Heterogeneity of Trypanosoma cruzi infection rates in vectors and animal reservoirs in Colombia: a systematic review and meta-analysis

Background The heterogeneity of Trypanosoma cruzi infection rates among triatomines insects and animal reservoirs has been studied in independent studies, but little information has been systematised to allow pooled and comparative estimates. Unravelling the main patterns of this heterogeneity could contribute to a further understanding of T. cruzi transmission in Colombia. Methods A systematic search was conducted in PubMed, Medline, LILACS, Embase, Web of Knowledge, Google Scholar and secondary sources with no filters of language or time and until April 2018. Based on selection criteria, all relevant studies reporting T. cruzi infection rates in reservoirs or triatomines were chosen. For pooled analyses, a random effects model for binomial distribution was used. Heterogeneity among studies is reported as I2. Subgroup analyses included: taxonomic classification, ecotope and diagnostic methods. Publication bias and sensitivity analyses were performed. Results Overall, 39 studies reporting infection rates in Colombia were found (22 for potential reservoirs and 28 for triatomine insects) for a total sample of 22,838 potential animals and 11,307 triatomines evaluated for T. cruzi infection. We have found evidence of 38/71 different animal species as potential T. cruzi reservoirs and 14/18 species as triatomine vectors for T. cruzi. Among animals, the species with the highest pooled prevalence were opossum (Didelphis marsupialis) with 48.0% (95% CI: 26–71%; I2 = 88%, τ2 = 0.07, P < 0.01) and domestic dog (Canis lupus familiaris) with 22.0% (95% CI: 4–48%; I2 = 96%, τ2 = 0.01, P < 0.01). Among triatomines, the highest prevalence was found for Triatoma maculata in the peridomestic ecotope (68.0%, 95% CI: 62–74%; I2 = 0%, τ2 = 0, P < 0.0001), followed by Rhodnius prolixus (62.0%, 95% CI: 38–84%; I2 = 95%, τ2 = 0.05, P < 0.01) and Rhodnius pallescens (54.0%, 95% CI: 37–71%; I2 = 86%, τ2 = 0.035, P < 0.01) in the sylvatic ecotope. Conclusions To our knowledge, this is the first systematic and quantitative analyses of triatomine insects and potential animal reservoirs for T. cruzi infection in Colombia. The results highlight a marked heterogeneity between species and provide initial estimates of infection rates heterogeneity

Development and evaluation of a duplex TaqMan qPCR assay for detection and quantification of Trypanosoma cruzi infection in domestic and sylvatic reservoir hosts

Background: A question of epidemiological relevance in Chagas disease studies is to understand Trypanosoma cruzi transmission cycles and trace the origins of (re)emerging cases in areas under vector or disease surveillance. Conventional parasitological methods lack sensitivity whereas molecular approaches can fill in this gap, provided that an adequate sample can be collected and processed and a nucleic acid amplification method can be developed and standardized. We developed a duplex qPCR assay for accurate detection and quantification of T. cruzi satellite DNA (satDNA) sequence in samples from domestic and sylvatic mammalian reservoirs. The method incorporates amplification of the gene encoding for the interphotoreceptor retinoid-binding protein (IRBP), highly conserved among mammalian species, as endogenous internal amplification control (eIAC), allowing distinction of false negative PCR findings due to inadequate sample conditions, DNA degradation and/or PCR interfering substances. Results: The novel TaqMan probe and corresponding primers employed in this study improved the analytical sensitivity of the assay to 0.01 par.eq/ml, greater than that attained by previous assays for Tc I and Tc IV strains. The assay was tested in 152 specimens, 35 from 15 different wild reservoir species and 117 from 7 domestic reservoir species, captured in endemic regions of Argentina, Colombia and Mexico and thus potentially infected with different parasite discrete typing units. The eIACs amplified in all samples from domestic reservoirs from Argentina and Mexico, such as Canis familiaris, Felis catus, Sus scrofa, Ovis aries, Equus caballus, Bos taurus and Capra hircus with quantification cycles (Cq´s) between 23 and 25. Additionally, the eIACs amplified from samples obtained from wild mammals, such as small rodents Akodon toba, Galea leucoblephara, Rattus rattus, the opossums Didelphis virginiana, D. marsupialis and Marmosa murina, the bats Tadarida brasiliensis, Promops nasutus and Desmodus rotundus, as well as in Conepatus chinga, Lagostomus maximus, Leopardus geoffroyi, Lepus europaeus, Mazama gouazoubira and Lycalopex gymnocercus, rendering Cq´s between 24 and 33. Conclusions: This duplex qPCR assay provides an accurate laboratory tool for screening and quantification of T. cruzi infection in a vast repertoire of domestic and wild mammalian reservoir species, contributing to improve molecular epidemiology studies of T. cruzi transmission cycles.Fil: Wehrendt, Diana Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Gómez Bravo, Andrea. Fundación Mundo Sano; ArgentinaFil: Ramirez Gomez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Cura, Carolina Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Pech May, Angélica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Ramsey, Janine M.. Instituto Nacional de Salud Pública; MéxicoFil: Abril, Marcelo. Fundación Mundo Sano; ArgentinaFil: Guhl, Felipe. Universidad de los Andes; ColombiaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

Chagas Disease in the United States: a Public Health Approach.

Trypanosoma cruzi is the etiological agent of Chagas disease, usually transmitted by triatomine vectors. An estimated 20 to 30% of infected individuals develop potentially lethal cardiac or gastrointestinal disease. Sylvatic transmission cycles exist in the southern United States, involving 11 triatomine vector species and infected mammals such as rodents, opossums, and dogs. Nevertheless, imported chronic T. cruzi infections in migrants from Latin America vastly outnumber locally acquired human cases. Benznidazole is now FDA approved, and clinical and public health efforts are under way by researchers and health departments in a number of states. Making progress will require efforts to improve awareness among providers and patients, data on diagnostic test performance and expanded availability of confirmatory testing, and evidence-based strategies to improve access to appropriate management of Chagas disease in the United States

Serum banking of the Mississippi shelter dog population to estimate seroprevalence of diseases affecting animal and human health

Shelter dog populations in the United States are poorly quantified and characterized, but may be effective targets for measuring the occurrence of select diseases affecting animal and human health. Dogs in this population may have increased risk for disease due to intrinsic and extrinsic risk factors. Accurate estimates of disease in this population require sound sampling strategies within a comprehensive sampling frame. Knowledge of the prevalence of disease in the Mississippi shelter dog population is important for diagnostic test interpretation, shelter allocation of resources, and public health risk assessment. A serum bank provides a valuable resource to investigate both zoonotic diseases in which dogs are the primary reservoir, such as canine brucellosis, and for diseases where dogs may be effective sentinels for exposure risk, such as American trypanosomiasis. Implications of this research extend beyond Mississippi through the frequent movement of shelter dogs to adoption centers across the United States

Enfermedad de chagas en perros : una revisión

32 páginas : ilustraciones, gráficasChagas disease or american trypanosomiasis, caused by the flagellated protozoan Trypanosoma cruzi and transmitted mainly in a vectorial way by triatomines, is a zoonotic endemic disease and a public health problem in Colombia, which is one of the countries with the highest rates of acute annual cases, leading to labor inhability, reduced life expectancy and huge economic expenses. It is important to study this disease in dogs due to the epidemiological role they perform, being the closest reservoir to human, and considered 14 times more effective than humans at propagating the disease. Though recent studies in Colombian dogs show elevated prevalences in endemic areas, this disease is still not frequently included as a differential diagnostic by veterinarians. Therefore, the necessity of spreading information on the subject and the proper preparation of veterinarians in this area must be considered as a priority. This bibliographic review attempts to offer a significant and updated informative contribution about the epidemiology, clinical presentation, and diagnosis of Chagas disease in dogs and its current situation in Colombia, as well as demonstrating where research advances should be directed. Emphasizing the necessity of creating, developing and implementing preventive strategies as essential tools for the eradication of Chagas disease, mainly based on vigilance, control and elimination of triatomines as biological vectors of Trypanosoma cruziLa enfermedad de Chagas o tripanosomosis americana, ocasionada por el protozoo flagelado Trypanosoma cruzi y transmitida principalmente de manera vectorial mediante triatominos, es una zoonosis endémica de interés en salud pública en Colombia, siendo uno de los países que capta más pacientes en fase aguda anualmente, generando incapacidad laboral, reduciendo la expectativa de vida y produciendo grandes pérdidas económicas. La importancia de estudiar el comportamiento de esta enfermedad en los perros radica en el papel epidemiológico que desempeñan, siendo el reservorio de mayor contacto con los seres humanos y considerándose 14 veces más efectivos para propagar la enfermedad. Estudios recientes en el país señalan altas prevalencias en caninos pertenecientes a zonas endémicas, sin embargo, esta enfermedad no suele incluirse como diagnóstico diferencial en la clínica diaria, por lo que la difusión de información y la preparación profesional por parte de los médicos veterinarios en esta área debe considerarse una prioridad. Esta revisión bibliográfica pretende ofrecer un aporte informativo significativo y actualizado acerca de la epidemiología, la presentación clínica y el diagnóstico de la tripanosomosis americana canina y su situación en Colombia, además de reflejar hacia dónde se deben dirigir los avances investigativos en esta enfermedad. Se hace énfasis en la necesidad de elaborar, desarrollar e implementar estrategias preventivas como estrategia fundamental para erradicar la enfermedad de Chagas, principalmente basadas en la vigilancia, el control y la eliminación de los triatominos como vectores biológicos de Trypanosoma cruziPregradoMédico(a) Veterinari

Translational Research for Zoonotic Parasites: New Findings toward Improved Diagnostics, Therapy and Prevention

In this book is reported novel information on diagnosis, treatment, and control of parasites that are naturally transmitted from animal reservoirs to humans. Subjects: Public Health and Healthcare: Prevention; Medicine and Pharmacology: Therapy

Abstract Book of the II Congress of the Latin American Society for Vector Ecology

Recopilación de los resúmenes de las conferencias, simposios, paneles de discusión y "turbo talks" ofrecidos en el II Congreso de la Sociedad Latinoamericana de Ecología de Vectores (LA SOVE), realizado entre el 29 de octubre y el 3 de noviembre de 2022 en la ciudad de La Plata (Buenos Aires, Argentina).Sociedad Latinoamericana de Ecología de Vectores (LA SOVE

Protein Mass Spectrometry Aids In Chagas Vector Blood Meal Identification And Offers An Innovative Approach To Battling Vector-Borne Diseases

Vector borne-diseases make up a significant portion of morbidity and mortality worldwide, being responsible for around 700,000 deaths annually according to the World Health Organization. Neglected, tropical diseases such as Chagas disease have a significant impact on people in Latin America, affecting millions, and especially those residing in rural areas. Chagas disease is the number one cause for heart disease in Latin America, and is caused by the Trypanosoma cruzi parasite, carried by Triatominae insect vectors. The intricate life cycle of the parasite, ecology and behavior of the vector, and lack of disease treatment options, make Chagas disease challenging to control. Prevention measures are highly sought after, and implementation science approaches such as Ecohealth management engage affected communities in disease prevention. Knowing what insect vectors are feeding on sheds light on vector ecology and behavior, aiding in vector management which is pivotal in disease prevention. While DNA-based methods have traditionally been used to study vector blood meals, they come with limitations and challenges, such as the need for fresh, high abundance blood meals. Therefore, the goal of this research was to evaluate Chagas vector blood meal sources using an innovative protein mass spectrometry-based approach. We demonstrate first the ability to utilize liquid chromatography tandem mass spectrometry (LC-MS/MS) to correctly identify hemoglobin protein peptides from mouse blood and subsequently identify Chagas vector blood meal sources from field-collected insect vectors where blood meal identification is compared with traditional DNA-based methods as a control. An experimental feeding study allowed us to then demonstrate the longevity of hemoglobin protein peptides for blood meal detection, showing LC-MS/MS-based blood meal identification outperforms DNA-based polymerase chain reaction (PCR) at least 4 weeks post-feeding and 12 weeks post-molting. This allowed us to test the limits of our innovative detection method experimentally and comparatively. Finally, we evaluated blood meals in field-caught insect vectors collected as part of a large collaborative Ecohealth project in Central America. LC-MS/MS identified two times as many blood meals in insect vectors, including those that did not have blood meals detected with DNA-based PCR. As single vectors often feed on multiple sources, we also validated our ability to decipher multiple blood meals from an individual vector and showed the ability to quantify a blood meal using synthetic AQUA (Absolute QUAntification) peptides, a first step in using quantification data for identifying blood meals not currently in our underlying database. Furthermore, we show that lower resolution mass spectrometers are able to identify blood meals from taxa correctly, an important and strong attribute of our LC-MS/MS-based method, opening the door to using proteomics in countries where Chagas disease is endemic and resources are limited. Even though expertise and resources of research labs differ in locations across the globe, herein is described how LC-MS/MS is a valuable additional tool for fighting neglected tropical diseases. Ultimately, hemoglobin-based LC-MS/MS vector blood meal identification is a complementary technique to available molecular methods and can confidently identify Chagas vector blood meal sources to aid in understanding vector biology and ecology, and aid in developing appropriate Ecohealth vector control measures

Genetic diversity in Trypanosoma cruzi: marker development and applications; natural population structures, and genetic exchange mechanisms

Chagas disease remains the most important parasitic infection in Latin America. The aetiological agent, Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae), is a complex vector-borne zoonosis transmitted in the faeces of hematophagous triatomine bugs (Hemiptera: Reduviidae: Triatominae), and maintained by mammalian reservoir hosts ranging from the southern United States to Argentinean Patagonia. In the absence of chemotherapy, infection is life-long and can lead to a spectrum of pathological sequelae ranging from subclinical to lethal cardiac and/or gastrointestinal complications in up to 30% of patients. T. cruzi displays remarkable genetic diversity, which has long been suspected to contribute to the considerable variation in clinical symptoms observed between endemic regions. Currently, isolates of T. cruzi can be assigned to a minimum of six stable genetic lineages or discrete typing units (DTUs) (TcI-TcVI), which are broadly associated with disparate ecologies, transmission cycles and geographical distributions. The principal mode of reproduction among T. cruzi strains is the subject of an intense, decades-old debate. Despite the existence of two recent natural hybrid lineages (TcV and TcVI), which resemble meiotic F1 progeny, a pervasive view is that recombination has been restrained at an evolutionary scale and is of little epidemiological relevance to contemporary parasite populations. The aim of this PhD project was to investigate T. cruzi genetic diversity through significant development of phylogenetic markers and their application to the characterization of natural parasite population structures and genetic exchange mechanisms. Multiple, single-copy, chromosomally-independent, nuclear housekeeping genes were assessed initially for their ability to allocate isolates to DTU-level, to facilitate higher resolution intra-lineage analyses and finally for their inclusion alongside additional targets in a standardized T. cruzi multilocus sequence typing (nMLST) scheme. For the immediate future, nuclear MLST, using a panel of four to seven nuclear loci, is a robust, reproducible and highly discriminatory method that has potential to become the new gold standard for T. cruzi DTU assignment. To investigate natural parasite population structures and uncover evidence of genetic exchange, a high resolution mitochondrial MLST (mtMLST) scheme, based on ten gene fragments, was developed and evaluated against current nuclear markers (multilocus microsatellite typing; MLMT) using isolates belonging to the oldest and most widely distributed lineage (TcI). Observations of gross nuclear-mitochondrial phylogenetic incongruence indicate that recombination is ongoing, geographically widespread and continues to influence natural populations, challenging the traditional paradigm of clonality in T. cruzi. Application of this combined nuclear-mitochondrial methodology to intensively sampled, minimally-subdivided TcI populations revealed extensive mitochondrial introgression within a disease focus in North-East Colombia as well as among arboreal transmission cycles in Bolivia. Failure to detect any reciprocal nuclear hybridization among recombinant strains ! 4 may be indicative of alternate, cryptic mating strategies in T. cruzi, which are challenging to reconcile with both in vitro parasexual mechanisms of genetic exchange described, and patterns of Mendelian allele inheritance among natural hybrid DTUs. High resolution genotyping of TcI populations was also undertaken to explore the interaction between parasite genetic heterogeneity and ecological biodiversity, exposing the significant impact human activity has had on T. cruzi evolution. Reduced genetic diversity, accelerated parasite dissemination between densely populated areas and mitochondrial gene flow between domestic and sylvatic populations, suggests humans may have played a crucial role in T. cruzi dispersal across the Bolivian highlands. Parallel reductions in genetic diversity were observed among isolates from the Brazilian Atlantic Forest, attributable to ongoing anthropogenic habitat fragmentation. By comparison domestic TcI isolates (TcIDOM) are divergent from their sylvatic counterparts, but also genetically homogeneous, and likely to have originated in North/Central America before distribution southwards. Molecular dating of Colombian TcIDOM clones confirmed that this clade emerged 23,000 ± 12,000 years, coinciding with the earliest human migration into South America. Lastly, Illumina amplicon deep sequencing markers were developed to explore the interaction between parasite multiclonality and clinical status of chronic Chagas disease. An unprecedented level of intra-host genetic diversity was detected, highlighting putative diversifying selection affecting antigenic surface proteases, which may facilitate survival in the mammalian host. In lieu of comparative genomics of representative T. cruzi field isolates, not yet a reality, as is the case with other more experimentally-tractable trypanosomatids, presented herein are some of the highest resolution genotyping techniques developed in T. cruzi to date, which have the potential to expand our current understanding of parasite genetic diversity and its relevance to clinical outcome of Chagas disease

Important Canine Zoonoses from a Public Health Perspective and the Introduction of Companion Animal Surveillance in the Prairie Provinces of Canada

ABSTRACT Prioritizing zoonotic and/or sapronotic pathogens of domestic animal populations and initiating ongoing surveillance of such pathogens is needed in Canada. From a One Health perspective, gathering and recording more comprehensive disease data on the population of animals most closely associated with humans is extremely valuable and necessary. Therefore, the purpose of this thesis was to identify a subset of domestic canine pathogens of public health significance specific to the Prairie Provinces of Canada and to establish a framework for a companion animal surveillance initiative to the region. This research was conducted within a two- year period from September 2019 to April 2021. The first component of this research involved the creation of a comprehensive list of any pathogen historically reported in the domestic dog by reviewing several companion animal infectious disease textbooks, which resulted in 594 pathogens total. This list was then pared down to identify only those pathogens that were significant from a public health perspective in Canada and the prairies. This was accomplished using a formulated stepwise approach that pathogens only moved on to the final list if: (1) the pathogen was zoonotic/sapronotic/anthroponotic, (2) the domestic dog was involved in transmission, maintenance or detection of the pathogen, and (3) there was a level of risk for occurrence of the pathogen in Canada. Following this stepwise approach, of the initial 594 canine pathogens 84 pathogens were deemed important in Canada and the prairies from a public health perspective. A follow-up study to this research involved a prioritization exercise using experts in the field of veterinary medicine, public health, and epidemiology to identify the top 5 highest priority pathogens from the final list of 84 canine pathogens upon which to focus a companion animal surveillance program specific to the Prairie Provinces. The exercise was accomplished through a voluntary survey using a semi-quantitative ranking strategy. The resulting top 5 pathogens to come out of the exercise were: (1) Echinococcus spp. (granulosus, multilocularis), (2) MRSA, (3) Salmonella enterica, (4) MRSP, and (5) Borrelia burgdorferi. The final component of this research examined the utility of clinical veterinarians and veterinary clinics in a companion animal surveillance program. In addition, responses from clinical veterinarians were used to formulate case definitions for the top 5 highest priority pathogens intended for surveillance. Assessing dogs as sentinels for pathogens of public health concern using Lyme disease as an example was also conducted in this research chapter. Data was gathered through a voluntary survey disseminated to clinical veterinarians in the provinces of Alberta, Saskatchewan, and Manitoba. The results of this survey identified that clinical veterinarians are willing to participate in a surveillance program, that there is important in-clinic veterinary data not currently being captured from a population or disease monitoring standpoint, and that domestic dogs can serve as good sentinels for Lyme disease risk in humans, specific to the prairies. This thesis provided the foundational steps for a companion animal surveillance initiative specific to the Prairie Provinces of Canada. It identified which pathogens involving the domestic dog pose a significant public health risk in Canada and the prairies, prioritized these pathogens from highest to lowest concern using expert opinion, and established the importance of cooperation with practicing veterinarians and veterinary clinics for a companion animal surveillance program to be successful