Thesis (M.P.H.)--University of Michigan, 1948.

Thesis (M.P.H.)--University of Michigan, 1947.

Thesis (M.Sc. (Tropical Medicine))--Mahidol University, 1976.

Thesis (M.P.H.)--University of Michigan, 1947.

Thesis (M.P.H.)--University of Michigan, 1948.

The mosquito Aedes aegypti is the primary worldwide vector of dengue fever, of which there are an estimated 390 million infections annually. Traditional vector control methods have been unsuccessful in preventing Ae. aegypti from posing a serious threat to human health worldwide, and as a result increasing emphasis is being placed on new control technologies. One of these is RIDL® (Release of Insects carrying a Dominant Lethal), a modified form of the sterile insect technique. Released RIDL males of strain OX513A are genetically engineered to possess a repressible lethal construct. Upon mating with a wild female, the construct is inherited by the offspring, causing their death. The RIDL strategy depends on the mass production and release of vigorous male insects, capable of competing with wild males to mate with wild females. <b>Chapter 2</b> investigates how rearing conditions can influence the size, asymmetry, quantity, and timing of OX513A mosquitoes produced. <b>Chapter 3</b> describes the design and testing of devices for the release of these adult males, and their implementation during the world's first release of transgenic mosquitoes. <b>Chapter 4</b> discusses how the modification of male size and nutritional status may affect subsequent performance, and how these changes to male vigour will be assessed in subsequent chapters. <b>Chapter 5</b> measures changes in competitiveness by examining longevity. Larger males lived longer, and longevity was increased by increasing the duration of the initial sugar feed. <b>Chapter 6</b> examines the potential improvements in male performance by measuring the flight capacity of OX513A males, using a purpose-built mosquito flight mill. Male size or nutritional status was not found to affect flight capacity, although light intensity was unexpectedly found to modulate the flight speed of the males. Finally, <b>Chapter 7</b> examines potential improvements in the mating performance of male OX513A Ae. aegypti. When OX513A males and wild-type males were placed in direct competition for virgin females, smaller OX513A males were found to have a significant mating advantage over larger wild-type males. The results of all three of these performance measures are discussed with relevance to field releases. The results presented in this thesis improve current knowledge of how the performance of male mosquitoes can be effectively measured and improved. This is a vital part of ensuring the success of male-release vector control strategies such as RIDL.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Produção, Florianópolis, 2000 / Made available in DSpace on 2012-10-17T19:57:46Z (GMT). No. of bitstreams: 1 275607.pdf: 383974 bytes, checksum: 28188c6ad7042643989b6f810717c0a6 (MD5) / O desenvolvimento acelerado está gerando desequilíbrio e consequentemente agredindo o meio ambiente e o homem. A degradação e a utilização inadequada dos recursos naturais estão provocando efeitos muitas vezes irreversíveis. O borrachudo, pequeno inseto está se tornando uma praga em muitos municípios do estado catarinense. O gerenciamento inadequado dos dejetos de animais, principalmente dos suínos, o descuido com os resíduos sólidos e a utilização inadequada de agrotóxicos estão ocasionando explosões populacionais deste inseto, de forma exponencial. A partir do ano de 1996 técnicos da Secretaria do Desenvolvimento Rural e da Agricultura de Santa Catarina, juntamente com pesquisadores catarinenses elaboraram um Programa Estadual de Controle Mecânico/Ecológico do Borrachudo, visando minimizar a incidência do mesmo, através de ações educacionais e de saneamento ambiental. Diante disso, surgiu o interesse em analisar o programa, subsidiando um processo de gestão ambiental. Esta análise foi desenvolvida nos municípios de Concórdia e Joaçaba, no oeste catarinense. Nestes municípios os autores do programa apresentaram o mesmo para as comunidades que sofrem com o borrachudo. Nas reuniões foi explicado o programa, bem como repassado informações sobre o inseto. Em cada comunidade foi escolhida uma comissão local, composta por agricultores locais e técnicos. A função desta comissão foi de visitar as propriedades e preencher o laudo de vistoria. Este laudo mostra quais ações estão ajudando na proliferação dos borrachudos, bem como quais melhorias devem ser efetuadas, minimizando os problemas ambientais da propriedade. Após as reuniões foi aplicado um questionário com os agricultores das comunidades escolhidas e seus professores; com os técnicos a aplicação do questionário se deu no termino da aplicação dos laudos de vistoria. No município de Joaçaba todas as propriedades da comunidade escolhida foram visitadas e feitas o laudo de vistoria, já no município de Concórdia das 86 propriedades só 59 propriedades foram visitadas e vistoriadas. Através das observações e análises feitas destacamos que o programa é uma boa ferramenta para a gestão ambiental com relação ao borrachudo, mas algumas atitudes e ações devem ter mais planejamento. / The rapid development is creating imbalance and consequently damaging the environment and man. The degradation and misuse of natural resources are causing effects are often irreversible. The black flies, small insect are becoming a pest in many cities in the state of Santa Catarina. The mismanagement of animal waste, especially of pigs, the carelessness with solid waste and misuse of pesticides are causing population explosions of this insect, exponentially. As of 1996 technicians from the Department of Rural Development and Agriculture of Santa Catarina, Santa Catarina with researchers developed a State Program Control Mechanical / Ecological Borrachudo to minimize the incidence of it, through educational activities and environmental sanitation. In this light, this led us to examine the program, supporting a process of environmental management. This analysis was developed in the cities of Concórdia and Joaçaba, in western Santa Catarina. In these counties the program's authors presented the same to the communities that suffer from the blackfly. The meetings explained the program and passed on information about the insect. In each community has chosen a local committee composed of local farmers and technicians. The function of this committee was to visit the properties and complete the survey report. This report shows which actions are helping the proliferation of black flies as well as what improvements should be made to minimize the environmental problems of property. After the meeting a questionnaire was given to farmers in selected communities and their teachers, with the technical implementation of the questionnaire took place in the end application of the survey reports. In the city of Joaçaba all properties of the chosen community were visited and made the survey report, in the municipality of Concordia of only 86 properties 59 properties were visited and inspected. Through observations and analysis point out that the program is a good tool for environmental management in relation to black flies, but some attitudes and actions should be more planning.

La génétique inverse est la manipulation génétique des virus à ARN pour créer un virus de type sauvage ou modifié. Les techniques de génétique inverse conduit à bien comprendre les fonctions des gènes viraux et leur pathogénicité dans les cellules d’hôte ou de vecteur. Les virus à ARN comme les arbovirus ceux qui ont comme vecteurs les arthropodes représente une vraie menace pour la santé humaine mondiale. Les techniques de génétique inverse sont un moyen adéquat pour protéger l’homme contre les virus par la création des vaccins at par bloquer leur transmission par les vecteurs comme les moustiques. De nos jours, la plupart des systèmes de génétique inverse se concentraient exclusivement sur l’étude d’interaction entre les virus et les cellules de mammifères. Cependant, la transmission de l'arbovirus se situe entre un hôte mammifère et un vecteur d'invertébré.Nous présentons ici ISA (Infectious-Subgenomic-Amplicons) comme une méthode universelle de génétique inverse qui a prouvé son applicabilité sur les cellules de mammifères et de moustiques pour générer des virus infections ARN simple brin de polarité positive.Ainsi, ISA est une méthode adéquate pour étudier le cycle de vie de l'arbovirus chez le moustique vecteur et l'hôte mammifère at ainsi avoir une idée générale de la circulation de l’arbovirus pour créer d’autre outils de blocage. / Reverse genetics, the genetic manipulation of RNA viruses to create a wild-type or modified virus, has led to important advances in our understanding of viral gene function and interaction with host cells. Since arboviruses the most threatening viruses to human and animal are RNA viruses, thus reverse genetics is an extremely powerful technique with important application for the protection from these viruses and to control their spread.Hitherto, most reverse genetics systems focused exclusively on mammalian cells. However, arbovirus transmission is between a mammalian host and invertebrate vector.Herein, we present ISA (Infectious-Subgenomic-Amplicons) as a universal reverse genetic method that proved it applicability to rescue infectious single stranded positive RNA viruses on mammalian and mosquito cells.Thereby, ISA is an adequate method to study the arbovirus life cycle in mosquito vector and mammalian host. Thus, providing information about the global arbovirus circulation to provide further technique that protect mammalian from their infection and inhibit vector to transmit the virus.

Dengue is a mosquito-borne disease that has gone from isolated sylvatic spill-overs to a pathogen of global public health importance in less than a century. Surveillance and control efforts have continually lagged behind contemporary needs and this thesis investigates the pressing need to reassess the current geographic limits and case burden of dengue including how these are measured. First, the global distribution of reported dengue infections was mapped. In many areas dengue reporting is sparse as it can be asymptomatic or clinically similar to other diseases. The maps identified surveillance gaps, particularly in Africa and the Middle East, where targeted efforts are needed to reliably measure the contemporary global extent of dengue transmission. Second, the global case burden of dengue was estimated by pairing risk maps with longitudinal cohort study data. This gave the first cartographic estimate of dengue cases and at 390 million per year (95&percnt; CI: 284-528) was over three times the World Health Organization official estimate. Reconciling these estimates with reported case data allowed an assessment of existing national surveillance strategies. Third, existing methods for outbreak identification were compared. High burden dengue outbreaks are preventable if timely and appropriate measures are applied. This analysis suggested, however, that commonly used outbreak definitions are not consistent, which could have an adverse effect on outbreak response. An alternative framework for outbreak identification based on healthcare capacities is thus outlined. Fourth, an analysis was undertaken that quantified how mosquito vectors place geographic and seasonal limits on dengue transmission. This involved updating estimates of mosquito longevity which were integrated with temperature-dependent dynamic transmission models to produce global maps. These suggested that while temperature places strong limits on the distribution of dengue in some settings, mosquito ecology may be more important in others. Finally, these findings are discussed in the context of global dengue surveillance gaps, with recommendations of how these can be addressed at a time when providing an evidence base for deployment of new control strategies will be critical.

Submitted by FABIANA DA SILVA FRANÇA (fabiana21franca@gmail.com) on 2017-11-09T15:38:24Z No. of bitstreams: 2 arquivototal.pdf: 3033279 bytes, checksum: f2b56b36fa23f100495d8d218c7e3669 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-11-09T15:38:24Z (GMT). No. of bitstreams: 2 arquivototal.pdf: 3033279 bytes, checksum: f2b56b36fa23f100495d8d218c7e3669 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2013-08-30 / Dengue is a viral systemic disease caused by an arboviral of Flaviviridae family, affecting about a 100 million cases per year in Brazil. It is endemic in tropical regions such as Southeast Asia, South Pacific, East Africa, Caribbean and Latin America. The disease is transmitted by Aedes aegypti (Linnaeus, 1762), a mosquito that is the main target for the disease control through strategies ranging from the larval to the adult combat. The larvicides commonly used to combat the vector, besides being toxic, present drop in larvicide efficacy since the A. aegypti larvae has developed resistance to these products. Thus, the search for new active principles that are effective in combating the mosquito is required. In this sense, Agave sisalana is a plant that is produced in several states in the Brazilian northeast region, which is used in the sisal industry. Only 5% of the plant is recovered, and its residual liquid completely wasted. In this way, the aim of this research project was to investigate the larvicidal action of the juice of Agave sisalana against larvae of A. aegypti. In larvicidal activity assays, fourth stage A. aegypti larvae were used, exposed to different concentrations of A. sisalana liquid waste during 24 hours. After the larvicidal activity assays, it was possible to determine the LC50 that was 5.9 mg / mL. Next we explored the cytotoxic activity of A. sisalana in hemocytes of A. aegypti larvae through the flow cytometry. The experiments showed an increase of cellular necrosis after 12 hours of exposure of the larvae to submaximal concentrations of sisal liquid waste (7.4% in control group vs. 28.5% in the experimental group after 12 hours; 6.2% in the control group vs. 22.7% in the experimental group after 24 hours). The histological alterations were confirmed by histopathological analysis, which showed lyses of the mesentery epithelial cells of larvae as well as peritrophic membrane destruction. Furthermore, nitric oxide (NO) production by hemocytes, an important defense strategy of mosquitoes, was checked after 3, 6 and 24 hours of larvae exposure to the A. sisalana liquid waste. There was a reduction in NO levels of approximately 76.6% after 3 hours, 83% after 6 hours and 83.8% after 24 hours of exposure. In this way, the A. sisalana liquid waste constitutes an effective alternative and economically feasible for the dengue vector combat. The outcomes of our research resulted in the patent application for an insecticide against A. aegypti larvae. / A dengue é uma doença viral sistêmica, causada por um arbovírus da família Flaviviridae, acometendo cerca de 700 mil casos por ano no Brasil. É endêmica de regiões tropicais como o sudeste asiático, sul do Pacífico, África Oriental, Caribe e América Latina. A dengue é transmitida pelo mosquito Aedes aegypti (Linnaeus, 1762), que é o principal alvo de combate para controle da doença, por meio de estratégias que vão desde o combate às formas larvares até o mosquito adulto. Os larvicidas comumente utilizados no combate do vetor, além de serem tóxicos, vêm apresentando queda na capacidade larvicida já que as larvas do A. aegypti tem desenvolvido resistência a esses produtos. Sendo assim, a busca por novos princípios ativos que sejam eficientes no combate do mosquito se faz necessária. Nesse sentido, a Agave sisalana é uma planta que é produzida em vários estados do nordeste brasileiro, a qual é utilizada na indústria sisaleira. Apenas 5% da planta é aproveitada, sendo o seu resíduo líquido completamente desperdiçado. Dessa forma, este projeto de pesquisa teve como objetivo investigar a ação larvicida do suco de Agave sisalana contra larvas de A. aegypti. Nos ensaios de atividade larvicida, utilizou-se larvas de quarto estágio de A. aegypti, testando-se diferentes concentrações de suco de A. sisalana durante 24 horas. Após os ensaios de atividade larvicida foi possível determinar a CL50, que foi de 5,9 mg/mL. A pesquisa também explorou a atividade citotóxica da A. sisalana em hemócitos de larvas de A. aegypti, através da citometria de fluxo. Verificou-se um aumento no percentual de necrose celular a partir de 12 horas de exposição das larvas a concentrações submáximas de suco de sisal (7,4% no grupo controle vs. 28,5% no grupo experimental após 12 horas; 6,2% no grupo controle vs.22,7% no grupo experimental após 24 horas). As alterações histológicas foram confirmadas em exames histopatológicos, que mostraram lise celular de células epiteliais do mesentério das larvas e destruição da membrana peritrófica. A produção de óxido nítrico (NO) pelos hemócitos, uma importante estratégia de defesa dos mosquitos, foi verificada após 3,6 e 24 horas de exposição das larvas ao suco de A. sisalana. Observou-se uma diminuição dos níveis de NO da ordem de 76,6% após 3 horas de exposição, 83 % após 6 horas de exposição, e 83,8 % após 24 horas de exposição. Sendo assim, o suco de A. sisalana pode se constituir numa alternativa efetiva e economicamente viável para o combate ao vetor da Dengue. Essa pesquisa resultou no pedido de patente de um inseticida formulação a base de A. sisalana para combate às larvas de A. aegypti.