Estudio espacial y temporal de los ��ndices larvales de Aedes aegypti (l.) y su relaci��n con los casos de dengue en Guadalupe, N.L., durante 1994-1997, mediante un sistema de informaci��n geogr��fica

Tesis (Doctorado en Ciecias Biol��gicas con Especialidad en Ecolog��a) UANL

Frecuencia de la mutaci��n KDR ILE1, 016 en aedes aegypti (d��ptera : culicidae) en zonas de riesgo de dengue en M��xico.

Tesis (Doctor en Ciencias con Acentuaci��n en Entomolog��a M��dica) UANL, 2011.

Identificaci��n y serotipificaci��n del virus dengue, densidades y tasa de infecci��n de poblaciones dom��sticas de Ae. Aegypti en Canc��n, Quintana Roo, M��xico.

Tesis (Doctorado en Ciencias con Acentuaci��n en Entomolog��a M��dica) UANL, 2013.

Infecci��n potencial secundaria a dengue asociada a la presencia de poblaciones de Aedes aegypti (Linnaeus, 1762) en ��reas domiciliares de casos confirmados de dengue cl��sico y dengue hemorr��gico en Monterrey, M��xico.

Tesis (Doctor en Ciencias con Acentuaci��n en Entomolog��a M��dica) UANL, 2012

El virus de la fiebre amarilla ���un virus cient��ficamente olvidado���

La fiebre amarilla es una enfermedad viral propia de regiones subtropicales que afecta principalmente el h��gado produciendo hemorragias agudas y da��os graves a nivel del tejido; es causada por un virus perteneciente al g��nero Flavivirus, y es transmitida en el n��cleo urbano por el mosquito Aedes aegypti, y selv��ticamente, por mosquitos del g��nero Haemagogus. En Colombia, se presentaron 20 casos en el 2005 de los cuales el 65% fue letal (OMS, 2006) (*). Sobre la fiebre amarilla, se logr�� un control importante, sin embargo, actualmente es considerada como una enfermedad reemergente debido a m��ltiples factores que han venido aumentando a trav��s de los ��ltimos veinte a��os, tales como la amplia diseminaci��n del vector, la deforestaci��n, el aumento de la poblaci��n susceptible no vacunada, diversos fen��menos clim��ticos (Fen��meno del Pac��fico, por ejemplo), y la falta de programas de vigilancia epidemiol��gica. En pa��ses como el nuestro, la situaci��n se agudiza con el desplazamiento forzado de la poblaci��n, la explotaci��n de las zonas selv��ticas v��rgenes, la violencia y el narcotr��fico. A pesar de la disponibilidad de una vacuna con una alta eficacia, la fiebre amarilla contin��a siendo una causa importante de morbilidad y mortalidad en regiones tropicales de ��frica y de Am��rica del Sur (OMS, 2006) (**). La metodolog��a de producci��n de la vacuna est�� muy bien definida, es eficiente, e incluye un estricto control de calidad sobre los efectos neurol��gicos del virus, induce un periodo de protecci��n de diez a��os con una sola dosis y es, adem��s, barata. No obstante, desde 1996 se han reconocido casos de la enfermedad, la cual no s��lo es neurol��gica, sino, tambi��n, viscerotr��pica (afecci��n hep��tica principalmente), como consecuencia de la vacunaci��n. Los efectos adversos producidos por la vacuna, y que hoy en d��a se conocen gracias a la implantaci��n de programas de seguimiento postvacunal, no tienen una explicaci��n cient��fica, en parte, por la aceptaci��n absoluta que hubo sobre su eficacia y su seguridad desde que se inici�� su utilizaci��n en seres humanos; sin embargo, el problema mismo ha despertado un inter��s mundial por el desarrollo de una vacuna que no presente ning��n riesgo para el hombre, lo cual conlleva a la necesidad de conocer cient��ficamente las causas que originan esta situaci��n, como un prerrequisito para abordar adecuadamente cualquier estrategia de mejoramiento de la vacuna actual. Atendiendo a esta necesidad, el grupo de Bioqu��mica y Biotecnolog��a en Salud de la Facultad de Medicina de la Universidad del Rosario ha tomado el virus de la fiebre amarilla como modelo de investigaci��n, buscando dilucidar, por qu�� la vacuna est�� produciendo la enfermedad.

Caracteriza����o da resposta imunol��gica de Aedes aegypti e Culex quinquefasciatus �� infec����o pelo sorotipo 1 do Dengue v��rus

Os insetos podem atuar como pragas agr��colas e vetores de pat��genos causadores de doen��as ao homem e outros animais. Investiga����es a respeito do sistema imunol��gico de Ae. aegypti e Cx. quinquefasciatus poder��o contribuir para o desenvolvimento de m��todos de controle das doen��as veiculadas por estes insetos, principalmente a dengue, enfermidade causadora de s��rio problema de sa��de p��blica no mundo. Apesar de Ae. aegypti ser a ��nica esp��cie vetora confirmada na transmiss��o do v��rus Dengue no Brasil, considera-se tamb��m importante um melhor entendimento dos mecanismos imunol��gicos de Cx. quinquefasciatus tido como refrat��rio ao v��rus. Neste estudo foram utilizadas linhagens de Ae. aegypti e Cx. quinquefasciatus mantidas no Inset��rio do Departamento de Entomologia do CPqAM/FIOCRUZ. Tr��s grupos experimentais de f��meas com 10 dias de idade foram formados para cada esp��cie. Grupo I, composto por f��meas alimentadas com solu����o sacarose (10 por cento); grupo II, f��meas alimentadas com sangue limpo e grupo III, f��meas alimentadas com sangue infectado com o sorotipo DENV-1. De cada grupo foram obtidos hemolinfa, gl��ndula salivar, intestino m��dio e corpo gorduroso para avalia����o da express��o dos antimicrobianos defensina e transferrina. Essa avalia����o foi realizada atrav��s de PCR em Tempo Real utilizando o kit QuantiFast SYBR Green - One-Step qRT-PCR. A avalia����o da hemodin��mica foi realizada utilizando 10 microlitros de hemolinfa de cada grupo, atrav��s da contagem das c��lulas em c��mara de Neubauer. Nossos resultados demonstraram que o Cx. quinquefasciatus tem um maior aumento da express��o de defensina e um maior n��mero total de hem��citos quando infectados com DENV-1 em rela����o ao Ae. aegypti e a transferrina teve sua express��o alterada somente no Ae. aegypti. Em ambas as esp��cies estudadas, apenas a alimenta����o sangu��nea n��o interfere na produ����o de hem��citos ou quanto na indu����o de defensina e transferrina. Esses dados sugerem que f��meas de Cx. quinquefasciatus parecem apresentar uma resposta imune celular e humoral mais intensa do que Ae. aegypti quando infectados com DENV-1

LARVICIDAL ACTIVITY OF GRANDISIN AGAINST AEDES AEGYPTI

Dengue is a tropical disease caused by an arbovirus transmitted by the mosquito Aedes aegypti. Because no effective vaccine is available for the disease, the strategy for its prevention has focused on vector control by the use of natural insecticides. The aim of this study was to evaluate the larvicidal activity of the lignan grandisin, a leaf extract from Piper solmsianum, against Ae. aegypti.

Global stabilizing feedback law for a problem of biological control of mosquito-borne diseases

The control of the spread of dengue fever by introduction of the intracellular parasitic bacterium Wolbachia in populations of the vector Aedes aegypti, is presently one of the most promising tools for eliminating dengue, in the absence of an efficient vaccine. The success of this operation requires locally careful planning to determine the adequate number of mosquitoes carrying the Wolbachia parasite that need to be introduced into the natural population. The latter are expected to eventually replace the Wolbachia-free population and guarantee permanent protection against the transmission of dengue to human. In this paper, we propose and analyze a model describing the fundamental aspects of the competition between mosquitoes carrying Wolbachia and mosquitoes free of the parasite. We then introduce a simple feedback control law to synthesize an introduction protocol, and prove that the population is guaranteed to converge to a stable equilibrium where the totality of mosquitoes carry Wolbachia. The techniques are based on the theory of monotone control systems, as developed after Angeli and Sontag. Due to bistability, the considered input-output system has multivalued static characteristics, but the existing results are unable to prove almost-global stabilization, and ad hoc analysis has to be conducted.

Potencial larvicida��de extratos de plantas regionais no controle de larvas de��Aedes��aegypti

Dengue, amongst the virus illnesses one can get by vectorial transmission, is the one that causes more impact in the morbidity and mortality of world s population. The resistance to the insecticides has caused difficulties to control of vector insect (Aedes aegypti) and has stimulated a search for vegetables with larvicidal activity. The biodiversity of Caatinga is barely known and it is potential of use even less. Some plants of this biome are commercialized in free fairs northeast of Brazil, because of its phytotherapics properties. The vegetables in this study had been selected by means of a questionnaire applied between grass salesmen and natives of the Serido region from Rio Grande do Norte state; culicids eggs had been acquired with traps and placed in container with water for the larva birth. Thirty larvae had been used in each group (a group control and five experimental groups), with four repetitions four times. The vegetables had been submitted to the processes of decoction, infusion and maceration in the standard concentration of 100g of the vegetable of study in 1l of H2O and analyzed after ��, 1, 2, 4, 8, 12, 24 and 48 hours for verification of the average lethal dose (LD50) from the groups with thirty larva. The LD50 was analyzed in different concentrations (50g/l, 100g/l, 150g/l, 200g/l e 300g/l) of Aspidosperma pyrifolium Mart. 48 extracts of rind, leaf and stem of the seven vegetal species: Aspidosperma pyrifolium Mart., Mimosa verrucosa Benth, Mimosa hostilis (Mart.) Benth., Myracrodruon urundeuva Allem��o, Ximenia americana L, Bumelia sartorum Mart Zizyphus joazeiro Mart, had been analyzed. The extracts proceeding from the three methods were submitted to the freezedrying, to evaluate and to quantify substances extracted in each process. The results had shown that Aspidosperma pyrifolium Mart. and Myracrodruon urundeuva Allem��o are the species that are more distinguished as larvicidal after 24 hours of experiment, in all used processes of extraction in the assays. The Zizyphus joazeiro Mart species has not shown larvicidal activity in none of the assays. In relation to the extraction method, the decoction was the most efficient method in the mortality tax of the A. aegypti larvae

Atividade t��xica de isolados de Bacillus Thuringiensis a larvas de Aedes Aegypti (l.) (diptera: culicidae)

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Estudo te��rico-bioclim��tico da potencialidade de desenvolvimento do Aedes aegypti no estado do Rio Grande do Norte

In the current climate of global public health there is the emergence of urban dengue, a disease regarded as acute infectious fever. The disease annually, has affected millions of people worldwide, mostly in the range of the intertropical globe. The disease's main vector in urban areas, the Aedes aegypti mosquito. Recent studies indicate that the distribution of the insect vector of dengue in the geographical area is directly tied to the behavior of environmental restrictions that area, especially among those, the air temperature and relative humidity. From that context, the work aims to estimate and spatializing, monthly, for each municipality in the state of Rio Grande do Norte, the potential of biophysical conditions conducive to the development of Aedes aegypti. Yet, made use of the following methodology: collection of epidemiological data and climatological, Normal climatological, descriptive statistics (measures of central tendency and scatter), uniform distribution, estimation geostatistics and sufer program, version 8.0. The results flagged for a behavior very heterogeneous, both in space and in time, in the case of the potential of biophysical conditions conducive to the development of Aedes aegypti in the state of Rio Grande do Norte. Still, he noted that there is a tendency for lifting the potential of development for the entire state, from the month of January, ending in the month of April mainly in central and western portions of the state. By contrast, there is the permanence of increased potential for development in the eastern portion of the state. The latter record maximum potential in the month of July, resulting probability of greater than 70% have been favorable conditions for the development of Aedes aegypti in that area. In the period between the months of August to December, it is small potential for development of Aedes aegypti in all parts of the state

Association of insecticide use and alteration on Aedes aegypti susceptibility status

Dengue and dengue hemorrhagic fever, vector-borne diseases transmitted by the mosquito Aedes aegypti, are presently important public health problems in Brazil. As the strategy for disease control is based on vector control through the use of insecticides, the development of resistance is a threat to programs efficacy. The objective of this study was to compare the Aedes aegypti susceptibility in nine vector populations from the state of S��o Paulo and seven from Northeast region of Brazil, since there was a difference on group of insecticide used between the areas. Bioassays with larvae and adult were performed according to the World Health Organization methods.The results showed higher resistance levels to organophosphates group in populations from the Northeast region where this group was used for both larvae and adult control than in S��o Paulo where organophosphates were used for larvae and pyretroids for adult control. Resistance to pyretroids in adults was widespread in S��o Paulo after ten years of use of cypermethrin while in vector populations from the Northeast region it was punctual. The difference in resistance profile between the areas is in accordance to the group of insecticide used.

Mitochondrial DNA polymorphism and heteroplasmy in populations of Aedes aegypti in Brazil

The tropical mosquito Aedes aegypti (Diptera: Culicidae) is the most important domestic vector of urban yellow fever and dengue viruses. Ae. aegypti originated from Africa and was probably introduced into Brazil during the colonial period through embarkations, and dengue epidemics soon followed. Genetic analysis of 12 Ae. aegypti populations from five states in Brazil was conducted based on two mitochondrial DNA fragments: cytochrome oxidase I and NADH dehydrogenase subunit 4. Analyses comparing individual haplotypes indicated the existence of two well-defined clades, probably representing two mitochondrial lineages. Analysis of molecular variance showed significant variability in genetic structure among collections within groups. Mantel regression analysis showed a correlation between genetic and geographic distances, mainly because of northern and northeastern populations, in comparison with those in the southeast. The population from Santos, the largest port in Brazil, showed the greatest diversity, with 10 unique haplotypes, an indication of recent introductions that have not yet spread to other Brazilian cities. Different mitochondrial DNA sequences were found in three specimens, indicating the presence of heteroplasmy.

Short report: Application of an alternative Aedes species (Diptera : Culicidae) surveillance method in Botucatu City, S��o Paulo, Brazil

One of the main problems with dengue is the control of Aedes aegypti, its major vector. In Brazil, the current control program for Ae. aegypti and Aedes albopictus populations includes larval density surveys. An interesting alternative is the use of a distinct index, the Premise Condition Index (PCI). This tool relates conditions of property, such as houses and yards, and the degree of shade with the occurrence of Aedes sp. oviposition, and is calculated as scores from 3 to 9. The lowest score indicates property in good condition and an unfavorable breeding environment, while the highest score indicates property at high risk for infestation by Aedes sp. The present study is based on the application of the PCI in an urban area of Botucatu, Brazil to confirm its effectiveness.