oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Public Street Lights Increase House Infestation by the Chagas Disease Vector Triatoma dimidiata  [PDF]
Freddy Santiago Pacheco-Tucuch, Maria Jesus Ramirez-Sierra, Sébastien Gourbière, Eric Dumonteil
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0036207
Abstract: Triatoma dimidiata is one of the primary vectors of Chagas disease. We previously documented the spatio-temporal infestation of houses by this species in the Yucatan peninsula, Mexico, and found that non-domiciliated triatomines were specifically attracted to houses. However, the factors mediating this attraction remained unclear. Artificial light has been known for a long time to attract many insect species, and therefore may contribute to the spread of different vector-borne diseases. Also, based on the collection of different species of triatomines with light traps, several authors have suggested that light might attract triatomines to houses, but the role of artificial light in house infestation has never been clearly demonstrated and quantified. Here we performed a spatial analysis of house infestation pattern by T. dimidiata in relation to the distribution of artificial light sources in three different villages from the Yucatan peninsula, Mexico. In all three villages, infested houses were significantly closer to public street light sources than non-infested houses (18.0±0.6 vs 22.6±0.4 m), and street lights rather than domestic lights were associated with house infestation. Accordingly, houses closer to a public street lights were 1.64 times more likely to be infested than houses further away (OR, CI95% 1.23–2.18). Behavioral experiments using a dual-choice chamber further confirmed that adult male and females were attracted to white light during their nocturnal activity. Attraction was also dependent on light color and decreased with increasing wavelength. While public lighting is usually associated with increased development, these data clearly show that it also directly contributes to house infestation by non-domiciliated T. dimidiata.
House improvements and community participation in the control of Triatoma dimidiata re-infestation in Jutiapa, Guatemala
Monroy, Carlota;Bustamante, Dulce Maria;Pineda, Sandy;Rodas, Antonieta;Castro, Xochitl;Ayala, Virgilio;Qui?ónes, Javier;Moguel, Bárbara;
Cadernos de Saúde Pública , 2009, DOI: 10.1590/S0102-311X2009001300016
Abstract: the deterioration or absence of plaster walls in houses and poor hygienic conditions are the most important risk factors for indoor triatoma dimidiata infestation in guatemala. a cross-disciplinary study was conducted addressing t. dimidiata infestation, household hygiene, and housing construction. the study focused on local materials and cultural aspects (including gender roles) that could lead to long-term improvements in wall construction. a new plaster mix for walls was developed on the basis of laboratory studies on construction materials recommended by local villagers. four villages with persistent (post-spraying) t. dimidiata infestation were studied. in two villages, an ecosystem approach was implemented, and the homeowners conducted wall improvements and household sanitation with the support of the interdisciplinary team (the ecosystem intervention). in the other two villages, a vector control approach based on insecticide spraying was adopted (traditional intervention). both interventions were associated with a reduction in t. dimidiata infestation, but only the ecosystem approach produced important housing improvements (sanitation and wall construction) capable of preventing t. dimidiata re-infestation in the long term.
Eco-Bio-Social Determinants for House Infestation by Non-domiciliated Triatoma dimidiata in the Yucatan Peninsula, Mexico  [PDF]
Eric Dumonteil ,Pierre Nouvellet,Kathryn Rosecrans,Maria Jesus Ramirez-Sierra,Rubi Gamboa-León,Vladimir Cruz-Chan,Miguel Rosado-Vallado,Sébastien Gourbière
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002466
Abstract: Background Chagas disease is a vector-borne disease of major importance in the Americas. Disease prevention is mostly limited to vector control. Integrated interventions targeting ecological, biological and social determinants of vector-borne diseases are increasingly used for improved control. Methodology/principal findings We investigated key factors associated with transient house infestation by T. dimidiata in rural villages in Yucatan, Mexico, using a mixed modeling approach based on initial null-hypothesis testing followed by multimodel inference and averaging on data from 308 houses from three villages. We found that the presence of dogs, chickens and potential refuges, such as rock piles, in the peridomicile as well as the proximity of houses to vegetation at the periphery of the village and to public light sources are major risk factors for infestation. These factors explain most of the intra-village variations in infestation. Conclusions/significance These results underline a process of infestation distinct from that of domiciliated triatomines and may be used for risk stratification of houses for both vector surveillance and control. Combined integrated vector interventions, informed by an Ecohealth perspective, should aim at targeting several of these factors to effectively reduce infestation and provide sustainable vector control.
Phylogeography and Genetic Variation of Triatoma dimidiata, the Main Chagas Disease Vector in Central America, and Its Position within the Genus Triatoma  [PDF]
María Dolores Bargues ,Debora R. Klisiowicz,Fernando Gonzalez-Candelas,Janine M. Ramsey,Carlota Monroy,Carlos Ponce,Paz María Salazar-Schettino,Francisco Panzera,Fernando Abad-Franch,Octavio E. Sousa,Christopher J. Schofield,Jean Pierre Dujardin,Felipe Guhl,Santiago Mas-Coma
PLOS Neglected Tropical Diseases , 2008, DOI: 10.1371/journal.pntd.0000233
Abstract: Background Among Chagas disease triatomine vectors, the largest genus, Triatoma, includes species of high public health interest. Triatoma dimidiata, the main vector throughout Central America and up to Ecuador, presents extensive phenotypic, genotypic, and behavioral diversity in sylvatic, peridomestic and domestic habitats, and non-domiciliated populations acting as reinfestation sources. DNA sequence analyses, phylogenetic reconstruction methods, and genetic variation approaches are combined to investigate the haplotype profiling, genetic polymorphism, phylogeography, and evolutionary trends of T. dimidiata and its closest relatives within Triatoma. This is the largest interpopulational analysis performed on a triatomine species so far. Methodology and Findings Triatomines from Mexico, Guatemala, Honduras, Nicaragua, Panama, Cuba, Colombia, Ecuador, and Brazil were used. Triatoma dimidiata populations follow different evolutionary divergences in which geographical isolation appears to have had an important influence. A southern Mexican–northern Guatemalan ancestral form gave rise to two main clades. One clade remained confined to the Yucatan peninsula and northern parts of Chiapas State, Guatemala, and Honduras, with extant descendants deserving specific status. Within the second clade, extant subspecies diversity was shaped by adaptive radiation derived from Guatemalan ancestral populations. Central American populations correspond to subspecies T. d. dimidiata. A southern spread into Panama and Colombia gave the T. d. capitata forms, and a northwestern spread rising from Guatemala into Mexico gave the T. d. maculipennis forms. Triatoma hegneri appears as a subspecific insular form. Conclusions The comparison with very numerous Triatoma species allows us to reach highly supported conclusions not only about T. dimidiata, but also on different, important Triatoma species groupings and their evolution. The very large intraspecific genetic variability found in T. dimidiata sensu lato has never been detected in a triatomine species before. The distinction between the five different taxa furnishes a new frame for future analyses of the different vector transmission capacities and epidemiological characteristics of Chagas disease. Results indicate that T. dimidiata will offer problems for control, although dwelling insecticide spraying might be successful against introduced populations in Ecuador.
Comparison of intervention strategies for control of Triatoma dimidiata in Nicaragua
Acevedo, F;Godoy, E;Schofield, CJ;
Memórias do Instituto Oswaldo Cruz , 2000, DOI: 10.1590/S0074-02762000000600022
Abstract: the effectiveness of three operational strategies for the control of triatoma dimidiata was compared by a field trial in the department of madriz, nicaragua. one strategy involved full pretrial evaluation, followed by spraying of all houses irrespective of whether or not they had been found to be infested. the second strategy minimised the pretrial evaluation by considering the locality infested as soon as one house was found to be positive, followed by spraying all houses. the third strategy involved full pretrial evaluation, followed by spraying only those houses found to be positive. evaluation after twelve months indicated that all three strategies were similarly effective, since all sprayed houses remained free of infestation. however, comparative estimates of the unit intervention costs indicated that strategies 1 and 2 were substantially less efficient than the third strategy of spraying only positive houses.
Comparison of intervention strategies for control of Triatoma dimidiata in Nicaragua  [cached]
Acevedo F,Godoy E,Schofield CJ
Memórias do Instituto Oswaldo Cruz , 2000,
Abstract: The effectiveness of three operational strategies for the control of Triatoma dimidiata was compared by a field trial in the Department of Madriz, Nicaragua. One strategy involved full pretrial evaluation, followed by spraying of all houses irrespective of whether or not they had been found to be infested. The second strategy minimised the pretrial evaluation by considering the locality infested as soon as one house was found to be positive, followed by spraying all houses. The third strategy involved full pretrial evaluation, followed by spraying only those houses found to be positive. Evaluation after twelve months indicated that all three strategies were similarly effective, since all sprayed houses remained free of infestation. However, comparative estimates of the unit intervention costs indicated that strategies 1 and 2 were substantially less efficient than the third strategy of spraying only positive houses.
Impact of residual spraying on Rhodnius prolixus and Triatoma dimidiata in the department of Zacapa in Guatemala
Nakagawa, J;Cordón-Rosales, C;Juárez, J;Itzep, C;Nonami, T;
Memórias do Instituto Oswaldo Cruz , 2003, DOI: 10.1590/S0074-02762003000200019
Abstract: as a vector control program to control chagas disease in guatemala, residual spraying of rhodnius prolixus and triatoma dimidiata was performed, and its impact was measured in the department of zacapa. in order to identify infested villages and determine the degree of infestation, a baseline entomological survey to identify municipalities infested with vectors followed by an additional vector survey in areas known to be infested was conducted. residual spraying using pyrethroid insecticides was performed at all the villages identified as being infested with the vectors. the residual spraying was shown to be highly effective against both vectors by the decrease in infestation indices after spraying. analysis of the cost-effectiveness of the spraying showed that the average cost of insecticides per house is high when compared with that in southern cone countries.
Impact of residual spraying on Rhodnius prolixus and Triatoma dimidiata in the department of Zacapa in Guatemala  [cached]
Nakagawa J,Cordón-Rosales C,Juárez J,Itzep C
Memórias do Instituto Oswaldo Cruz , 2003,
Abstract: As a vector control program to control Chagas disease in Guatemala, residual spraying of Rhodnius prolixus and Triatoma dimidiata was performed, and its impact was measured in the department of Zacapa. In order to identify infested villages and determine the degree of infestation, a baseline entomological survey to identify municipalities infested with vectors followed by an additional vector survey in areas known to be infested was conducted. Residual spraying using pyrethroid insecticides was performed at all the villages identified as being infested with the vectors. The residual spraying was shown to be highly effective against both vectors by the decrease in infestation indices after spraying. Analysis of the cost-effectiveness of the spraying showed that the average cost of insecticides per house is high when compared with that in Southern Cone countries.
Evidence of colonization of man-made ecotopes by Triatoma dimidiata (Latreille, 1811) in Costa Rica
Zeledón, Rodrigo;Montenegro, Víctor M;Zeledón, Oswaldo;
Memórias do Instituto Oswaldo Cruz , 2001, DOI: 10.1590/S0074-02762001000500012
Abstract: triatoma dimidiata adults have been frequently found, during the last five years, in a dog kennel and a chicken coop, in the back yard of a well-built house, 15 km from san josé, the capital of costa rica. in the chicken coop nymphs were also found. two of the 11 dogs from the kennel were serologically positive for trypanosoma cruzi infection. the inhabitants of the house, three adults and two children, were negative. this type of colonization by the insect, which is attracted to lights, is becoming common in old and new settlements, with different degrees of success, a fact with epidemiological implications and great relevance in the control strategies that can be applied.
Evidence of colonization of man-made ecotopes by Triatoma dimidiata (Latreille, 1811) in Costa Rica
Zeledón Rodrigo,Montenegro Víctor M,Zeledón Oswaldo
Memórias do Instituto Oswaldo Cruz , 2001,
Abstract: Triatoma dimidiata adults have been frequently found, during the last five years, in a dog kennel and a chicken coop, in the back yard of a well-built house, 15 km from San José, the capital of Costa Rica. In the chicken coop nymphs were also found. Two of the 11 dogs from the kennel were serologically positive for Trypanosoma cruzi infection. The inhabitants of the house, three adults and two children, were negative. This type of colonization by the insect, which is attracted to lights, is becoming common in old and new settlements, with different degrees of success, a fact with epidemiological implications and great relevance in the control strategies that can be applied.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.