Políticas públicas par el control de enfermedades transmitidas por vectores en México

Las enfermedades transmitidas por vectores (ETV) persisten como un problema nacional de salud pública. A fin de disminuir su impacto, existen políticas públicas dirigidas al manejo de estas infecciones. Las soluciones propuestas, así como su implementación, se estipulan dentro de documentos como la ley general de salud (LGS) y normas oficiales mexicanas (NOM). Pese a que la ejecución de las políticas públicas ha conducido a resultados favorables en contra de las ETV, existen nuevas pautas internacionales establecidas por la Organización Mundial de la Salud (OMS) que incrementarían la eficacia de las políticas actuale

Mecanismos asociados a la resistencia al derribo “kdr” a la deltametrina en Aedes aegypti del occidente de Venezuela

moleculares involucrados con la resistencia al derribo “kdr” a la deltametrina en poblaciones de Aedes aegypti de los estados Trujillo, Lara y Táchira. Las poblaciones fueron expuestas a CK50 previamente determinadas mediante bioensayos con botellas impregnadas siguiendo la metodología de Brogdon (1989) por 1h. Posteriormente los insectos fueron colocados en envases post-recuperación libres de insecticidas y separados en 4 fenotipos: los no derribados luego de 1h, los recuperados a las 4h, los supervivientes y los muertos a las 24 horas post-exposición. Todos los ejemplares fueron seccionados; con cabeza y tórax se determinaron los niveles de esterasas α y β, oxidasas de función múltiple, glutation S transferasas y acetilcolinesterasa insensible y con el abdomen se extrajo ADN y se realizaron PCR para amplificar los alelos específicos Val1016 e Ile1016. Las enzimas desintoxicantes se incrementaron en la mayoría de las poblaciones entre las 4 y 24h posteriores a la exposición a la deltametrina sin encontrarse diferencia significativa con los niveles expresados en la cepa susceptible New Orleans (NO), excepto en la población de Ureña donde se encontró aumento significativo en las β-esterasas siendo superiores en el fenotipo superviviente con respecto al fenotipo muertos a las 24h. El genotipo silvestre V1016/V1016 prevaleció sobre el heterocigoto y homocigoto mutante en los cuatro fenotipos, en la mayoría de las poblaciones estudiadas, con excepción de la población Ureña donde el homocigoto mutante I1016/I1016 fue el genotipo predominante en los no derribados, lo cual se vio reflejado en la frecuencia alélica. Se asocia la mutación V1016I con la resistencia al derribo mostrada en las poblaciones evaluadas, destacando la importancia de la temprana detección de esta y otras mutaciones en el canal del sodio asociadas con resistencia a piretroides, lo cual debe ser considerado antes de incorporar el uso de deltametrina en el programa de control de Ae. aegypti en estas poblaciones

Susceptibility of Larvae of Chrysomya rufifacies (Diptera: Calliphoridae) to the Insecticides Methyl Parathion and Carbofuran, 2011

Chrysomya rufifacies (Macquart) is widely known as a colonizer on corpses. In the state of Nuevo León, Mexico, it has been usually found as part of the cadaveric fauna of human corpses, in “necro” traps with pigs, and in bottle traps with carrion. In the archives of the Attorney General of the State of Nuevo Leon, there is abundant evidence that criminals have used organophosphate and carbamate insecticides to poison persons and cause death. The trial was conducted at the Facultad de Ciencias Biológicas of Universidad Autónoma de Nuevo León and Instituto de Criminalística y Servicios Periciales of Procuradurı´a General de Justicia del Estado de Nuevo León, on larvae of Ch. rufifacies collected from human cadavers used for forensic research. In this study, bioassays were performed in 250-ml polyethylene terephthalate containers containing 13.5 g of beef liver paste ground in a blender to which was added 1.5 ml of insecticide solution and subsequently mixed with a wooden applicator. Distilled water rather than insecticide was used for check treatments. Groups of 20 larvae of each stadium were exposed for 24 h to either treatment or check containers, with three replications for each insecticide concentration. Containers were placed in a bioclimatic chamber (ThermoScientific, model 3759; Marietta, OH), set at 2761C and 70610% RH, with a photoperiod of 12:12 (L:D) h. After the 24-h exposure time, the number of dead larvae was recorded, where the criterion of mortality was immobility as the response to a mechanical stimulus. The insecticide formulations tested, Parathion metilico 720 (methyl parathion) and Furadan 350 L (carbofuran), were diluted in distilled water to make a stock solution of 1,000 mg/ml of active ingredient (AI) which was then further diluted for each bioassay and recorded as mg AI per g of beef liver. AI concentrations resulting in mortality from 10 to 90% of larvae are shown in Table 1 with the LC50 and corresponding confidence interval (95% CI) for each AI determined by log-Probit analysis using SPSS version 17.0 shown in Table 2. The LC50 values of both AIs differed significantly at each larval stadium, with larvae more susceptible to carbofuran than to methyl parathion. The LC50 values in all three larval stadia are in the ranges of concentrations that might be expected in a human poisoned with these insecticides. The purpose of the study was to determine the susceptibility of larvae of Ch. rufifacies to the insecticides to complement the medical and chemistry analysis in the estimation of the concentration of toxic at the time of death, when the corpses are at advanced decay

Variation in Competence for ZIKV Transmission by Aedes aegypti and Aedes albopictus in Mexico

BACKGROUND: ZIKV is a new addition to the arboviruses circulating in the New World, with more than 1 million cases since its introduction in 2015. A growing number of studies have reported vector competence (VC) of Aedes mosquitoes from several areas of the world for ZIKV transmission. Some studies have used New World mosquitoes from disparate regions and concluded that these have a variable but relatively low competence for the Asian lineage of ZIKV. METHODOLOGY/PRINCIPAL FINDINGS: Ten Aedes aegypti (L) and three Ae. albopictus (Skuse) collections made in 2016 from throughout Mexico were analyzed for ZIKV (PRVABC59-Asian lineage) VC. Mexican Ae. aegypti had high rates of midgut infection (MIR), dissemination (DIR) and salivary gland infection (SGIR) but low to moderate transmission rates (TR). It is unclear whether this low TR was due to heritable salivary gland escape barriers or to underestimating the amount of virus in saliva due to the loss of virus during filtering and random losses on surfaces when working with small volumes. VC varied among collections, geographic regions and whether the collection was made north or south of the Neovolcanic axis (NVA). The four rates were consistently lower in northeastern Mexico, highest in collections along the Pacific coast and intermediate in the Yucatan. All rates were lowest north of the NVA. It was difficult to assess VC in Ae. albopictus because rates varied depending upon the number of generations in the laboratory. CONCLUSIONS/SIGNIFICANCE: Mexican Ae. aegypti and Ae. albopictus are competent vectors of ZIKV. There is however large variance in vector competence among geographic sites and regions. At 14 days post infection, TR varied from 8-51% in Ae. aegypti and from 2-26% in Ae. albopictus

Field Effectiveness of Drones to Identify Potential Aedes aegypti Breeding Sites in Household Environments from Tapachula, a Dengue-Endemic City in Southern Mexico

Aedes aegypti control programs require more sensitive tools in order to survey domestic and peridomestic larval habitats for dengue and other arbovirus prevention areas. As a consequence of the COVID-19 pandemic, field technicians have faced a new occupational hazard during their work activities in dengue surveillance and control. Safer strategies to monitor larval populations, in addition to minimum householder contact, are undoubtedly urgently needed. Drones can be part of the solution in urban and rural areas that are dengue-endemic. Throughout this study, the proportion of larvae breeding sites found in the roofs and backyards of houses were assessed using drone images. Concurrently, the traditional ground field technician’s surveillance was utilized to sample the same house groups. The results were analyzed in order to compare the effectiveness of both field surveillance approaches. Aerial images of 216 houses from El Vergel village in Tapachula, Chiapas, Mexico, at a height of 30 m, were obtained using a drone. Each household was sampled indoors and outdoors by vector control personnel targeting all the containers that potentially served as Aedes aegypti breeding sites. The main results were that the drone could find 1 container per 2.8 found by ground surveillance; however, containers that were inaccessible by technicians in roofs and backyards, such as plastic buckets and tubs, disposable plastic containers and flowerpots were more often detected by drones than traditional ground surveillance. This new technological approach would undoubtedly improve the surveillance of Aedes aegypti in household environments, and better vector control activities would therefore be achieved in dengue-endemic countries

Las enferemedades emergentes transmitidas por vectores: Paludismo, dengue, chinkunguya y zika.

Los vectores son animales que transmiten patógenos, entre ellos parásitos, de una persona (o animal) infectada a otra y ocasionan enfermedades graves en el ser humano. Estas enfermedades emergentes y re-emergentes representan un grave problema de salud pública en regiones tropicales y subtropicales, donde gran parte de la población está en riesgo. Los países de escasos recursos son, particularmente, vulnerables al impacto social y económico de estas enfermedades, debido a los recursos limitados en el sector de salud pública para el manejo y prevención de estos padecimiento

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

The use of sticky ovitraps to estimate dispersal of Aedes aegypti in northeastern Mexico

A newly designed sticky ovitrap was used to determine the dispersal Right of the dengue vector Aedes aegypti in northeastern Mexico. Unfed marked females were released in the field where 100 sticky ovitraps had been positioned within a circular area 300 m in diameter. Success of this method was represented by a 7.7% (31 of 401) recapture rate during a 19-day sampling period. The maximum dispersal distance was 120 m with a mean of 30.5 m +/- 4.5 SD. Drastic hot and dry climatic conditions at the study site may have restricted mosquito dispersal. As expected, mostly gravid female mosquitoes were captured in the ovitraps. The method of sticky ovitraps proved to be useful and inexpensive for Ae. aegypti dispersal studies in Latin American countries. In addition to the marked mosquito populations, unmarked Ae. aegypti, Culex sp.. roaches, and even small vertebrates such as lizards and sparrows were found glued to the sticky ovitraps. Based on these studies, the use of sticky ovitraps is recommended for iie. aegypti dispersal studies, specially for dengue control programs in developing countries