Dengue importado y autóctono en España / Imported and autochthonous dengue in Spain

El dengue es, globalmente, la arbovirosis más importante. Está causado por el virus del dengue y transmitido generalmente por la picadura de mosquitos del género Aedes (Ae aegypti o Ae albopictus). En España fue inicialmente erradicado en el siglo xx, junto con el vector Aeaegypti, y en la actualidad la mayoría de los casos notificados en España son importados por viajeros procedentes de países con transmisión de dengue (dengue importado). Sin embargo, en los últimos años se han descrito casos de dengue de personas residentes en España que no habían viajado a zonas con transmisión conocida del virus (dengue autóctono), transmitidos por Aedes albopictus (el denominado mosquito tigre), presente especialmente en la cuenca mediterránea. Se requiere por lo tanto un buen conocimiento de esta enfermedad, ya que puede dar lugar a cuadros clínicos graves, de modo que pueda ser diagnosticada precozmente y manejada correctamente, disminuyendo con ello su mortalidad, así como su eventual transmisión autóctona (AU)

Dengue is globally the most important arboviral infection. It is caused by the dengue virus and it is generally transmitted by Aedes mosquitoes’ bites (Ae aegypti or Ae albopictus). In Spain it was initially eradicated in the 20th century, together with the Ae aegypti vector, and currently most of the cases reported in Spain are imported by travelers from countries with dengue transmission (imported dengue). However, in recent years, cases of dengue have been described in people residing in Spain who had not traveled to areas with known transmission (autochthonous dengue), transmitted by Aedes albopictus (the so-called tiger mosquito), present especially in the Mediterranean basin. Therefore, a good knowledge of this potentially severe disease is required, so that it can be diagnosed early, and managed correctly, thus reducing its mortality, as well as its eventual autochthonous transmission (AU)

Imported and autochthonous dengue in Spain.

Dengue is globally the most important arboviral infection. It is caused by the dengue virus and it is generally transmitted by Aedes mosquitoes' bites (Ae aegypti or Ae albopictus). In Spain it was initially eradicated in the 20th century, together with the Ae aegypti vector, and currently most of the cases reported in Spain are imported by travelers from countries with dengue transmission (imported dengue). However, in recent years, cases of dengue have been described in people residing in Spain who had not traveled to areas with known transmission (autochthonous dengue), transmitted by Aedes albopictus (the so-called tiger mosquito), present especially in the Mediterranean basin. Therefore, a good knowledge of this potentially severe disease is required, so that it can be diagnosed early, and managed correctly, thus reducing its mortality, as well as its eventual autochthonous transmission.

Determination of synthetic cannabinoids in oral fluids by liquid chromatography with fluorescence detection after solid-phase extraction.

Synthetic cannabinoids are one of the most consumed new psychoactive substances, being absolutely necessary the development of analytical methodologies for the determination of these substances in biological fluids. In this study, a liquid chromatography with fluorescence detection (LC-FD) method has been developed for the analysis of 8 synthetic cannabinoids in oral fluids. The method has been validated in terms of linearity, precision and extraction recoveries, giving limits of detection as low as 0.7 µg L-1, and limits of quantification of 2.6 µg L-1. Different silica and polymeric commercial solid sorbents such as C18, Supel-Select HLB, EB2 ExtrabondⓇ and SampliQ-OPT were tested, concluding that Supel-Select HLB provided quantitative recoveries for the extraction of synthetic cannabinoids in oral fluids.•Analysis of synthetic cannabinoids in oral fluids.•Analytical procedure based on liquid chromatography with fluorescence detection.•Sample treatment based on solid phase extraction with HLB cartridges.

Combining microfluidic paper-based platform and metal-organic frameworks in a single device for phenolic content assessment in fruits.

A microfluidic paper-based device (µPAD) has been combined with metal-organic frameworks (MOFs) for total phenolic compounds (TPC) quantification in fruit samples for the first time. The performance of the µPAD, based upon the vertical flow approach, was enhanced in order to determine the TPC content with high accuracy in fruit samples. The method was based on the traditional Folin-Ciocalteu Index using gallic acid or oenotannin as reference phenolic compounds. This novel design and construction of the device are in agreement with the principles of Green Chemistry avoiding wax technology (lower toxicity). The analytical parameters that affect the colorimetric method (using digital imaging of the colored zone) performance were optimized including design, sample volume, and MOF amount. Then, the analytical features of the developed method were investigated such as dynamic range (1.6-30 mg L-1), limit of detection (0.5 mg L-1), and precision (RSD < 9%). Besides, the in-field analysis is achievable with a color stability up to 6 h after the loading process of the sample and storage stability for at least 15 days without performance losses (under vacuum at - 20 °C). Furthermore, the MOF ZIF-8@paper was characterized to study its composition and the successful combination. The feasibility of the proposed method was demonstrated by determining the TPC in 5 fruit samples using oenotannin as reference solute. The accuracy was validated by comparison of the data with the results obtained with the recommended protocol proposed by the International Organisation of Vine and Wine (OIV).

Development of paper-immobilized molecularly imprinted polymers by laser pointer activation for methamphetamine extraction with analysis by ion mobility spectrometry.

A fast, simple, cheap, and versatile strategy has been proposed for the synthesis of paper-immobilized molecularly imprinted polymers (MIPs) by photoactivated bulk polymerization over a piece of nitrocellulose using a 405 nm laser pointer. Polymerization was carried out using a mixture of methacrylic acid and ethylene glycol dimethacrylate, using methamphetamine as template molecule and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide as radical initiator. After investigation of different polymerization parameters, the following experimental conditions were found to give best results: size of nitrocellulose strip (13.5 × 4.0 × 0.8 mm), type of porogen (acetonitrile), polymerization mixture volume (75 µL), and irradiation times (10 min). Experimental conditions (such as sample pH, extraction and desorption time, and type and volume of desorption solvent) were also adjusted for the extraction of methamphetamine using the proposed paper-MIP. Methamphetamine determination was carried out by ion mobility spectrometry providing a limit of detection of 14 µg L-1 and quantitative recoveries from 81 to 95% using spiked urine and oral fluid samples. The proposed paper-immobilized MIP device allows a simple and selective sample extraction procedure for the determination of methamphetamine in oral fluids and urine with a high portability, minimal solvent consumption, and reduced costs compared to other conventional approaches.

Design of a microfluidic paper-based device for the quantification of phenolic compounds in wine samples.

In this work, the design and development of a microfluidic paper-based device (µPAD) for the quantification of total phenolic compounds (TPC) in wines is described. The developed µPAD was based upon the vertical flow concept and the colour reaction used was the known Folin-Ciocalteu reaction using gallic acid as reference phenolic compound. After studying operational parameters, namely type of paper, reagents and sample volume, a dynamic range of 5-50 mg L-1 was obtained with a limit of detection of 1.2 mg L-1. The described device proved to have good precision (relative standard deviation < 5%) and no significant interferences were observed from known compounds present in wines. Furthermore, the stability of the colour product and of the device itself were assessed; the µPAD was stable for 30 days (in the dark at room temperature) and it could be scanned up to 8 h after sample introduction. The developed µPAD pose as a simple method for TPC quantification and was successfully applied to several wine samples including sparkling and table wines with two different approaches: i) using gallic acid as reference compound with standard addition; and ii) using taniraisin with external calibration. The accuracy of the proposed µPAD method was assessed by comparison with the reference spectrophotometric method according to the International Organisation of Vine and Wine (OIV) recommendations.

Paper-based monolith extraction of psychoactive substances from biological fluids.

A monolith of poly(methacrylic acid-co-ethylene glycol dimethacrylate) has been immobilised to a nitrocellulose strip by radical photopolymerisation to be used in the extraction of psychoactive substances in biological fluids. Codeine, methylone, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine, butylone, norketamine, ketamine, heroin, cocaine, lysergic acid diethylamide and fentanyl were employed as model drugs and final extracts were analysed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Polymerisation parameters were adjusted in order to obtain a stable and homogeneous layer of monolith onto the nitrocellulose strip. The resulting sorptive phase was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Extraction conditions were investigated by the evaluation of sample pH, extraction and desorption times and desorption solvent volume, providing enrichment factor values ranging from 5.3 to 39.9. The proposed methodology provided limit of quantification values from 0.013 µg L-1 for methylone to 0.057 µg L-1 for amphetamine, and recoveries from 64 to 120%. Urine and serum certified reference materials were employed in the validation of the proposed methodology, providing results statistically comparable. The developed approach is simple and straightforward for the determination of psychoactive substances in urine and serum samples.

Development of hybrid monoliths incorporating metal-organic frameworks for stir bar sorptive extraction coupled with liquid chromatography for determination of estrogen endocrine disruptors in water and human urine samples.

A novel coating based on hybrid monolith with metal-organic framework (MOF) onto conventional Teflon-coated magnetic stir bars was developed. For this purpose, the external surface of the Teflon stir bar was firstly vinylized in order to immobilize a glycidyl methacrylate (GMA)-based polymer onto the magnet. Then, an amino-modified MOF of type MIL-101 (NH2-MIL-101(Al)) was covalently attached to the GMA-based monolith. After the synthesis process, several parameters affecting extraction of target estrogens by stir bar sorptive extraction (SBSE) including pH, ionic strength, extraction time, stirring rate, desorption solvent, and desorption time were also investigated. The resulting hybrid monolith was evaluated as SBSE sorbent for extraction of three estrogens (estrone, 17ß-estradiol, estriol) and synthetic 17ß-ethinylestradiol from water and human urine samples followed by HPLC with fluorescence detection (excitation and emission wavelengths, 280 and 310 nm, respectively). Under the optimal experimental conditions, the analytical figures of the method were established, achieving satisfactory limits of detection in the range of 0.015-0.58 µg L-1, recovery results ranging from 70 to 95% with RSD less than 6%, and precision values (intra- and inter-extraction units) below 6%.

Molecularly imprinted polymer-based device for field collection of oral fluid samples for cocaine identification.

In this paper, a low-cost, rapid, easy, and potentially portable tool for the identification of cocaine and its semi-quantitative determination in oral fluid has been proposed. A field collection device has been designed, based on a cotton pad with an indicator and a molecularly imprinted polymer (MIP) sorbent, to selective retain cocaine from oral fluid components. After sample collection, cocaine is transferred by using phosphate buffer to the MIP and then eluted with 2-propanol. The obtained extract is analysed by ion mobility spectrometry (IMS), providing a cut-off value of 20 µg L-1 that identifies 100 % true-positive and 95 % true-negative samples. The MIP-IMS procedure has been validated by the analysis of oral fluid samples, collected from cocaine users at recreation environments, by comparing the results with lateral flow immunoassay and chromatographic reference methods. Thus, the proposed methodology allows a simple and fast cocaine identification that can be carried out in field by non-specialized personnel, such as health personnel, law enforcement bodies, and customs staff.

Tuning the selectivity of molecularly imprinted polymer extraction of arylcyclohexylamines: From class-selective to specific.

A molecularly imprinted polymer (MIP) has been prepared in presence of 3-hydroxy phencyclidine (3-OH PCP) as template by bulk polymerization using N,N-dimethylformamide, as porogenic solvent, for the selective solid-phase extraction (SPE) of arylcyclohexylamines from oral fluids. Experimental variables of the extraction procedure have been studied in order to increase both, extraction recovery of 3-OH PCP, used as model analyte, and imprinting factor. By modifying the composition of the washing solvent, the selectivity of the MIP extraction procedure can be tuned, moving from an arylcyclohexylamine selective method to a 3-OH PCP specific method. The applicability of the synthesized MIP was evaluated by the analysis of oral fluids spiked with 3-OH PCP at different concentration levels, extracted using both recommended SPE procedures and analyzed by ion mobility spectrometry. Recovery values ranging from 70 to 101% and a limit of detection of 15 µg L-1 were obtained.

Influence of photo-initiators in the preparation of methacrylate monoliths into poly(ethylene-co-tetrafluoroethylene) tubing for microbore HPLC.

In this study, poly(butyl methacrylate-co-ethyleneglycol dimethacrylate) polymeric monoliths were in situ developed within 0.75 mm i.d. poly(ethylene-co-tetrafluoroethylene) (ETFE) tubing by UV polymerization via three different free-radical initiators (α,α'-azobisisobutyronitrile (AIBN), 2,2-dimethoxy-2-phenylacetophenone (DMPA) and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MTMPP). The influence of the nature of each photo-initiator and irradiation time on the morphological features of the polymer was investigated by scanning electron microscopy, and the chromatographic properties of the resulting microbore columns were evaluated using alkyl benzenes as test substances. The beds photo-initiated with MTMPP gave the best performance (minimum plate heights of 38 µm for alkyl benzenes) and exhibited a satisfactory reproducibility in the chromatographic parameters (RSD < 11%). These monolithic columns were also successfully applied to the separation of phenylurea herbicides, proteins and a tryptic digest of ß-casein.

Modelling retention and peak shape of small polar solutes analysed by nano-HPLC using methacrylate-based monolithic columns.

The development of methacrylate-based monolithic columns was studied for the separation of pharmaceutical hydrophilic compounds in nano-liquid chromatography. The selected polymerisation mixture consisted of 7.5% hexyl methacrylate, 4.5% methacrylic acid and 18.0% ethylene dimethacrylate (w/w), in a binary porogenic solvent (35:35 w/w 1-propanol/1,4-butanediol). The polymer synthesised with this mixture has a good permeability, not excessive back-pressure, and reasonable retention times for polar and non-polar solutes. Monolithic columns (12 cm total capillary length, 100 µm i.d.), prepared with this mixture, were able to produce hydrogen bonding and electrostatic interactions, giving rise to promising separations. To evaluate the chromatographic system, alkylbenzenes (neutral and hydrophobic compounds) and sulphonamides (hydrophilic drugs) were assayed. To optimise the chromatographic mobile phase in isocratic elution and characterise the retention mechanism for a mixture of eight sulphonamides, the performance of several mathematic models was checked in the description of retention. The behaviour of the monolithic capillary column was compared, in terms of selectivity and peak shape, to that obtained with a C18 column (9 cm × 4.6 mm i.d., 5 µm particle size) using a conventional HPLC equipment. The results revealed substantial differences in the interactions established for sulphonamides between the monolithic and C18 columns.

Development of pipette tip-based poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolith for the extraction of drugs of abuse from oral fluid samples.

In this work, a monolithic polymer based on poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EDMA) was prepared inside 200 µL pipette tips for the extraction of drug of abuse from oral fluid samples. After an appropriate surface tip modification, several polymerization mixtures with different monomer/cross-linker ratios, and percentage of porogen were studied. The most appropriate monolith to easily flow organic solvents and oral fluid samples was prepared with a MAA/EDMA ratio of 8:92 wt/wt and dodecanol containing 10 wt% toluene, as porogenic solvent. Parameters affecting the extraction procedure were evaluated and the monolith was characterized in terms of binding capacity, reusability, and precision, using α-pyrrolidinovalerophenone as model compound. Cocaine, diazepam, methamphetamine and 20 new psychoactive substances were determined in oral fluids, using the synthesized poly(MAA-co-EDMA) monolith in-tip on an eight-channel micropipette extraction and ultra-high performance liquid chromatography tandem mass spectrometry. Appropriate recoveries were obtained, ranging from 64 to 115%, with limit of detection values from 0.03 to 0.6 µg L-1, and a high precision with relative standard deviation values lower than 10% for all the evaluated drugs.

Development of a molecularly imprinted monolithic polymer disk for agitation-extraction of ecgonine methyl ester from environmental water.

In this study, a new extraction approach based on rotating molecularly imprinted polymer (MIP) disks was developed. The preparation procedure of MIP-disk is simple. Firstly, in order to immobilize MIP onto the surface of polytetrafluoroethylene (PTFE) disk, previous modification and vinylization steps of this fluoropolymer were conducted. Then, MIP synthesis was done by in situ polymerization. The resulting MIP was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Afterwards, two ring magnets were placed in the sides of the MIP-disk to integrate the stirring and preconcentration of sample in just one step. To demonstrate the feasibility of this novel extraction system, the selective extraction of ecgonine methyl ester (EME) from water samples was performed. Extraction conditions were also evaluated and the extracts were analyzed by ion mobility spectrometry and by ultrahigh performance liquid chromatography-tandem mass spectrometry, allowing limits of detection of 13 and 75 ng L-1, respectively. Field surface water and wastewater were analyzed using the proposed methodology, being a good alternative for the fast and potentially portable methodology for in-field screening analysis.

Comparative study of two commercial tests for Strongyloides stercoralis serologic diagnosis.

Background: Serological diagnosis of Strongyloides stercoralis is often limited by its low specificity due to cross-reactivity with other parasitic nematodes. Novel serological tests assumed to be more specific have been recently developed. The aim of our study was to compare two commercial tests based on different antigens for S. stercoralis diagnosis in humans from a non-endemic area. Methods: A retrospective laboratory-based study was conducted in the Hospital Universitario 12 de Octubre, Madrid, Spain. Samples from patients with a requested S. stercoralis serology from January 2013 to October 2016 were tested with two commercial enzyme-linked immunosorbent assay (ELISA) tests (crude larval suspension ELISA [CrAg-ELISA] and recombinant antigen ELISA [NIE-ELISA]). Sensitivity, specificity and predictive values were calculated using primary and composite gold standards. The κ index was calculated. Results: A total of 249 samples from 233 patients were tested (κ=0.735). The CrAg-ELISA yielded sensitivities from 89.2% (95% confidence interval [CI] 80.7 to 94.2) to 94.7% (95% CI 75.4 to 99.0) and the NIE-ELISA from 72.3% (95% CI 58.2 to 83.1) to 78.9% (95% CI 56.7 to 91.5). Specificity ranged from 72.3% (95% CI 58.2 to 83.1) to 89.3% (95% CI 83.1 to 93.4) for the CrAg-ELISA and from 85.1% (95% CI 72.3 to 92.6) to 93.6% (95% CI 88.2 to 96.6) for the NIE-ELISA. Conclusions: The NIE-ELISA is more specific than the CrAg-ELISA, but its low sensitivity limits its use in S. stercoralis screening. New diagnostic tests are needed for the diagnosis of S. stercoralis.

Photografted fluoropolymers as novel chromatographic supports for polymeric monolithic stationary phases.

In this study, porous polymer monoliths were in situ synthesized in fluoropolymers tubing to prepare microbore HPLC columns. To ensure the formation of robust homogeneous polymer monoliths in these housing supports, the inner surface of fluoropolymer tubing was modified in a two-step photografting process. Raman spectroscopy and scanning electron microscopy (SEM) confirmed the successful modification of the inner poly(ethylene-co-tetrafluoroethylene) (ETFE) wall and the subsequent attachment of a monolith onto the wall. Poly(glycidyl methacrylate-co-divinylbenzene), poly(butyl methacrylate-co-ethyleneglycol dimethacrylate) and poly(styrene-co-divinylbenzene) monoliths were in situ synthesized by thermal polymerization within the confines of surface vinylized ETFE tubes. The resulting monoliths exhibited good permeability and mechanical stability (pressure resistance up to 9 MPa). The chromatographic performance of these different monolithic columns was evaluated via the separation of alkyl benzenes and proteins in a conventional HPLC system.

Polymer-based materials modified with magnetite nanoparticles for enrichment of phospholipids.

A polymeric material modified with magnetic nanoparticles (MNPs) has been synthesized and evaluated as sorbent both for solid-phase extraction (SPE) and dispersive magnetic solid-phase extraction (MSPE) of phospholipids (PLs) in human milk samples. The synthesized sorbent was characterized by scanning electron microscopy and its iron content was also determined. Several experimental variables that affect the extraction performance (e.g. loading solvent, breakthrough volume and loading capacity) were investigated and a comparison between conventional SPE and MSPE modalities was done. The proposed method was satisfactorily applied to the analysis of PLs in human milk fat extracts in different lactation stages and the extracted PLs were determined by means of hydrophilic interaction liquid chromatography using evaporative light scattering detection.

Preparation of organic monolithic columns in polytetrafluoroethylene tubes for reversed-phase liquid chromatography.

In this work, a method for the preparation and anchoring of polymeric monoliths in a polytetrafluoroethylene (PTFE) tubing as a column housing for microbore HPLC is described. In order to assure a covalent attachment of the monolith to the inner wall of the PTFE tube, a two-step procedure was developed. Two surface etching reagents, a commercial sodium naphthalene solution (Fluoroetch®), or mixtures of H2O2 and H2SO4, were tried and compared. Then, the obtained hydroxyl groups on the PTFE surface were modified by methacryloylation. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM) confirmed the successful modification of the tubing wall and the stable anchorage of monolith to the wall, respectively. Special emphasis was also put on the reduction of the unwanted effects of shrinking of monolith during polymerization, by using an external proper mold and by selecting the adequate monomers in order to increase the flexibility of the polymer. Poly(glycidyl methacrylate-co-divinylbenzene) monoliths were in situ synthesized by thermal polymerization within the confines of surface-vinylized PTFE tubes. The modified PTFE tubing tightly held the monolith, and the monolithic column exhibited good pressure resistance up to 20 MPa. The column performance was also evaluated via the isocratic separation of a series of alkylbenzenes in the reversed-phase mode. The optimized monolithic columns gave plate heights ranged between 70 and 80 µm. The resulting monoliths were also satisfactorily applied to the separation of proteins.

Cocaine abuse determination by ion mobility spectrometry using molecular imprinting.

A cocaine-based molecular imprinted polymer (MIP) has been produced by bulk polymerization and employed as selective solid-phase extraction support for the determination of cocaine in saliva samples by ion mobility spectrometry (IMS). The most appropriate conditions for washing and elution of cocaine from MIPs were studied and MIPs were characterized in terms of analyte binding capacity, reusability in water and saliva analysis, imprinting factor and selectivity were established and compared with non-imprinted polymers. The proposed MIP-IMS method provided a LOD of 18µgL-1 and quantitative recoveries for blank saliva samples spiked from 75 to 500µgL-1 cocaine. Oral fluid samples were collected from cocaine consumers and analysed by the proposed MIP-IMS methodology. Results, ranging from below the LOD to 51±2mgL-1, were statistically comparable to those obtained by a confirmatory gas chromatography-mass spectrometry method. Moreover, results were compared to a qualitative lateral flow immunoassay procedure providing similar classification of the samples. Thus, MIP-IMS can be considered an useful alternative that provided fast, selective and sensitive results with a cost affordable instrumentation that does not require skilled operators.