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ABSTRACT Background: Information regarding the distribution of Culicidae species in the northeastern region of Brazil is scarce. Methods: Immatures were collected from approximately four fragments of the Atlantic Forest. Results: This study presents new occurrences of 18 Culicidae species in Pernambuco state: Anopheles kompi, Georgecraigius fluviatilis, Culex bidens, Culex chidesteri, Culex bastagarius, Culex imitator, Mansonia humeralis, Wyeomyia incaudata, Uranotaenia apicalis, Culex mollis, Culex usquatus, Culex dunni, Culex serratimarge, Culex ybarmis, Culex microphyllus, Sabethes purpureus, Wyeomyia pilicauda, and Wyeomyia airosai. The last nine species were also new records for the northeast region. Conclusions: With the inclusion of these newly recorded species, the total number of mosquitoes documented in Pernambuco state now rises to 94.
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Background & objectives: The role of mosquitoes is instrumental in the transmission of various diseases. Mosquitoeborne diseases account for a significant share of the global burden of total infectious diseases. Vector control is the principal method for the control of these mosquito-borne diseases. Plant-derived insecticides serve as an effective alternative to chemical insecticides. The present study has been undertaken to assess the larvicidal potential of methanol and petroleum ether extracts of leaves of Solanum xanthocarpum, Parthenium hysterophorus, Manihot esculenta, and Chamaecyparis obtusa. Methods: Larvicidal activity was tested against the early four-stage instar larvae of laboratory-reared susceptible strains of the malaria vector, Anopheles stephensi, dengue fever vector, Aedes aegypti, and the lymphatic filariasis vector, Culex quinquefasciatus at 20 to 120 ppm concentrations. Further, liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectroscopy (GC-MS) analyses were carried out to identify the bioactive compounds present in the methanolic leaf extracts of Solanum xanthocarpum for designing a larvicidal product in future. Results: After 72 h of exposure high larvicidal activities were observed in methanolic and petroleum ether leaves extract of S. xanthocarpum against An. stephensi, Ae. aegypti and Cx. quinquefasciatus. The larvicidal activities for methanol and petroleum ether leaf extract of S. xanthocarpum with LC50 = 09.201 and 12.435 ppm and LC90 = 21.578 and 27.418 ppm for An. stephensi; LC50 = 11.450 and 10.026 ppm and LC90 = 26.328 and 22.632 ppm for Ae. aegypti and LC50 = 12.962 and 13.325 ppm and LC90 = 26.731 and 30.409 ppm for Cx. quinquefasciatus, respectively, were found to be most effective. GC-MS analysis revealed 43 compounds, amongst these phytol (13.09%), 3-allyl-2- methoxy phenol (9.55%), (9Z, 12Z)-9, 12-octadecadienoyl chloride (7.93%), linoleic acid (5.45%), alpha-tocospiro B (5.08%) and hexadecanoic acid (4.35%) were identified as major compounds. Interpretation & conclusion: Present work showed that leaf extracts of S. xanthocarpum are a source of potential natural candidate that possess several phytochemicals which can be explored further for the development of ecologically safer mosquito control products.
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Resumo As coleções e pesquisas feitas nas primeiras décadas do século XX, no Rio de Janeiro, foram fundamentais para o estudo da sistemática e da história natural dos mosquitos no Brasil. Um personagem de destaque nesse cenário foi Antonio Gonçalves Peryassú. Analisamos o histórico de uma coleção por ele organizada no Museu Nacional do Rio de Janeiro, entre 1918 e 1922.
Abstract Collections formed and studies conducted in the early decades of the twentieth century in Rio de Janeiro, Brazil, were crucial for the study of the systematization and natural history of mosquitoes in Brazil. One key figure in this context was Antonio Gonçalves Peryassú. The history of a collection he organized at Museu Nacional [National Museum] in Rio de Janeiro between 1918 and 1922 is analyzed.
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Collection , Entomology , Culicidae , Brazil , History, 20th CenturyABSTRACT
ABSTRACT Aedes (Stegomyia) albopictus (Skuse, 1854) was reported in Brazil for the first time in 1986 and has shown marked expansion throughout the Brazilian territory. During a routine activity to control dengue fever conducted by the Division of Entomology of the Municipal Health Department in Rio Branco city, adults and immatures of Culicidae were collected in a peri-urban area. The identified Culicidae forms indicated that they belonged to the species Ae. albopictus. This is the first official record of the presence of Ae. albopictus in the Acre State, confirming its current presence in all Brazilian states.
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@#Abstract: Mosquitoes are involved in the transmission of serious diseases such as malaria, dengue, chikungunya, yellow fever, Zika virus disease, and filariasis, and their prevention and control have always been a research hotspot. Currently, mosquito control methods mainly include physical control, chemical control and biological control. Physical control methods are environmentally friendly, but they are slow to take effect and have unsatisfactory control effects; although chemical control can quickly eliminate mosquitoes, it has been eliminated due to its high pollution, high residual, and easy drug resistance; biological control uses natural enemies or pathogens to kill mosquitoes and reduce their ability to transmit disease. Therefore, environmentally friendly biological control has become the main measure for controlling and preventing mosquitoes. In recent years, significant progress has been made in bacterial mosquito control agents, among which Bacillus thuringiensis has been the most extensively studied. Bacillus thuringiensis is a Gram-positive soil microorganism, which is the pathogenic bacterium of a variety of agricultural pests such as Lepidoptera, Coleoptera and Diptera. During the sporulation process, its strains produce a variety of insecticidal crystal proteins (ICPs) or δ-endotoxins with insecticidal activity against mosquito larvae. This review firstly introduces the crystal proteins of Bacillus thuringiensis, describes in detail the types and structures of crystal proteins in detail, and also reveals the mechanism of action of crystal proteins related to receptors.
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Objective:To learn about the characteristics of natural foci and the spatial distribution of mosquitoes and ticks in Yadong County, Tibet Autonomous Region (Tibet for short).Methods:The eco-geographical characteristics, demographic information, agricultural and animal husbandry data of the natural foci in Yadong County, Tibet were collected from the Yadong County 2020 statistical yearbook, vector data were collected from the Yadong County Center for Disease Control and Prevention, and the data of the meteorological station in Yadong County from 2010 to 2021 were collected from the World Weather Network. In July 2021, a total of 20 mosquito and tick sampling points were selected for field investigation according to the distribution characteristics of vegetation and animal husbandry of Yadong County. The light trap method was used to trap mosquitoes, and the manual inspection and flag dragging method were used to catch ticks. The spatial distribution characteristics of mosquitoes and ticks were analyzed.Results:The natural epidemic foci in Yadong County, Tibet, were high in the north and low in the south, with an elevation difference of about 5 000 m. It was rich in water resources, and the average runoff of Yadong River was 20.1 m 3/s. The climate in the north was cold and dry, and the south was mild and humid. From 2010 to 2021, the annual average station air pressure in Yadong County was 452.8 mmHg (1 mmHg = 0.133 kPa), the maximum monthly average temperature, precipitation and relative humidity of air were 8.7 ℃, 134.5 mm and 81.3%, respectively, all in July. A total of 6 897 diptera insects were attracted by the light trap method, all of which were non-blood-sucking mosquitoes. The total density was 163.77 pieces/(lamp·h), the dominant population was Muscaridae, accounting for 89.69% (6 186/6 897). In different sampling areas, Xiayadong Township collected the most mosquitoes, accounting for 67.17% (4 633/6 897); the others were Yadong County and Shangyadong Township, accounting for 27.36% (1 887/6 897) and 5.47% (377/6 897), respectively. A total 2 014 host animals were examined, and 23 parasitic ticks were caught, of which 20 were of the genus Ixodes and 3 were of the genus Haemophilus. No free ticks were caught in all ticks sampling points. Conclusions:The climate and ecological environment of the natural foci in Yadong County, Tibet have obvious vertical gradient. Mosquitoes and ticks are active, but the density is not high, the density of mosquitoes is generally high in the south and low in the north.
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Background & objectives: Recently, the use of biodegradable and environment friendly plant-based bioinsecticides has received a great deal of attention from researchers to control insect disease vectors. The aim of this research is to determine the larvicidal efficacy of Ruta graveolens essential oil against third instar larvae of two species of mosquito (Culex pipiens and Culiseta longiareolata) and a biological model Drosophila melanogaster. Methods: Culiseta longiareolata and Culex pipiens larvae were collected from untreated areas located in Tebessa and Drosophila melanogaster, the wild strain collected from rotten apples in the Tebessa region. Ruta graveolens essential oil has been tested at different concentrations between 2.5µL/mL and 140µL/mL against third instar larvae of the three species under standard laboratory conditions according to the recommendations from the Word Health Organization. The effects were examined on mortality, growth and the main components (proteins, carbohydrates, lipids). Results: The essential oil showed larvicidal activity with LC50 and LC90 values (10.85µL/mL, 70.95µL/mL and 39.41µL/mL), (26.5µL/mL, 144.5µL/mL and 89.57µL/mL) against third instar larvae of Drosophila melanogaster, Culex pipiens and Culiseta longiareolata respectively. In addition, it disrupted the growth and several morphological malformations were observed. It also affected growth and the main components (proteins, carbohydrates, lipids). Interpretation & conclusion: The essential oil affected growth and energy reserves for all three species. The results indicated that the essential oil of Ruta graveolens has good potential as a source of natural larvicides.
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Background & objectives: Although, the number of considerable cases of dengue and lymphatic filariasis have been reported from Galle District, Sri Lanka in the past several years, contribution of abandoned boats to spread vector mosquitoes of Aedes and Culex in the coast is not well studied. Our aim was to assess the positive composition of different types of abandoned boats by larval vector mosquitoes to investigate their occurrence and habitat preference, and the monsoonal and co-existence variation of Aedes mosquitoes. Methods: The 4th instar larvae of Aedes and Culex species from three different abandoned boat types in nine subsampling sites at three municipal areas in Galle District were collected during 2017–2019. In total, 15 sampling rounds were conducted in each site for three years duration as five sample rounds per year. Larval collections and identifications were carried out using standard techniques and identification keys according to WHO guidelines. The occurrence of mosquito larvae was analysed by boat type, locations within area and year. Further, the average infestation variation of Aedes mosquitoes were compared with monsoonal and co-existence changers. Results: Out of the total abandoned boats, majority (51%) were engine boats and, 32.7%, 16.35% were troller boats and canoe boats, respectively. Troller boats were highly infested boat type for vector mosquitoes. Aedes albopictus was the dominant vector in abandoned boats other than recorded Ae. aegypti and Culex quinquefasciatus. Culex quinquefasciatus showed comparatively low infestation percentages. The average infestation of Ae. albopictus showed a consistent pattern with monsoon variation. A competitive rapid invasion of Aedes aegypti was observed with the suppressing Ae. albopictus in abandoned boats after 2018. Interpretation & conclusion: Abandoned boats contribute noteworthy to spread of Aedes and Culex vector mosquitoes in coastal belt, Galle District. These study findings would be helpful for researchers and health authorities to design appropriate vector control measures and to mitigate future dengue and filariasis outbreaks
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Background: Dengue fever has become a major public health concern in our country, causing significant morbidity and mortality. Because there is no definite drug or commercially available vaccine for dengue, prevention is the only option. As a result, early reporting of dengue cases is required in order to implement preventive measures before the disease spreads to epidemic proportions. Therefore, healthcare providers should notify every dengue incident to local authorities in the current format, including the District Health Officer or Chief Medical Officer of district concerned and the Municipal Health Officer of municipality concerned every week (daily during the transmission period). Materials and Methods: The data on dengue (2015-2021 till Oct.) was available at the National Vector Borne Disease Control Programme under the Ministry of Health & Family Welfare, Government of India, and has been used in this paper. Results and discussion: During the last two decades (2000-2009 and 2010-2019), significant geographical spread of the dengue has been experienced in India with the repeated outbreaks, and an 11 fold increase in number of cases. Despite an increase in the incidence of dengue fever, the case fatality rate in India has decreased from 3.3% in 1996 to 0.4% in 2010 to 0.1% in 2019. Early diagnosis and timely referral play a critical role in bringing down Case Fatality Rate (CFR). Conclusion: Dengue is a manifestation arising from the process of increasing vector density and adaptation to human habitation, as well as human lifestyle transformation, unplanned developmental activities exacerbated by climate change.
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Objective: To evaluate 11 Cuban native Bacillus (B.) thuringiensis isolates in order to select one with the best larvicidal activity against Aedes (Ae.) aegypti and low cytotoxicity. Methods: The cry and cyt genes of the isolates (A21, A51, L95, L910, M29, R84, R85, R87, R89, U81 and X48) were amplified by PCR. The influence of organic matter and NaCl on the larvicidal activity was tested by bioassays. Cytotoxicity was assayed on peritoneal macrophages of BALB/c mice. Results: The cyt1 (Aa, Ab, Ba), cyt2, cry4aA, cry4Ba, cry11 (Aa, Ba, Bb) and cry10 genes were identified in all native Cuban isolates. The larvicidal activity (LC90) of seven isolates was affected by the presence of organic matter in the water, while A21, A51, L910, R84, U81 and X48 had better LC50, LC90, LC95 than the 266/2 9-VI-98 control strain. The LC50 of two isolates was affected by the presence of NaCl and A21, A51, R85 isolate had better larvicidal activity than the 266/2 9-VI-98 control strain. In terms of toxicity against macrophages, the extracts of nine isolates were less cytotoxic than the control strains. Conclusions: Native isolate A21 had the main virulence factors against Ae. aegypti larvae, displayed a good larvicidal activity in presence of different factors related with Ae. aegypti breeding sites, and had low citotoxicity against macrophages. These results can contribute to the improvement of existing biological control strategies and the development of new biolarvicides.
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ABSTRACT In Colombia Aedes aegypti is present in 80% of the country up to 2,300 m; however, little is known of its genetic relations within a country context and, hence, within a broader context, for example, America. The aforementioned, herein, analyzed the gene flow within a context of the Americas, its directionality and genetic diversity of the mitochondrial lineages in the A. aegypti populations for Colombia. This called for the use of the sequences for A. aegypti available of the mitochondrial ND4 gene in the GenBank for Colombia and the American continent. No presence was found of nuclear mitochondrial pseudogenes (NUMTs) for Colombia. It is estimated that in Colombia the gene flow of the A. aegypti populations is occurring from the southeast and northeast toward the center of the country. In comparison with the mitochondrial sequences for America, the vector's haplotypes in Colombia suggest connections between the populations of mosquitoes from the south with those from the north of the continent. The gene flow model at continental scale suggests bidirectional connections between the populations from the north of the continent with those from the south, while at South American scale it proposes the gene flow in all the directions with respect to the Colombian. The Colombian A. aegypti vector monitoring and control strategies must pay special attention to the vector's points of entry into Colombia related with Peru, Venezuela, Brazil, Mexico, and North America to avoid the entry of populations with characteristics like resistance to insecticides or vector competition.
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Este estudio forma parte de la primera etapa de una serie de estudios sobre la ecología, biodiversidad y biogeografía de los mosquitos de la familia Culicidae de Venezuela, principalmente en Bolívar y Delta Amacuro. El objetivo del estudio fue caracterizar la composición de especies, la abundancia y la biodiversidad de mosquitos (Diptera; Culicidae) en el municipio Gran Sabana del estado Bolívar. Las capturas de mosquitos adultos se realizaron con aspiradores bucales mediante capturas por atracción al cebo humano y con trampas de luz negra. Se determinó la riqueza de especies, su abundancia relativa e índices ecológicos de diversidad Shannon-Wiener (H'), equidad de Simpson (E) y dominancia-D, del área general de estudio y sitios o comunidades de muestreo. Los resultados del estudio, generaron el registro de 7.860 ejemplares adultos de Culicidae identificados a nivel de especie, pertenecientes a 69 especies y 17 géneros, de ellos 7.797 (99,19%) fueron hembras adultas capturadas picando o con trampas de luz y 63 (0,81%) fueron machos capturados con trampas de luz. El 16,6% (1.297) de las hembras fue atraído por trampas de luz y el 83,4% (6.500) por cebo humano. Entre las especies más abundantes del estudio están: Culex quinquefasciatus (26,67 %), Anopheles peryassui (12,32 %), Aedes aegypti (11,87 %), Coquilletidia juxtamansonia (8,28 %), Anopheles braziliensis (6,97 %) Anopheles triannulatus s.l. (6,39 %), Coquilletidia nigricans (2,88 %), Coquilletidia venezuelensis (2,51 %) y Anopheles albitarsis s.l. (2,44 %), las cuales en conjunto representan 80,33 % del total de adultos capturado. Se discuten algunos aspectos sobre su ecología, importancia médica y el riesgo epidemiológico que representan para el país algunas especies reportadas. La diversidad de Shannon-Wiener (H') del área general de estudio fue de 2,665, la equidad de Simpson (E) fue igual a 0,8787222 y la dominancia (D) fue de 0,1213. El mayor índice de diversidad (Shannon-Wiener) ocurrió en Chiririka (2,675), seguido de Betania (2,409), Santa Elena Capital (2,354), Manak-Krü (2,203) y Waramasén (2,181). En cuanto a la riqueza de especies por localidad, las comunidades con mayor riqueza de especies fueron: Santa Elena (Capital), Waramasén y Chiririka con 50, 35 y 30 especies respectivamente, seguidas por San Antonio del Morichal con 23 y Kinok-Pon Parú, con 22 especies(AU)
This is the first part of a series of studies related to biodiversity, ecological and biogeographic aspects of the mosquitoes of Culicidae family in Venezuela. The objective of this study was the ecological characterization of species composition, diversity and abundance of Culicidae mosquitoes (Diptera: Culicidae) in the Gran Sabana Municipality, Bolívar State. Mosquitoes were captured in adult collections, with aspirators on human landing catches and with black light traps. A total of 7.860 adult's mosquitoes were collected and 69 species and 17 genera of Culicidae were identified. A total of 7.797 mosquitoes (99.19%) were females and 63 (0,81%) were males. Some 16,6 % (1.297) of females mosquitoes were attracted to the light traps and 83,4% (6.500) to human bait. The most abundant species in adult stage were: Culex quinquefasciatus (26,67%), Anopheles peryassui (12,32 %), Aedes aegypti (11,87 %), Coquilletidia juxtamansonia (8,28%), Anopheles braziliensis (6,97%), Anopheles triannulatus s.l. (6,39%), Coquilletidia nigricans (2,88%), Coquilletidia venezuelensis (2,51%) and Anopheles albitarsis s.l. (2,44%). Their medical importance of some mosquito species is commented, and some ecological and epidemiological aspects of the mosquito reported are discussed. The diversity index (Shannon-Wiener) of the estudy area was 2,665, the Simpson equity index was 0, 8787222 and the index of dominance was 0, 1213. The higher diversity index was registered in Chiririka (2,675), Betania (2,409), Santa Elena Capital (2,354), Manak-Krü (2,203) and Waramasén (2,181). The higher species richness was registered in Santa Elena (50 species), Waramasén (35 species), Chiririka (30 species), San Antonio del Morichal (23 species) and Kinok-Pon Parú (22 species) (AU)
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Animals , Aedes , Culex , Biodiversity , Anopheles , Culicidae , Culicidae/classification , Venezuela , Diptera , Mosquito Vectors/classificationABSTRACT
Los Flavivirus constituyen virus transmitidos por artrópodos, principalmente mosquitos. Pueden producir enfermedades en humanos y animales, también incluyen virus específicos de insectos que solo infectan y se replican en los insectos, no así en vertebrados. En Paraguay los virus dengue, fiebre amarilla y Zika fueron detectados en infecciones humanas, pero los estudios de flavivirus en mosquitos son aún escasos. Por ello, el objetivo del presente estudio fue implementar un sistema de detección de flavivirus en mosquitos en el IICS-UNA. Primero, se organizaron capacitaciones en colecta, preparación de pools y procesamiento por técnicas de RT-PCRs convencionales realizadas por expertos internacionales a profesionales locales (bioquímicos y biólogos). Además, se implementaron planillas de registro de datos y de control de transporte de muestras de los lugares de colectas hasta el IICS-UNA. Se prepararon en total 201 pools de 1 a 35 mosquitos cada uno agrupados por especie, localidad, entre otros criterios. Para asegurar la integridad del RNA extraído se realizó la detección de un control interno (Actina-1), siendo todos los pools positivos para el mismo, 91/201 pools fueron positivos para flavivirus. Se realizó la secuenciación de 19/91 pools positivos para flavivirus identificándose flavivirus de insectos (detectándose principalmente Culex Flavivirus, cell fusing agents Flavivirus y Kamiti river virus), evidenciando la elevada distribución de estos virus. Estos resultados demuestran que fue factible implementar el sistema de detección de flavivirus en mosquitos, lo cual podría contribuir a fortalecer la vigilancia y control de estas virosis, así como el conocimiento sobre la importancia ecológica de flavivirus de insectos
Flaviviruses are viruses transmitted by arthropods, mainly mosquitoes. They can cause diseases in humans and animals, they also include specific insect viruses that only infect and replicate in insects, not in vertebrates. In Paraguay, dengue, yellow fever, and Zika viruses were detected in human infections, but studies of flaviviruses in mosquitoes are still scarce. Therefore, the objective of the present study was the implementation of a flavivirus detection system in mosquitoes at IICS-UNA. First, trainings on collection, pool preparation and processing by conventional RT-PCR techniques were organized by international experts for local professionals (biochemists and biologists). In addition, data log sheets and sample transport control forms from the collection sites to the IICS were implemented. A total of 201 pools of 1 to 35 mosquitoes were prepared, each grouped by species, locality, among others. To ensure the integrity of the extracted RNA, an internal control (Actin-1) detection was performed, all pools being positive for it; 91/201 pools were positive for flaviviruses. The sequencing of 19/91 pools positive for flavivirus was carried out, identifying flavivirus in all cases of insects (mainly detecting Culex Flavivirus, cell fusing agents Flavivirus and Kamiti river virus), evidencing the high distribution of these viruses. These results demonstrate that it was feasible to implement the flavivirus detection system in mosquitoes, which could contribute to strengthen the detection, surveillance and control of these viruses, as well as, the knowledge about the ecological importance of insect flaviviruses
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Animals , Real-Time Polymerase Chain Reaction , Flavivirus , Culicidae/virology , ParaguayABSTRACT
Objective To investigate the distribution and density of Culex mosquito populations and the resistance of Culex pipiens pallens to insecticides in Jiangsu Province in 2018 and 2019. Methods During the period from June to October in 2018 and 2019, six counties (districts, cities) were sampled in southern, northern and central Jiangsu Province as surveillance sites. The density of Culex mosquitoes was measured overnight using the light trapping technique. In addition, Culex pipiens pallens mosquitoes were collected from Hai’an of Nantong City and Yandu District of Yancheng City, central Jiangsu Province, and the sensitivity of female first filial generations to dichlorodiphenyltrichloroethane (DDT), malation, proposur, beta cypermethrin and deltamethrin was tested using the standard WHO insecticide susceptibility test assay. Results A total of 104 423 Culex mosquitoes were captured in six surveillance sites of Jiangsu Province in 2018 and 2019, and Culex quinquefasciatus (49.11%), Culex pipiens pallens (28.38%), and Culex tritaeniorhynchus (21.04%) were predominant species. The density of Culex mosquitoes started to increase since early June, peaked in July and tended to be low in late October. Culex pipiens pallens mosquitoes captured from Hai’an was susceptible to malation, while those from Yandu District were moderately resistant to malation. Culex pipiens pallens mosquitoes from both Yandu and Hai’an were moderately resistant to proposur, and were resistant to DDT, beta cypermethrin and deltamethrin. Conclusions Culex quinquefasciatus, Culex pipiens pallens and Culex tritaeniorhynchus are predominant Culex species in Jiangsu Province. Culex pipiens pallens is resistant to DT, beta cypermethrin and deltamethrin in central Jiangsu Province.
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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 , MexicoABSTRACT
Abstract Leptolegnia chapmanii is pathogenic to mosquito larvae. The compatibility betweenL. chapmanii and two insect growth regulators (IGR), diflubenzuron and neem oil, was evaluated. L. chapmanii was grown on culture media containing different concentrations of eachIGR. The mycelial growth was significantly reduced with the highest concentrations of IGR(F6,98= 268, p < 0.05). However, the production of zoospores (F6,56= 0.93, p > 0.05) and the lar-val mortality of Aedes aegypti (F6,56= 0.95, p > 0.05) were not significantly different amongtreatments. Furthermore, the percentage of adult emergence in the presence of different con-centrations of diflubenzuron or a neem formulation was determined, and the pathogenic activityof zoospores was evaluated at the concentrations that inhibit the emergence at 30, 50 and 90%.The pathogenicity of zoospores was not significantly different among treatments (F6,14= 0.54,p > 0.05), and the larval mortalities were above 90% in all cases.
Resumen Leptolegnia chapmanii es un patógeno de larvas de mosquitos. Se evaluó la com-patibilidad entre L. chapmanii y dos reguladores del crecimiento de insectos (IGR, por sus siglasen inglés), diflubenzurón y aceite de neem. L. chapmanii creció en medios de cultivo con diferentes concentraciones de estos IGR. El crecimiento micelial fue menor con las concentraciones más altas (F6,98= 268; p < 0,05). No hubo diferencias significativas en la producción de zoosporas (F6,56= 0,93; p > 0,05) ni en la mortalidad de las larvas de Aedes aegypti (F6,56= 0,95; p > 0,05).Se determinó el porcentaje de emergencia de adultos en presencia de diferentes concentra-ciones de diflubenzurón o de un formulado a base del aceite de neem. También se evaluó lapatogenicidad de las zoosporas a las concentraciones de los IGR que inhibieron la emergenciadel 30, 50 y 90% de adultos. No hubo diferencias significativas en la actividad de las zoosporasal comparar los tratamientos (F6,14= 054; p > 0,05). La mortalidad de las larvas fue superior al90%.
Subject(s)
Animals , Oomycetes , Diflubenzuron , Aedes , Terpenes , Diflubenzuron/pharmacology , Glycerides , LarvaABSTRACT
This study is conducted to determine the population density of mosquitoes in three selected area (Kofar Taramniya, Mabera and Bello Way) in Sokoto metropolis. To identified and count the population of mosquito, different breeding sites were investigated for the preferences of mosquitoes. Mosquito larvae were collected using dipper, ladle spoon from drainages, stagnant water, gutters, open wells, local pots, water tanks and cattle sheds. A total population of 4,764 mosquito larvae were collected and identified From the three (3) selected areas larvae and pupae were encounters in abundance. In Mabera area, a total of 1799 (37.7%) larvae are collected in which 1199 (45.8%) belonging to Anophelesgenera and 600 (27.9%) belong to culexgenera. In kofar Taramniya a total of 1649 (34.6%) larvae are collected in which 1000 (38.2%) belong to Anopheles genera and 649 (30.2%) belong to culexgenera, in Bello Way, A total of 1317 (27.5%) larvae were collected,417 (15.9%) belong to Anophelesgenera and 900 (41.9%)belongto culexgenera. Statistical analysis conducted indicated a significant difference (p<0.05) between the three collections. Mosquitoes encountered belong to two genera of Anophelesand Culex. The predominant genus was Anopheleswith a total of 2,615 larvaewhile Culexhas a total of 2149 larvae in all the three study areas. Considering the medical importance of mosquitoes, the information provided from this study will serve as a basis for understanding the implication of mosquitoes nuisance and provide effective control strategies against the vector and to reduce mosquitoes born disease
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Introduction: Dengue fever, otherwise called break bonefever, is a mosquito borne tropical illness brought aboutby the dengue virus. In the present study an attempt wasmade to identify the reason for the year wise increase ofdengue incidence in Madurai District .The object of MedicalGeography is to study the geographical environment of humansociety and its influence on the health of man. In this directionthe present study helps to understand how the disease governedby people attitude, behavior and knowledge among dengueMaterial and Methods: To fulfill the objectives Primary andSecondary data were collected. Stratified random samplingmethod was used to collect the primary data.450 respondentswho were interviewed by direct questionnaire method, 20variables were selected. Year wise dengue cases were collectedfrom Deputy Directorate of Health Department Madurai.Results: During the previous ten years dengue cases becomeexpanding significantly in Madurai district. In 2017 thepercentage of dengue infection attains its zenith. Whencompared to 2012 dengue infection is doubled as 51% of casesin 2017. The increasing or decreasing rate of dengue infectiondepends on the knowledge, attitude and practice of peopleamong dengue and it seems low in educated people also.Conclusion: Dengue affected areas not up to the mark evenin educated people also. The initial phase in real life againstthe dengue mosquito is to educate communities about whatdengue is and what measure can be taken to battle it. A reliablewater supply is essential to prevent dengue fever. Watershortage force people to store water, which leads to breedingplaces for dengue mosquitoes.
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Background: The blood-feeding patterns are crucial in incriminating disease vectors as well as facilitating the design and consolidation of effective vector control interventions in an area. Objective: This study aimed to establish if prolonged use of insecticide-treated bed nets (ITNs) caused a shift in the preferred hosts of the common malaria vectors as the hosts were under the bed net. Such a shift would render ITNs less effective and would probably explain the continued morbidity and mortality due to malaria in the highly endemic Kamuli district. Methods: A total of 3,519 indoor and outdoor human biting female Anopheles gambiae sensu latoand An. funestusmosquitoes were collected from 48 householdsusing human-baited bed net traps. All 187 indoor resting blood-fed anophelines collected were tested by direct enzyme-linked immunosorbent assay (ELISA) for blood meal host identification. Of these, 73 mid guts came from 24 households in villages with a 69% ITNs coverage, while 114 mid guts were from 24 households in non-ITN villages. Results: Blood meal hosts were identified in only 10.96% (n = 8) and 14.91% (n = 17) of the Anophelesblood meals from the intervention and non-intervention zones, respectively. Other blood meals could not be clearly identified. Eight (100%) blood meals in the intervention zone were from humans, while in the non-intervention zone, 15 (88.24%), one (5.88%) and one (5.88%) came from humans, cattle and goat, respectively. These findings demonstrated that the malaria vectors in Kamuli district are anthropophilic, with nearly all the mosquitoes collected from both zones feeding on humans during every blood meal (p = 0.82). This indicated high vector-human contacts, and thus implicating these species as important in the transmission of Plasmodiumspecies and probably other infections. Conclusion: The use of insecticide-treated bed nets is effective for controlling malaria vectors inside houses, evoking universal coverage of houses in the area.
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Introduction:Health sector is one of the most important sectors of any country. Many aspects such as diseases, health practices, and institutions are associated with health. Among different infectious diseases, dengue has become a major health issue for human in most tropical and subtropical regions. It is a viral disease originatedand spread from mosquito and it is in several forms. Since, this seriously affects human life, taking necessary measures, including policies, rules, regulation and best practices to bring this menace into a minimum level, is essential. Such actions require proper background about the disease including factors that this disease depends on. Several factors may be associated with dengue fever and climatic variables take a greater place. Effect of these variables may vary from area to area. Aims:This study aimed to investigate the impact of climatic variables for progression of dengue disease in the Eastern Province of Sri Lanka, which is consisted of three districts: Batticaloa; Trincomaleeand Ampara. Study Design:Number of dengue incidences and climatic variables such as rainfall, temperature, number of rainy days, day time humidity, night-time humidity, number of sunny days, and UV Index were obtained for each month in the period from 2009to 2017 from Meteorology Department and statistical abstracts of Sri Lanka. Analysis was carried out by using the statistical techniques:correlation analysis;regression analysis;principle component analysis and a graphical technique, contour maps. Results:Only a few climatic factors affect dengue incidences in these three districts. However, no any regular pattern could be observed. Impact of each climatic factor varies from district to district. In Batticaloa district, a number of rainy days and day time humidity affect dengue incidences negatively and positively respectively meanwhile wind speed positively affects dengue incidences in Ampara district. No any climatic variables in Trincomalee district show a relationship with dengue incidences in the district. In general, moderate humidity creates a favourable situation for the spread of dengue disease irrespective of districts. Heavy rainfall does not show a relation with dengue incidences as people believe.Conclusion:It is difficult to investigate the impact of each climatic factor alone on dengue incidences because there are inter correlated. Number of dengue incidences may depend on many other variables such as population density, geographical location, health practices, personal health status, knowledge, policies of different institutes and organizations. It is essential to incorporate these sorts of variables also to have a proper understanding of the dengue disease and its spread.