Ana Clara Silva

Aedes aegypti on Madeira Island (Portugal): genetic variation of a recently introduced dengue vector

The increasing population of Aedes aegypti mosquitoes on Madeira Island (Portugal) resulted in the first autochthonous dengue outbreak, which occurred in October 2012. Our study establishes the first genetic evaluation based on the mitochondrial DNA (mtDNA) genes [cytochrome oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4)] and knockdown resistance ( kdr ) mutations exploring the colonisation history and the genetic diversity of this insular vector population. We included mosquito populations from Brazil and Venezuela in the analysis as putative geographic sources. The Ae. aegypti population from Madeira showed extremely low mtDNA genetic variability, with a single haplotype for COI and ND4. We also detected the presence of two important kdr mutations and the quasi-fixation of one of these mutations (F1534C). These results are consistent with a unique recent founder event that occurred on the island of Ae. aegypti mosquitoes that carry kdr mutations associated with insecticide resistance. Finally, we also report the presence of the F1534C kdr mutation in the Brazil and Venezuela populations. To our knowledge, this is the first time this mutation has been found in South American Ae. aegypti mosquitoes. Given the present risk of Ae. aegypti re-invading continental Europe from Madeira and the recent dengue outbreaks on the island, this information is important to plan surveillance and control measures.

Strengthening the perception-assessment tools for dengue prevention: a cross-sectional survey in a temperate region (Madeira, Portugal)

BackgroundCommunity participation is mandatory in the prevention of Dengue outbreaks. Taking public views into account is crucial to guide more effective planning and quicker community participation in preventing campaigns. This study aims to assess community perceptions of Madeira population in order to explore their involvement in the A. aegypti’s control and reinforce health-educational planning. Due to the lack of accurate methodologies for measuring perception, a new tool to assess the community’s perceptions was built.MethodsA cross-sectional survey was performed in the Island’s aegypti-infested area, exploring residents’ perceptions regarding most critical community behaviour: aegypti-source reduction and their domestic aegypti-breeding sites. A novel tool defining five essential topics which underlie the source reduction’s awareness and accession was built, herein called Essential-Perception (EP) analysis.ResultsOf 1276 individuals, 1182 completed the questionnaire (92 · 6%). EP-Score analysis revealed that community’s perceptions were scarce, inconsistent and possibly incorrect. Most of the population (99 · 6%) did not completely understood the five essential topics explored. An average of 54 · 2% of residents only partially understood each essential topic, revealing inconsistencies in their understanding. Each resident apparently believed in an average of four false assumptions/myths. Significant association (p<0.001) was found between both the EP-Score level and the domestic presence of breeding sites, supporting the validity of this EP-analysis. Aedes aegypti’s breeding sites, consisting of décor/leisure containers, presented an atypical pattern of infestation comparing with dengue prone regions.ConclusionsThe studied population was not prepared for being fully engaged in dengue prevention. Evidences suggest that EP-methodology was efficient and accurate in assessing the community perception and its compliance to practices. Moreover, it suggested a list of myths that could persist in the community. This is the first study reporting an aegypti-entomological pattern and community’s perception in a developed dengue-prone region. Tailored messages considering findings of this study are recommended to be used in future campaigns in order to more effectively impact the community perception and behaviour.

Insecticide resistance is mediated by multiple mechanisms in recently introduced Aedes aegypti from Madeira Island (Portugal)

Background Aedes aegypti is a major mosquito vector of arboviruses, including dengue, chikungunya and Zika. In 2005, Ae. aegypti was identified for the first time in Madeira Island. Despite an initial insecticide-based vector control program, the species expanded throughout the Southern coast of the island, suggesting the presence of insecticide resistance. Here, we characterized the insecticide resistance status and the underlying mechanisms of two populations of Ae. aegypti from Madeira Island, Funchal and Paúl do Mar. Methodology/Principal findings WHO susceptibility bioassays indicated resistance to cyfluthrin, permethrin, fenitrothion and bendiocarb. Use of synergists significantly increased mortality rates, and biochemical assays indicated elevated activities of detoxification enzymes, suggesting the importance of metabolic resistance. Microarray-based transcriptome analysis detected significant upregulation in both populations of nine cytochrome P450 oxidase genes (including four known pyrethroid metabolizing enzymes), the organophosphate metabolizer CCEae3a, Glutathione-S-transferases, and multiple putative cuticle proteins. Genotyping of knockdown resistance loci linked to pyrethroid resistance revealed fixation of the 1534C mutation, and presence with moderate frequencies of the V1016I mutation in each population. Conclusions/Significance Significant resistance to three major insecticide classes (pyrethroid, carbamate and organophosphate) is present in Ae. aegypti from Madeira Island, and appears to be mediated by multiple mechanisms. Implementation of appropriate resistance management strategies including rotation of insecticides with alternative modes of action, and methods other than chemical-based vector control are strongly advised to delay or reverse the spread of resistance and achieve efficient control.

Hemolytic activity of Trichomonas vaginalis and Tritrichomonas foetus

The hemolytic activity of live isolates and clones of Trichomonas vaginalis and Tritrichomonas foetus was investigated. The isolates were tested against human erythrocytes. No hemolytic activity was detected by the isolates of T. foetus. Whereas the isolates of T. vaginalis lysed erythrocytes from all human blood groups. No hemolysin released by the parasites could be detected. Our preliminary results suggest that hemolysis depend on the susceptibility of red cell membranes to destabilization and the intervention of cell surface receptors as a mechanism of the hemolytic activity. The mechanism could be subject to strain-species-genera specific variation of trichomonads. The hemolytic activity of T. vaginalis is not due to a hemolysin or to a product of its metabolism. Pretreatment of trichomonads with concanavalin A reduced levels of hemolysis by 40%.

A study protocol to evaluate the relationship between outdoor air pollution and pregnancy outcomes

BackgroundThe present study protocol is designed to assess the relationship between outdoor air pollution and low birth weight and preterm births outcomes performing a semi-ecological analysis. Semi-ecological design studies are widely used to assess effects of air pollution in humans. In this type of analysis, health outcomes and covariates are measured in individuals and exposure assignments are usually based on air quality monitor stations. Therefore, estimating individual exposures are one of the major challenges when investigating these relationships with a semi-ecologic design.Methods/DesignSemi-ecologic study consisting of a retrospective cohort study with ecologic assignment of exposure is applied. Health outcomes and covariates are collected at Primary Health Care Center. Data from pregnant registry, clinical record and specific questionnaire administered orally to the mothers of children born in period 2007-2010 in Portuguese Alentejo Litoral region, are collected by the research team. Outdoor air pollution data are collected with a lichen diversity biomonitoring program, and individual pregnancy exposures are assessed with spatial geostatistical simulation, which provides the basis for uncertainty analysis of individual exposures. Awareness of outdoor air pollution uncertainty will improve validity of individual exposures assignments for further statistical analysis with multivariate regression models.DiscussionExposure misclassification is an issue of concern in semi-ecological design. In this study, personal exposures are assigned to each pregnant using geocoded addresses data. A stochastic simulation method is applied to lichen diversity values index measured at biomonitoring survey locations, in order to assess spatial uncertainty of lichen diversity value index at each geocoded address. These methods assume a model for spatial autocorrelation of exposure and provide a distribution of exposures in each study location. We believe that variability of simulated exposure values at geocoded addresses will improve knowledge on variability of exposures, improving therefore validity of individual exposures to input in posterior statistical analysis.

Dengue in Madeira Island

Dengue is a vector-borne disease and 40 % of world population is at risk. Dengue transcends international borders and can be found in tropical and subtropical regions around the world, predominantly in urban and semi-urban areas. A model for dengue disease transmission, composed by mutually-exclusive compartments representing the human and vector dynamics, is presented in this study. The data is from Madeira, a Portuguese island, where an unprecedented outbreak was detected on October 2012. The aim of this work is to simulate the repercussions of the control measures in the fight of the disease.

Double transgenic zebrafish for somatotrophic axis: a tool for muscle development and growth studies.

Transgenic zebrafish lines overexpressing growth-related genes are rare. Our research group has developed two of them expressing growth hormone (GH) ubiquitously (actb1 promoter) or its receptor (GHR) specifically in the skeletal muscle (mylz2 promoter). Besides GH, the former line also expresses GFP under control of the actb1 promoter. Similarly, the GHR line expresses DsRED in the skeletal muscle. Breeding the two lines generated Mendelian proportions of four genotypes (1:1:1:1): nontransgenic, GH transgenic, GHR transgenic, and a double FIG. 1. (A) The GH line [Tg(actb1:GH/actb1:GFP)] expresses both GH and GFP from a ubiquitous actb1 promoter that includes the first intron (I1a). (B) The GHR line [Tg(mylz2:GHR/mylz2:DsRED)] expresses both GHR and DsRED from a muscle-specific mylz2 promoter

Impact of a Dengue Outbreak Experience in the Preventive Perceptions of the Community from a Temperate Region: Madeira Island, Portugal

The ability to effectively modify behaviours is increasingly relevant to attain and maintain a good health status. Current behaviour-change models and theories present two main approaches for (healthier) decision-making: one analytical/logical, and one experiential/emotional/intuitive. Therefore, to achieve an integral and dynamic understanding of the public perceptions both approaches should be considered: community surveys should measure cognitive understanding of health-risk contexts, and also explore how past experiences affect this understanding. In 2011, community perceptions regarding domestic source reduction were assessed in Madeira Island. After Madeira’s first dengue outbreak (2012) a unique opportunity to compare perceptions before and after the outbreak-experience occurred. This was the aim of this study, which constituted the first report on the effect of an outbreak experience on community perceptions regarding a specific vector-borne disease. A cross-sectional survey was performed within female residents at the most aegypti-infested areas. Perceptions regarding domestic source reduction were assessed according to the Essential Perception (EP)-analysis tool. A matching process paired individuals from studies performed before and after the outbreak, ensuring homogeneity in six determinant variables. After the outbreak, there were more female residents who assimilated the concepts considered to be essential to understand the proposed behaviour. Nevertheless, no significant difference was observed in the number of female residents who achieved the defined ‘minimal understanding’’. Moreover, most of the population (95.5%) still believed at least in one of the identified myths. After the outbreak some myths disappeared and others appeared. The present study quantified and explored how the experience of an outbreak influenced the perception regarding a dengue-preventive behaviour. The outbreak experience surprisingly led to the appearance of new myths within the population, apart from the expected increase of relevant concepts’ assimilation. Monitoring public perceptions is therefore crucial to make preventing dengue campaigns updated and worthy.

HEMOLYTIC ASPECTS OF STRAINS AND CLONES OF Trichomonas vaginalis

Se investigo la actividad hemolitica de 11 cepas y 6 clones vivos de Trichomonas vaginalis. Las cepas y los clones fueron subsecuentemente estudiados frente a los eritrocitos de 7 especies animales adultas. Cada una das 11 cepas y 6 clones liso los eritrocitos de todos los grupos sanguineos humanos, lo mismo que los de conejo, rata, pollo, caballo, bovino y ovino. No se detecto la liberacion de hemolisina por el parasito (cepas y clones). Los resultados sugieren que la acividad hemolitica no es debida a la liberacion de hemolisina por la T. vaginalis o por un producto de su metabolismo

Prevalence, awareness, treatment and control of diabetes in Portugal: Results from the first National Health examination Survey (INSEF 2015)

AIMS Diabetes Mellitus is a major public health threat worldwide and continues to increase in numbers and significance. Estimates of diabetes prevalence, awareness, treatment and control are essential to effectively monitor its trends, plan and evaluate interventions. METHODS We conducted a nationwide health examination survey in the population residing in Portugal aged between 25 and 74 years old in 2015. It consisted in a cross sectional prevalence study which included the measurement of HbA1c, a physical examination and a general health interview of a probabilistic sample of 4911 individuals (Authorization n°9348/2010 of the National Committee for Data Protection). RESULTS The overall prevalence of diabetes was 9.9% (95%CI: 8.4; 11.5). It was higher in males than in females (12.1% vs 7.8%). Diabetes was more prevalent among individuals of lower education and without any professional activity. The majority of persons with diabetes was aware of their condition (87.1%) and was taking antidiabetic medication (79.7%). Of these, 63.2% had glycated hemoglobin levels lower than 7.0% (53 mmol/mol), but the majority failed to comply with the LDL and blood pressure recommended clinical targets (71.9% and 59.0%). Similarly, the prevalence of prediabetes was 16%, higher among women than men (17.5% vs 14.4%). CONCLUSION The prevalence of diabetes and prediabetes remains higher than the global and European estimates, although there is increasing awareness of this disorder.