Publications by authors named "Rosa-Freitas M"

Mosquitoes are the most important vectors of emerging infectious diseases. During the past decade, our understanding of the diversity of viruses they carry has greatly expanded. Most of these viruses are considered mosquito-specific, but there is increasing evidence that these viruses may affect the vector competence of mosquitoes.

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Article Synopsis
  • Haiti faces a significant malaria issue, primarily caused by Plasmodium falciparum, with Anopheles albimanus mosquitoes as the main carriers.
  • Between 2009 and 2018, a total of 232,479 malaria cases were reported, showing a peak in 2010 followed by a sharp decline due to interventions, from 60,130 cases in 2010 to 8,978 by 2018.
  • The study underscores the need for improved data collection and epidemiological monitoring to better understand malaria's impact in Haiti, which affects both urban and rural areas.
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Identifying the species of the subfamily Anophelinae that are vectors is important to vector and malaria control. Despite the increase in cases, vector mosquitoes remain poorly known in Brazilian indigenous communities. This study explores Anophelinae mosquito diversity in the following areas: (1) a Yanomami reserve in the northwestern Amazon Brazil biome and (2) the Pantanal biome in southwestern Brazil.

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Background: Aedes albopictus is a very invasive mosquito, which has recently colonized tropical and temperate regions worldwide. Of concern is its role in the spread of emerging or re-emerging mosquito-borne diseases. Ae.

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  • Mosquito oviposition behaviors vary across species, with a focus on the unique egg-laying process of Sabethes albiprivus observed through high-speed video.
  • Researchers used a sapucaia nut trap to mimic the natural tree hole habitat of Sa. albiprivus, allowing for detailed observation of its egg-laying technique.
  • Females perform rapid up-and-down flights before catapulting eggs at nearly 1 m/s by curling their abdomen, demonstrating a complex and efficient egg-laying mechanism.
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The GloPID-R (Global Research Collaboration for Infectious Disease Preparedness) chikungunya (CHIKV), o'nyong-nyong (ONNV) and Mayaro virus (MAYV) Working Group has been established to investigate natural history, epidemiology and clinical aspects of infection by these viruses. Here, we present a report dedicated to entomological aspects of CHIKV, ONNV and MAYV. Recent global expansion of chikungunya virus has been possible because CHIKV established a transmission cycle in urban settings using anthropophilic vectors such as Aedes albopictus and Aedes aegypti.

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  • Studies conducted in Central Brazil's Pantanal biome aimed to update records on malaria-carrying mosquitoes and assess the area's vulnerability to malaria transmission.
  • Over the course of a year, researchers collected nearly 25,000 anopheline mosquitoes, finding that the primary malaria vector, Anopheles darlingi, was significantly present, especially near the river during specific seasonal transitions.
  • The study concluded that due to the influx of workers and tourists from malaria-endemic regions, ongoing surveillance and control measures are essential to prevent malaria from returning to the Pantanal area.
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Here, we describe the development of the MosqTent, an innovative double-chamber mosquito trap in which a human being attracts mosquitoes while is protected from being bitten within the inner chamber of the trap, while mosquitoes are lured to enter an outer chamber where they are trapped. The MosqTent previously collected an average of 3,000 anophelines/man-hour compared to 240 anophelines/man-hour for the human landing catch (HLC), thereby providing high numbers of human host-seeking mosquitoes while protecting the collector from mosquito bites. The MosqTent performed well by collecting a high number of specimens of Anopheles marajoara, a local vector and anthropophilic mosquito species present in high density, but not so well in collecting An.

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Here we present the first in a series of articles about the ecology of immature stages of anophelines in the Brazilian Yanomami area. We propose a new larval habitat classification and a new larval sampling methodology. We also report some preliminary results illustrating the applicability of the methodology based on data collected in the Brazilian Amazon rainforest in a longitudinal study of two remote Yanomami communities, Parafuri and Toototobi.

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Distribution, abundance, feeding behaviour, host preference, parity status and human-biting and infection rates are among the medical entomological parameters evaluated when determining the vector capacity of mosquito species. To evaluate these parameters, mosquitoes must be collected using an appropriate method. Malaria is primarily transmitted by anthropophilic and synanthropic anophelines.

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Roraima is the northernmost state of Brazil, bordering both Venezuela and Guyana. Appropriate climate and vector conditions for dengue transmission together with its proximity to countries where all four dengue serotypes circulate make this state, particularly the capital Boa Vista, strategically important for dengue surveillance in Brazil. Nonetheless, few studies have addressed the population dynamics of Aedes aegypti in Boa Vista.

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Knowledge of vector distribution is important for the design of effective local malaria control programs. Here we apply ecological niche modeling to analyze and predict the distributions of malaria vectors based on entomological collection points in the State of Roraima in the northern Brazilian Amazon Basin. Anopheline collections were conducted from 1999 to 2003 at 76 localities, all with active malaria transmission.

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Toxorhynchites guadeloupensis (Dyar Knab), a poorly known mosquito species, was observed preying upon Aedes aegypti (L.) larvae, in an oviposition trap placed for routine dengue entomological surveillance, during 2003-2004 in the urban area of Boa Vista, Roraima, Brazil. This is the first report for Tx.

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As for the entire Amazon Region, malaria continues to be a major health public problem in Roraima that presented an Annual Parasitic Index of 85.4 in 2005, the highest in Brazil. Information on anopheline breeding sites is an essential component in malaria control strategies.

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Parity and age composition for Anopheles darlingi and Anopheles albitarsis in the northern Amazon Basin, Brazil, were investigated. Anopheline ovaries and ovarioles were examined in order to determine whether hourly and seasonal parity status for the vectors An. albitarsis and An.

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Understanding the different background landscapes in which malaria transmission occurs is fundamental to understanding malaria epidemiology and to designing effective local malaria control programs. Geology, geomorphology, vegetation, climate, land use, and anopheline distribution were used as a basis for an ecological classification of the state of Roraima, Brazil, in the northern Amazon Basin, focused on the natural history of malaria and transmission. We used unsupervised maximum likelihood classification, principal components analysis, and weighted overlay with equal contribution analyses to fine-scale thematic maps that resulted in clustered regions.

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Objectives: Dengue has become the most important endemic disease in Brazil. The Amazonian state of Roraima has one of the highest incidence rates of dengue in the country. The objective of this study was to determine whether significant temporal relationships exist between the number of reported dengue cases and short-term climate measures for the city of Boa Vista, the capital of Roraima.

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Objective: To evaluate a new method of deriving the reproductive number for vector-borne diseases from the early epidemic curves for vector-borne diseases with incubations in the vectors and in the hosts.

Method: We applied the model to several dengue epidemics in different climatic regions of Brazil: Brasilia, Belém, Fortaleza, Boa Vista.

Results: The new method leads to higher estimates of the reproductive number than previous models.

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Even though Chagas disease is rare in the Brazilian Amazon, the conditions for the establishment of domiciliated cycles prevail in many areas where triatomines are of frequent occurrence. In Roraima, a previous serological and entomological survey in three agricultural settlements showed the existence of all transmission cycle elements, i.e.

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Chagas disease has been almost entirely eradicated from the arid zones in Central and Northeastern Brazil where rare or no autochthonous cases have been reported. However, in the last 10 years the disease has increasingly been registered in the Amazon Region. Aiming to investigate the possibility of the occurrence of autochthonous cycle of Chagas disease in Roraima, triatomine collections, vectorial susceptibility studies (this one to be shown elsewhere), parasitological and serological analyses were conducted in three agricultural settlement areas (Rorainópolis, Passarão Project and Ilha Community).

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The development of genetically modified vectors refractory to parasites is seen as a promising strategy in the future control of endemic diseases such as malaria. Nevertheless, knowledge of mosquito embryogenesis, a pre-requisite to the establishment of transgenic individuals, has been presently neglected. We have here studied the eggs from two neotropical malaria vectors.

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Construction of transgenic Anopheles mosquitoes refractory to Plasmodium requires knowledge of mosquito developmental biology. In order to study Anopheles embryology the removal or, alternatively, the permeabilization of the melanized and sclerotized egg chorion were attempted. The protocol classically used for chorion removal of Drosophila eggs was applied, with partial efficacy, to Anopheles albitarsis, a neotropical malaria vector.

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Article Synopsis
  • Laboratory-reared Lutzomyia longipalpis sand flies were tested with extracts from two Amazonian ichthyotoxic plants, Antonia ovata and Derris amazonica, known for their use as fishing poisons.
  • Extracts were prepared from dried leaves and roots, diluted in water, and applied to the sand flies, with mortality rates recorded every 2 hours over a 72-hour period.
  • Results showed that A. ovata resulted in up to 80% mortality (LD50 = 233 mg/ml) and D. amazonica caused 100% mortality (LD50 = 212 mg/ml), compared to a maximum of 13% mortality in control groups, indicating their potential as insecticides against
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