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1.
Arq. bras. med. vet. zootec. (Online) ; 73(1): 162-168, Jan.-Feb. 2021. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1153064

ABSTRACT

Aedes aegypti is the vector of several viral diseases. The main way to control these diseases is to fight the vector. Thus, it is necessary to breed mosquitoes in the laboratory in order to develop strategies to control these insects. In laboratories, different carbohydrates are used for feeding mosquitoes. The aim of this study is to evaluate the longevity and the weight of Ae. aegypti fed with different carbohydrates diets. As methods, 120 mosquitoes were distributed in insectaries and each group received a different diet, based on honey, dextrose or maltodextrin. To assess the longevity, survival analysis was performed using the Long Rank test and chi square test. To assess the weight, the dead insects were frozen and weighed at the end of the experiment. As results it was observed that mosquitoes fed with the honey, maltodextrin and dextrose diet lived on average 33, 35 and 47 days respectively. When weight was assessed, mosquitoes fed with honey weighed 125 ± (35.3) µg, while those fed with dextrose and maltodextrin weighed 225 ± (35.3) µg and 275 ± (35.3) µg respectively. The results show that the intake of dextrose and maltodextrin by Ae. aegypti adults increases their survival and their weight.(AU)


O Aedes aegypti é vetor de várias doenças virais. A principal maneira de controlar essas doenças é combatendo o seu vetor. Nesse sentido, é necessário criar esses mosquitos em laboratório, visando desenvolver estratégias de controle. Nos laboratórios, diferentes carboidratos são utilizados na alimentação de mosquitos. O objetivo deste estudo é avaliar longevidade e peso de Ae. aegypti alimentados com diferentes fontes de carboidratos. Como método, distribuíram-se 120 mosquitos insetários. Cada grupo recebeu uma dieta diferente à base de mel, dextrose ou maltodextrina. Para avaliar a longevidade, a análise de sobrevida foi realizada pelo teste de Logrank e pelo teste de qui quadrado. Para avaliar o peso, os insetos mortos foram congelados e pesados ​​no final do experimento. Como resultado, observou-se que os mosquitos alimentados com a dieta à base de mel, maltodextrina e dextrose viveram em média 33, 35 e 47 dias, respectivamente. Com relação ao peso, os mosquitos alimentados com mel pesavam 125 ± (35,3)µg, enquanto os alimentados com dextrose e maltodextrina pesavam 225 ± (35,3)µg e 275 ± (35,3)µg, respectivamente. Os resultados mostram que a ingestão de dieta à base de dextrose e maltodextrina por Ae. aegypti adultos aumenta sua sobrevivência e seu peso.(AU)


Subject(s)
Animals , Aedes/growth & development , Aedes/metabolism , Dextrins/administration & dosage , Diet, Carbohydrate Loading/methods , Glucose/administration & dosage , Honey , Weight Gain , Survival Analysis
2.
Rio de Janeiro; Fiocruz; 2021. 172 p. (Temas em Saúde).
Monography in Portuguese | LILACS | ID: biblio-1368588

ABSTRACT

Pretende refletir sobre a biologia e hábito de Aedes aegypti, discutir como ganhou a fama que tem hoje, que processos históricos e sociais geraram as condições para o aparecimento das arboviroses no Brasil. Apresenta iniciativas de prevenção vigilância e controle atualmente em vigor ou em avaliação, percorrendo a dimensão da comunicação sobre o mosquito.


Subject(s)
Arbovirus Infections , Communicable Disease Control , Aedes/growth & development , Vector Control , Health Communication , Public Health Surveillance
3.
Gac. méd. Méx ; 156(5): 388-395, sep.-oct. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1249936

ABSTRACT

Resumen Introducción: La Ciudad de México no tiene presencia endémica de Aedes aegypti, por lo que está libre de enfermedades transmitidas por vector como dengue, Zika y chikunguña. Sin embargo, existe evidencia de la presencia de huevecillos en la urbe desde 2015. Objetivo: Reportar la presencia constante y en aumento de huevecillos de Aedes aegypti en la Ciudad de México de 2015 a 2018. Método: Se realizó vigilancia a través de ovitrampas; se contabilizaron y eclosionaron huevecillos para determinar la especie. Resultados: De 2015 a 2018 fueron identificados 378 organismos como Aedes aegypti. En total fueron colectadas 76 ovitrampas positivas a Aedes aegypti en 50 sitios distintos de 11 alcaldías. El noreste de la Ciudad de México fue el área con mayor positividad. Conclusiones: Los resultados pueden estar indicando un periodo de colonización incipiente y la probable la existencia de colonias crípticas del mosquito, por lo que la Ciudad de México podría estar en riesgo de presentar epidemias de enfermedades transmitidas por vector.


Abstract Introduction: Mexico City has no endemic presence of Aedes aegypti, and it is therefore free of vector-borne diseases, such as dengue fever, Zika and chikungunya. However, evidence has shown the presence of Aedes aegypti eggs in the city since 2015. Objective: To report the constant and increasing presence of Aedes aegypti eggs in Mexico City from 2015 to 2018. Methods: Surveillance was carried out using ovitraps. Eggs were counted and hatched in order to determine the species. Results: From 2015 to 2018, 378 organisms were identified as Ae. aegypti. In total, 76 Aedes aegypti-positive ovitraps were collected at 50 different places in 11 boroughs of the city. Northeastern Mexico City was the area with the highest number of positive traps. Conclusions: The results may be indicating a period of early colonization and the probable existence of cryptic colonies of the mosquito, and Mexico City could be therefore at risk of experiencing vector-borne epidemics.


Subject(s)
Animals , Aedes/classification , Dengue , Eggs , Mosquito Vectors , Species Specificity , Cities , Aedes/growth & development , Larva/classification , Larva/growth & development , Mexico
4.
Rev. cuba. med. trop ; 71(2): e353, mayo.-ago. 2019. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1093556

ABSTRACT

Introducción: Aedes aegypti (L) (Diptera: Culicidae), es una especie cosmopolita y vector de arbovirosis. Las variaciones de la temperatura y salinidad del agua influyen en la eclosión y supervivencia de fases larvales. Objetivo: Evaluar el efecto de diferentes temperaturas y salinidades en la eclosión de huevos y la supervivencia de larvas, pupas y adultos bajo condiciones de laboratorio. Métodos: Se colectaron larvas de Ae. aegypti, de reservorios artificiales en la zona periurbana de Puerto Vallarta, Jalisco, México, y se mantuvieron hasta la fase adulta. Los huevos obtenidos se sometieron a ocho temperaturas (15, 17, 20, 25, 27, 30, 32 y 35 °C). Se colocaron 15 huevos por quintuplicado y se evaluó la eclosión durante 96 h. Se colocaron 100 huevos con agua ajustada a 0.3, 2, 5, 10, 15,18 y 22 ups y se evaluó la eclosión hasta las 96 h. Adicionalmente se utilizaron larvas del estadio IV, por quintuplicado, sometiéndose a las mismas salinidades y se evaluó la supervivencia hasta las 48 h. El efecto de la salinidad en la ovoposición de las hembras se llevó a cabo introduciendo recipientes con las mismas concentraciones salinas, dentro en las jaulas entomológicas. Resultados: Se registró el 100 por ciento de eclosión a las 24 y 48 h; la temperatura de 35° C no registró eclosión. Las salinidades de 22 y 18 ups, provocaron mortalidad del 100 por ciento a las 24 h. En la salinidad de 15 ups, sobrevivió el 50 por ciento. Las concentraciones de 2, 5 y 10 ups demostraron 100 por ciento de supervivencia hasta la fase de adulto. La supervivencia de larvas del estadio IV en los tratamientos 2, 5 y 10 fue del 100 por ciento y en 15,18 y 22 ups disminuyó a 50, 80 y 100 por ciento, respectivamente (p˂ 0,05). Las diferentes concentraciones salinas no afectaron significativamente la ovoposición. La eclosión solo se presentó en las concentraciones de 0,3; 2; 5 y 10 ups. Los huevos ovopositados en concentraciones de 15, 18 y 22 ups no eclosionaron hasta que fueron transferidos a agua dulce con porcentajes de eclosión de entre el 80 y 90 por ciento. Conclusiones: Los embriones de Ae. aegypti poseen una amplia plasticidad para soportar cambios drásticos de temperatura y salinidad. El control efectivo de sus poblaciones debe incluir la revisión de charcas o reservorios que contengan aguas salobres hasta 18 ups(AU)


Introduction: Aedes aegypti (L) (Diptera: Culicidae) is a cosmopolitan species and a vector of arboviruses. Variations in the temperature and salinity of the water affect eclosion and survival during the larval stages. Objective: Evaluate the effect of different temperatures and salinities on the eclosion of eggs and the survival of larvae, pupae and adults in laboratory conditions. Methods: Ae. aegypti larvae were collected from artificial reservoirs in a peri-urban area of Puerto Vallarta, Jalisco, Mexico, and maintained until the adult stage. The eggs obtained were subjected to eight temperatures (15, 17, 20, 25, 27, 30, 32 and 35 °C). Fifteen eggs were placed in quintuplicate and eclosion was evaluated for 96 h. One hundred eggs were placed with water adjusted to 0.3, 2, 5, 10, 15, 18 and 22 psu and eclosion was evaluated until 96 h. Additionally, stage IV larvae were used in quintuplicate, subjecting them to the same salinities and evaluating survival until 48 h. The effect of salinity on oviposition by females was determined by introducing containers with the same salinity into the entomological cages. Results: 100 percent eclosion was recorded at 24 and 48 h, whereas no eclosion occurred at a temperature of 35 °C. Salinities of 22 and 18 psu caused 100 percent mortality at 24 h, whereas 50 percent survived at a salinity of 15 psu. At concentrations of 2, 5 and 10 psu 100 percent of the larvae survived until the adult stage. Survival of stage IV larvae in treatments 2, 5 and 10 was 100%, whereas in 15, 18 and 22 psu it fell to 50, 80 and 100 percent, respectively (p˂ 0.05). The different salinities did not affect oviposition significantly. Eclosion only occurred at concentrations of 0.3, 2, 5 and 10 psu. Oviposited eggs at concentrations of 15, 18 and 22 psu did not eclose until they were transferred to fresh water, where eclosion percentages ranged between 80 percent and 90 percent. Conclusions: Ae. aegypti embryos have great plasticity to endure drastic changes in temperature and salinity. Effective control of their populations should include inspection of ponds and reservoirs containing brackish water of up to 18 psu(AU)


Subject(s)
Temperature , Water Microbiology , Aedes/growth & development , Larva/microbiology , Salinity , Mosquito Vectors/immunology , Survivorship
5.
Rev. saúde pública (Online) ; 53: 29, jan. 2019. graf
Article in English | LILACS | ID: biblio-991645

ABSTRACT

ABSTRACT OBJECTIVE: To evaluate whether sites with large amount of potential breeding sites for immature forms of Aedes aegypti, called strategic points, influence in the active vector's dispersion into properties in their surroundings. METHODS: We selected four areas in the municipality of Campinas, three of them with strategic points classified as high, moderate, and low risk according to infestation and a control area, without strategic points. Between October 2015 and September 2016, we monthly installed oviposition traps and evaluated the infestation by Ae. aegypti in all properties of each selected area. To verify if there was vector dispersion from each strategic point, based on its location, we investigated the formation of clusters with excess of eggs or larvae or pupae containers, using the Gi spatial statistics. RESULTS: The amount of eggs collected in the ovitraps and the number of positive containers for Ae. aegypti did not show clusters of high values concerning its distance from the strategic point. Both presented random distribution not spatially associated with the positioning of strategic points in the area. CONCLUSIONS: Strategic points are not confirmed as responsible for the vector's dispersion for properties in their surroundings. We highlight the importance of reviewing the current strategy of the vector control program in Brazil, seeking a balance from the technical, operational, and economic point of view, without disregarding the role of strategic points as major producers of mosquitoes and their importance in the dissemination of arboviruses in periods of transmission.


RESUMO OBJETIVO: Avaliar se locais com grande quantidade de potenciais criadouros de formas imaturas de Aedes aegypti, denominados pontos estratégicos, influenciam a dispersão ativa do vetor aos imóveis no seu entorno. MÉTODOS: Foram selecionadas quatro áreas no município de Campinas, três delas com pontos estratégicos classificados como alto, médio e baixo risco segundo a infestação e uma área controle, sem ponto estratégico. Entre outubro de 2015 e setembro de 2016, instalaram-se mensalmente armadilhas de oviposição e avaliou-se a infestação por Ae. aegypti em todos os imóveis de cada área selecionada. Para verificar se houve dispersão do vetor a partir de cada ponto estratégico, com base em sua localização, investigou-se a formação de aglomerados com excesso de ovos ou de recipientes com larvas ou pupas, utilizando a estatística espacial Gi. RESULTADOS: o número de ovos coletados nas ovitrampas e o número de recipientes positivos para Ae. aegypti não apresentaram aglomerados de altos valores relativos à sua distância do ponto estratégico. Ambos apresentaram distribuição aleatória não associada espacialmente com o posicionamento dos pontos estratégicos na área. CONCLUSÕES: Pontos estratégicos não se confirmaram como responsáveis pela dispersão do vetor para os imóveis no seu entorno. Destaca-se a importância de rever a estratégia atual do programa de controle de vetores do Brasil, buscando um equilíbrio do ponto de vista técnico, operacional e econômico, sem desconsiderar o papel dos pontos estratégicos como grandes produtores de mosquitos e sua importância na disseminação de arboviroses em momentos de transmissão.


Subject(s)
Animals , Female , Oviposition/physiology , Pupa/growth & development , Mosquito Control/methods , Aedes/growth & development , Dengue/prevention & control , Mosquito Vectors/growth & development , Urban Population , Brazil , Environmental Monitoring , Mosquito Control/statistics & numerical data , Risk Factors , Aedes/virology , Dengue/transmission , Spatial Analysis , Animal Distribution/physiology , Mosquito Vectors/virology
6.
Epidemiol. serv. saúde ; 28(1): e2017316, 2019. tab
Article in English, Portuguese | LILACS | ID: biblio-984375

ABSTRACT

Objetivo: avaliar, em condições simuladas de campo, a eficácia do pyriproxyfen (hormônio juvenil), do novaluron (inibidor de quitina) e do spinosad (biolarvicida) no controle do Aedes aegypti. Métodos: exposição periódica de larvas de Ae. aeypti obtidas em Itabuna a recipientes tratados com os larvicidas, e comparação do efeito residual do tratamento com cepa Rockfeller. Resultados: o efeito inibitório na emergência de adultos, após 60 dias, foi de 89,5% spinosad, 96,5% novaluron e 75,4% pyriproxifen para larvas de Itabuna, não havendo diferença estatística (p=0,412) entre os tratamentos; spinosad e novaluron apresentaram maior percentual de mortalidade na fase larval, 98,8% e 97,9% respectivamente; pyriproxifen apresentou mortalidade maior na fase pupal, 95,1%. Conclusão: os três larvicidas apresentaram controle semelhante; no entanto, o pyriproxifen pode deixar a falsa impressão de positividade dos criadouros, por agir em fase pupal, comprometendo os indicadores de infestação que são parâmetros estratégicos para as ações de controle.


Objetivo: evaluar en condiciones simuladas de campo la eficacia del piriproxifén (hormona juvenil), novaluron (inhibidor de quitina) y spinosad (biolarvicida) en el control del Ae. Aegypti. Métodos: exposición periódica de larvas obtenidas de Itabuna, BA, Brasil, a recipientes tratados con larvicida y comparación del efecto residual con cepa Rockefeller. Resultados: el efecto inhibidor en la emergencia de adultos, después de 60 días, fue de 89,5% spinosad, 96,5% novaluron y 75,4% piriproxifén para larvas de Itabuna, no habiendo diferencia estadística (p=0,412) entre los tratamientos; spinosad y novaluron presentaron mayor mortalidad en la fase larval, 98,8% y 97,9% respectivamente; piriproxifén presentó mayor mortalidad en la fase de pupa, 95,1%. Conclusión: los tres larvicidas fueron eficaces en el control de larvas de Ae. Aegypti; sin embargo, piriproxifén puede dejar falsa positividad de los criaderos, por actuar en fase de pupa, comprometiendo los indicadores de infestación, parámetros estratégicos para las acciones de control.


Objective: to evaluate, under simulated field conditions, the efficacy of pyriproxyfen (juvenile hormone), novaluron (chitin inhibitor) and spinosad (biolarvicide) in controlling Aedes aegypti. Methods: periodic exposition of Ae. aegypti larvae collected in Itabuna, BA, Brazil, to recipients treated with larvicides and comparison of residual effect of treatment with the Rockefeller strain. Results: the inhibitory effect on adult emergence after 60 days was spinosad 89.5%, novaluron 96.5% and pyriproxifen 75.4% for Itabuna larvae, with no statistical difference (p=0.412) between treatments; spinosad and novaluron had a higher percentage of mortality in the larval stage, 98.8% and 97.9% respectively; pyriproxyfen showed higher mortality (95.1%) in the pupal stage. Conclusion: the three larvicides demonstrated similar control; however, pyriprofyxen might give a false impression of breeding ground positivity as it acts at the pupal stage, compromising the indicators of infestation that are strategic parameters for control actions.


Subject(s)
Mosquito Control/methods , Epidemiology, Experimental , Aedes/growth & development , Aedes/drug effects , Larvicides , Larva/drug effects , Survival Analysis , Mosquito Vectors/growth & development , Insecticides/pharmacology , Larva/growth & development
7.
São Paulo; s.n; 2018. 74 p.
Thesis in Portuguese | LILACS | ID: biblio-909912

ABSTRACT

Doenças como a dengue, chikungunya, Zika e febre amarela urbana são causadas por patógenos transmitidos pela picada de fêmeas infectadas de Ae. aegypti e Ae. albopictus. Fatores bióticos, como a competição na fase larval, e abióticos, como a variação da temperatura, provocam alterações no ciclo de desenvolvimento dessas espécies. O presente estudo avaliou os efeitos da competição intraespecífica e da temperatura na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus. Os objetivos do trabalho foram: comparar o tamanho das fêmeas de Ae. aegypti e Ae. albopictus oriundas de criadouros com baixa e alta competição intraespecífica; avaliar o efeito da competição intraespecífica na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, à 25ºC e analisar o padrão da atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, sob diferentes temperaturas (20ºC, 25ºC e 30ºC). As colônias dos mosquitos utilizados nos experimentos são provenientes da FIOCRUZ-RJ. Para o experimento de competição, larvas de ambas as espécies foram criadas sob condições de alta (100 larvas) e baixa (20 larvas) densidades. Para isso, foram utilizadas 14 bacias preenchidas com 500 ml de água e 0,2 g de ração para peixes. Após a competição, as fêmeas oriundas de cada densidade foram transferidas para incubadoras para a realização da análise da atividade locomotora. Após a atividade, verificou-se o tamanho dos adultos oriundos de cada densidade larvária, por meio da medição das asas de cada fêmea. Para a análise da atividade locomotora sob diferentes temperaturas, as fêmeas utilizadas foram desenvolvidas em ambiente com quantidade de ovos similares. Foi utilizado o mesmo procedimento para análise da atividade do experimento anterior, porém, cada experimento ocorreu sob diferentes temperaturas: 20°C, 25°C e 30°C. Para a análise dos dados obtidos foram utilizados os testes T e ANOVA multifatorial. Para o experimento de competição, fêmeas de ambas as espécies oriundas de competição de baixa densidade foram maiores do que as oriundas de desenvolvimento sob alta densidade larvária. A atividade das fêmeas de Ae. aegypti e Ae. albopictus de ambas as densidades foi muito semelhante, sugerindo que fêmeas menores tem atividade equivalente à de fêmeas maiores. Já no experimento que avaliou a atividade das fêmeas sob faixas térmicas distintas, notou-se que, em Ae. aegypti, houve diferença significativa na atividade total sob 20°C quando comparadas a 25°C e 30°C, demonstrando que a temperatura mais baixa foi limitante para a atividade desta espécie. Houve diferenças em algumas médias avaliadas na atividade de Ae. albopictus, porém, esta espécie pareceu ter sido menos influenciada com a variação da temperatura. Análises estatísticas confirmaram que as fêmeas de Ae. aegypti respondem de forma distinta das fêmeas de Ae. albopictus quando as temperaturas foram modificadas. O presente estudo ajuda a esclarecer alguns aspectos relacionados ao comportamento dos mosquitos Ae. aegypti e Ae. albopictus, que são considerados de grande importância para a saúde pública


Diseases such as dengue, chikungunya, Zika and urban yellow fever are caused by pathogens transmitted by the bites of infected females of Ae. aegypti and Ae. albopictus. Biotics factors essentially competition on larval stages, and abiotics factors, for instance, temperature variation, occasion adjustments on development cycle of these species. The present study evaluated the effects of intraspecific competition and temperature on locomotor activity of Ae. aegypti and Ae. albopictus. The aims of this study were: to compare the size of females Ae. aegypti and Ae. albopictus from breeding sites with low and high intraspecific competition; to evaluate the effect of intraspecific competition on locomotor activity of virgin females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark at 25°C and to analyze the pattern of the locomotor activity of virgins females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark, under different temperatures (20ºC, 25ºC e 30ºC). The mosquitoes colonies used on experiment are from FIOCRUZ-RJ. For the competition experiment, larvae from both species were raised under conditions of high (100 larvae) and low (20 larvae) densities. For this 14 containers filled with 500 ml of water and 0,2 g of fish food were used. After the competition, the females from each density were transferred to incubators to perform locomotor activity analysis. After the activity, the size of adult from each larval density, were verified by wings measurement of each female. For the analysis of the locomotor activity under different temperatures, the females used were developed in an environment with similar amount of eggs. The same procedure was used to the analyze the activity of the previous experiment, however, each experiment happened under different temperatures: 20°C, 25°C e 30°C. For the analysis of the obtained data were applied T tests and ANOVA multivariate. For the competition experiment, females of both species from low density of competition were longer than females from competition under high larval density. The activity of females of Ae. aegypti and Ae. albopictus from both densities was very similar, suggesting that smaller females have equivalent activity to that of larger females. In the experiment that evaluated the activity of females under different thermal bands, it was noticed that in Ae. aegypti there was significant difference in total activity under 20°C when compared with 25°C and 30°C degrees, demonstrating the lower temperature was limiting to activity for this species. There were differences in some averages evaluated in Ae. albopictus activity, however, this species seemed to have been less influenced with the temperature variation. Statistical analysis confirmed that females of Ae. aegypti respond differently than females of Ae. albopictus when the temperatures were modified. The present study helps to clarify some aspects about the behavior of mosquitoes Ae. aegypti and Ae. albopictus which are considered of great concern for public health


Subject(s)
Animals , Aedes/growth & development , Competitive Behavior , Insect Vectors , Locomotion , Temperature , Analysis of Variance , Animals, Laboratory , Larva , Species Specificity
8.
Braz. j. biol ; 77(2): 396-401, Apr.-June 2017. tab, graf
Article in English | LILACS | ID: biblio-888740

ABSTRACT

Abstract The viability of Aedes aegypti eggs was assessed in the Amazon region. The eggs were maintained under different conditions: indoors (insectarium) and outdoors (natural environment), as well as in different storage types (plastic cup, paper envelope, plastic bag) for different days. Egg viability was measured as the mean of hatchings observed from egg-bearing sheets of filter paper immersed in water, using three sheets randomly selected from each storage type and at both sites. There were significant differences in the viability of Ae. aegypti eggs with respect to the location (F=30.40; DF=1; P<0.0001), storage type (F=17.66; DF=2; P<0.0001), and time of storage (F=49.56; DF=9; P<0.0001). The interaction between storage site versus storage type was also significant (F=15.96; DF=2; P<0.0001). A higher hatching mean was observed for the eggs kept in the insectarium than for those outdoors (32.38 versus 7.46). Hatching rates of egg batches stored for 12 to 61 days ranged between 84 and 90%. A reduction was observed between 89 and 118 days, with values of 63 and 48%, respectively. With respect to type of storage, mean egg hatching was higher for the eggs in plastic cups (44.46). It was concluded that the viability of the eggs of Ae. aegypti in the Amazon region remains high up to 4 months, after which it declines drastically, although in this study hatching occurred for up to 8 months in very low percentages.


Resumo Testou-se a viabilidade dos ovos de Ae. aegypti na região amazônica armazenados em copos plásticos, envelopes de papel e sacos plásticos que foram mantidos em área interna e em área externa por dias diferentes. Verificaram-se diferenças significativas na viabilidade dos ovos considerando-se a localização (F=30,40; GL=1; P<0,0001), os tipos de armazenamento (F=17,66; GL=2; P<0,0001) e os tempos (F=49,56; GL=9; P<0,0001) e na interação localização versus tipo de armazenamento (F=15,96; GL=2; P<0,0001). A média de eclosão dos ovos armazenados no insetário foi maior: 32,38, do que a dos lotes armazenados na área externa: 7,46. As taxas de eclosão dos ovos armazenados de 12 a 61 dias ficaram entre 90% e 84% com reduções a partir de 89 e 118 dias, quando atingiu de 63% e 48%, respectivamente. Em relação aos tipos de armazenamento a média de ovos dos copos foi significativa (44,46). Conclui-se que a viabilidade dos ovos de Ae. aegypti na região amazônica é mantida em níveis elevados até 4 meses, e a partir daí ocorrem reduções drásticas, com eclosões até 8 meses em percentuais muito baixos.


Subject(s)
Animals , Aedes/physiology , Environment , Ovum/physiology , Seasons , Specimen Handling , Brazil , Aedes/growth & development
9.
Rev. salud pública Parag ; 7(1): 33-36, ene-jun. 2017. tab, mapa
Article in Spanish | LILACS, BDNPAR | ID: biblio-884653

ABSTRACT

INTRODUCCIÓN: Las poblaciones propensas a sufrir la aparición del dengue y otras enfermedades transmitidas por el Aedes aegypti en aquellas que no cuentan con un adecuado sistema de eliminación de residuos (desechos sólidos) y el suministro de agua potable es deficiente, lo cual contribuye a la aparición de los criaderos del mosquito vector. OBJETIVO: Describir los tipos de criaderos de Aedes aegypti en la ciudad de Asunción en el periodo 2011-2014. METODOLOGÍA: Estudio observacional descriptivo sobre los criaderos registrados en la base de datos del Servicio Nacional de Erradicación del Paludismo del levantamiento larval de Aedes aegypti en Asunción en el periodo 2011-2014. Resultados: Se denotó el predominio de criaderos inservibles, representando entre el 58% y el 72% del total de criaderos positivos encontrados, seguidos de los criaderos útiles (26% y el 40%), y por último los criaderos naturales (≤2%). Los criaderos útiles, inservibles y naturales exhiben una homogeneidad en los diferentes años analizados, representada por floreros, bebedero con agua para los criaderos considerados de utilidad para el ciudadano; neumáticos usados, cubetas descartables y desechos sólidos para los criaderos inservibles y axilas de hojas en lo que respecta a criaderos naturales. CONCLUSIÓN: La información obtenida podrá optimizar las decisiones y acciones del control vectorial del Aedes aegypti en lo referente a la focalización de los criaderos y su posterior disposición final por parte de la comuna o entidades responsables.


INTRODUCTION: The populations prone to dengue and other diseases transmitted by Aedes aegypti are those that do not have an adequate waste disposal system (solid waste) and the drinking water supply is deficient, which contributes to the emergence of mosquito vector breeding containers. OBJECTIVE: To describe the types of Aedes aegypti breeding site in the city of Asunción in the 2011-2014period. METHODOLOGY: Observational descriptive study on breeding siteregistered in the database of the National Malaria Eradication Service of the larval survey of Aedes aegypti in Asunción in the 2011- 2014period. Results: There was a predominance of unusable breeding sites, representing between 58% and 72% of the total number of positive breeding, followed by the useful breeding site (26% and 40%), and finally the natural breeding sites (≤2%) . The useful, unusable and natural breeding places exhibit a homogeneity in the different years analyzed, represented by vases, drinker with water for the breeding site considered useful for people; used tires, disposable buckets and unserviceable solid waste for useless hatcheries and leaf armpits for natural breeding site. CONLCUSION: The information obtained will allow optimizing decisions and actions onAedes aegypti vector control in relation to the targeting of breeding sites and their subsequent final disposal by the commune or responsible entities.


Subject(s)
Aedes , Aedes/growth & development , Dengue , Dengue/prevention & control , Dengue/transmission , Paraguay
10.
Rev. panam. salud pública ; 41: e120, 2017. tab, graf
Article in English | LILACS | ID: biblio-961651

ABSTRACT

ABSTRACT Objective To assess the potential occurrence of Zika transmission throughout Argentina by the mosquito Aedes aegypti considering the basic reproduction number (R0). Methods A model originally developed for dengue was adapted for Zika. R0 was estimated as a function of seven parameters, three of them were considered temperature-dependent. Seasonal Zika occurrence was evaluated in 9 locations representing different climatic suitability for the vector. Data of diary temperatures were extracted and included in the model. A threshold of R0 = 1 was fixed for Zika occurrence. Sensitivity analyses were performed to evaluate the uncertainty around the results. Results Zika transmission has the potential to occur in all studied locations at least in some moment of the year. In the northern region, transmission might be possible throughout the whole year or with an interruption in winter. The maximum R0 was estimated in 6.9, which means an average of 7 secondary cases from a primary case. The probabilistic sensitivity analysis showed that during winter the transmission can only be excluded in the southern fringe of geographic distribution of the vector and in part of central Argentina. Conclusion Zika virus has the potential to be transmitted in Argentina throughout the current geographic range of the mosquito vector. Although the transmission would be mainly seasonal, the possibility of winter transmission cannot be excluded in northern and central Argentina, meaning that there is a potential endemic maintenance of the disease.


RESUMEN Objetivo Evaluar la posibilidad de transmisión de zika en la Argentina por el mosquito Aedes aegypti considerando el número de reproducción básica (R0). Métodos Se adaptó para el zika un modelo desarrollado originalmente para el dengue. Se estimó R0 en función de siete parámetros, tres de los cuales se consideraron dependientes de la temperatura. Se evaluó la ocurrencia estacional de zika en nueve localidades que representan diferente aptitud climática para el vector. Se obtuvieron los datos de las temperaturas diarias y se incluyeron en el modelo. Se fijó un umbral de R0 = 1 para la ocurrencia de zika. Se realizaron análisis de sensibilidad para evaluar la incertidumbre de los resultados. Resultados En todos los lugares estudiados es posible la transmisión de zika al menos en algún momento del año. En la región norte, la transmisión podría ser posible durante todo el año o con una interrupción en invierno. Se estimó el R0 máximo en 6,9, lo que significa un promedio de siete casos secundarios a partir de un caso primario. El análisis de sensibilidad probabilística demostró que durante el invierno la transmisión sólo puede ser excluida en la franja sur de distribución geográfica del vector y en parte de la región central de Argentina. Conclusión El virus del Zika puede ser transmitido en Argentina en todo el rango geográfico actual del mosquito vector. Aunque la transmisión sería principalmente estacional, no es posible descartar la posibilidad de transmisión invernal en el norte y centro de la Argentina, lo que significa que la enfermedad puede mantenerse de manera endémica.


RESUMO Objetivo Avaliar a ocorrência potencial de transmissão de zika em Argentina pelo mosquito Aedes aegypti considerando o número de reprodução básico (R0). Métodos Foi adaptado para zika um modelo originalmente desenvolvido para dengue. R0 foi estimado como uma função de sete parâmetros, três deles considerados dependentes da temperatura. A ocorrência de zika sazonal foi avaliada em nove locais que representam diferentes adequações climáticas para o vetor. Os dados das temperaturas diárias foram extraídos e incluídos no modelo. Um limite de R0 = 1 foi fixado para a ocorrência de zika, e foram realizadas análises de sensibilidade para avaliar a incerteza em torno dos resultados. Resultados A transmissão de zika pode ocorrer em todos os locais estudados pelo menos em algum momento do ano. Na região norte, a transmissão pode ser possível durante todo o ano ou com uma interrupção no inverno. O R0 máximo foi estimado em 6.9, o que significa uma média de 7 casos secundários a partir de um caso primário. A análise de sensibilidade probabilística mostrou que durante o inverno a transmissão só pode ser excluída na franja sul da distribuição geográfica do vetor e em parte da Argentina central. Conclusão O vírus Zika tem o potencial de ser transmitido na Argentina ao longo da atual faixa geográfica do vetor. Embora a transmissão seja principalmente sazonal, a possibilidade de transmissão no inverno não pode ser excluída no norte e centro da Argentina, o que significa que existe uma potencial manutenção endêmica da doença.


Subject(s)
Humans , Aedes/growth & development , Basic Reproduction Number/statistics & numerical data , Zika Virus , Zika Virus Infection/prevention & control , Argentina/epidemiology
11.
Cad. Saúde Pública (Online) ; 33(1): e00071016, 2017. tab, graf
Article in Portuguese | LILACS | ID: biblio-1039357

ABSTRACT

Resumo: O objetivo deste trabalho foi observar a ocorrência de larvas de mosquitos, em especial do Aedes aegypti e Aedes albopictus, no tanque e axilas de bromélias do Jardim Botânico Municipal de Bauru, São Paulo, Brasil, destacando implicações epidemiológicas do uso dessas plantas. A maioria de larvas encontradas foi de mosquitos do gênero Culex, enquanto as de A. aegypti e A. albopictus foi ocasional. O uso de telas para proteção das plantas, a exposição ao sol e a maior quantidade de água no tanque podem ter influenciado a ocorrência e agrupamento das larvas.


The aim of this study was to observe the occurrence of mosquito larvae, especially Aedes aegypti and Aedes albopictus, in the tanks and axillae of bromeliads at the Bauru Municipal Botanical Gardens, São Paulo, Brazil, highlighting the epidemiological implications for the use of these plants. The majority of the larvae belonged to mosquitos from genus Culex, with only occasional findings of A. aegypti and A. albopictus. The use of screens for protection of the plants, exposure to sunlight, and larger amounts of water in the tanks may have influenced the occurrence and grouping of larvae.


El objetivo de este trabajo fue observar la ocurrencia de larvas de mosquitos, en especial las del Aedes aegypti y Aedes albopictus, en el tanque y axilas de bromelias del Jardín Botánico Municipal de Bauru, Sao Paulo, Brasil, destacando las implicaciones epidemiológicas en el cultivo de esas plantas. La mayoría de larvas encontradas fueron de mosquitos del género Culex, mientras que las de A. aegypti y A. albopictus fueron ocasionales. La utilización de telas para la protección de las plantas, su exposición al sol y la mayor cantidad de agua en el tanque pueden haber influenciado la ocurrencia y agrupamiento de larvas.


Subject(s)
Animals , Aedes/classification , Bromelia/parasitology , Gardening , Insect Vectors/classification , Seasons , Brazil , Population Density , Aedes/growth & development , Dengue/transmission , Insect Vectors/growth & development , Larva
12.
Rev. saúde pública (Online) ; 51: 122, 2017. graf
Article in English | LILACS | ID: biblio-1043310

ABSTRACT

ABSTRACT We describe the discovery of Aedes aegypti underground breeding site in the Pinheiros neighborhood of São Paulo, SP, during an entomological survey program performed in 2016. Even with intense surveillance and vector control, large numbers of mosquitoes were present in this area. A detailed investigation allowed for the detection of Ae. aegypti in an underground reservoir used for rainwater storage. After the implementation of protection screens in the accesses, the presence of the vector was no longer detected. In this study, we discuss the frequent use of this type of reservoir structure and its risk for mosquito production.


RESUMO Descreve-se o encontro de criadouro subterrâneo de Aedes aegypti no bairro de Pinheiros, São Paulo, SP, ocorrido durante um programa de levantamento entomológico, realizado em 2016. Mesmo com intensa vigilância e controle vetorial, grande quantidade de mosquitos estava presente nessa área. Investigação minuciosa permitiu a detecção de Ae. aegypti em reservatório subterrâneo para armazenamento de água pluvial. Após a implantação de telas de proteção nos acessos, não foi mais detectada a presença do vetor. O uso frequente desse tipo de estrutura e o seu risco para a produção de mosquitos é discutido.


Subject(s)
Humans , Animals , Rain , Water Supply , Disease Reservoirs , Aedes/growth & development , Insect Vectors/growth & development , Seasons , Brazil , Mosquito Control , Dengue/prevention & control
13.
Rev. biol. trop ; 64(4): 1487-1493, oct.-dic. 2016. tab, ilus
Article in Spanish | LILACS | ID: biblio-958228

ABSTRACT

Resumen:Actualmente varias enfermedades de origen vectorial tienen una gran relevancia médico-veterinaria, debido a las adaptaciones que han desarrollado las especies involucradas en su transmisión. Se llevó a cabo una encuesta entomológica durante 2013 con el objetivo de actualizar los conocimientos ecológicos de las poblaciones de Aedes aegypti presentes en tres Áreas de Salud de Camagüey, Cuba. Se cuantificó en cada depósito o receptáculo positivo las larvas y pupas según ubicación en las viviendas, determinando el porcentaje de representatividad. Se calculó el Índice Pupal por Depósitos específicos (ÍPDe). Los totales de viviendas así como los depósito permanentes y útiles positivos fueron comparados entre estaciones climáticas, utilizando la prueba no paramétrica de Chi2 en tablas de contingencia de 2 X 2, mientras que la relación existente entre el total de viviendas positivas y los depósitos positivos permanentes y útiles, fue explorada a través del test de proporciones de hipótesis, con un nivel de significación de P ≤ 0.05. A. aegypti colonizó 73 tipos de depósitos siendo permanentes y útiles el 23.2 %. Este número incluyó el 76 % de los depósitos positivos. Hubo mayor colecta en el exterior en tanques bajos y toneles con importante producción pupal (ÍPDe = 3.04 y 1.75, respectivamente), así como diferencias significativas durante la estación lluviosa al comparar el número de viviendas positivas (PUIA: Chi2 = 32.89; P = 0.00; PUE: Chi2 = 127.44; P = 0.00 and PUJAM: Chi2 = 127.44; P = 0.00), y depósitos permanentes y útiles (PUIA: Chi2 = 30.37; P = 0.00; PUE: Chi2 = 37.26; P = 0.00 and PUJAM: Chi2 = 81.82; P = 0.00). Estos datos refuerzan la prioridad que tienen en las acciones de vigilancia y control, por la comunidad en sus respectivas viviendas.


Abstract:Several illnesses of vectorial origin have a great medical and veterinary relevance, due to the adaptations developed by the species involved in their transmission. To support preventive programs with updated ecological information of A. aegypti populations, an entomological survey was carried out in three Health Areas of Camagüey, Cuba, during low and high rain seasons of 2013. For this, we assessed the type and number of positive containers, quantified larvae and pupae in positive containers, according to the container location in or outside the house. Both the container representativeness percentage and the pupal index by specific containers were calculated (PIsC). The total of houses as well as the positive habitual-use and non-disposable containers were compared among weather seasons, using the non parametric Chi2 test. The existent relationship between the total of positive houses and the habitual-use and non-disposable container was explored through the test of proportions hypothesis, with a level of significance of P ≤ 0.05. A. aegypti colonized 73 different types of containers, being habitual-use and non-disposable a 23.2 %. This number included 76 % of the positive containers. The greatest larvae collections were obtained in exterior water tanks and barrels, with important pupal production (PIsC = 3.04 and 1.75, respectively), and as well as significant differences towards the rainy season respect to positive houses (PUIA: Chi2 = 32.89; P = 0.00; PUE: Chi2 = 127.44; P = 0.00 and PUJAM: Chi2 = 127.44; P = 0.00), and the habitual-use and non-disposable container (PUIA: Chi2 = 30.37; P = 0.00; PUE: Chi2 = 37.26; P = 0.00 and PUJAM: Chi2 = 81.82; P = 0.00). These data reinforce the priority given to the control and surveillance actions conducted by the community in their respective houses. Rev. Biol. Trop. 64 (4): 1487-1493. Epub 2016 December 01.


Subject(s)
Animals , Ecosystem , Aedes/growth & development , Insect Vectors/growth & development , Larva/growth & development , Pupa/growth & development , Seasons , Cuba , Dengue/prevention & control , Dengue/transmission
14.
Weekly Epidemiological Monitor. 2016; 09 (18): 1
in English | IMEMR | ID: emr-187358

ABSTRACT

As of May 2016, a total of 58 countries and territories across the world have reported continuing mosquitoborne transmission, of which, 46 countries are experiencing a first outbreak of Zika virus since 2015, with no previous evidence of circulation. No country in the Eastern Mediterranean Region has yet reported any transmission of Zika virus infection till date


Subject(s)
Humans , Zika Virus Infection/epidemiology , Aedes/growth & development , Zika Virus/isolation & purification , Mosquito Vectors
15.
Salud pública Méx ; 57(3): 201-210, may.-jun. 2015. ilus, tab
Article in Spanish | LILACS | ID: lil-756612

ABSTRACT

Objetivos. Determinar la importancia de los criaderos de Ae. aegypti en Mérida; evaluar el impacto del programa Recicla por tu bienestar (RxB) sobre la presencia/abundancia de éstos y la percepción de los habitantes. Material y métodos. Se calculó la importancia de los criaderos por su productividad pupal. Se realizaron muestreos pre y post RxB en colonias para cuantificar el total de recipientes/criaderos. Se aplicó una encuesta a participantes sobre la percepción sobre RxB en colonias seleccionadas. Resultados. Los botes, cubetas y diversos objetos chicos fueron los criaderos más importantes. RxB tuvo un impacto significativo en la reducción del número de recipientes (IRR=0.74), en los recipientes positivos (IRR=0.33) y en la positividad de las viviendas para Ae.aegypti (OR=0.41 j.Todos los entrevistados opinaron que RxB es necesario y la gran mayoría piensa que es útil. Conclusiones. RxB debe ser considerada una buena práctica para el control del vector del dengue.


Objectives. To determine the importance of Ae. aegypti breeding-sites in Merida;to evaluate the impact of Recicla por tu bienestar (RxB, a recycling program) on the reduction of breeding sites and the perception of participants. Materials and methods. The relative importance for pupae production of the different types of breeding-sites was determined. Pre-and post-RxB entomological surveys were performed in participant neighborhoods to evaluate the impact on total containers and positive breeding-sites. A survey on the perception of participating people about dengue prevention and control and RxB was applied. Results. Buckets/pots and "small diverse items" were the most important breeding-sites. RxB had a significant impact in the reduction of total containers (IRR = 0.74), positive containers (IRR = 0.33) and the risk of a house being positive for Ae. aegypti (OR = 0.41). All the interviewed participants referred RxB as needed and most consider it useful. Conclusions. RxB should be considered as a good practice for the dengue vector control.


Subject(s)
Animals , Disease Reservoirs , Mosquito Control , Aedes/growth & development , Recycling , Government Programs , Household Articles/statistics & numerical data , Insect Vectors/growth & development , Public Opinion , Pupa , Water , Dengue/prevention & control , Larva , Mexico
16.
Recife; s.n; 2015. 85 p. ilus, graf.
Thesis in Portuguese | LILACS | ID: biblio-870275

ABSTRACT

Este estudo avaliou o desempenho biológico e reprodutivo de machos de Aedes aegypti esterilizados por radiação gama e seu potencial para uso no controle da espécie, através da técnica do inseto estéril (TIE). A eficácia de esterilização de diferentes doses de radiação gama, 30, 40 e 50 Gy, foi avaliada em machos irradiados (MI) na fase de pupa. O seu efeito sobre a longevidade e competitividade de acasalamento dos MI, sobre a fecundidade e fertilidade das fêmeas acasaladas com estes machos, bem como de fêmeas também irradiadas (FI), foram parâmetros analisados. Os testes de competitividade foram conduzidos em gaiolas teladas (2 X 2 m) em condições simuladas de campo, onde foram liberados machos irradiados e machos não irradiados (MNI), nas seguintes proporções: 5:1, 10:1 e 15:1. Os resultados revelaram que o fitness biológico e reprodutivo dos mosquitos são afetados pela radiação, de modo que os efeitos são diretamente proporcionais a dose de radiação utilizada. O parâmetro de longevidade apresentou diferenças significativas, tanto quando os MI foram analisados de forma individual quanto em grupo. Para a maior dose, MI e FI viveram em média 19,6 ± 2,2 dias e 25,8 ± 2,2 dias, respectivamente, enquanto que no grupo controle, estes valores foram de 24,9 ± 2,5 dias e 30,4 ± 2,5 dias...


This study evaluated the biological and reproductiv e performance of Aedes aegyptimales sterilized by gamma radiation and its potential for use in controlling the species through the Sterile Insect Technique (SIT). The sterilization efficacy of different doses of gamma radiation, 30, 40 and 50 Gy, was assessed in irradiated males (IM) in the pupal stage. The direct effects of gama radiation on the longevity and competitiveness of IM, as well as the effect on the fecundity and fertility of females mated with these males, and also irradiated females (IF), were analyzed. The competitiveness was examined by tests conducted in large cage (2 x 2 meters) in semi field conditions where irradiated males (IM) and non-irradiated males (NIM) were released in the following proportions: 5:1, 10:1 and 15:1. The results revealed that the biological and reproductive fitness of the mosquitoes are affected by radiation, so that the effects are directly proportional to the radiation dose. The longevity parameter showed significant differences...


Subject(s)
Animals , Male , Female , Aedes/radiation effects , Gamma Rays , Infertility , Insect Control , Radiation Effects , Aedes/growth & development , Brazil , Competitive Behavior/radiation effects , Population Control/methods , Pest Control, Biological , Urban Area
17.
Mem. Inst. Oswaldo Cruz ; 109(8): 1070-1077, 12/2014. tab, graf
Article in English | LILACS | ID: lil-732600

ABSTRACT

Two hypotheses for how conditions for larval mosquitoes affect vectorial capacity make opposite predictions about the relationship of adult size and frequency of infection with vector-borne pathogens. Competition among larvae produces small adult females. The competition-susceptibility hypothesis postulates that small females are more susceptible to infection and predicts frequency of infection should decrease with size. The competition-longevity hypothesis postulates that small females have lower longevity and lower probability of becoming competent to transmit the pathogen and thus predicts frequency of infection should increase with size. We tested these hypotheses for Aedes aegypti in Rio de Janeiro, Brazil, during a dengue outbreak. In the laboratory, longevity increases with size, then decreases at the largest sizes. For field-collected females, generalised linear mixed model comparisons showed that a model with a linear increase of frequency of dengue with size produced the best Akaike’s information criterion with a correction for small sample sizes (AICc). Consensus prediction of three competing models indicated that frequency of infection increases monotonically with female size, consistent with the competition-longevity hypothesis. Site frequency of infection was not significantly related to site mean size of females. Thus, our data indicate that uncrowded, low competition conditions for larvae produce the females that are most likely to be important vectors of dengue. More generally, ecological conditions, particularly crowding and intraspecific competition among larvae, are likely to affect vector-borne pathogen transmission in nature, in this case via effects on longevity of resulting adults. Heterogeneity among individual vectors in likelihood of infection is a generally important outcome of ecological conditions impacting vectors as larvae.


Subject(s)
Animals , Female , Aedes/growth & development , Body Size/physiology , Dengue/transmission , Epidemics , Insect Vectors/growth & development , Aedes/anatomy & histology , Aedes/virology , Bayes Theorem , Brazil/epidemiology , Crowding , Competitive Behavior/physiology , Dengue Virus/isolation & purification , Dengue/epidemiology , Environmental Monitoring , Insect Vectors/virology , Larva/anatomy & histology , Larva/growth & development , Longevity/physiology , Reverse Transcriptase Polymerase Chain Reaction
18.
Rev. saúde pública ; 48(5): 775-782, 10/2014. tab, graf
Article in English | LILACS | ID: lil-727253

ABSTRACT

OBJECTIVE To evaluate the resistance of Aedes aegypti to temephos Fersol 1G (temephos 1% w/w) associated with the adaptive disadvantage of insect populations in the absence of selection pressure. METHODS A diagnostic dose of 0.28 mg a.i./L and doses between 0.28 mg a.i./L and 1.40 mg a.i./L were used. Vector populations collected between 2007 and 2008 in the city of Campina Grande, state of Paraíba, were evaluated. To evaluate competition in the absence of selection pressure, insect populations with initial frequencies of 20.0%, 40.0%, 60.0%, and 80.0% resistant individuals were produced and subjected to the diagnostic dose for two months. Evaluation of the development of aquatic and adult stages allowed comparison of the life cycles in susceptible and resistant populations and construction of fertility life tables. RESULTS No mortality was observed in Ae. aegypti populations subjected to the diagnostic dose of 0.28 mg a.i./L. The decreased mortality observed in populations containing 20.0%, 40.0%, 60.0%, and 80.0% resistant insects indicates that temephos resistance is unstable in the absence of selection pressure. A comparison of the life cycles indicated differences in the duration and viability of the larval phase, but no differences were observed in embryo development, sex ratio, adult longevity, and number of eggs per female. CONCLUSIONS The fertility life table results indicated that some populations had reproductive disadvantages compared with the susceptible population in the absence of selection pressure, indicating the presence of a fitness cost in populations resistant to temephos. .


OBJETIVO Avaliar a resistência de Aedes aegypti ao temefós Fersol 1G (temefós 1% p/p) quanto à desvantagem adaptativa ao inseto, na ausência de pressão de seleção. MÉTODOS Foi aplicada a dose diagnóstica de 0,28 mg i.a/L e concentrações entre 0,28 mg i.a/L e 1,4 mg i.a/L. Foram avaliadas amostras do vetor coletadas no município de Campina Grande entre 2007 e 2008, no estado da Paraíba. Para avaliar a competição na ausência de pressão de seleção, foram constituídos grupos de insetos com frequências iniciais de 20,0%, 40,0%, 60,0% e 80,0% de insetos resistentes, submetendo-os a dose diagnóstica por dois meses. Os ciclos de vida das populações suscetível e resistentes foram comparados avaliando-se as fases de desenvolvimento aquática e adulta, construindo-se tabelas de vida de fertilidade. RESULTADOS Não foram verificadas mortalidades nas populações de Ae. aegypti quando submetidas à dose diagnóstica de 0,28 mg i.a./L. A diminuição da mortalidade nas populações com 20,0%, 40,0%, 60,0% e 80,0% de indivíduos resistentes indica que a resistência ao temefós é instável na ausência de pressão de seleção. A comparação do ciclo de vida mostrou diferenças na duração da fase e viabilidade larval, mas não quanto ao desenvolvimento embrionário, razão sexual, longevidade dos adultos e número de ovos/fêmea. CONCLUSÕES Pelos parâmetros da tabela de vida de fertilidade constatou-se que algumas populações apresentaram desvantagens reprodutivas em relação à população suscetível na ausência de pressão de seleção, havendo custo adaptativo resultante da resistência ao temefós. .


Subject(s)
Animals , Female , Male , Aedes , Insecticide Resistance , Temefos , Aedes/growth & development , Brazil , Dengue/prevention & control , Insect Vectors/growth & development , Mosquito Control/methods
19.
Rev. Inst. Med. Trop. Säo Paulo ; 56(5): 369-374, Sep-Oct/2014. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: lil-722319

ABSTRACT

Aedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact.


Foram utilizadas curvas de sobrevida para analisar o tempo de desenvolvimento do Aedes aegypti, principal vetor da dengue no Brasil. Foram comparadas as curvas de sobrevida dos vetores criados individualmente e coletivamente quando posicionados dentro e fora do laboratório no inverno e na primavera. O estudo foi realizado em São Vicente, cidade costeira do sudeste do Brasil. A temperatura mínima da água atingiu 20 °C no inverno e na primavera, e a máxima 26 °C na primavera. As temperaturas mais elevadas e estáveis foram medidas dentro do laboratório em comparação com as medidas fora em ambas as estações. Consequentemente as larvas posicionadas dentro apresentaram menor tempo mediano de desenvolvimento no experimento individual e coletivo (nove e dez dias, respectivamente). Pelo menos 25% das larvas criadas individualmente dentro do laboratório levaram apenas sete dias para atingir a forma adulta. As proporções macho/fêmea e o tempo de desenvolvimento por sexo não diferiu significativamente. Estes resultados indicam que as medidas para controlar o Aedes aegypti e reduzir o contato humano com o vetor devem ser contínuas e dirigidas, principalmente para os locais dentro dos domicílios uma vez que o ciclo do vetor pode durar apenas uma semana nestes locais.


Subject(s)
Animals , Aedes/growth & development , Seasons , Temperature , Aedes/classification , Laboratories , Larva/growth & development , Sex Ratio , Time Factors
20.
Biomédica (Bogotá) ; 34(3): 409-424, July-Sept. 2014. ilus, graf, mapas, tab
Article in Spanish | LILACS | ID: lil-726788

ABSTRACT

Introducción. Aedes ( Stegomyia ) aegypti es el principal vector del dengue. En el control del mosquito se han usado insecticidas químicos contra los cuales ha desarrollado resistencia. Es necesaria la evaluación de estrategias alternativas que sean eficientes, económicas y de fácil aplicación, como las ovitrampas con Bacillus thuringiesis var. israeliensis. Objetivo. Evaluar el impacto de ovitrampas con B. thuringiesis var. israeliensis sobre los índices aédicos tradicionales, como estrategia para la vigilancia y el control de A. aegypti . Materiales y métodos. Se seleccionaron ocho barrios de los municipios de Apartadó y Carepa, Antioquia, de los cuales se escogieron dos barrios para la intervención y dos para el control en cada municipio. La intervención consistió en la instalación de una ovitrampa con B. thuringiesis var. israeliensis en cada una de las viviendas. Las ovitrampas se visitaron mensualmente entre septiembre de 2009 y marzo de 2010. Se obtuvieron los índices aédicos tradicionales y se hicieron comparaciones entre los barrios. Se calculó el índice de ovitrampas positivas y el de densidad de huevos, y se generaron los mapas de densidad. Resultados. Se colocaron 519 ovitrampas muestreadas mensualmente. Se hicieron 3.114 muestreos, con un porcentaje de registros positivos de 76,4 %. Se recolectaron 501.425 huevos. En Apartadó se observaron diferencias significativas entre el índice de infestación de viviendas, el índice de infestación de depósitos y el índice de Breteau en los barrios intervenidos comparados con los barrios de control. El índice de ovitrampas positivas evidenció un alto riesgo de infestación por A. aegypti y, los índices tradicionales, niveles de riesgo medio y bajo. Conclusiones. Las ovitrampas tuvieron impacto sobre los índices tradicionales y demostraron ser estrategias útiles en la vigilancia de A. aegypti en el Urabá antioqueño.


Introduction: Aedes (Stegomyia) aegypti is the main vector of dengue. Chemical insecticides have been used to control the mosquito and it has developed resistance. It is necessary to evaluate alternative strategies that are efficient, economical and easy to apply, such as ovitraps with Bacillus thuringiesis israeliensis . Objective: To evaluate the impact of ovitraps loaded with B. t. israeliensis on traditional indexes, as strategies for surveillance and control of A. aegypti . Materials and methods: We selected eight neighborhoods from the municipalities of Apartadó and Carepa. Two neighborhoods in each municipality were chosen for intervention and two for control. The intervention consisted in the installation of ovitraps with B. t. israeliensis in every house. The traps were visited each month between September, 2009, and March, 2010. Traditional indexes were obtained and compared among the neighborhoods. Ovitrap positivity index and egg density index were calculated and we generated density maps. Results: Five hundred and nineteen ovitraps were placed monthly; 3,114 samples were obtained, from which 76.4% were positive. We collected 501,425 eggs. In Apartadó, statistically significant differences were observed in the house, container and Breteau indexes. The ovitrap positivity index showed high risk of A. aegypti infestation and traditional indexes showed medium and low risk levels. Conclusions: Ovitraps had an impact on traditional indexes and proved to be useful strategies for surveillance and control of A. aegypti in Urabá, Antioquia.


Subject(s)
Animals , Female , Male , Aedes , Bacillus thuringiensis/physiology , Dengue Virus , Insect Vectors , Pest Control, Biological/instrumentation , Aedes/growth & development , Aedes/virology , Cities , Colombia , Dengue/prevention & control , Dengue/transmission , Equipment Design , Housing , Insect Vectors/growth & development , Insect Vectors/virology , Larva , Ovum , Pupa , Urban Health
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