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In Ecuador, the status of insecticide resistance for Aedes aegypti, the principal arboviral vector in the country, has not been previously evaluated. The aim of this research was to describe the resistance status of Ae. aegypti to the principal insecticides used for vector control in provinces with high reports of arboviral clinical cases. This was a descriptive study performed on Ae. aegypti collected from 2016 to 2017 in 14 localities of Ecuador. The larvae were reared and tested using bioassays applying the adulticides malathion and deltamethrin, and the larvicide temephos. The lethal concentrations were obtained for field-collected specimens and compared to the susceptible reference strain ROCK, MRA-734. Mosquitoes from all the localities showed resistance to deltamethrin and susceptibility to malathion. On the other hand, mosquitoes demonstrated resistance to the larvicide temephos in 5 of the 14 localities analyzed. The results obtained in this research may be used by healthcare decision-makers to improve vector control in Ecuador. Rotation of insecticides and alternative biological vector control strategies should be considered to manage the resistance observed in Ae. aegypti to deltamethrin and temephos. New strategies to use insecticides should also be aimed to prevent selective pressure with malathion.

Aedes (Stegomyia) albopictus (Skuse), (Diptera: Culicidae), the Asian tiger mosquito, is one of the most widespread invasive vector-borne disease insect in tropical and temperate zones. This species has invaded the Americas over the past 3 decades and has spread to six countries. We report Ae. albopictus in Guayaquil city, the first time it has been identified in Ecuador. Outdoor BG-Sentinel traps without lures collected a total of 21 Ae. albopictus.

The detection and identification of natural infections in sand flies by Leishmania protozoan species in endemic areas is a key factor in assessing the risk of leishmaniasis and in designing prevention and control measures for this infectious disease. In this study, we analyzed the Leishmania DNA using nuclear ribosomal internal transcript spacer (ITS) sequences. Parasite DNA was extracted from naturally infected, blood-fed sand flies collected in nine localities considered leishmaniasis-endemic foci in Ecuador.The species of parasites identified in sand flies were Leishmania major-like, Leishmania naiffi, Leishmania mexicana, Leishmania lainsoni, and “Leishmania sp. siamensis”. Sand fly specimens of Brumptomyia leopoldoi, Mycropigomyia cayennensis, Nyssomyia yuilli yuilli, Nyssomyia trapidoi, Pressatia triacantha, Pressatia dysponeta, Psychodopygus carrerai carrerai, Psychodopygus panamensis, and Trichophoromyia ubiquitalis were found positive for Leishmania parasite. These findings contribute to a better understanding of the epidemiology and transmission dynamics of the disease in high-risk areas of Ecuador.

No abstract

Introduction: Malaria is a vector-borne disease widely distributed in the Amazon region and the coastal area of northern Ecuador. Its epidemiology involves related factors such as human settlements, vector reproduction sites, mobility, productive activity, and the response capacity of health systems, among others.Objective: To describe malaria transmission by Plasmodium vivax in a non-endemic area of Ecuador by analyzing the epidemiological and entomological factors involved.Materials and methods: We conducted the epidemiological study of the cases reported in the Salinas canton and the characterization of vector breeding sites through captures of larvae and adult mosquitoes by human capture of resting mosquitoes.Results: We detected 21 cases of malaria with local transmission related to the presence of initial cases in Venezuelan migrant patients and identified Anopheles albimanus as the predominant vector in natural breeding sites such as estuaries, wells, and water channels.Conclusions: We detected an outbreak of malaria triggered by imported cases from Venezuela. Climatic, social, environmental, and ecological conditions have favored the development of the vector maintaining the transmission cycle. Strategies to control imported malaria should be multiple including early case detection and control of productive breeding sites to avoid local transmission.

Chagas disease is a chronic and systemic parasitosis caused by the hemoflagellate protozoan Trypanosoma cruziandtransmittedmainlybyinsectsoftheTriatominae subfamily. Currently, at least 151 species of Triatominae are recognized, with species of the genera, Triatoma, Rhodnius and Panstrongylus, with an important epidemiological role in the transmission of the disease. In Ecuador it is difficult to know the trueepidemiological situation of this disease, its implications and the situation regarding its prevention and control management. A review of the epidemiological data of Chagas disease, publishedintheEpidemiologicalSurveillanceSubsystem of the Ministry of Public Health from 2013 to 2019, was carried out. The systematic review of triatomine species was carried out based on original research published on the basis of public access data. The review carried out reported 439 confirmed cases of Chagas with a high incidence in the last two years. The prevalence has been slightlyobservedinwomenwithaprevalentagegroupof 20 to 49 years. In Ecuador 17 species of triatomines are registered. The species Triatoma dimidiata and Rhodnius ecuadoriensis are the main vectors of the disease, with a high density in the provinces of Loja and Manabí due to their high capacity for adaptation and the colonization of new habitats. Chagas surveillance and control strategies should be carried out by linking epidemiological and vectoraspectstostratifyandstrengthencontrolprograms.

Cutaneous leishmaniasis (CL) is a neglected tropical disease transmitted by species of Phlebotominae sand flies. CL is responsible for more than 1000 reported cases per year in Ecuador. Vector collection studies in Ecuador suggest that there is a strong association between the ecological diversity of an ecosystem, the presence of potential alternative or reservoir hosts and the abundance of sand fly species. Data collected from a coastal community in Ecuador showed that Leishmania parasites may be circulating in diverse hosts, including mammalian and potentially avian species, and these hosts may serve as potential hosts for the parasite. There has been limited reporting of CL cases in Ecuador because the disease is non-fatal and its surveillance system is passive. Hence, the actual incidence of CL is unknown. In this study, an epidemic model was developed and analysed to understand the complexity of CL transmission dynamics with potential non-human hosts in the coastal ecosystem and to estimate critical epidemiological quantities for Ecuador. The model is fitted to the 2010 CL outbreak in the town of Valle Hermoso in the Santo Domingo de los Tsachilas province of Ecuador and parameters such as CL transmission rates in different types of hosts (primary and alternative), and levels of case reporting in the town are estimated. The results suggest that the current surveillance in this region fails to capture 38% (with 95% CI (29%, 47%)) of the actual number of cases under the assumption that alternative hosts are dead-end hosts and that the mean CL reproduction number in the town is 3.9. This means that on the average 3.9 new human CL cases were generated by a single infectious human in the town during the initial period of the 2010 outbreak. Moreover, major outbreaks of CL in Ecuador in coastal settings are unavoidable until reporting through the surveillance system is improved and alternative hosts are managed properly. The estimated infection transmission probabilities from alternative hosts to sand flies, and sand flies to alternative hosts are 27% and 32%, respectively. The analysis highlights that vector control and alternative host management are two effective programmes for Ecuador but need to be implemented concurrently to avoid future major outbreaks.