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1.
Mem. Inst. Oswaldo Cruz ; 115: e200070, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135278

ABSTRACT

BACKGROUND Nyssorhynchus deaneorum is a potential malaria vector because it has been shown to be competent to transmit Plasmodium vivax and Plasmodium falciparum, and because it exhibits antropophilic and endophilic behaviors in some regions of the Amazon. This profile makes Ny. deaneorum a useful mosquito for experiments that model Plasmodium-vector interactions in the Amazon. OBJECTIVE Herein we describe how a free-mating colony of Ny. deaneorum has been established using an automated light stimulation system. METHODS Mosquitoes were captured in São Francisco do Guaporé, Rondônia. The F1 generation was reared until adult emergence at which point copulation was induced using an automatic copulation induction system (ACIS). FINDINGS After four generations, natural mating and oviposition began to occur without light stimulation. The number of pupae and adult mosquitoes increased from the F5 to F10 generations. The new Ny. deaneorum colony exhibited susceptibility to P. vivax. MAIN CONCLUSIONS Automated light stimulation is an effective method for establishing an Ny. deaneorum colony under laboratory conditions as it produces enough adults to create a stenogamic colony. The establishment of a stable, P. vivax-susceptible colony of Ny. deaneorum makes it possible to model parasite-vector interactions and to test novel drug therapies that target parasite development in mosquitoes.


Subject(s)
Animals , Female , Oviposition , Copulation/physiology , Mosquito Vectors/parasitology , Insect Vectors/growth & development , Malaria , Anopheles/parasitology , Plasmodium falciparum , Plasmodium vivax , Brazil , Insect Vectors/physiology , Anopheles/physiology
2.
Rev. Assoc. Med. Bras. (1992) ; 63(11): 957-961, Nov. 2017. tab, graf
Article in English | LILACS | ID: biblio-896318

ABSTRACT

Summary Introduction: Global climate changes directly affect the natural environment and contribute to an increase in the transmission of diseases by vectors. Among these diseases, dengue is at the top of the list. The aim of our study was to understand the consequences of temporal variability of air temperature in the occurrence of dengue in an area comprising seven municipalities of the Greater São Paulo. Method: Characterization of a temporal trend of the disease in the region between 2010 and 2013 was performed through analysis of the notified number of dengue cases over this period. Our analysis was complemented with meteorological (temperature) and pollutant concentration data (PM10). Results: We observed that the months of January, February, March, April and May (from 2010 to 2013) were the ones with the highest number of notified cases. We also found that there is a statistical association of moisture and PM10 with the reported cases of dengue. Conclusion: Although the temperature does not statistically display an association with recorded cases of dengue, we were able to verify that temperature peaks coincide with dengue outbreak peaks. Future studies on environmental pollution and its influence on the development of Aedes aegypti mosquito during all stages of its life cycle, and the definition of strategies for better monitoring, including campaigns and surveillance, would be compelling.


Resumo Objetivo: As alterações globais que têm ocorrido interferem no ambiente natural, influenciando diretamente no crescimento da transmissão de doenças ocasionadas por vetores, das quais se destaca a dengue. O objetivo deste estudo foi compreender as consequências da variabilidade temporal das condições climáticas em relação à ocorrência de dengue na população da região metropolitana de São Paulo, constituída por sete municípios. Método: A caracterização da tendência temporal da dengue foi realizada por meio da análise dos números de casos de dengue notificados nos anos de 2010 a 2013, de dados meteorológicos (umidade e temperatura) e dados de concentração de poluentes (PM10). Resultados: Observou-se que os meses de janeiro a abril (de 2010 a 2013) foram os que apresentaram maior número de casos notificados de dengue, com associação estatística entre a umidade e PM10 com os casos de dengue notificados. Conclusão: Embora a temperatura não assuma, estatisticamente, uma associação com os casos de dengue registrados, foi possível verificar que os picos de temperatura coincidem com os picos epidêmicos de dengue. Seriam interessantes futuros estudos referentes à poluição ambiental e a sua influência no desenvolvimento do mosquito Aedes aegypti em todas as suas fases do ciclo de vida e definição de estratégias para melhor monitoração, campanhas e vigilância.


Subject(s)
Humans , Animals , Dengue/epidemiology , Insect Vectors/growth & development , Urban Population , Brazil/epidemiology , Incidence , Cross-Sectional Studies , Cities/epidemiology , Aedes , Dengue/transmission , Dengue Virus/isolation & purification , Air Pollution , Insect Vectors/virology , Meteorological Concepts
3.
Biomédica (Bogotá) ; 37(3): 324-332, jul.-set. 2017. tab, graf
Article in Spanish | LILACS | ID: biblio-888473

ABSTRACT

Resumen Introducción. La principal herramienta para el control de los triatominos, vectores de Trypanosoma cruzi, ha sido el uso masivo e intensivo de piretroides. La aparición de resistencia a estas moléculas ha planteado la necesidad de encontrar estrategias nuevas, alternativas y complementarias de control. Objetivo. Evaluar el efecto tóxico de la ivermectina, la doramectina y la eprinomectina sobre Triatoma infestans y sus consecuencias en la alimentación con sangre en un modelo de roedor. Materiales y métodos. Se alimentaron ninfas de quinto estadio de T. infestans en distintos momentos sobre ratas Wistar tratadas previamente con doramectina, ivermectina, eprinomectina o dimetilsulfóxido (excipiente de control), administrados tópicamente o por vía oral. Se determinó el efecto de cada endectocida y del dimeltilsulfóxido en la cantidad de sangre ingerida, el volumen de excreciones y el porcentaje de mortalidad. Resultados. Únicamente la mortalidad de los insectos dependió del endectocida suministrado a las ratas y de la vía de administración utilizada. La doramectina causó mayor mortalidad (21,5 %) comparada con la ivermectina, la eprinomectina y el dimetilsulfóxido (16, 11 y 2,5 %, respectivamente), y la administración tópica fue más efectiva que la vía oral (23 Vs. 9,3 %). Conclusión. Los resultados obtenidos demuestran el efecto tóxico de los tres endectocidas en T. infestans. Su utilización en animales domiciliarios o que viven en el peridomicilio podría ser una interesante estrategia complementaria de la aspersión con piretroides para el control de T. infestans.


Abstract Introduction: Pyrethroids have been frequently and intensively used for controlling the triatomine vectors of Trypanosoma cruzi. The emergence of resistance to these insecticides has resulted in an urgent need to identify novel, alternative and complementary control strategies. Objective: To evaluate the toxic effects of ivermectin, doramectin and eprinomectin on the blood-feeding behaviour of Triatoma infestans using a rodent model. Materials and methods: Fifth instar nymphs of T. infestans were fed at different times on Wistar rats pretreated with doramectin, ivermectin, eprinomectin or dimethylsulfoxide (excipient control) topically or orally administered. We determined the effects of each insecticide and of dimethyl sulfoxide on the amount of ingested blood, the volume of faecal discharge, and the mortality rates in triatomines. Results: Only the rate of triatomine mortality was associated with the antiparasitic compounds administered and the route of administration utilized. Doramectin administration was associated with a higher mortality rate (21.5%) than ivermectin, eprinomectin and dimethylsulfoxide (16, 11 and 2.5%, respectively), and topical administration was found to be most effective for inducing mortality (23 vs. 9.3 %). Conclusion: These results demonstrate the toxic effects of the three assessed insecticides onT. infestans. The administration of ecto/endoparasiticides to domiciliary or peridomiciliary animals may serve as an interesting complementary strategy to the use of pyrethroids for the control of T. infestans.


Subject(s)
Animals , Female , Male , Rats , Triatoma , Ivermectin/analogs & derivatives , Insect Vectors , Insecticides , Triatoma/growth & development , Trypanosoma cruzi , Blood , Ivermectin/administration & dosage , Ivermectin/pharmacology , Insecticide Resistance , Random Allocation , Administration, Oral , Administration, Topical , Rats, Wistar , Feeding Behavior/drug effects , Insect Vectors/growth & development , Insecticides/administration & dosage , Insecticides/pharmacology , Nymph
4.
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
5.
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
6.
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
7.
Mem. Inst. Oswaldo Cruz ; 111(10): 605-613, Oct. 2016. tab, graf
Article in English | LILACS | ID: lil-796904

ABSTRACT

For a long time, haematophagy was considered an obligate condition for triatomines (Hemiptera: Reduviidae) to complete their life cycle. Today, the ability to use haemolymphagy is suggested to represent an important survival strategy for some species, especially those in genus Belminus. As Eratyrus mucronatus and Triatoma boliviana are found with cockroaches in the Blaberinae subfamily in Bolivia, their developmental cycle from egg to adult under a “cockroach diet” was studied. The results suggested that having only cockroach haemolymph as a food source compromised development cycle completion in both species. Compared to a “mouse diet”, the cockroach diet increased: (i) the mortality at each nymphal instar; (ii) the number of feedings needed to molt; (iii) the volume of the maximum food intake; and (iv) the time needed to molt. In conclusion, haemolymph could effectively support survival in the field in both species. Nevertheless, under laboratory conditions, the use of haemolymphagy as a survival strategy in the first developmental stages of these species was not supported, as their mortality was very high. Finally, when Triatoma infestans, Rhodnius stali and Panstrongylus rufotuberculatus species were reared on a cockroach diet under similar conditions, all died rather than feeding on cockroaches. These results are discussed in the context of the ecology of each species.


Subject(s)
Animals , Male , Female , Rats , Diet , Feeding Behavior/physiology , Hemolymph , Insect Vectors/growth & development , Triatominae/growth & development , Cockroaches , Insect Vectors/physiology , Laboratories , Life Cycle Stages/physiology , Triatominae/physiology
8.
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
9.
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
10.
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
11.
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
12.
Biomédica (Bogotá) ; 34(3): 473-482, July-Sept. 2014. ilus, graf
Article in Spanish | LILACS | ID: lil-726792

ABSTRACT

Introducción. El dengue es una enfermedad viral de transmisión vectorial de importancia en salud pública. La ausencia de una vacuna ha llevado a que las acciones de control se enfoquen principalmente en la disminución del mosquito vector. Sin embargo, estas estrategias tienen costos elevados. Las ovitrampas letales podrían contribuir de forma práctica en estrategias costo-efectivas para el control vectorial. Objetivo. Determinar el tipo de ovitrampas letales más eficiente para el control vectorial de Aedes aegypti , combinando diferentes tipos de insecticidas, sustrato de ovipostura e infusión atrayente. Materiales y métodos. El estudio se llevó a cabo en dos etapas. En la primera, se evaluaron en el laboratorio 18 ovitrampas diferentes provenientes de la combinación de insecticidas (deltametrina y permetrina), sustratos de ovipostura (toalla, dacrón y franela) e infusiones atrayentes (infusión de heno al 10 y 20 % y agua declorada). Para esta evaluación, las ovitrampas se colocaron en el interior de una jaula de evaluación y se liberaron 100 hembras grávidas de A. aegypti . Se seleccionaron las seis mejores ovitrampas con base en la mayor cantidad de oviposturas y en la menor emergencia larvaria. La segunda etapa consistió en evaluar las seis mejores ovitrampas en condiciones de campo. Resultados. Se observó una diferencia estadística entre las 18 ovitrampas en el laboratorio. Las que tenían deltametrina fueron las que presentaron los mejores resultados. En campo se observó que la ovitrampa más eficiente fue la compuesta por deltametrina, toalla e infusión de heno al 10 %. Conclusiones. La combinación de deltametrina, toalla y solución de heno al 10 % fue la más eficiente para la reducción vectorial de A. aegypti .


Introduction: Dengue fever is a vector-borne viral disease of major public health importance. In the absence of a vaccine, control measures are primarily focused on reducing the mosquito vector. However, these strategies are very expensive, and the use of lethal ovitraps could contribute, in a practical manner, to the design of cost-effective strategies for vector control. Objective: To determine the most efficient type of lethal ovitrap for Ae. aegypti vector control by combining different types of insecticides, oviposition substrates and attractant infusions. Materials and methods: The study was conducted in two stages. In the first, 18 different ovitraps resulting from the combination of insecticides (deltamethrin and permethrin), oviposition substrates (towel, dacron and flannel), and attractant infusion (10 and 20% hay infusion, and dechlorinated water) were evaluated in the laboratory. For this evaluation, ovitraps were placed into a mosquito holding cage, and 100 gravid Ae. aegypti females were released. The top six ovitraps were selected based on the higher number of registered eggs, and the lower hatched eggs percentage. In the second, the top six ovitraps were evaluated in field conditions. Results: In laboratory conditions, statistical differences were observed between the 18 ovitraps. The ovitraps with deltamethrin were the most efficient showing the best results. In field conditions, the ovitraps with the highest vector reduction were those combining deltamethrin/towel/10% hay infusion. Conclusions: The ovitrap combining deltamethrin, towel as oviposition substrate, and 10% hay infusion as attractant was the most efficient Ae. aegypti vector control.


Subject(s)
Animals , Female , Aedes , Dengue Virus , Insect Vectors , Insecticides , Mosquito Control/instrumentation , Aedes/growth & development , Aedes/virology , Colombia , Drug Stability , Dengue/prevention & control , Dengue/transmission , Equipment Design , Insect Vectors/growth & development , Insect Vectors/virology , Larva , Nitriles , Ovum , Permethrin , Poaceae , Pyrethrins , Time Factors , Urban Health , Water
13.
Rev. Soc. Bras. Med. Trop ; 47(3): 307-312, May-Jun/2014. tab, graf
Article in English | LILACS | ID: lil-716401

ABSTRACT

Introduction Triatoma carcavalloi is a wild species that is found in sympatry with Triatoma rubrovaria and Triatoma circummaculata, which are vectors of Trypanosoma cruzi currently found in rural areas of Rio Grande do Sul, Brazil. Methods Fertility was assessed and to determine the incubation period, the eggs were observed until hatching. The first meal was offered to 1st stage nymphs. The intermolt period was also determined. The number of blood meals was quantified at each nymphal stage and the resistance to fasting as the period between ecdysis and death. Mortality was assessed and longevity was determined by recording the time that elapsed from molting to the adult stage and until death. The developmental cycle was assessed by recording the length in days of each stage from molting to adult hood. Results The average incubation period was 22.7 days. The average first meal occurred 3.1 days after hatching. The 5th stage nymph to adult intermolting period was the longest at 193.4 days. The average number of feedings during nymphal development was 13.4. The resistance to fasting assay indicated that the 3rd, 4th and 5th stage nymphs presented higher resistance than did adults. The highest mortality rate was observed in the 3rd stage nymphs (22.2%). The average length of adult survival was 25.6 weeks, and the average total life cycle lasted 503.4 days. Conclusions This study is the first report on the biology of T. carcavalloi that fed on mice. The presented findings expand the bionomic knowledge of these species. .


Subject(s)
Animals , Female , Male , Mice , Insect Vectors/physiology , Life Cycle Stages/physiology , Triatoma/physiology , Fertility/physiology , Insect Vectors/classification , Insect Vectors/growth & development , Laboratories , Longevity/physiology , Triatoma/classification , Triatoma/growth & development
14.
Rev. salud pública ; 16(2): 270-281, mar.-abr. 2014. ilus, mapas
Article in Spanish | LILACS | ID: lil-725010

ABSTRACT

Objetivo Identificar los conocimientos, actitudes y prácticas sobre dengue en un barrio de la ciudad de Cartagena de Indias. Métodos Estudio descriptivo transversal en 870 sujetos residentes de un barrio ubicado en la zona suroriental de la ciudad. El muestreo fue probabilístico, aleatorio en tres etapas. Se indagó sobre los conocimientos, actitudes y prácticas sobre dengue. Para el análisis de los datos se utilizó la base de datos Stata versión 11.1 para determinar las frecuencias absolutas y relativas de cada variable estudiada. Resultados Se encontró que el 93,7 % de los encuestados conocen que existe la enfermedad; el 49,7 % no sabe cuál es el agente causal de la enfermedad. Mientras que el 80,5 % de los encuestados manifiesta tener disposición para recibir clases de educación sanitaria. El 60,1 % de la población encuestada almacena agua en sus viviendas y el 73,8 % utiliza los tanques como recipientes. El 24,8 % manifiesta que evita tener agua estancada. Conclusiones Los habitantes ratifican la alta incidencia de casos de dengue en el barrio, la cual ha sido reportada por el ente de distrital de salud. Los conocimientos sobre dengue son escasos, se adoptan prácticas de riesgo que favorecen el desarrollo de la enfermedad; sin embargo, se evidencia una actitud favorable para el control. Se requiere, entonces, promover cambios de comportamiento no solo en la comunidad, sino también, en la manera como los programas de prevención y control se están llevando a cabo.


Objective Identifying attitudes, practice and knowledge regarding dengue in a neighborhood of the city of Cartagena. Methods This was a cross-sectional study of 870 people living in a neighborhood in the south-eastern part of Cartagena. Probabilistic, randomized, three-staged sampling was used; it was intended to ascertain attitudes, practice and knowledge about dengue. The Stata statistics package (version 11.1) was used for analyzing the data to determine the absolute and relative frequency for each variable studied. Results It was found that 93.7 % of those surveyed knew about the disease; although 49.7 % did not know what the causal agent of the disease was, 80.5 % of those surveyed did express an interest. In receiving health education classes. 60.1 % of the population surveyed here stored water in their homes and 73.8 % used tanks as containers. 24.8 % of those surveyed stated that they avoided having/using stagnant water. Conclusions The residents confirmed the high incidence of dengue cases reported by the district health department. Knowledge about dengue was limited; risky practices favoring the disease's development were adopted, but an attitude towards controlling this issue was evident. Changes in current behavior patterns must thus be promoted in the community and also regarding how prevention and control programs are being carried out.


Subject(s)
Adolescent , Adult , Aged , Animals , Female , Humans , Male , Middle Aged , Young Adult , Dengue/prevention & control , Health Knowledge, Attitudes, Practice , Urban Population , Aedes/growth & development , Aedes/virology , Cities , Colombia , Cross-Sectional Studies , Dengue/transmission , Disease Reservoirs , Educational Status , Insect Vectors/growth & development , Insect Vectors/virology , Residence Characteristics , Surveys and Questionnaires , Urban Health , Water Supply
15.
Mem. Inst. Oswaldo Cruz ; 108(7): 854-864, 1jan. 2013. tab, graf
Article in English | LILACS | ID: lil-696012

ABSTRACT

Triatominae are widely recognised for their role as vectors of Trypanosoma cruzi. One of the main biological characteristics of this subfamily is their obligate haematophagous condition. However, previous studies on Belminus herreri and Belminus ferroae suggested that cockroaches are their principal hosts in domiciles. Due to this peculiar behaviour, the aim of this study was to analyse several demographic and reproductive parameters of B. ferroae fed on three different hosts (mice, cockroaches and Rhodnius prolixus) and relate B. ferroae fitness to these alternative hosts. The cohorts were reared under constant conditions. The egg hatching rate was similar for cohorts fed on cockroaches (69.4%) and R. prolixus (63.8%), but was much lower for the cohort fed on mice (16%). The development time from the nymph to adult stage and the average age of first reproduction (α) presented lower values in the cohort fed on cockroaches, which is consistent with the higher population growth rate associated with this host. Demographic parameters [intrinsic rate of natural increase, finite rate of population growth, net reproductive rate and damping ratio] showed statistically significant differences between the cohorts. Analysis of the life history of B. ferroae revealed a higher fitness related to the cockroach. The implications of these results for the origin of the subfamily are discussed.


Subject(s)
Animals , Female , Male , Mice , Feeding Behavior/physiology , Host-Parasite Interactions/physiology , Insect Vectors/physiology , Triatominae/physiology , Cockroaches , Insect Vectors/growth & development , Life Cycle Stages , Reproduction , Sex Ratio , Triatominae/growth & development
16.
Rev. saúde pública ; 47(3): 579-587, jun. 2013. tab, graf
Article in Portuguese | LILACS, SES-SP | ID: lil-690827

ABSTRACT

OBJETIVO: Analisar o efeito da qualidade da água de reservatórios domésticos de abastecimento público na resposta oviposicional de fêmeas de Aedes aegypti. MÉTODOS: Estudo conduzido em laboratório a partir de imaturos de Ae. aegypti, coletados em caixas d'água do município de Potim, SP, 2009. Foram disponibilizados simultaneamente três tipos de água por gaiola para a deposição dos ovos: ovipositor (A) com água coletada em caixa d'água de Taubaté, SP; ovipositor (B) com água destilada (controle); e ovipositor (C) com água coletada em caixa d'água de Potim. Foram analisados parâmetros fisicoquímicos. O teste de Kruskall-Wallis foi utilizado para analisar a média de ovos nas diferentes amostras de água e nas comparações posteriores, o teste Dwass-Steel-Chritchlow-Flingner. O índice de atividade de oviposição foi adotado para avaliar a resposta oviposicional. RESULTADOS: Foi observada diferença significativa no número de ovos entre as soluções líquidas testadas (H = 45; p < 0,0001). O número de ovos na água de caixas d'água de abastecimento público de captação em poços profundos (C) foi estatisticamente superior a amostras de água de caixas d'água de abastecimento público de superfície (A) (p < 0,0001) e do Controle (B) (p < 0,0001). Não houve diferença significante entre o número de ovos do Controle (B) e água de superfície (A). A primeira postura foi a mais produtiva em todas as soluções testadas nas três gaiolas. A amostra de água (C) produziu índice positivo (0,54), i.e., atrativo para oviposição. CONCLUSÕES: A qualidade da água influiu na oviposição de Ae. aegypti. As elevadas concentrações de nitrogênio ...


OBJETIVO: Analizar el efecto de la calidad de agua de reservatorios domésticos de abastecimiento público en la respuesta de oviposición por hembras de Aedes aegypti. MÉTODOS: Estudio conducido en laboratorio a partir de inmaduros de Ae. aegypti, colectados en tanques de agua del municipio de Potim, SP, Brasil, 2009. Se disponibilizaron simultáneamente tres tipos de agua por jaula para la deposición de los huevos: ovipositor (A) con agua colectada en tanque de agua de Taubaté, SP (Brasil), ovipositor (B) agua destilada (control) y ovipositor (C) con agua colectada en el tanque de agua de Potim. Se analizaron parámetros fisicoquímicos. La prueba de Kruskall-Wallis fue usada para analizar el promedio de huevos en las diferentes muestras de agua y en las comparaciones posteriores, la prueba de Dwass-Steel-Chritchlow-Flingner. El índice de actividad de oviposición fue adoptado para evaluar la respuesta en las diferentes muestras. RESULTADOS: Se observó diferencia significativa en el número de huevos entre las soluciones líquidas evaluadas (H= 45; p˂0,0001). El número de huevos en el agua de los tanques para abastecimiento público, de captación en pozos profundos (C) fue estadísticamente superior a las muestras de tanques para abastecimiento público de superficie (A) (p˂0,0001) y del Control (B) (p˂0,0001). No hubo diferencia significativa entre el número de huevos del Control (B) y el agua de superficie (A). La primera postura fue la más productiva en todas las soluciones evaluadas en las tres jaulas. La muestra de agua (C) produjo índice positivo (0,54), es decir, atractivo para oviposición. CONCLUSIONES: La calidad de agua influyó en la oviposición de Ae. aegypti. Las elevadas concentraciones de nitrógeno amoniacal en el agua de abastecimiento público sugieren que dicho componente ...


OBJECTIVE: To evaluate the effect of the quality of publicly supplied water in domestic water tanks on egg laying by female Aedes aegypti. METHODS: Laboratory study on immature Ae. aegypti, collected from water-tanks in the municipality of Potim, SP, Southeastern Brazil. Each cage contained three types of water in which eggs could be laid: Three choice per test were simultaneously used to deposit the eggs, ovipositor (A) with water collected from a water tank in Taubaté, ovipositor (B) with distilled water (control) and ovipositor (C) water collected from a water tank in the municipality of Potim. Physiochemical parameters were analyzed. The Kruskall-Wallis test was used to analyze the mean number of eggs in each water sample and the Dwass-Steel-Critchlow-Fligner test was used in making comparisons. To evaluate egg laying, an ovipositional activity index was adopted. RESULTS: A significant difference in the number of eggs was found between the liquid solutions tested (H = 45; p < 0.0001). The number of eggs found in water tank samples originating from deep wells (C), was statistically superior to water samples from water tanks originating from superficial wells (A) (p < 0.0001) and from the Control (C) p < 0.0001. There was no significant difference between the number of eggs in Control (B) and the surface water (A). In all three tests, the first position was the most productive in all tested solutions. Only water sample (C) produced a positive index (0.54), i.e., attractive to egg laying. CONCLUSIONS: Water quality influences egg laying by Aedes aegypti. The high concentrations of ammonium nitrate in public water supplies suggest that this chemical component was responsible for attracting pregnant female Aedes aegypti to lay eggs in these environments. .


Subject(s)
Animals , Female , Aedes/anatomy & histology , Drinking Water/analysis , Mosquito Control/methods , Oviposition/physiology , Water Pollutants, Chemical/analysis , Water Quality , Water Supply/analysis , Drinking Water/parasitology , Household Articles , Insect Vectors/growth & development , Larva/growth & development
17.
Cad. saúde pública ; 29(2): 368-378, Fev. 2013. tab
Article in Portuguese | LILACS | ID: lil-666840

ABSTRACT

A melhor forma de evitar novas epidemias de dengue é controlar o vetor, o mosquito Aedes aegypti. Assim, este estudo objetivou identificar e analisar a distribuição espacial dos imóveis-chave para Ae. aegypti em Aracaju, Sergipe, Brasil. Para isso, três levantamentos entomológicos foram realizados em períodos antes, durante e após a epidemia de dengue e em diferentes condições de precipitação: fim do período chuvoso, início da estação chuvosa e estiagem. Para identificar os imóveis-chave, foram consideradas as variáveis: positividade em mais de um levantamento e presença de pupas; e para verificar a distribuição espacial e dispersão dos mosquitos, foi realizada análise de padrões pontuais, por meio do estimador de densidade de kernel e buffer. Constatou-se que os imóveis-chave são responsáveis pela manutenção da infestação na localidade independente das condições ambientais e do período epidêmico e são focos geradores de mosquitos que podem se dispersar para áreas vizinhas ao bairro. Dessa forma, as ações de controle vetorial, para serem mais efetivas, devem ser direcionadas para esses imóveis.


Currently the best way to avoid new dengue epidemics is to control the mosquito vector Aedes aegypti. This study thus aimed to identify and analyze the spatial distribution of "key premises" for Ae. aegypti in Aracaju, Sergipe State, Brazil. Three entomological surveys were performed prior to, during, and after the dengue epidemic and in different conditions of precipitation: the end of the rainy season, beginning of the rainy season, and the dry season. Key premises were identified by positivity in more than one survey and presence of pupae. Spatial distribution and dispersal of mosquitoes used analysis of point patterns, with the kernel and buffer density estimator. Key premises were responsible for maintaining infestation of the area, independently of environmental conditions and the period in the epidemic, serving as foci generating mosquitoes that can spread to areas adjacent to the neighborhood. Thus, in order to be more effective, vector control measures should target these properties.


La mejor forma de evitar nuevas epidemias de dengue es controlar el vector, el mosquito Aedes aegypti. Por ello, este estudio tuvo por objetivo identificar y analizar la distribución espacial de los recipientes-clave para Ae. aegypti en Aracaju, Sergipe, Brasil. Con este fin, tres estudios entomológicos se realizaron en períodos anteriores, durante y después de la epidemia de dengue y en diferentes condiciones de precipitación pluvial: fin del período lluvioso, inicio de la estación de lluvias y período seco. Para identificar los recipientes-clave, se consideraron las variables: positividad en más de un estudio y presencia de crisálidas; y para verificar la distribución espacial y la dispersión de los mosquitos, se realizó un análisis de padrones puntuales, por medio del estimador de densidad de kernel y buffer. Se constató que los recipientes-clave son responsables del mantenimiento de la infestación en la localidad, independientemente de las condiciones ambientales y del período epidémico, además, son focos generadores de mosquitos que pueden dispersarse hacia áreas vecinas del barrio. De esta forma, las acciones de control vectorial, para ser más efectivas, deben estar dirigidas hacia esos inmuebles.


Subject(s)
Animals , Aedes , Dengue/prevention & control , Aedes/growth & development , Brazil , Dengue/transmission , Geographic Information Systems , Insect Vectors/growth & development , Mosquito Control , Risk Factors , Spatial Analysis , Urban Population
18.
Belo Horizonte; s.n; 2013. 72 p. ilus.
Thesis in Portuguese | LILACS, ColecionaSUS | ID: biblio-938629

ABSTRACT

Os mosquitos da espécie Anopheles (Nyssorhynchus) aquasalis, Curry 1932 são vetores da malária humana nas Américas. Desde o ano de 2004, esse vetor tem sido mantido em colônia no Laboratório de Malária do Centro de Pesquisas René Rachou (Lamal), Fiocruz-MG, onde tem sido utilizado para estudos de interação parasito-vetor. Na natureza, as larvas desses insetos desenvolvem-se em água salobra e, no insetário de criação do Lamal utiliza-se água do mar na proporção de 1:10 em água da torneira. No ano de 2008, observou-se uma queda significativa na produção de mosquitos da colônia, devido, principalmente, à mortalidade excessiva de larvas. As larvas, de 3º e 4º estádios, apresentavam características morfológicas semelhantes àquelas relacionadas com contaminação por bacilos entomopatogênicos. Como algumas bactérias do gênero Bacillus são patogênicas às larvas de mosquitos, o objetivo do presente trabalho foi identificar a (as) espécie (es) responsável (is) pela mortalidade das larvas de Anopheles aquasalis, bem como identificar as toxinas envolvidas nessa mortalidade. Através da caracterização morfológica e molecular foi possível identificar o Bacillus sphaericus como contaminante na colônia de criação de Anopheles aquasalis.


Visando uma comparação inter-insetários, analisou-se ainda amostras de três insetários distintos, sendo a presença dos bacilos identificadas em dois desses. Pela técnica de PCR buscou-se amplificar as 5 toxinas mais frequentes das estirpes de B. sphaericus (BinA, BinB, Mtx1, Mtx2 e Mtx3 ), sendo que apenas 3 (família das MTxs) foram detectadas nas amostras estudadas. Os resultados dos ensaios biológicos confirmaram a toxidade destas toxinas para as larvas de 3º e 4º estádios. Os ensaios biológicos realizados identificaram as estirpes isoladas do Laboratório de Malária como de alta toxicidade para o Anopheles aquasalis. Em resumo, este trabalho foi o primeiro a demonstrar a ocorrência de contaminação natural por bacilos entomopatogênico sem colônias de mosquitos mantidas em insetário e a caracterizar as toxinas envolvidas nesta contaminação. Espera-se que estes resultados possam contribuir para traçar estratégias de monitoramento e controle de contaminação em insetários de experimentação


Subject(s)
Animals , Guinea Pigs , Mice , Anopheles/parasitology , Bacillus/isolation & purification , Insect Vectors/growth & development , Malaria/transmission , Plasmodium/parasitology
19.
Belo Horizonte; s.n; 2013. 72 p. ilus.
Thesis in Portuguese | LILACS | ID: lil-681490

ABSTRACT

Os mosquitos da espécie Anopheles (Nyssorhynchus) aquasalis, Curry 1932 são vetores da malária humana nas Américas. Desde o ano de 2004, esse vetor tem sido mantido em colônia no Laboratório de Malária do Centro de Pesquisas René Rachou (Lamal), Fiocruz-MG, onde tem sido utilizado para estudos de interação parasito-vetor. Na natureza, as larvas desses insetos desenvolvem-se em água salobra e, no insetário de criação do Lamal utiliza-se água do mar na proporção de 1:10 em água da torneira. No ano de 2008, observou-se uma queda significativa na produção de mosquitos da colônia, devido, principalmente, à mortalidade excessiva de larvas. As larvas, de 3º e 4º estádios, apresentavam características morfológicas semelhantes àquelas relacionadas com contaminação por bacilos entomopatogênicos. Como algumas bactérias do gênero Bacillus são patogênicas às larvas de mosquitos, o objetivo do presente trabalho foi identificar a (as) espécie (es) responsável (is) pela mortalidade das larvas de Anopheles aquasalis, bem como identificar as toxinas envolvidas nessa mortalidade. Através da caracterização morfológica e molecular foi possível identificar o Bacillus sphaericus como contaminante na colônia de criação de Anopheles aquasalis. Visando uma comparação inter-insetários, analisou-se ainda amostras de três insetários distintos, sendo a presença dos bacilos identificadas em dois desses. Pela técnica de PCR buscou-se amplificar as 5 toxinas mais frequentes das estirpes de B. sphaericus (BinA, BinB, Mtx1, Mtx2 e Mtx3 ), sendo que apenas 3 (família das MTxs) foram detectadas nas amostras estudadas. Os resultados dos ensaios biológicos confirmaram a toxidade destas toxinas para as larvas de 3º e 4º estádios. Os ensaios biológicos realizados identificaram as estirpes isoladas do Laboratório de Malária como de alta toxicidade para o Anopheles aquasalis. Em resumo, este trabalho foi o primeiro a demonstrar a ocorrência de contaminação natural por bacilos entomopatogênico sem colônias de mosquitos mantidas em insetário e a caracterizar as toxinas envolvidas nesta contaminação. Espera-se que estes resultados possam contribuir para traçar estratégias de monitoramento e controle de contaminação em insetários de experimentação.


Subject(s)
Animals , Guinea Pigs , Mice , Anopheles/parasitology , Bacillus/isolation & purification , Insect Vectors/growth & development , Malaria/transmission , Plasmodium/parasitology
20.
Biomédica (Bogotá) ; 32(3): 321-331, jul.-set. 2012. mapas, tab
Article in Spanish | LILACS | ID: lil-663704

ABSTRACT

Introducción. Los estudios entomológicos en las grandes obras de infraestructura hidroeléctrica constituyen una herramienta para la prevención y el control de enfermedades transmitidas por vectores, debido a que con frecuencia las alteraciones causadas en el medio producen aumento de criaderos naturales y artificiales en el área de influencia y, por ende, incremento de las poblaciones de artrópodos, entre ellos, insectos de interés en salud pública. Objetivo. Realizar estudio y vigilancia de la fauna de Culicidaey Phlebotominae en el área de los proyectos hidroeléctricos Porce II y Porce III, 1990-2009. Materiales y metódos. Se realizaron muestreos entomológicos periódicos para la vigilancia en salud pública de las comunidades ubicadas en el área de influencia y en campamentos y frentes de obra. Los adultos fueron capturados con red para mariposas, trampas de luz Shannon y CDC, y cebo humano protegido. Resultados. Se encontraron larvas de mosquitos de Culex coronator, Cx. nigripalpus, Cx. corniger, Cx. quinquefasciatus y Limatus durhami. Los depósitos más frecuentes fueron: tanques bajos, canecas, llantas y matas sembradas en agua. Aedes aegypti solo fue capturado en dos localidades rurales de dos municipios del área de influencia. En las zonas de bosque se capturaron mosquitos Aedes, Mansonia, Culex, Psorophora, Wyeomyia, Phonyomyia, Uranotaenia, Haemagogus y Sabethes; el principal fue Haemogogus janthinomis, eficiente vector de fiebre amarilla en Colombia. La zona es endémica para leishmaniasis y se identificaron 20 especies de Lutzomyia. Entre los vectores de malaria, las principales especies encontradas fueron Anopheles nuñeztovari y An. pseudopunctipennis. Conclusión. En la zona de Porce II y Porce III existe diversidad de vectores de importancia en salud pública, que es necesario continuar vigilando para minimizar el riesgo de transmisión de enfermedades a los trabajadores de las obras y comunidades aledañas.


Introduction. Entomological studies conducted in large hydroelectric infrastructure projects are a tool for the prevention and control of vector-borne diseases. These diseases emerge as a consequence of changes made to the terrain that often increase the natural and artificial mosquito larval habitats. Many of these insects are of public health importance and population increases result in an increased risk of disease transmission. Objective. The culicine (mosquito) and phlebotomine (sand fly) populations were characterized in the area of the Porce II and Porce III hydroelectric projects of Antioquia between 1990 to 2009. Materials and methods. Periodical entomological samplings were made in the area of impact, in the workers camps, and construction sites. Adult specimens were captured with nets, Shannon light traps, CDC light traps, and protected human bait. Results. Mosquito larvae of the following species were identified: Culex coronator, Culex nigripalpus, Culex corniger, Culex quinquefasciatus and Limatus durhami. The most frequently identifiers of larval habitats were low tanks, waste cans, tires, and aquatic plants. Aedes aegypti specimens were captured in only two rural locations from two municipalities within the area of influence. Specimens from the following mosquito genera were captured in forest areas: Aedes, Mansonia, Culex, Psorophora, Wyeomyia, Phonyomyia, Uranotaenia, Haemagogus and Sabethes. The most important mosquito found was Haemogogus janthinomis, an efficient yellow fever vector in Colombia. The area has been endemic for leishmaniasis and in the current study, 20 species of Lutzomyia sand flies, potential vectors, were identified. Among malaria vectors, the most important species found in the area were Anopheles nuneztovari and Anopheles pseudopunctipennis. Conclusion. A wide variety of vectors were discovered in the area of the Porce II and Porce III hydroelectric projects, and many of these were relevant for public health. Further monitoring will be necessary to minimize disease transmission risks among the workers and the inhabitants of the surrounding areas.


Subject(s)
Animals , Humans , Culicidae , Disease Reservoirs , Insect Vectors , Power Plants , Psychodidae , Public Health Surveillance , Colombia , Culicidae/growth & development , Ecosystem , Environment , Insect Control , Insect Vectors/growth & development , Larva , Leishmania , Plasmodium , Psychodidae/growth & development , Species Specificity , Trees , Water/parasitology , Yellow fever virus
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