High-resolution prediction models for Rhipicephalus microplus and Amblyomma cajennense s.l. ticks affecting cattle and their spatial distribution in continental Ecuador using bioclimatic factors.

In Ecuador, the main tick species affecting cattle are Rhipicephalus microplus and Amblyomma cajennense sensu lato. Understanding their spatial distribution is crucial. To assess their distribution, data from 2895 farms visited between 2012 and 2017 were utilized. Ticks were collected during animal inspections, with each farm's location georeferenced. Bioclimatic variables and vapor pressure deficit data were obtained from Climatologies at High resolution for the Earth´s Land Surface Areas (CHELSA) dataset. They were overlaid to develop predictive maps for each species using Random Forest (RF) models. The cross-validation results for RF prediction models showed high accuracy for both R. microplus and A. cajennense s.l. presence with values of accuracy = 0.97 and 0.98, sensitivity = 0.96 and 0.99, and specificity = 0.96 and 0.93, respectively. A carefully selected subset of bioclimatic variables was used to describe the presence of each tick species. Higher levels of precipitation had positive effect on the presence of R. microplus but a negative effect on A. cajennense s.l. In contrast, isothermality (BIO3) was more important for the presence of A. cajennense s.l. compared to R. microplus. As a result, R. microplus had a broader distribution across the country, while A. cajennense s.l. was mainly found in coastal areas with evident seasonality. The coexistence of both species in some regions could be attributed to transitional zones, whereas high altitudes limited tick presence. This information can aid in developing appropriate tick management plans, particularly considering A. cajennense s.l.'s broad host range species and R. microplus's specificity for cattle. Moreover, the predictive models can identify areas at risk of associated challenging hemoparasite, requiring special attention and mitigation measures.

Spatial-Temporal Analysis of Lutzomyia trapidoi and Lutzomyia reburra (Diptera: Phlebotominae), in Rural Tourist Locations, Biosphere Reserve and Leishmaniasis Endemic Area, Ecuador.

This research represents the first attempt to assess the spatial and temporal distribution based on micro-meso scales on two species with different host preference habits (anthropophilic vs zoophilic), in the major Leishmaniasis endemic area in Ecuador, tourist locations, and Biosphere reserve. Phlebotomine species, Lutzomyia trapidoi (Fairchild) and Lutzomyia reburra (Fairchild and Hertig), were analyzed by trap/habitat/month/locality/altitude, through the Poisson generalized regression model. Our data reveal a bimodal pattern for both species related with low precipitations and preference for forest habitat. Altitude, proximity to the forest, and the river were the variables that determine the hypervolume of the spatial distribution of relative abundance, where the overlap of these two species increases the risk of translocation and circulation of the etiological agent of leishmaniasis in sylvatic environments to rural-tourist-biosphere reserve areas and vice versa. The ecological characteristics of these two phlebotomines could explain the permanence of the major active and endemic focus of cutaneous leishmaniasis in the North-Western Ecuador a key aspect in tourism health-security in alternative tourism.

[Eco-epidemiological aspects, natural detection and molecular identification of Leishmania spp. in Lutzomyia reburra, Lutzomyia barrettoi majuscula and Lutzomyia trapidoi].

INTRODUCTION: The province of Pichincha in Ecuador is an endemic area of cutaneous leishmaniasis, where anthropophilic sand flies with natural infection by Leishmania, have been reported as vectors. However, the role in transmission of zoophilic species has not been evaluated. OBJECTIVE: To evaluate natural infection by Leishmania in two zoophilic phlebotomine sand fly species, Lutzomyia reburra and Lu. barrettoi majuscula, and one anthropophilic species, Lu. trapidoi, as well as the endophagy and synanthropism of these species in the northwest of Pichincha. MATERIALS AND METHODS: Phlebotomines were collected using CDC light traps in different habitats and altitudes with presence of cutaneous leishmaniasis. Leishmania infection was detected using genomic DNA from females of the collected sand flies. We amplified the internal transcribed spacer gene of ribosomal RNA I (ITS1), the mitochondrial topoisomerase II gene (mtTOPOII), and the nuclear topoisomerase II gene (TopoII). Percentages of positivity for Leishmania, at spatio-temporal scale, proportion of endophagy and synanthropism index were calculated. RESULTS: Natural infection was determined for Le. amazonensis in Lu. reburra (9.5%) and Lu. b. majuscula (23.8%), while in Lu. trapidoi we detected Le. amazonensis, Le. brazilienis and Le. naiffi-lainsoni. Phlebotomines were asynanthropic and with low endophagy. CONCLUSION: Natural infection with Le. amazonensis was recorded for the first time in Lu. reburra and Lu. b. majuscula, demonstrating the importance of zoophilic phlebotomines in the maintenance of the Leishmania transmission cycle in endemic foci.

Aspectos ecoepidemiológicos, detección natural e identificación molecular de Leishmania spp. en Lutzomyia reburra, Lutzomyia barrettoi majuscula y Lutzomyia trapidoi / Eco-epidemiological aspects, natural detection and molecular identification of Leishmania spp. in Lutzomyia reburra, Lutzomyia barrettoi majuscula and Lutzomyia trapidoi

Resumen Introducción. La provincia de Pichincha, Ecuador, es un área endémica de leishmaniasis cutánea, en donde se han determinado como vectores los flebotomíneos antropofílicos con infección natural por Leishmania spp. Sin embargo, no se ha evaluado el papel en la transmisión de las especies zoofílicas. Objetivo. Evaluar la infección natural por Leishmania en dos especies de flebotomíneos zoofílicos, Lutzomyia reburra y Lu. barrettoi majuscula, y en una antropofílica, Lu. trapidoi, así como la endofagia y la sinantropía de estas especies en el noroccidente de Pichincha. Materiales y métodos. Los flebotomíneos se recolectaron en trampas de luz CDC colocadas en diferentes hábitats y altitudes en sitios que son focos de leishmaniasis cutánea. La infección con Leishmania spp. se detectó en el ADN genómico de hembras de las especies de flebotomíneos de interés. Se amplificó el gen espaciador interno de la transcripción del ARN ribosómico, unidad I (ITS1), y los genes de las topoisomerasas mitocondrial II (mtTOPOII) y nuclear II (TopoII). Se determinaron los porcentajes de positividad para Leishmania a escala espaciotemporal, la proporción de endofagia y el índice de sinantropía. Resultados. Se determinó la presencia de infección natural por Le. amazonensis en Lu. reburra (9,5 %) y Lu. b. majuscula (23,8 %); en Lu. trapidoi se detectaron Le. amazonensis, Le. brazilienis y Le. naiffilainsoni. Los flebotomíneos eran asinantrópicos y con baja endofagia. Conclusión. Se registró por primera vez la presencia de infección natural en Lu. reburra y Lu. barrettoi majuscula por Le. amazonensis, y se demostró la importancia de los flebotomíneos zoofílicos en el mantenimiento del ciclo de transmisión de Leishmania spp. en focos endémicos.

Abstract Introduction: The province of Pichincha in Ecuador is an endemic area of cutaneous leishmaniasis, where anthropophilic sand flies with natural infection by Leishmania, have been reported as vectors. However, the role in transmission of zoophilic species has not been evaluated. Objective: To evaluate natural infection by Leishmania in two zoophilic phlebotomine sand fly species, Lutzomyia reburra and Lu. barrettoi majuscula, and one anthropophilic species, Lu. trapidoi, as well as the endophagy and synanthropism of these species in the northwest of Pichincha. Materials and methods: Phlebotomines were collected using CDC light traps in different habitats and altitudes with presence of cutaneous leishmaniasis. Leishmania infection was detected using genomic DNA from females of the collected sand flies. We amplified the internal transcribed spacer gene of ribosomal RNA I (ITS1), the mitochondrial topoisomerase II gene (mtTOPOII), and the nuclear topoisomerase II gene (TopoII). Percentages of positivity for Leishmania, at spatio-temporal scale, proportion of endophagy and synanthropism index were calculated. Results: Natural infection was determined for Le. amazonensis in Lu. reburra (9.5%) and Lu. b. majuscula (23.8%), while in Lu. trapidoi we detected Le. amazonensis, Le. brazilienis and Le. naiffilainsoni. Phlebotomines were asynanthropic and with low endophagy. Conclusion: Natural infection with Le. amazonensis was recorded for the first time in Lu. reburra and Lu. b. majuscula, demonstrating the importance of zoophilic phlebotomines in the maintenance of the Leishmania transmission cycle in endemic foci.

Nuclear DNA replication and repair in parasites of the genus Leishmania: Exploiting differences to develop innovative therapeutic approaches.

Leishmaniasis is a common tropical disease that affects mainly poor people in underdeveloped and developing countries. This largely neglected infection is caused by Leishmania spp, a parasite from the Trypanosomatidae family. This parasitic disease has different clinical manifestations, ranging from localized cutaneous to more harmful visceral forms. The main limitations of the current treatments are their high cost, toxicity, lack of specificity, and long duration. Efforts to improve treatments are necessary to deal with this infectious disease. Many approved drugs to combat diseases as diverse as cancer, bacterial, or viral infections take advantage of specific features of the causing agent or of the disease. Recent evidence indicates that the specific characteristics of the Trypanosomatidae replication and repair machineries could be used as possible targets for the development of new treatments. Here, we review in detail the molecular mechanisms of DNA replication and repair regulation in trypanosomatids of the genus Leishmania and the drugs that could be useful against this disease.

Taenia solium Human Cysticercosis: A Systematic Review of Sero-epidemiological Data from Endemic Zones around the World.

BACKGROUND: Taenia solium cysticercosis is a zoonotic neglected disease responsible for severe health disorders such as seizures and death. Understanding the epidemiology of human cysticercosis (HCC) in endemic regions will help to expose critical information about the transmission of the disease, which could be used to design efficient control programs. This review gathered serological data on apparent prevalence of T. solium circulating antigens and/or seroprevalence of T. solium antibodies, apparent prevalence of human taeniasis and risk factors for HCC from endemic communities in order to understand the differences in exposure to the parasite and active infections with T. solium metacestodes in endemic areas around the world. METHODS: Three databases were used to search sero-epidemiological data from community-based studies conducted between 1989 and 2014 in cysticercosis endemic communities worldwide. The search focused on data obtained from T. solium circulating antigen detection by monoclonal antibody-based sandwich ELISA and/or T. solium antibody seroprevalence determined by Enzyme-linked Immunoelectrotransfer Blot (EITB). A meta-analysis was performed per continent. PRINCIPAL FINDINGS: A total of 39,271 participants from 19 countries, described in 37 articles were studied. The estimates for the prevalence of circulating T. solium antigens for Africa, Latin America and Asia were: 7.30% (95% CI [4.23-12.31]), 4.08% (95% CI [2.77-5.95]) and 3.98% (95% CI [2.81-5.61]), respectively. Seroprevalence estimates of T. solium antibodies were 17.37% (95% CI [3.33-56.20]), 13.03% (95% CI [9.95-16.88]) and 15.68% (95% CI [10.25-23.24]) respectively. Taeniasis reported prevalences ranged from 0 (95% CI [0.00-1.62]) to 17.25% (95% CI [14.55-20.23]). SIGNIFICANCE: A significant variation in the sero-epidemiological data was observed within each continent, with African countries reporting the highest apparent prevalences of active infections. Intrinsic factors in the human host such as age and immunity were main determinants for the occurrence of infections, while exposure was mostly related to environmental factors which varied from community to community.

Spatio-temporal clusters of incident human brucellosis cases in Ecuador.

This study aimed to determine whether variations in the incidence of reported cases of human brucellosis in Ecuador were clustered in space and time. In addition, the effects of cattle and small ruminant population density and other socio-economic factors on the incidence were investigated. Significant space-time clusters were found in the northern and southern highlands and parts of Ecuadorian Amazonia. Customs of people, cattle, goat and sheep population density appeared to influence the incidence of brucellosis. In this study, the incidence of reported cases of human brucellosis was found to be higher in the highlands (sierra) and in municipalities near Peru and Colombia. The results of this study highlight the need for prevention and control measures aimed at abating the incidence of brucellosis among livestock and humans.