Browsing by Tema "Aedes"

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A sex-structured model of Wolbachia invasion to design sex-biased release strategies in Aedes spp mosquitoes populations
(Centre National de la Recherche Scientifique, 2023) Pierre‐Alexandre Bliman; Yves Dumont; Oscar E. Escobar-Lasso; Héctor J. Martínez; Olga Vasilieva
Arbovirus vectors in municipalities with a high risk of dengue in Cauca, Southwestern Colombia
(2022) Catalina Marceló-Díaz; Carlos Andrés Morales; María Camila Lesmes; Patricia Fuya; Sergio Méndez-Cardona; Horacio Cadena; Alvaro Ávila-Díaz; Erika Santamaría
The Culicidae family has two of the most important disease vector genus: Aedes spp. and Culex spp. Both of these are involved in the transmission of arboviruses. Here, we provide novel data for the geographical distribution of 2,383 specimens in the Culicidae family. We also report the percentage of houses infested with these vectors, and Shannon and Simpson diversity indices in three municipalities located in Cauca, Colombia. This dataset is relevant for research on vector-borne diseases because Aedes spp. can transmit arboviruses such as dengue, Zika and chikungunya, and Culex spp. is a well-known vector of West Nile virus and Venezuelan equine encephalitis.
Ascogregarina culicis (apicomplexa: lecudinidae) en Aedes aegypti naturalmente infectado
(2019) Francisco Javier Montilla Fernández; José Vicente Scorza Benitez; Arelis Josefina Briceño Azuaje
As activity surveillance system for controlling Aedes in the country, potential breeding sites were reviewed in several locations. By manual capture of mosquito larvae in 15 locations in five states of Venezuela, the infection was detected in 26.8% of a total of 750 larvae collected and identified as Aedes aegypti, using the taxonomic keys. Dissecting infected larvae allowed exposure tubes Malpii ghian and inside the digestive cavity, on a glass slide, it was possible to identify the presence of a microorganism of 90µm long and 24µm wide with a core located slightly the posterior pole of the organism, and mucron, easily distinguishable in the previous pole. Comma-shaped and has presented a very slow moving, they allowed identifying characteristics as a Ascogregarina culisis, parasitizing the digestive tract of Aedes aegypti, with possible pathogenic potential for your guest. It was possible to have more than two hundred parasites within one larva. In the same it was possible to observe several of the developmental stages of the parasite and to dissect tubes malpigio infected adults, it was possible to identify large numbers of spores or oocytes, which are the infectious form, completing the observation of the life cycle of the parasite.
Biological control of Aedes polynesiensis with the copepod Mesocyclops aspericornis. Experimentation in Huahine. I. Survey and search for study sites
(1987) Frédéric Lardeux; Yves Séchan; Marc Faaruia; Léon Colombani; Louis Teriitepo
Biological control of Aedes polynesiensis with the copepod Mesocyclops aspericornis. Experimentation in Rangiroa. I. Pre-treatment study - treatment
(Centre National de la Recherche Scientifique, 1987) Frédéric Lardeux
Control of the Aedes vectors of the dengue viruses and Wuchereria bancrofti: the French Polynesian experience
(Maney Publishing, 2002) Frédéric Lardeux; François Rivière; Yves Séchan; S. Loncke
In most of the 130 islands of French Polynesia, the stenotopic mosquitoes Aedes aegypti (the main local vector for the viruses causing dengue) and Aedes polynesiensis (the main local vector of Wuchereria bancrofti) share many breeding sites in water containers such as discarded cans, coconut shells, buckets and water-storage pots and drums. In addition to selective application of insecticides, non-polluting methods of controlling these mosquitoes have been evaluated during the last decade in two main ecological situations: (1) villages, where Aedes breeding sites are typically peridomestic; and (2) flooded burrows of land crabs, the major source of Ae. polynesiensis throughout the South Pacific region. Large-scale trials of biological control agents, such as mosquito fish (Gambusia affinis and Poecilia reticulata) and copepods (Mesocyclops aspericornis), and of integrated-control strategies have demonstrated the efficacy of certain techniques and control agents against the target Aedes populations in some village situations. Generally, mechanical methods (the use of layers of polystyrene beads against mosquito larvae and pupae, and screening against adult mosquitoes) were more efficient than use of the biological control agents. By integrating several methods of control, mosquito densities (as measured by human-bait collections and larval surveys) were reduced significantly compared with the results of concurrent sampling from untreated villages, and control remained effective for months after the interventions ceased. In land-crab burrows, the first attempts to control Aedes larvae used bacterial agents (Bacillus thuringiensis) and predatory copepods gave disappointing results. Mesocyclops aspericornis could be an effective control agent if the burrows were constantly flooded, but most burrows dry out and refill periodically, so copepod populations do not survive. As it proved difficult to reach all corners of the long sinuous burrows with any control agent, larvicidal (chlorpyrifos-methyl) baits were developed for foraging crabs to carry into their burrows. This novel technique proved to be effective and could become the method of choice for treating crab burrows. Further research is underway to find the optimum (biological or chemical) larvicidal ingredient for the crab bait. Despite the ecological and logistical challenges of controlling the Aedes vectors of the dengue viruses and W. bancrofti in so many scattered islands, the French Polynesian experience indicates that relatively simple methods can be integrated and applied effectively and economically. Operationally, however, success also depends on a strong political commitment and on at-risk communities that are sufficiently motivated to maintain a good level of Aedes control.
Discovery and characterization of chromosomal inversions in the arboviral vector mosquito Aedes aegypti
(2024) Jiangtao Liang; Noah H. Rose; Ilya I. Brusentsov; Varvara Lukyanchikova; Dmitriy A. Karagodin; Yifan Feng; Andrey A. Yurchenko; Massamby Sylla; Joel Lutomiah; Athanase Badolo
Chromosomal inversions play a fundamental role in evolution and have been shown to regulate epidemiologically important traits in malaria mosquitoes. However, they have never been characterized in Aedes aegypti, the major vector of arboviruses, because of the poor structure of its polytene chromosomes. In this study, we applied a Hi-C proximity ligation approach to identify chromosomal inversions in 25 strains of Ae. aegypti, acquired from its worldwide distribution, as well as in one strain of Ae. mascarensis. The study identified 21 multi-megabase inversions with uneven distributions along the three chromosomes. All chromosomal inversions, including one specific for Ae. mascarensis, were polymorphic. Nevertheless, geographic origin separated the strains into two clusters carrying African and non-African inversions suggesting their potential association with Ae. aegypti subspecies. Some of the inversions colocalized with chemoreceptor genes and quantitative trait loci associated with pathogen infection, implicating the potential role of inversions in host choice and disease transmission.
Diverse mosquito-specific flaviviruses in the Bolivian Amazon basin
(Microbiology Society, 2021) Yasuko Orba; Keita Matsuno; Ryo Nakao; Kirill Kryukov; Yumi Saito; Fumihiko Kawamori; Ariel Loza Vega; Tokiko Watanabe; Tadashi Maemura; Michihito Sasaki
The genus Flavivirus includes a range of mosquito-specific viruses in addition to well-known medically important arboviruses. Isolation and comprehensive genomic analyses of viruses in mosquitoes collected in Bolivia resulted in the identification of three novel flavivirus species. Psorophora flavivirus (PSFV) was isolated from Psorophora albigenu. The coding sequence of the PSFV polyprotein shares 60 % identity with that of the Aedes-associated lineage II insect-specific flavivirus (ISF), Marisma virus. Isolated PSFV replicates in both Aedes albopictus- and Aedes aegypti-derived cells, but not in mammalian Vero or BHK-21 cell lines. Two other flaviviruses, Ochlerotatus scapularis flavivirus (OSFV) and Mansonia flavivirus (MAFV), which were identified from Ochlerotatus scapularis and Mansonia titillans, respectively, group with the classical lineage I ISFs. The protein coding sequences of these viruses share only 60 and 40 % identity with the most closely related of known lineage I ISFs, including Xishuangbanna aedes flavivirus and Sabethes flavivirus, respectively. Phylogenetic analysis suggests that MAFV is clearly distinct from the groups of the current known Culicinae-associated lineage I ISFs. Interestingly, the predicted amino acid sequence of the MAFV capsid protein is approximately two times longer than that of any of the other known flaviviruses. Our results indicate that flaviviruses with distinct features can be found at the edge of the Bolivian Amazon basin at sites that are also home to dense populations of human-biting mosquitoes.
Evaluación de Temephos 50% CE sobre poblaciones de Aedes aegypti (Diptera: Culicidae) en Trujillo, Venezuela
(2008) LESLIE ÁLVAREZ-GONZÁLEZ; Milagros Oviedo-Araujo; ARELIS BRICEÑO-AZUAJE
El estado Trujillo de la región andina de Venezuela es considerado de alta casuística por dengue, además de coexistir con otras enfermedades metáxenicas como leishmaniasis, malaria y enfermedad de Chagas. El programa nacional de control de dengue contempla el uso de temephos como principal larvicida por lo que el objetivo de este estudio, fue determinar las concentraciones letales 50 y 95 para temephos 50% CE en poblaciones de Aedes aegypti procedentes de diferentes focos de alta endemicidad por dengue en el estado Trujillo. Se seleccionaron cuatro poblaciones (TE, HTO, PTO y MT) recolectadas a lo largo de un transecto en dirección noreste-sureste de la ciudad de Trujillo y evaluadas siguiendo la metodología de la OMS. Los valores de las CL50 para las cuatro poblaciones oscilaron entre 0,0031 ppm y 0,0317 ppm y para las CL95 entre 0,0170 ppm y 0,0567 ppm. Las poblaciones HTO, PTO y TR se comportaron de manera similar observándose en ellas valores hasta diez veces por encima de los encontrados con la población de referencia. La distribución espacial de estas tres poblaciones y la influencia del relieve de la ciudad, facilita el intercambio genético entre ellas, lo que sugiere realizar monitoreos continuos.
Evaluation of the Human IgG Antibody Response to Aedes albopictus Saliva as a New Specific Biomarker of Exposure to Vector Bites
(Public Library of Science, 2012) Souleymane Doucouré; François Mouchet; Sylvie Cornélie; J.S. Dehecq; Abdul Hamid Rutee; Yelin Roca; Annie Walter; Jean Pierre Hervé; Dorothée Missé; F. Favier
Ab responses to saliva could be used as an immuno-epidemiological tool for evaluating exposure to Aedes albopictus bites. Combined with entomological and epidemiological methods, a "salivary" biomarker of exposure to Aedes albopictus could enhance surveillance of its spread and the risk of arbovirus transmission, and could be used as a direct tool for the evaluation of Aedes albopictus control strategies.
First concrete documentation for presence of Aedes (Stegomyia) albopictus in Bolivia: Dispelling previous anecdotes
(2024) Frédéric Lardeux; Philippe Boussès; Rosenka Tejerina; Audric Berger; Christian Barnabé; Lineth García
Abstract Background The presence of Aedes albopictus in Bolivia has been a subject of controversy, lacking concrete documentation until now. Objectives This study aimed to furnish evidence of Ae. albopictus presence in Bolivia. Methods Larval breeding sites were sampled in two northern Bolivian localities, Rosario del Yata and San Agustin, both situated in the Beni department within the Vaca Diez province and Guayaramerin Municipio, approximately 10 km apart. Mosquito larvae collected underwent rearing to L4 and adult stages for morphological identification, with some specimens sequenced for confirmation. Findings Ae. albopictus was identified in multiple breeding sites in both localities, confirming its establishment in the area. This marks the first concrete documentation of the species in Bolivia. The collections (larvae and adults) have been deposited in the Medical Entomology Laboratory of the Universidad Mayor de San Simón in Cochabamba, Bolivia, and the Laboratory of Entomology of the Instituto Nacional de Laboratorios de Salud of the Ministry of Health in La Paz, Bolivia. Main conclusion Acknowledging its role as a vector for arboviruses like dengue and Chikungunya, Ae. albopictus should be incorporated into the Bolivian National Program of Vector Control for monitoring.
First concrete documentation for presence of Aedes (Stegomyia) albopictus in Bolivia: dispelling previous anecdotes
(Instituto Oswaldo Cruz, Ministério da Saúde, 2024) Frédéric Lardeux; Philippe Boussès; Rosenka Tejerina; Audric Berger; Christian Barnabé; Lineth García
Given its role as a vector for arboviruses such as dengue and Chikungunya, Ae. albopictus should be incorporated into the Bolivian National Programme of Vector Control for monitoring.
Gene Flow Between Domestic and Sylvan Populations of Aedes aegypti (Diptera: Culicidae) in North Cameroon
(Oxford University Press, 2008) Christophe Paupy; Cécile Brengues; Basile Kamgang; Jean-Pierre Hervé; Didier Fontenille; Frédéric Simard
Polymorphisms at eight microsatellite loci and a fragment of the mitochondrial DNA (mtDNA)-ND4 gene were surveyed in Aedes aegypti (L.) (Diptera: Culicidae) populations collected from six localities in North Cameroon, with emphasis on comparing domestic versus sylvan populations. The microsatellites revealed significant genetic differentiation among sylvan populations, with mean FST = 0.066. Domestic collections were genetically homogeneous (mean FST = 0.012). No pattern of isolation by distance was detected, and one of highest levels of genetic differentiation was estimated between populations sampled a few kilometers apart, each in a distinctly different ecological environment (FST = 0.076). Analyses of mtDNA-ND4 polymorphisms and divergence between the two neighboring populations revealed increased genetic diversity within the domestic population, with molecular signatures suggesting recent demographic expansion, whereas a single haplotype was observed in the sylvan sample. These data suggest reduced gene flow between sylvan and domestic Ae. aegypti populations in North Cameroon, reminiscent of the situation for Ae. aegypti in Kenya in East Africa.
Genetic structure and phylogeography of Aedes aegypti populations from Bolivia
(Centre National de la Recherche Scientifique, 2009) Christophe Paupy; Gilbert Le Goff; Cécile Brengues; Mabel Guerra-Giraldez; Norman Valdez-Zamorano; R. Revollo-Guzman Jimmy; Zaira Barja-Sima; Jean-Pierre Hervé
International audience
Genetic structure and phylogeography of Aedes aegypti, the dengue and yellow-fever mosquito vector in Bolivia
(Elsevier BV, 2012) Christophe Paupy; Gilbert Le Goff; Cécile Brengues; Mabel Guerra; Jimmy Revollo; Z. Barja Simon; Jean-Pierre Hervé; Didier Fontenille
Human Antibody Response to Aedes aegypti Saliva in an Urban Population in Bolivia: A New Biomarker of Exposure to Dengue Vector Bites
(American Society of Tropical Medicine and Hygiene, 2012) Souleymane Doucouré; François Mouchet; Amandine Cournil; Gilbert Le Goff; Sylvie Cornélie; Yelin Roca; Mabel Guerra Giraldez; Z. Barja Simon; Roxana Loayza; Dorothée Missé
Aedes mosquitoes are important vectors of re-emerging diseases in developing countries, and increasing exposure to Aedes in the developed world is currently a source of concern. Given the limitations of current entomologic methods, there is a need for a new effective way for evaluating Aedes exposure. Our objective was to evaluate specific antibody responses to Aedes aegypti saliva as a biomarker for vector exposure in a dengue-endemic urban area. IgG responses to saliva were strong in young children and steadily waned with age. Specific IgG levels were significantly higher in persons living in sites with higher Ae. aegypti density, as measured by using entomologic parameters. Logistic regression showed a significant correlation between IgG to saliva and exposure level, independently of either age or sex. These results suggest that antibody responses to saliva could be used to monitor human exposure to Aedes bites.
Importancia de los floreros como criaderos de aedes aegypti en tres cementerios del Estado Trujillo, Venezuela
(2016) Carmen Castillo; E. S. Brown; Luis Castillo; Melina Caprazo; Libert Sánchez
Aedes aegypti es una especie bien adaptada a las condiciones encontradas en sitios de cría artificiales. Sitios públicos, como los cementerios representan potenciales sitios de cría. Para establecer la importancia de los floreros de los cementerios como criaderos productivos de Aedes aegypti se realizó un estudio en 3 cementerios del estado Trujillo, Venezuela. En total, se inspeccionaron 478 tumbas, para un total de 537 floreros con agua de los cuales 218 (41%) resultaron positivos para formas inmaduras de mosquitos. Se recolectó un total de 2.040 larvas y 942 pupas, de las cuales el 72% (677/942) fueron identificadas como Ae. aegypti en el laboratorio. De los adultos identificados como Ae. aegypti el 51% fueron hembras y el 49% machos. Se registró un gran número de tumbas abandonadas. Estos resultados resaltan la necesidad de incluir en los programas tradicionales de control de vectores, programas de educación comunitaria. Se realizaron varios talleres contando con el apoyo de las Alcaldía de los municipios Pampán y Pampanito, a través de las Vocerías de Salud, para explicar la importancia de la implementación de la Ordenanza Municipal que prohíbe el uso de agua en los envases floreros de los cementerios y promover el uso de arena húmeda para colocar las flores.
Isolation of andrograpanin from Andrographis paniculata and its bioactivity against Aedes aegypti and Culex quinquefasciatus
(Springer Nature, 2025) Jelin Vilvest; M. C. John Milton; Alex Yagoo; Kedike Balkrishna
Lutte biologique contre Aedes polynesiensis avec le copépode Mesocyclops aspericornis. Experimentation à Tikehau. I. Prospection et recherche de sites d'étude. Proposition de lutte intégrée
(1987) Frédéric Lardeux; Brian H. Kay; Léon Colombani
As part of the biological control program against Aedes polynesiensis using the copepod Mesocyclops aspericornis, an experimental action was planned by ORSTOM and ITRMLM to test the effectiveness of this method on a large scale. This method, developed in the Tahiti laboratory, involves introducing the predator into mosquito breeding sites, particularly the burrows of the land crab Cardisoma carnifex.In French Polynesia, selecting an experimental site is subject to various constraints that affect the implementation of large-scale experimentation. The atoll of Tikehau in the Tuamotu Archipelago was theoretically chosen as a potential site. A scientific mission visited Tikehau from April 3 to 10, 1987, to identify suitable study sites.The surveys conducted in Tikehau did not reveal an islet meeting the criteria for experimental work with the copepod in crab burrows. However, the village islet presents characteristics suitable for an integrated biological and ecological control action against mosquitoes and Culex. This approach deserves further development and implementation.
Niveles de resistencia a dos insecticidas en poblaciones de Aedes aegypti (Díptera: Culicidae) del Perú
(2005) Julio César Chávez G; Judith Roldán R; Franklin Vargas
The purpose of this study was to determine resistance leveis to temephos and deltametrine in two natural populations of Aedes aegypti from Peru. Bioassays in larvae and adults were carried out following the methodology of the World Health Organization. The visualization of Besterase bands was made by poliacrylamide gel electrophoresis (PAQE) in fourth instar larvae. Natural populations from Sullana (Piura) and El Porvenir (La Libertad) presented resistance ratios to temephos of 1.67 X and 1.45 X, respectively, indicating susceptibility in both populations; for deltametrine the Sullana population presented resistance with a KDT50 of 106 min and 68% mortality at 24 h; in the El Porvenir population susceptibility was observed, with a KDTS0 of 36.9 min and 99% mortality. Esterase B., was identified with a Rf of 0.23 only in El Porvenir population. The insecticide temephos can continue being used in control programs of the Aedes aegypti vector because the species is still susceptible to this organophosphorate; on the contrary with deltametrine, where its effects should be evaluated in natural populations since some of them should be presenting resistance, as in the case of the Sullana population.