Dengue Vector Dynamics (Aedes aegypti) Influenced by Climate and Social Factors in Ecuador: Implications for Targeted Control

Background Dengue fever, a mosquito-borne viral disease, is now the fastest spreading tropical disease globally. Previous studies indicate that climate and human behavior interact to influence dengue virus and vector (Aedes aegypti) population dynamics; however, the relative effects of these variables depends on local ecology and social context. We investigated the roles of climate and socio-ecological factors on Ae. aegypti population dynamics in Machala, a city in southern coastal Ecuador where dengue is hyper-endemic. Methods/Principal findings We studied two proximate urban localities where we monitored weekly Ae. aegypti oviposition activity (Nov. 2010-June 2011), conducted seasonal pupal surveys, and surveyed household to identify dengue risk factors. The results of this study provide evidence that Ae. aegypti population dynamics are influenced by social risk factors that vary by season and lagged climate variables that vary by locality. Best-fit models to predict the presence of Ae. aegypti pupae included parameters for household water storage practices, access to piped water, the number of households per property, condition of the house and patio, and knowledge and perceptions of dengue. Rainfall and minimum temperature were significant predictors of oviposition activity, although the effect of rainfall varied by locality due to differences in types of water storage containers. Conclusions These results indicate the potential to reduce the burden of dengue in this region by conducting focused vector control interventions that target high-risk households and containers in each season and by developing predictive models using climate and non-climate information. These findings provide the region's public health sector with key information for conducting time and location-specific vector control campaigns, and highlight the importance of local socio-ecological studies to understand dengue dynamics. See Text S1 for an executive summary in Spanish

Room-temperature synthesis of nanometric and luminescent silver-MOFs

Three silver-MOFs were prepared using an optimized, room-temperature methodology starting from AgNO₃ and dicarboxylate ligands in water/ethanol yielding Ag2BDC, Ag2NDC (UAM-1), and Ag2TDC (UAM-2) at 38%–48% (BDC, benzenedicarboxylate; NDC, 1,8-naphthalene-dicarboxylate; TDC, p-terphenyl-4,4″-dicarboxylate). They were characterized by PXRD/FT-IR/TGA/photoluminescence spectroscopy, and the former two by SEM. These materials started decomposing at 330°C, while showing stability. The crystal structure of UAM-1 was determined by PXRD, DFT calculations, and Rietveld refinement. In general, the structure was 3D, with the largest Ag-O bond interlinking 2D layers. The FT-IR spectra revealed 1450 and 1680 bands (cm−1) of asymmetrically stretching aniso-/iso-bidentate -COO in coordination with 2/3-Ag atoms, accompanied by Ag-O bands at 780–740 cm−1, all demonstrating the network formation. XRD and SEM showed nanometric-scale crystals in Ag₂BDC, and UAM-1 developed micrometric single-stranded/agglomerated fibrillar particles of varying nanometric widths. Luminescence spectroscopy showed emission by Ag₂BDC, which was attributed to ligand-to-metal or ligand-to-metal–metal transitions, suggesting energy transfer due to the short distance between adjacent BDC molecules. UAM-1 and UAM-2 did not show luminescence emission attributable to ligand-to-metal transition; rather, they presented only UV emission. The stabilities of Ag₂BDC and UAM-1 were evaluated in PBS/DMEM/DMEM+FBS media by XRD, which showed that they lost their crystallinity, resulting in AgCl due to soft–soft (Pearson’s principle) affinity

Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines

Background: Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools. Methods: Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, see Supplementary data) concluded the following: Results: Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50–200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added. Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico. Conclusions: Countries where European and American AIT extracts are available should adjust AIT according to which school is followed

Arquitectura para transmisores HART de alta exactitud

In this paper a novel HART transmitter architecture is presented, based on a high accuracy 4-20 mA transmitter. Its main purpose is to develop a transmitter with a digital communication protocol without negatively affecting the 4-20 mA transmitter performance. It was used in this work a high accuracy pressure transmitter (error of less than 0.1% F.S.) that requires the use of digital signal processing for the compensation and calibration process. This circuit uses a digital sensor signal processor (DSSP) and the digital communication capacity in order to acquire the needed data to meet the HART standard requirements.Los transmisores 4-20 mA de alta exactitud generalmente utilizan procesamiento digital de señales para compensar y calibrar su salida, debido a esto, el consumo de corriente está cerca del límite de los 4 mA. En este trabajo se presenta una arquitectura que permite adicionar la capacidad de comunicación digital HART y al mismo tiempo mantener los componentes y algoritmos usados en el transmisor original. Para el desarrollo de este trabajo se utilizó como base la arquitectura de un transmisor de presión piezoresistivo con un error de 0,2% de fondo de escala que usa un procesador digital de señales para sensores DSSP. Las pruebas demostraron que la arquitectura propuesta cumple con todos los requisitos del protocolo HART versión 6.0 y el error de la salida analógica y digital se conservó en el 0,2% de fondo de escala

Local climate parameters and lags in the best-fit model for <i>Aedes aegypti</i> ovitrap abundance data for both localities combined, for the central area (CA) and peripheral area (PA).

<p>Local climate parameters and lags in the best-fit model for <i>Aedes aegypti</i> ovitrap abundance data for both localities combined, for the central area (CA) and peripheral area (PA).</p

<i>Aedes aegypti</i> oviposition dynamics predicted by lagged local climate.

<p>Time series of observed and predicted (95% CI) log eggs/ovitrap/week over the study period (Nov. 2010 to June 2011) from the best-fit models for the (A) peripheral area (PA) and (B) central area (CA).</p

Climatic and social factors interact to influence seasonal dengue risk.

<p>A synthesis of the important socio-ecological predictors for the presence of <i>Aedes aegypti</i> during rainy and post-rainy (dry) seasons in Machala, Ecuador.</p

<i>Aedes aegypti</i> pupae per container type by location and season.

<p>Percentage of all pupae collected from abandoned, domestic-use, and other types of containers (i.e., decorative, animal drinking water) in pupae surveys conducted during pre-rainy, rainy, and post-rainy seasons in the (A) central study area (CA), (B) peripheral study area (PA), and (C) both localities combined in Machala, Ecuador.</p