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1.
Braz. j. biol ; 83: e248122, 2023. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1355851

ABSTRACT

Abstract Being vector of West Nile Virus and falariasis the control of Culex quinquefasciatus is likely to be essential. Synthetic insecticide treatment is looking most effective for vectors mosquito control. However, these products are toxic to the environment and non-target organisms. Consequently, ecofriendly control of vectors mosquito is needed. In this regard botanical insecticide is looking more fruitful. Therefore, the present research aimed to investigate the effectiveness of methanolic extract and various fractions, including, n-hexane, ethyl-acetate, chloroform, and aqueous fraction, obtained from methanolic extract of Ailanthus altissima, Artemisia scoparia, and Justicia adhatoda using separating funnel against larval, pupal, and adult stages of Culex quinquefasciatus. The larvae and pupae of Culex quinquefasciatus were exposed to various concentrations (31.25-1000 ppm) of methanolic extract and its fractions for 24 hours of exposure period. For knock-down bioassay (filter paper impregnation bioassay) different concentration of the methanolic extract and its various fractions (i.e. 0.0625, 0.125, 0.25, 0.5 and 1mg/mL) were applied for 1 hour exposure period. The results were statistically analysed using standard deviation, probit analysis, and linear regression. The R2 values of larvae, pupae, and adult range from 0.4 to 0.99. The values of LC50 (concentration causing 50% mortality) for late 3rd instar larvae after 24 hours exposure period range from 93-1856.7 ppm, while LC90 values range from 424 -7635.5ppm. The values of LC50for pupae range form 1326.7-6818.4ppm and and values of LC90 range from 3667.3-17427.9ppm, respectively. The KDT50 range from 0.30 to 2.8% and KDT90 values range from1.2 to 110.8%, respectively. In conclusion, Justicia adhatoda may be effective for controlling populations of vector mosquito.


Resumo Por ser o vetor do vírus do Nilo Ocidental e da falaríase, o controle de Culex quinquefasciatus Say é provavelmente essencial. O tratamento com inseticida sintético parece ser mais eficaz para o controle dos mosquitos vetores. No entanto, esses produtos são tóxicos para o meio ambiente e organismos não visados. Consequentemente, o controle ecológico dos mosquitos vetores é necessário. Nesse sentido, o inseticida botânico parece mais produtivo. Portanto, a presente pesquisa teve como objetivo investigar a eficácia do extrato metanólico e de várias frações, incluindo n-hexano, acetato de etila, clorofórmio e fração aquosa, obtidos do extrato metanólico de Ailanthus altissima (Mill.) Swingle, Artemisia scoparia Waldst. & Kit. e Justicia adhatoda L. usando funil de separação contra os estágios larval, pupal e adulto de C. quinquefasciatus. As larvas e pupas de C. quinquefasciatus foram expostas a várias concentrações (31,25-1000 ppm) de extrato metanólico, e suas frações por 24 horas de período de exposição. Para o bioensaio knock-down (bioensaio de impregnação de papel de filtro), diferentes concentrações do extrato metanólico e suas várias frações (ou seja, 0,0625, 0,125, 0,25, 0,5 e 1 mg / mL) foram aplicadas por um período de exposição de 1 hora. Os resultados foram analisados ​​estatisticamente usando desvio padrão, análise Probit e regressão linear. Os valores de R2 de larvas, pupas e adultos variaram de 0,4 a 0,99. Os valores de LC50 (concentração que causa 50% de mortalidade) para larvas de terceiro estádio tardio após 24 horas de período de exposição variaram de 93-1856,7 ppm, enquanto os valores de LC90 variaram de 424-7635,5ppm. Os valores de LC50 para pupas variaram de 1326,7-6818,4 ppm e os valores de LC90 variaram de 3667,3-17427,9 ppm, respectivamente. O KDT50 variou de 0,30 a 2,8% e os valores de KDT90 variaram de 1,2 a 110,8%, respectivamente. Por fim, a espécie J. adhatoda pôde ser eficaz para controlar populações de mosquitos vetores.


Subject(s)
Animals , Culex , Insecticides/pharmacology , Anopheles , Plant Extracts/pharmacology , Plant Leaves , Mosquito Vectors , Larva
2.
Braz. j. biol ; 83: e246230, 2023. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1339369

ABSTRACT

Abstract Dengue fever vectored by the mosquito Aedes aegypti is one of the most rapidly spreading insect-borne diseases. Current reliance of dengue vector control is mostly on chemical insecticides. Growing insecticide resistance in the primary mosquito vector, Aedes aegypti, limits the effectiveness of vector control through chemical insecticides. These chemical insecticides also have negative environmental impacts on animals, plants and human health. Myco-biocontrol agents are naturally occurring organisms and are found to be less damaging to the environment as compared to chemical insecticides. In the present study, entomopathogenic potential of local strains of fungi isolated from soil was assessed for the control of dengue vector. Local fungal isolates presents better alternative to introducing a foreign biocontrol strain, as they may be better adapted to environmental conditions of the area to survive and may have more entomopathogenic efficacy against target organism. Larvicidal efficacy of Fusarium equiseti and Fusarium proliferatum was evaluated against Aedes aegypti. Local strains of F. equiseti (MK371718) and F. proliferatum (MK371715) were isolated from the soil of Changa Manga Forest, Pakistan by using insect bait method. Larvicidal activity of two Fusarium spp. was tested against forth instar larvae of A. aegypti in the laboratory, using concentrations 105, 106, 107 and 108 conidia /ml. LC50 values for F. equiseti after 24h, 48h, 72h and 96h of exposure were recorded as 3.8x 108, 2.9x107, 2.0x107, and 7.1x106 conidia /ml respectively while LC50 values for F. proliferatum were recorded as 1.21x108, 9.6x107, 4.2x107, 2.6x107 conidia /ml respectively after 24h, 48h, 72h and 96h of exposure. The results indicate that among two fungal strains F. equiseti was found to be more effective in terms of its larvicidal activity than F. proliferatum against larvae of A. aegypti.


Resumo A dengue transmitida pelo mosquito Aedes aegypti é uma das doenças transmitidas por insetos de propagação mais rápida. A dependência atual do controle do vetor da dengue é principalmente de inseticidas químicos. O aumento da resistência a inseticidas no principal vetor do mosquito, Aedes aegypti, limita a eficácia do controle do vetor por meio de inseticidas químicos. Esses inseticidas químicos também têm impactos ambientais negativos sobre os animais, plantas e saúde humana. Os agentes de micobiocontrole são organismos que ocorrem naturalmente e são menos prejudiciais ao meio ambiente em comparação com os inseticidas químicos. No presente estudo, avaliou-se o potencial entomopatogênico de cepas locais de fungos isolados do solo para o controle do vetor da dengue. Isolados de fungos locais apresentam melhor alternativa para a introdução de uma cepa de biocontrole estrangeira, pois podem ser mais bem adaptados às condições ambientais da área para sobreviver e podem ter maior eficácia entomopatogênica contra o organismo-alvo. A eficácia larvicida de Fusarium equiseti e Fusarium proliferatum foi avaliada contra Aedes aegypti. Cepas locais de F. equiseti (MK371718) e F. proliferatum (MK371715) foram isoladas do solo de Changa Manga Forest, Paquistão, usando o método de isca para insetos. Atividade larvicida de dois Fusarium spp. foi testado contra larvas de quarto ínstar de A. aegypti em laboratório, nas concentrações 105, 106, 107 e 108 conídios / ml. Os valores de LC50 para F. equiseti após 24 h, 48 h, 72 h e 96 h de exposição foram registrados como 3,8x 108, 2,9x107, 2,0x107 e 7,1x106 conídios / ml, respectivamente, enquanto os valores de LC50 para F. proliferatum foram registrados como 1,21x108, 9,6 x107, 4,2x107, 2,6x107 conídios / ml, respectivamente, após 24 h, 48 h, 72 h e 96 h de exposição. Os resultados indicam que entre duas cepas de fungos F. equiseti se mostrou mais eficaz em termos de atividade larvicida do que F. proliferatum contra larvas de A. aegypti.


Subject(s)
Humans , Animals , Aedes , Fusarium , Insecticides/pharmacology , Pakistan , Soil , Plant Extracts , Forests , Mosquito Vectors , Larva
3.
Braz. j. biol ; 83: e240118, 2023. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1278559

ABSTRACT

Abstract For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-1 and 1.0 mg mL-1 MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-1). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-1, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.


Resumo Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados ​​contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-1 e 1,0 mg mL-1 foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-1 de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-1, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.


Subject(s)
Humans , Animals , Zika Virus , Zika Virus Infection , Insecticides/toxicity , DNA Damage , Chromosome Aberrations , Plant Roots , Onions , Mosquito Vectors , Malathion/toxicity , Mitotic Index
4.
Ciênc. Saúde Colet ; 27(1): 231-242, jan. 2022. tab, graf
Article in English, Portuguese | LILACS | ID: biblio-1356022

ABSTRACT

Resumo Objetivou sintetizar os estudos, publicados na literatura cientifica, que abordem estratégias de enfrentamento às arboviroses mediante ações educativas. Os dados foram coletados nas bases de dados: LILACS, BDENF e MEDLINE utilizando os descritores "Educação em Saúde" e "Aedes" empregando o operador booleano "AND". Foram encontrados 242 estudos, dos quais após aplicação dos critérios de inclusão e exclusão, 14 foram incluídos na revisão. Os dados foram analisados utilizando a abordagem qualitativa. Foram identificadas quatro categorias: ações de enfrentamento vetorial mediante capacitação da comunidade; mobilização social em torno do combate às arboviroses; combate vetorial a partir de ações educativas associadas ao uso de controle biológico; ações integradas de enfrentamento às arboviroses. Infere-se que a educação em saúde é um elemento indispensável para o enfrentamento às arboviroses que deverá ser implementada de forma conjunta e articuladas às demais estratégia de combate vetorial.


Abstract The aim of this study was to provide a synthesis of published studies investigating education-based arbovirus control strategies. The data were collected from the LILACS, BDENF and MEDLINE databases using the descriptors "Health Education" and "Aedes", together with the Boolean operator "AND". The searches retrieved 242 studies, 14 of which were included in the review after applying the inclusion and exclusion criteria. The data were analyzed using a qualitative approach, resulting in the identification of four categories: vector control actions based on community capacity building; social mobilization for arbovirus control; education-based vector control combined with biological control; and integrated arbovirus control actions. The findings show that health education is an essential element of arbovirus control and should be implemented in conjunction with other vector control strategies.


Subject(s)
Humans , Animals , Aedes , Mosquito Control , Health Education , Mosquito Vectors
5.
Braz. j. biol ; 82: e237789, 2022. tab, graf
Article in English | LILACS | ID: biblio-1249272

ABSTRACT

Abstract Aedes aegypti is a culicide that has gained relevance over the years due to its ability to transmit various viruses that cause diseases in humans that all the years cause high mortality rates in the world population. The main problem is that Ae. aegypti has managed to establish and maintain a close relationship with humans and their habitat, which is why the search for alternatives to control vector populations becomes imperative. The objective of the present work was to study the effects of two Beauveria bassiana strains on Aedes aegypti. Third instar larvae of Ae. aegypti in 250 mL plastic containers were inoculated with the GHA and NB3 strains at different concentrations (1.5 × 104, 1.5× 105, 1.5 × 106 and 1.5 × 107 conidia/mL). The NB3 strain presented highest mortality values ​​with 63% in the highest concentration i.e., 1.5 × 107, while for the GHA strain the highest mortality value was 30.7% at the same concentration. The results showed significant difference in mortality with respect to the strain and days post treatment (P = 0.0001), but not with respect to the conidial concentration (P = 0.634). The average mortality of larvae per day for the NB3 for different concentrations ranged from 20 to 25 larvae per day, while for the GHA daily mortality ranged from 5 to 12 larvae. In post-treatment mortality, the highest mortality was recorded in the third stage larvae for the NB3, while for GHA the highest percentage mortality was observed in individuals who managed to reach the adult state. The findings of the current research depicted the noteworthy role of B. bassiana for the management of an important vector of human disease.


Resumo O Aedes aegypti é um culicida que vem ganhando relevância ao longo dos anos devido à sua capacidade de transmitir diversos vírus causadores de doenças em humanos que ao longo dos anos ocasionam altas taxas de mortalidade na população mundial. O principal problema é que Ae. aegypti tem conseguido estabelecer e manter uma relação próxima com o homem e seu habitat, por isso a busca por alternativas para o controle das populações de vetores torna-se imperativa. O objetivo do presente trabalho foi estudar os efeitos de duas cepas de Beauveria bassiana sobre Ae. aegypti. Larvas de terceiro instar de Ae. aegypti em recipientes plásticos de 250 mL foram inoculados com as cepas GHA e NB3 em diferentes concentrações (1.5 × 104, 1.5 × 105, 1.5 × 106 e 1.5 × 107 conídios/mL). A cepa NB3 apresentou os maiores valores de mortalidade com 63% na concentração mais alta, ou seja, 1.5 × 107, enquanto para a cepa GHA o maior valor de mortalidade foi 30.7% na mesma concentração. Os resultados mostraram diferença significativa na mortalidade com relação à cepa e dias pós-tratamento (P = 0.0001), mas não com relação à concentração de conídios (P = 0.634). A mortalidade média de larvas por dia para o NB3 para diferentes concentrações variou de 20 a 25 larvas por dia, enquanto para o GHA a mortalidade diária variou de 5 a 12 larvas. Na mortalidade pós-tratamento, a maior mortalidade foi registrada nas larvas de terceiro estágio para o NB3, enquanto para o GHA o maior percentual de mortalidade foi observado em indivíduos que conseguiram atingir o estado adulto. Os resultados da pesquisa atual retratam o papel notável de B. bassiana no manejo de um importante vetor de doenças humanas.


Subject(s)
Humans , Animals , Aedes , Beauveria , Disease Vectors , Mosquito Vectors , Larva
6.
Cad. Saúde Pública (Online) ; 38(3): e00110121, 2022. tab, graf
Article in Portuguese | LILACS | ID: biblio-1364629

ABSTRACT

O objetivo deste trabalho foi apresentar a proposta metodológica denominada de "Pronta Resposta" modelada nas cidades de Belo Horizonte (Minas Gerais) e Natal (Rio Grande do Norte), Brasil. A metodologia visa identificar e delimitar áreas prioritárias para o direcionamento das ações de vigilância em tempo oportuno, buscando a redução da intensidade e velocidade da dispersão de epidemias em áreas urbanas endêmicas. Para tanto, a metodologia utiliza três variáveis, que representam as causas necessárias para a produção e reprodução da dengue: casos notificados (vírus), ovos de Aedes (vetor) e população (hospedeiro). Trata-se de um estudo ecológico que utilizou os dados dos três planos de informações agregados em escalas temporais e espaciais mais finas, de três a quatro semanas e grades de 400 a 600 metros respectivamente. As áreas de pronta resposta foram definidas por meio de análise estatística de varredura Scan, com definição de clusters espaciais simultâneos para os três planos por meio do programa SaTScan. Os resultados observados foram: na cidade de Natal, as áreas definidas como pronta resposta ocuparam em média 15,2% do território do município e concentraram 67,77% dos casos de dengue do período posterior ao utilizado na delimitação das áreas de pronta resposta, e em Belo Horizonte, os números observados foram de 64,16% dos casos em 23,23% do território. Esses resultados foram obtidos em duas cidades com realidades socioambientais e geográficas diferentes e com perfis epidemiológicos também distintos, apontando que a metodologia pode ser aplicada em diferentes realidades urbanas, criando a possibilidade de os programas de controle atuarem em porções reduzidas do território e impactar num alto percentual de casos em tempo oportuno.


The study aimed to present the methodological proposal entitled "Prompt Response", modelled in the cities of Belo Horizonte (Minas Gerais State) and Natal (Rio Grande do Norte State), Brazil. The proposal aims to identify and demarcate priority areas for timely targeting of surveillance activities, aiming to reduce the intensity and velocity in the spread of epidemics in endemic urban areas. The methodology uses three variables that represent the necessary causes for the production and reproduction of dengue: notified cases (virus), Aedes eggs (vector), and population (host). This was an ecological study that used data from three information planes aggregated in finer temporal and spatial scales of 3 to 4 weeks and 400 to 600-meter grids, respectively. The prompt response areas were defined by Scan statistical analysis with definition of simultaneous spatial clusters for the three planes via the SaTScan program. In Natal, the areas defined as prompt response occupied, on average, 15.2% of the city's territory and concentrated 67.77% of the dengue cases in the period following demarcation of the prompt response areas. In Belo Horizonte, the observed proportions were 64.16% of cases in 23.23% of the territory. These results were obtained in two cities with different socioenvironmental and geographic realities and distinct epidemiological profiles, indicating that the methodology can be applied to different urban realities, allowing control programs to concentrate on reduced portions of the territory and impacting a high percentage of cases in timely fashion.


El objetivo del trabajo fue presentar la propuesta metodológica, denominada de "Resposta Rápida", modelada en las ciudades de Belo Horizonte (Minas Gerais) y Natal (Rio Grande do Norte), Brasil. Esta última tiene como meta identificar y delimitar áreas prioritarias para la ejecución de acciones de vigilancia en el momento oportuno, buscando la reducción de la intensidad y velocidad de la dispersión de epidemias en áreas urbanas endémicas. Para tal fin, la metodología utiliza tres variables, que representan las causas necesarias para la producción y reproducción del dengue: casos notificados (virus), huevos de Aedes (vector) y población (huésped). Se trata de un estudio ecológico que utilizó los datos de los tres planos de información agregados en escalas temporales y espaciales más finas, de 3 a 4 semanas y tablas de 400 a 600 metros respectivamente. Las áreas de respuesta rápida se definieron a través del análisis estadístico de exploración Scan, con definición de clústeres espaciales simultáneos para los tres planos mediante el programa SaTScan. Los resultados observados fueron: en la ciudad de Natal, las áreas definidas como de respuesta rápida ocuparon de media un 15,2% del territorio del municipio y concentraron un 67,77% de los casos de dengue del período posterior al utilizado en la delimitación de las áreas de respuesta rápida y, en Belo Horizonte, los números observados fueron un 64,16% de los casos en un 23,23% del territorio. Estos resultados se obtuvieron en dos ciudades con realidades socioambientales y geográficas diferentes y con perfiles epidemiológicos también distintos, apuntando que la metodología se puede aplicar en diferentes realidades urbanas. Dando la posibilidad de que los programas de control actúen en secciones reducidas del territorio e impactar en un alto porcentaje de casos en el momento oportuno.


Subject(s)
Humans , Animals , Arbovirus Infections/diagnosis , Arbovirus Infections/epidemiology , Aedes/physiology , Dengue/epidemiology , Brazil/epidemiology , Mosquito Vectors
8.
Braz. j. biol ; 81(4): 872-880, Oct.-Dec. 2021. tab, graf
Article in English | LILACS | ID: biblio-1153450

ABSTRACT

Abstract Bacillus thuringiensis is the most commonly used entomopathogen in the control of Aedes aegypti, which is a vector for different etiological agents that cause serious infections in humans. Several studies aim to isolate strains of this bacterium from different environments, with the perspective of selecting isolates with larvicidal activity for mosquitoes. Aiming at the insecticidal action of B. thuringiensis, the present study aimed to prospect B. thuringiensis of restinga and mangrove soils from the state of Maranhão, Brazil, with toxic potential for use in the biological control of Ae. aegypti. Bioassays were performed to determine the entomopathogenic activity of the bacilli against Ae. aegypti and lethal concentrations (LC50 and CL90) were estimated after the tests. Polymerase Chain Reaction and SDS-PAGE techniques were performed to verify the gene and protein content of the isolates, respectively. The soil of the mangrove and restinga ecosystems showed potential for obtaining B. thuringiensis. This isolate, in addition to having proteins with molecular mass similar to the toxins Cry and Cyt, also presented several diptera-specific genes cry and cyt, demonstrating that it has high potential to be used in the biological control of Ae. aegypti.


Resumo Bacillus thuringiensis é o entomopatógeno mais utilizado no controle do Aedes aegypti, vetor de diferentes agentes etiológicos que causam infecções graves em humanos. Diversos estudos têm como objetivo isolar cepas dessa bactéria de diferentes ambientes, com a perspectiva de selecionar isolados com atividade larvicida para mosquitos. Visando a ação inseticida de B. thuringiensis, o presente estudo teve como objetivo prospectar B. thuringiensis de solos de restinga e mangue do estado do Maranhão, Brasil, com potencial tóxico para uso no controle biológico de Ae. aegypti. Bioensaios foram realizados para determinar a atividade entomopatogênica do bacilo contra Ae. aegypti e as concentrações letais (CL50 e CL90) foram estimadas após os testes. As técnicas de Reação em Cadeia da Polimerase e SDS-PAGE foram realizadas para verificar o conteúdo de genes e proteínas dos isolados, respectivamente. Os solos dos ecossistemas de mangue e restinga apresentaram potencial para obtenção de B. thuringiensis. O isolado BtMA-750, obtido a partir da amostra de solo da restinga, foi interessantemente distinguido por sua alta toxicidade para Ae. aegypti. Este isolado, além de apresentar proteínas com massa molecular semelhante às toxinas Cry e Cyt, apresentou também diversos genes díptero-específicos cry e cyt, demonstrando que tem alto potencial para ser usado no controle biológico de Ae. aegypti.


Subject(s)
Humans , Animals , Bacillus thuringiensis/genetics , Aedes , Brazil , Pest Control, Biological , Ecosystem , Mosquito Vectors , Larva
9.
Biomédica (Bogotá) ; 41(1): 153-160, ene.-mar. 2021. tab, graf
Article in Spanish | LILACS | ID: biblio-1249067

ABSTRACT

Resumen | Introducción. El programa de enfermedades transmitidas por vectores en México tiene una red establecida de ovitrampas para la vigilancia entomológica de Aedes spp. Los servicios de salud del estado de Yucatán, en respuesta a reportes de Aedes albopictus en la periferia de Mérida, capital del estado, incrementaron la especificidad de dicha vigilancia. Objetivo. Describir la presencia y distribución de Ae. albopictus en Mérida y su abundancia relativa comparada con Aedes aegypti, en ovitrampas del programa de control de vectores. Materiales y métodos. Durante octubre de 2019, se seleccionaron al azar 91 ovitrampas en 31 barrios de Mérida. Los mosquitos adultos se obtuvieron del insectario de la Unidad Colaborativa para Bioensayos Entomológicos de la Universidad Autónoma de Yucatán a partir de huevos recolectados en campo. Se determinó la abundancia relativa de individuos adultos de cada especie identificada y por barrios evaluados. Resultados. En el 32 % de los barrios muestreados, se detectó Ae. albopictus y, en todos ellos, Ae. aegypti. Se recolectaron 28 adultos de Ae. albopictus (10 hembras y 18 machos) en las ovitrampas. No se observó correlación entre la abundancia de adultos ni de hembras Ae. aegypti y Ae. albopictus por barrio (p>0,05). Conclusiones. Los resultados confirmaron que Ae. albopictus estaba coexistiendo con Ae.aegypti en Mérida en el momento del estudio. La baja abundancia relativa sugiere que Ae.albopictus se encontraba en la fase inicial de invasión.


Abstract | Introduction:The vector-borne diseases program in México has an established network of ovitraps for entomological surveillance of Aedes spp. In response to reports of Aedes albopictus in the periphery of Mérida, the state capital of Yucatán, the Ministry of Health increased the specificity of this surveillance. Objective: To describe the presence and distribution of Ae. albopictus in Mérida and its relative abundance compared to Aedesaegypti in ovitraps of the vector control program. Materials and methods: During October, 2019, 91 ovitraps were randomly selected from 31 neighborhoods of Mérida. Mosquitoes were reared at the insectary of the Collaborative Unit for Entomological Bioassays of the Autonomous University of Yucatán from eggs collected in the field. Relative abundance was determined for adult individuals of each identified species and neighborhood. Results: 32 % of the neighborhoods were positive for Ae. albopictus and 100 % for Ae. aegypti. A total of 28 adults of Ae. albopictus (10 females and 18 males) were obtained from ovitraps. No correlation was observed between the abundance of Ae. aegypti and Ae. albopictus for both adults and females (p>0.05) at the neighborhood level. Conclusions: The results confirm that Ae. albopictus coexisted with Ae. aegypti in Mérida at the time of the study. The low relative abundance suggests that Ae. albopictus was in the initial phase of invasion.


Subject(s)
Aedes , Mexico , Vector Control , Mosquito Vectors , Vector Borne Diseases
10.
Braz. j. biol ; 81(1): 114-124, Feb. 2021. tab, graf
Article in English | LILACS | ID: biblio-1153325

ABSTRACT

Abstract Entomopathogenic agents are viable and effective options due to their selective action against insects but benign effects on humans and the environment. The most promising entomopathogens include subspecies of Bacillus thuringiensis (Bt), which are widely used for the biological control of insects, including mosquito vectors of human pathogens. The efficacy of B. thuringiensis toxicity has led to the search for new potentially toxic isolates in different regions of the world. Therefore, soil samples from the Amazon, Cerrado and Caatinga biomes of the state of Maranhão were evaluated for their potential larvicidal action against Aedes aegypti. The isolates with high toxicity to mosquito larvae, as detected by bioassays, were subjected to histological evaluation under a light microscope to identify the genes potentially responsible for the toxicity. Additionally, the toxic effects of these isolates on the intestinal epithelium were assessed. In the new B. thuringiensis isolates toxic to A. aegypti larvae, cry and cyt genes were amplified at different frequencies, with cry4, cyt1, cry32, cry10 and cry11 being the most frequent (33-55%) among those investigated. These genes encode specific proteins toxic to dipterans and may explain the severe morphological changes in the intestine of A. aegypti larvae caused by the toxins of the isolates.


Resumo Os agentes entomopatógenos são alternativas viáveis e eficazes, devido à sua ação seletiva para insetos sendo inofensivos ao homem e ao meio ambiente. Dentre os entomopatógenos mais promissores, destacam-se as subespécies de Bacillus thuringiensis (Bt) amplamente utilizadas no controle biológico de insetos incluindo espécies de mosquitos vetores de agentes patogênicos ao homem. A eficiência da toxicidade de Bt incentiva a prospecção de novos isolados em diversas regiões do mundo. Desta forma, em busca de novos isolados de B. thuringiensis potencialmente tóxicos, amostras de solo provenientes dos biomas Amazônia, Cerrado e Caatinga do estado do Maranhão foram avaliadas em relação ao seu potencial larvicida para Aedes aegypti. Os isolados que provocaram elevada toxicidade para larvas do mosquito, detectada por bioensaios, foram avaliados em relação aos potenciais genes responsáveis pela atividade tóxica, além da avaliação de efeitos tóxicos no epitélio intestinal através de análises histológicas em microscopia de luz. Os novos isolados de Bt tóxicos para larva de A. aegypti amplificaram frequências diferentes de genes cry e cyt sendo os mais frequentes (55-33%) os cry4, cyt1, cry32, cry10 e cry11 dentre os investigados. Esses genes codificam para proteínas tóxicas específicas para ordem Diptera, e podem explicar as severas alterações morfológicas provocadas pelas toxinas dos isolados observadas no intestino das larvas de A. aegypti.


Subject(s)
Humans , Animals , Bacillus thuringiensis/genetics , Aedes , Insecticides , Culicidae , Pest Control, Biological , Ecosystem , Mosquito Vectors , Larva
11.
Nursing (Säo Paulo) ; 24(273): 5229-5242, fev.2021.
Article in Portuguese | LILACS, BDENF | ID: biblio-1148490

ABSTRACT

Objetivo: descrever incidência de dengue em Santos/SP e relacionar coeficiente de incidência (CI) de dengue com indicadores socioeconômicos e entomológicos de 2012-2016. Método: estudo epidemiológico, descritivo, ecológico dos casos confirmados de dengue, residentes em Santos, de 2012-2016, do Sistema de Informação de Agravos de Notificação-Online; foram obtidos seis indicadores socioeconômicos da base de setores censitários do Instituto Brasileiro de Geografia e Estatística-2010; o sétimo do Índice Paulista de Vulnerabilidade Social-2010 e os indicadores entomológicos da Secretaria de Saúde; foi aplicada Correlação bivariada de Spearman (SPSS-Statistics®). Aprovado pelo Comitê de Ética em Pesquisa-CAAE nº79776017.1.0000.5479. Resultados: de 2012-2016 ocorreram 16.451 casos, com CI de 117,4 (2012) a 2.122,8 (2013) casos/100.000 habitantes, maior no sexo feminino e de 15-29 anos; os fatores socioeconômicos foram mais significativos entre 2015-2016; o Índice de Densidade de fêmeas Aedes aegypti apresentou maior correlação positiva. Conclusão: descreveu-se perfil epidemiológico/entomológico da dengue, apoiando gestores nas ações locais de controle.(AU)


Objectives: describe incidence of dengue in Santos/SP and relate dengue incidence coefficient (IC) with socioeconomic and entomological indicators from 2012-2016. Methods: epidemiological, descriptive, ecological study of confirmed cases of dengue, resident in Santos, from 2012-2016, of the Online-Notifiable Diseases Information System; six socioeconomic indicators were obtained from census sectors base of Brazilian Institute of Geography and Statistics-2010; the seventh from the São Paulo Index of Social Vulnerability-2010 and the entomological indicators from the Health Department; Spearman's Bivariate Correlation (SPSS-Statistics®) was applied. Approved by the Research Ethics Committee-CAAE nº79776017.1.0000.5479. Results: from 2012-2016 there were 16.451 cases, with IC from 117,4 (2012) to 2.122,8 (2013) cases/100.000 inhabitants, higher in females and between 15-29 years old; socioeconomic factors were more significant between 2015-2016; the Density Index of Aedes aegypti females showed a greater positive correlation. Conclusion: epidemiological/entomological profile of dengue was described, supporting managers in local control actions.(AU)


Objetivos: describir incidencia del dengue en Santos/SP y relacionar coeficiente de incidencia (CI) del dengue con indicadores socioeconómicos y entomológicos para 2012-2016. Métodos: estudio epidemiológico, descriptivo, ecológico de casos confirmados de dengue, residentes en Santos, desde 2012-2016, del Sistema de Información de Enfermedades de Notificación-Online; obtuvieron-se seis indicadores socioeconómicos desde base de sectores censales del Instituto Brasileño de Geografía y Estadística-2010, el séptimo del Índice de Vulnerabilidad Social de São Paulo-2010 y los indicadores entomológicos del Departamento de Salud. Aplicó-se Correlación Bivariada de Spearman (SPSS-Statistics®). Aprobado por el Comité de Ética en Investigación-CAAE nº79776017.1.0000.5479. Resultados: desde 2012-2016 hubo 16.451 casos, con CI de 117,4 (2012) a 2.122,8 (2013) casos/100.000 habitantes, mayor en mujeres y de 15-29 años; los factores socioeconómicos fueron más significativos entre 2015-2016; el Índice de Densidad de hembras Aedes aegypti mostró mayor correlación positiva. Conclusión: describió-se perfil epidemiológico/entomológico del dengue, apoyando a los gerentes en acciones de control local.(AU)


Subject(s)
Humans , Animals , Male , Female , Adolescent , Adult , Middle Aged , Aedes/virology , Dengue/epidemiology , Mosquito Vectors/virology , Socioeconomic Factors , Sex Factors , Incidence , Age Factors , Ecological Studies , Social Vulnerability Index
12.
Mem. Inst. Oswaldo Cruz ; 116: e210064, 2021. graf
Article in English | LILACS | ID: biblio-1279459

ABSTRACT

Unforeseen Plasmodium infections in the Atlantic Forest of Brazilian Extra-Amazonian region could jeopardise malaria elimination. A human malaria case was registered in Três Forquilhas, in the Atlantic Forest biome of Rio Grande do Sul, after a 45 years' time-lapsed without any malaria autochthonous notification in this southern Brazilian state. This finding represents the expansion of the malaria distribution areas in Brazil and the southernmost human malaria case record in South America in this decade. The coexistence of the bromeliad-breeding vector Anopheles (Kerteszia) cruzii and non-human primates in the Atlantic Forest regularly visited by the patient claimed for the zoonotic origin of this infection. The reemergence of Atlantic Forest human malaria in Rio Grande do Sul was also discussed.


Subject(s)
Animals , Malaria/epidemiology , Anopheles , Brazil/epidemiology , Forests , Mosquito Vectors
13.
Mem. Inst. Oswaldo Cruz ; 116: e200547, 2021. tab, graf
Article in English | LILACS | ID: biblio-1250365

ABSTRACT

BACKGROUND Forty percent of the world's population live in areas where they are at risk from dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Dengue viruses are transmitted primarily by the mosquito Aedes aegypti. In Cali, Colombia, approximately 30% of field collected Ae. aegypti are naturally refractory to all four dengue serotypes. OBJECTIVES Use RNA-sequencing to identify those genes that determine refractoriness in feral mosquitoes to dengue. This information can be used in gene editing strategies to reduce dengue transmission. METHODS We employed a full factorial design, analyzing differential gene expression across time (24, 36 and 48 h post bloodmeal), feeding treatment (blood or blood + dengue-2) and strain (susceptible or refractory). Sequences were aligned to the reference Ae. aegypti genome for identification, assembled to visualize transcript structure, and analyzed for dynamic gene expression changes. A variety of clustering techniques was used to identify the differentially expressed genes. FINDINGS We identified a subset of genes that likely assist dengue entry and replication in susceptible mosquitoes and contribute to vector competence. MAIN CONCLUSIONS The differential expression of specific genes by refractory and susceptible mosquitoes could determine the phenotype, and may be used to in gene editing strategies to reduce dengue transmission.


Subject(s)
Animals , Aedes , Dengue , Dengue Virus , RNA , Colombia , Transcriptome/genetics , Mosquito Vectors/genetics
14.
Mem. Inst. Oswaldo Cruz ; 116: e200497, 2021. graf
Article in English | LILACS | ID: biblio-1154873

ABSTRACT

BACKGROUND Flight tones play important roles in mosquito reproduction. Several mosquito species utilise flight tones for mate localisation and attraction. Typically, the female wingbeat frequency (WBF) is lower than males, and stereotypic acoustic behaviors are instrumental for successful copulation. Mosquito WBFs are usually an important species characteristic, with female flight tones used as male attractants in surveillance traps for species identification. Anopheles darlingi is an important Latin American malaria vector, but we know little about its mating behaviors. OBJECTIVES We characterised An. darlingi WBFs and examined male acoustic responses to immobilised females. METHODS Tethered and free flying male and female An. darlingi were recorded individually to determine their WBF distributions. Male-female acoustic interactions were analysed using tethered females and free flying males. FINDINGS Contrary to most mosquito species, An. darlingi females are smaller than males. However, the male's WBF is ~1.5 times higher than the females, a common ratio in species with larger females. When in proximity to a female, males displayed rapid frequency modulations that decreased upon genitalia engagement. Tethered females also modulated their frequency upon male approach, being distinct if the interaction ended in copulation or only contact. MAIN CONCLUSIONS This is the first report of An. darlingi flight acoustics, showing that its precopulatory acoustics are similar to other mosquitoes despite the uncommon male:female size ratio, suggesting that WBF ratios are common communication strategies rather than a physical constraint imposed by size.


Subject(s)
Animals , Male , Female , Mosquito Vectors , Malaria/transmission , Anopheles , Reproduction
15.
Mem. Inst. Oswaldo Cruz ; 116: e200513, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154879

ABSTRACT

BACKGROUND Different strategies for improvement of malaria control and elimination are based on the blockage of malaria parasite transmission to the mosquito vector. These strategies include the drugs that target the plasmodial sexual stages in humans and the early developmental stages inside mosquitoes. OBJECTIVES Here we tested Malaria Box compounds in order to evaluate their activity against male and female gametocytes in Plasmodium berghei, mosquito infection in P. vivax and ookinete formation in both species. METHODS/FINDINGS The membrane feeding assay and the development of ookinetes by a 24 h ex vivo culture and the ookinete yield per 1000 erythrocytes were used to test transmission-blocking potential of the Malaria Box compounds in P. vivax. For P. berghei we used flow cytometry to evaluate male and female gametocyte time course and fluorescence microscopy to check the ookinete development. The two species used in this study showed similar results concerning the compounds' activity against gametocytes and ookinetes, which were different from those in P. falciparum. In addition, from the eight Malaria Box compounds tested in both species, compounds MMV665830, MMV665878 and MMV665941 were selected as a hit compounds due the high inhibition observed. CONCLUSION Our results showed that P. berghei is suitable as an initial screening system to test compounds against P. vivax.


Subject(s)
Animals , Plasmodium berghei/drug effects , Plasmodium vivax/drug effects , Malaria, Vivax/prevention & control , Mosquito Vectors/parasitology , Malaria, Vivax/drug therapy , Malaria, Vivax/transmission
16.
Rev. Soc. Bras. Med. Trop ; 54: e0576-2020, 2021. tab
Article in English | LILACS | ID: biblio-1155533

ABSTRACT

Abstract INTRODUCTION: Aedes aegypti is the main vector of dengue and yellow fever. Recently, the use of plant-sourced larvicides has gained momentum. METHODS: The hydroethanolic extracts and fractions ofOcotea nutansleaves and stems were bioassayed to determine the larvicidal efficacy of these samples. RESULTS: S-HEX (hexane fraction from the crude stem extract) demonstrated high potential for controlling third-stage larvae, with an LC50 of 14.14 µg.mL-1 (concentration required to inhibit 50% of the treated larvae). CONCLUSIONS Extracts from O. nutans were effective against third-stage larvae ofA. aegyptiafter 24 h of exposure.


Subject(s)
Animals , Aedes , Mosquito Vectors , Insecticides/pharmacology , Plant Extracts/pharmacology , Plant Leaves , Ocotea , Larva
17.
Rev. Soc. Bras. Med. Trop ; 54: e20200146, 2021. tab
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1143889

ABSTRACT

Abstract INTRODUCTION: Aedes aegypti (L.) is the major vector of arboviruses that causes serious public health concerns in tropical and subtropical countries. METHODS: We examined the larvicidal activity of 1,2-diphenyldiselenide [(PhSe)2] and 1,2-bis(4-chlorophenyl) diselenide [(p-ClPhSe)2] and determine its toxicity to different non-target organisms. RESULTS: (PhSe)2 and (p-ClPhSe)2 killed Ae. aegypti L3 larvae with LC50/24h values of 65.63 µM (20.48 mg/L) and 355.19 µM (135.33 mg/L), respectively. (PhSe)2 was not toxic to the four model organisms. CONCLUSIONS: (PhSe)2 is a larvicidal compound with selective action against Ae. aegypti larvae. The mechanisms of action of (PhSe)2 under field conditions remain to be investigated.


Subject(s)
Animals , Aedes , Insecticides , Plant Extracts , Mosquito Vectors , Larva
18.
Medicina (B.Aires) ; 80(supl.6): 94-96, dic. 2020.
Article in Spanish | LILACS | ID: biblio-1250324

ABSTRACT

Resumen El dengue es una arbovirosis confinada a las áreas geográficas donde habitan sus vectores, los mosquitos Aedes aegypti y Aedes albopictus. La transmisión ocurre principalmente durante el verano, pero la persistencia del insecto en el ambiente puede extenderla hasta el otoño en climas templados y cálidos. En nuestro país, este año la trasmisión estacional del dengue se superpuso temporalmente con la pandemia de COVID-19, producida por el SARS-CoV-2, un coronavirus causante de afecciones respiratorias graves con eventual desenlace fatal. Por otro lado, el HIV es un retrovirus que debilita el sistema inmune favoreciendo las infecciones por numerosos patógenos oportunistas. Presentamos el caso de un paciente con infección HIV sin tratamiento que desarrolló infección simultánea por dengue y SARS-CoV-2 con evolución favorable.


Abstract Dengue is a mosquito-borne viral disease confined to the geographical areas where its vectors Aedes aegypti and Aedes albopictus are present. The transmission occurs mainly during the summer but it can extend to autumn months in warm climates. In our country, this year the seasonal transmission of dengue overlapped with the COVID-19 pandemic, caused by SARS-CoV-2, a novel coronavirus responsible of serious respiratory conditions with eventual fatal outcomes. On the other hand, the HIV is a retrovirus that causes disease by weakening the immune system, favoring infections by numerous opportunistic pathogens. We present the case of an untreated HIV patient who developed simultaneous infection with dengue and SARS-CoV-2 with favorable evolution.


Subject(s)
Humans , Animals , Aedes , Dengue/complications , Dengue/diagnosis , Dengue Virus , Coinfection , COVID-19 , HIV Infections/complications , Dengue/epidemiology , Pandemics , Mosquito Vectors , SARS-CoV-2
19.
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
20.
Ciênc. Saúde Colet ; 25(10): 3857-3868, Out. 2020. tab, graf
Article in Portuguese | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1132995

ABSTRACT

Resumo Quais as repercussões da urbanização mal planejada na saúde da população? Entender a saúde urbana, os riscos acarretados pelas cidades, as repercussões na saúde e as relações sociais auxiliam no planejamento no qual a prevenção deve ser investida. Assim, com o objetivo de verificar a relação entre urbanização e saúde urbana, em especial as infecções ocasionadas pelo vetor "Aedes aegypti", foi realizado um estudo qualitativo e uma investigação descritiva e analítica através de busca documental e bibliográfica. Os resultados apontam que os impactos ambientais decorrentes da falta de infraestrutura resultante da urbanização podem oferecer riscos à saúde humana, visto que a disposição de resíduos em lixões e aterros podem ocasionar exposição a substâncias químicas perigosas à saúde. Além disso, o saneamento ineficaz pode acarretar em doenças veiculadas pela água e propiciar a reprodução de vetores de outras enfermidades, como é o caso do "Aedes aegypti", responsável pela transmissão das arboviroses (dengue, chikungunya e Zika). Dessa forma, estudar saúde ambiental e urbana proporciona embasamento para a promoção de qualidade de vida das pessoas que residem nessas áreas e permite propor medidas que evitem doenças relacionadas à urbanização.


Abstract What are the repercussions of poorly planned urbanization for population health? Understanding urban health, the risks posed by cities, health repercussions, and urban social relations helps urban planners to decide where to target prevention interventions. We conducted a qualitative descriptive analytical study based on a document analysis and bibliographical review to explore the relationship between urbanization and urban health, focusing on diseases transmitted by the mosquito Aedes aegypti. Our findings show that environmental degradation and inadequate infrastructure pose a serious risk to human health, insofar as the disposal of waste in dumps and landfills can cause exposure to hazardous chemicals. In addition, inadequate urban infrastructure and sanitation is conducive to the transmission of water-borne diseases and the reproduction of vectors of other diseases such as Aedes aegypti, responsible for the transmission of arboviruses (dengue, chikungunya, and Zika). Research on environmental and urban health therefore provides an important foundation for improving the quality of life of people living in cities and developing measures designed to prevent diseases related to unplanned urbanization.


Subject(s)
Humans , Animals , Arboviruses , Aedes , Dengue/prevention & control , Dengue/epidemiology , Zika Virus , Zika Virus Infection , Quality of Life , Sanitation , Urban Health , Cities , Mosquito Vectors
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