (both adults and nymphs). In triatomines from domicile and peridomicile, Trypanosoma cruzi infection rate was > 20%, and reached 48% in sylvatic triatomines. Human is a common source of blood for triatomines whether they live in or near dwellings in both regions, and the high rate of T. cruzi infection represents an important risk of transmission of Chagas disease. Consequently, control strategies should also take into account possible nondomestic transmission.

Chagas Disease

Blood meal

Human blood

10.4269/ajtmh.20-1312

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Citations (2)

Additional file 1 of Remarkable genetic diversity of Trypanosoma cruzi and Trypanosoma rangeli in two localities of southern Ecuador identified via deep sequencing of mini-exon gene amplicons

Figshare (2020)

Jalil Maiguashca Sánchez Salem Oduro Beffi Sueto Philipp Schwabl Mario J. Grijalva Martin Llewellyn

Additional file 1: Table S1. Raw data for monoclones and Ecuadorian samples. Haplotype ID, identity and number of reads are included.

Amplicon

10.6084/m9.figshare.12308036

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Charitable Giving in the Context of Unfamiliar Organizations: The Effectiveness of Construal Level Theory in Predicting Donating Intentions and Antecedents

Southern Communication Journal (2021)

Shariq I. Sherwani Benjamin R. Bates Mario J. Grijalva

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 houses to prevent vectors that spread Chagas disease in rural communities in Ecuador. Drawing upon construal level theory (CLT), we explored charitable giving behaviors of potential donors. Our findings revealed: (a) smaller psychological distances did not influence charitable giving, and (b) message recipients showed favorable attitudes toward unfamiliar charities dealing with unfamiliar issues. We offer implications for CLT application in the context of charitable giving and fundraising by new charitable organizations and intention to share messages.

Construals

10.1080/1041794x.2021.1929434

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Chagas Disease across the Ages: A Historical View and Commentary on Navigating Future Challenges

Microorganisms (2024)

Denis Séréno Bruno Oury Mario J. Grijalva

Chagas disease, discovered over a century ago, continues to pose a global health challenge, affecting millions mainly in Latin America. This historical review with commentary outlines the disease’s discovery, its evolution into a global concern due to migration, and highlights significant advances in diagnostics and treatment strategies. Despite these advancements, the paper discusses ongoing challenges in eradication, including vector control, congenital transmission, the disease’s asymptomatic nature, and socioeconomic barriers to effective management. It calls for a multidisciplinary approach, enhanced diagnostics, improved treatment accessibility, and sustained vector control efforts. The review emphasizes the importance of global collaboration and increased funding to reduce Chagas disease’s impact.

Chagas Disease

Neglected Tropical Diseases

Global Health

Disease Control

Tropical disease

10.3390/microorganisms12061153

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Rhodnius pallescens microsatellite markers for population genetic analysis in Rhodnius ecuadoriensis: preliminary assessment

Revista Ecuatoriana de Medicina y Ciencias Biológicas (2019)

Mario J. Grijalva

Rhodnius ecuadoriensis Lent & León (Hemiptera: Reduviidae) es el prinicipal vector de la enfermedad de Chagas en Ecuador, donde la estructura genética de sus poblaciones es poco conocida. Nosotros probamos seis Repeticiones Cortas en Tamdem (RCT) de R. pallescens Barber en poblaciones selváticas y domésticas de R. ecuadoriensis. Dos microsatelites fueron monomórficos, dos dieron resultados ambiguos y dos fueron polimórficos (16 y 19 alelos) y fueron utilizados para análisis. Los resultados de las frecuencias alélicas, AMOVA y los pruebas Bayesianas para genética favorecen la teoría de la existencia de una sola población. Estos resultados preliminares sugieren que las poblaciones selváticas y domésticas d R. ecuadoriensis intercambian frecuentemente migrantes. Por consiguiente el control de la Enfermedad de Chagas requiere vigilancia entomológica continua en la costa del Ecuador.

Rhodnius

Triatominae

10.26807/remcb.v40i2.90

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Additional file 5 of Remarkable genetic diversity of Trypanosoma cruzi and Trypanosoma rangeli in two localities of southern Ecuador identified via deep sequencing of mini-exon gene amplicons

Figshare (2020)

Jalil Maiguashca Sánchez Salem Oduro Beffi Sueto Philipp Schwabl Mario J. Grijalva Martin Llewellyn

Additional file 5: Table S3. Accession numbers of downloaded sequences from NCBI database used in the generation of the NJ tree for T. rangeli. The retrieved sequences were trimmed to match with the amplicons generated with Ecuadorian samples. The discarded portions of the sequences are shown. Lineage (A, B, C, D and E) and KP1(+/−) information was included when available. Geographical origin of the samples is also in the file.

Amplicon

Amplicon sequencing

10.6084/m9.figshare.12308054

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Sex, Subdivision, and Domestic Dispersal of Trypanosoma cruzi Lineage I in Southern Ecuador

PLoS neglected tropical diseases (2010)

Sofía Ocaña-Mayorga Martin Llewellyn Jaime A. Costales Michael A. Miles Mario J. Grijalva

Background Molecular epidemiology at the community level has an important guiding role in zoonotic disease control programmes where genetic markers are suitably variable to unravel the dynamics of local transmission. We evaluated the molecular diversity of Trypanosoma cruzi, the etiological agent of Chagas disease, in southern Ecuador (Loja Province). This kinetoplastid parasite has traditionally been a paradigm for clonal population structure in pathogenic organisms. However, the presence of naturally occurring hybrids, mitochondrial introgression, and evidence of genetic exchange in the laboratory question this dogma. Methodology/Principal Findings Eighty-one parasite isolates from domiciliary, peridomiciliary, and sylvatic triatomines and mammals were genotyped across 10 variable microsatellite loci. Two discrete parasite populations were defined: one predominantly composed of isolates from domestic and peridomestic foci, and another predominantly composed of isolates from sylvatic foci. Spatial genetic variation was absent from the former, suggesting rapid parasite dispersal across our study area. Furthermore, linkage equilibrium between loci, Hardy-Weinberg allele frequencies at individual loci, and a lack of repeated genotypes are indicative of frequent genetic exchange among individuals in the domestic/peridomestic population. Conclusions/Significance These data represent novel population-level evidence of an extant capacity for sex among natural cycles of T. cruzi transmission. As such they have dramatic implications for our understanding of the fundamental genetics of this parasite. Our data also elucidate local disease transmission, whereby passive anthropogenic domestic mammal and triatomine dispersal across our study area is likely to account for the rapid domestic/peridomestic spread of the parasite. Finally we discuss how this, and the observed subdivision between sympatric sylvatic and domestic/peridomestic foci, can inform efforts at Chagas disease control in Ecuador.

Population Genetics

Introgression

10.1371/journal.pntd.0000915

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Knowledge, attitudes and practices on influenza vaccine during pregnancy in Quito, Ecuador

Research Square (Research Square) (2020)

Carlos E. Erazo Carlos Erazo Mario J. Grijalva Ana L. Moncayo

Abstract 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 influenza vaccination in Quito-Ecuador. Methods: A cross-sectional study enrolled 842 women who delivered at three main public gynecological-obstetric units of the Metropolitan District of Quito. A questionnaire regarding demographics, antenatal care, risk conditions and knowledge, attitudes and practices related to influenza vaccination was administered. We examined factors associated with vaccination using log-binomial regression models. Results: A low vaccination rate (36.6%) against influenza was observed among pregnant women. The factors associated with vaccination included the recommendations from health providers (adjusted PR: 15.84; CI 95% 9.62-26.10), belief in the safety of the influenza vaccine (adjusted PR: 1.53; CI 95% 1.03-2.37) and antenatal care (adjusted PR: 1.21; CI 95% 1.01-1.47). The most common reasons for not vaccinating included the lack of recommendation from health care providers (73.9%) and lack of access to vaccine (9.0%). Conclusions: Health educational programs aimed to pregnant women and antenatal care providers have the most potential to increase influenza vaccination rates. Further studies are needed to understand the barriers of health care providers regarding influenza vaccination in Ecuador.

Demographics

Cross-sectional study

10.21203/rs.3.rs-46051/v3

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High Household Infestation Rates by Synanthropic Vectors of Chagas Disease in Southern Ecuador

Journal of Medical Entomology (2005)

Mario J. Grijalva Francisco S. Palomeque Jaime A. Costales Santiago Davila Laura Arcos-Terán

Entomological surveys were conducted in five rural communities (138 domiciliary units [DUs]) in the southern Andes of Ecuador. Adobe walls and ceramic tile roofs were predominant construction materials. A 35% house infestation rate with Panstrongylus chinai (Del Ponte, 1929) (0.7%), Panstrongylus rufotuberculatus (Champion, 1899) (0.7%), Rhodnius ecuadoriensis (Lent & León, 1958) (27%), and/or Triatoma carrioni (Larrousse, 1926) (7%) was found. Adults and nymphs of R. ecuadoriensis and T. carrioni were found in intradomiciliary and peridomiciliary areas. Breeding triatomine colonies were present in 85% of infested DUs, and the average insect crowding was 52+/-113 triatomine bugs per infested house. T. cruzi-like organisms were found by microscopic examination in the feces or hindgut but not the salivary glands of 4% of examined R. ecuadoriensis and 12% T. carrioni. Serological tests detected a general anti-T. cruzi antibody seroprevalence of 3.9% (n = 1136). Only 2% of individuals had heard of Chagas disease, and although triatomines were reported as a major nuisance by the population they were not considered vectors of disease. Additional baseline field research is needed for the design and implementation of a Chagas disease control program in the region.

Chagas Disease

Triatoma

Rhodnius

Triatominae

Triatoma infestans

Seroprevalence

10.1093/jmedent/42.1.68

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Citations (55)

[Social factors associated with use of prenatal care in Ecuador].

PubMed (2016)

Amaya Sánchez‐Gómez William Cevallos Mario J. Grijalva Luis Carlos Silva Ayçaguer Susana Tamayo

Prenatal care is a pillar of public health, enabling access to interventions including prevention of mother-to-child transmission of HIV and congenital syphilis. This paper describes social factors related to use of prenatal care in Ecuador.In 2011 and 2012, participant clinical history and interview information was analyzed from a national probability sample of 5 998 women presenting for delivery or miscarriage services in 15 healthcare facilities in Ecuador, to estimate prevalence of HIV, syphilis, and Chagas disease, and prenatal care coverage.The study found that 94.1% of women had attended at least one prenatal visit, but that attendance at no less than four visits was 73.1%. Furthermore, lower educational level, greater number of pregnancies, occupation in the agriculture or livestock sector, and membership in ethnic indigenous, Afro-Ecuadorian, or other minority groups were factors associated with lack of use (no prenatal visits) or insufficient use of prenatal care (fewer than four visits or first visit at >20 weeks gestation) in Ecuador.These results point to persistence of marked inequalities in access to and use of prenatal health services attributable to socioeconomic factors and to the need to strengthen strategies to address them, to reach the goal of universal prenatal care coverage.

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