Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 17.078
Filtrar
1.
J Insect Sci ; 20(1)2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31916580

RESUMEN

The western tree hole mosquito, Aedes sierrensis (Ludlow), is a common nuisance mosquito and vector of Dirofilaria immitis (Leidy), the etiologic agent of dog heartworm, in western North America. Here, we compare weekly mosquito collections made with Mosquito Magnet (MM) traps, Biogents Sentinel (BGS) traps, and Biogents Bowl (BGS Bowl) traps set in Salt Lake City, UT, from the start of June to mid-August 2017. We found the number of mosquitoes decreased with rainfall and temperature independently of trap type. The highest number of mosquitoes were caught by BGS traps baited with carbon dioxide (CO2) and BG lure, which collected 62% (n = 422) of all mosquitoes, followed by the MM at 31% (n = 213), and both the BGS and BG Bowl with BG lure had 3.5% (n = 24) each. Aedes sierrensis females were caught weekly at similar densities (mean ±â€…SD) in BGS with CO2 and lure (1.17 ±â€…2.93) and the MM (1.17 ±â€…2.66) traps during the study period. Given that BGS with CO2 and lure traps have several operational advantages over MM traps, including a quicker setup, smaller size, and lower cost, we consider BGS with CO2 and lure traps as the best suited surveillance tool to detect and remove Ae. sierrensis in the western United States and similar settings throughout North America.


Asunto(s)
Aedes , Control de Mosquitos/métodos , Mosquitos Vectores , Vigilancia de la Población/métodos , Animales , Dirofilaria immitis , Femenino , Masculino , Mosquitos Vectores/fisiología , Dinámica Poblacional , Utah
2.
BMC Infect Dis ; 19(1): 963, 2019 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-31718580

RESUMEN

BACKGROUND: Colombia was the second most affected country during the American Zika virus (ZIKV) epidemic, with over 109,000 reported cases. Despite the scale of the outbreak, limited genomic sequence data were available from Colombia. We sought to sequence additional samples and use genomic epidemiology to describe ZIKV dynamics in Colombia. METHODS: We sequenced ZIKV genomes directly from clinical diagnostic specimens and infected Aedes aegypti samples selected to cover the temporal and geographic breadth of the Colombian outbreak. We performed phylogeographic analysis of these genomes, along with other publicly-available ZIKV genomes from the Americas, to estimate the frequency and timing of ZIKV introductions to Colombia. RESULTS: We attempted PCR amplification on 184 samples; 19 samples amplified sufficiently to perform sequencing. Of these, 8 samples yielded sequences with at least 50% coverage. Our phylogeographic reconstruction indicates two separate introductions of ZIKV to Colombia, one of which was previously unrecognized. We find that ZIKV was first introduced to Colombia in February 2015 (95%CI: Jan 2015 - Apr 2015), corresponding to 5 to 8 months of cryptic ZIKV transmission prior to confirmation in September 2015. Despite the presence of multiple introductions, we find that the majority of Colombian ZIKV diversity descends from a single introduction. We find evidence for movement of ZIKV from Colombia into bordering countries, including Peru, Ecuador, Panama, and Venezuela. CONCLUSIONS: Similarly to genomic epidemiological studies of ZIKV dynamics in other countries, we find that ZIKV circulated cryptically in Colombia. More accurately dating when ZIKV was circulating refines our definition of the population at risk. Additionally, our finding that the majority of ZIKV transmission within Colombia was attributable to transmission between individuals, rather than repeated travel-related importations, indicates that improved detection and control might have succeeded in limiting the scale of the outbreak within Colombia.


Asunto(s)
Genoma Viral , Infección por el Virus Zika/virología , Virus Zika/genética , Aedes/virología , Animales , Colombia/epidemiología , Brotes de Enfermedades , Evolución Molecular , Variación Genética , Humanos , Filogenia , Filogeografía , Virus Zika/clasificación , Virus Zika/aislamiento & purificación , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/transmisión
3.
Zootaxa ; 4691(3): zootaxa.4691.3.9, 2019 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-31719397

RESUMEN

A new species, Paraedes jambulingami, is described from Assam, northeastern India. The adult male and female are described in detail and an illustration of the male is provided. This species is easily distinguished from all known species of the genus Paraedes by the presence of broad silvery or golden scales on the paratergite and the outer arm of the basal mesal lobe of the male genitalia bearing a long, flattened blade-like seta. Dichotomous keys are provided for the identification of the adult females and males of the five species of the genus that are known to occur in India.


Asunto(s)
Aedes , Culicidae , Dípteros , Animales , Color , Femenino , Genitales Masculinos , India , Masculino
4.
Braz J Med Biol Res ; 52(11): e8339, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31721902

RESUMEN

A progressive increase in the circulation of arboviruses in tropical countries has been observed, accounting for 700,000 yearly deaths in the world. The main objective of this article was to identify the presence of Zika (ZIKV), dengue (DENV), and Chikungunya (CHIKV) viruses in immature stages of Aedes aegypti and Ae. albopictus. Household collections of immature phases of the vectors were carried out in the years 2015 and 2016. A total of 2902 dwellings were visited and the rate of infestation with larvae and pupae of Aedes mosquitoes was 283/1462 (19.4%) in March 2015 and 55/1440 (3.8%) in June 2015. In March 2015, 907 larvae/pupae were collected (583 or 64.3% of Ae. aegypti and 324 or 35.7% of Ae. albopictus) while in June 2015 there was a reduction in the number of immature forms found: 197 larvae/pupae (121 or 61.4% of Ae. aegypti and 76 or 38.6% of Ae. albopictus). This reduction was accompanied by a decrease in suspected human ZIKV cases from March to June 2015. The RT-qPCR performed in 18 pools identified that three (two of Ae. aegypti and one of Ae. albopictus) were positive for ZIKV, and none were positive for DENV or CHIKV. Our findings demonstrated that ZIKV was present in immature stages of insect vectors in the study region at least five months prior to the peak of ZIKV associated cases. Xenomonitoring of immature phases of the vectors may prove useful for predicting outbreaks.


Asunto(s)
Aedes/virología , Virus Chikungunya/aislamiento & purificación , Virus del Dengue/aislamiento & purificación , Mosquitos Vectores/virología , Virus Zika/aislamiento & purificación , Aedes/clasificación , Animales , Humanos , Mosquitos Vectores/clasificación , ARN Viral/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa , Estaciones del Año , Infección por el Virus Zika/transmisión
5.
Emerg Microbes Infect ; 8(1): 1668-1678, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31735122

RESUMEN

Since its emergence in Yap Island in 2007, Zika virus (ZIKV) has affected all continents except Europe. Despite the hundreds of cases imported to European countries from ZIKV-infested regions, no local cases have been reported in localities where the ZIKV-competent mosquito Aedes albopictus is well established. Here we analysed the vector competence of European Aedes (aegypti and albopictus) mosquitoes to different genotypes of ZIKV. We demonstrate that Ae. albopictus from France was less susceptible to the Asian ZIKV than to the African ZIKV. Critically we show that effective crossing of anatomical barriers (midgut and salivary glands) after an infectious blood meal depends on a viral load threshold to trigger: (i) viral dissemination from the midgut to infect mosquito internal organs and (ii) viral transmission from the saliva to infect a vertebrate host. A viral load in body ≥4800 viral copies triggered dissemination and ≥12,000 viral copies set out transmission. Only 27.3% and 18.2% of Ae. albopictus Montpellier mosquitoes meet respectively these two criteria. Collectively, these compelling results stress the poor ability of Ae. albopictus to sustain a local transmission of ZIKV in Europe and provide a promising tool to evaluate the risk of ZIKV transmission in future outbreaks.


Asunto(s)
Aedes/fisiología , Mosquitos Vectores/fisiología , Infección por el Virus Zika/transmisión , Virus Zika/fisiología , Aedes/genética , Aedes/virología , Animales , Europa (Continente) , Femenino , Humanos , Mosquitos Vectores/genética , Mosquitos Vectores/virología , Carga Viral , Virus Zika/genética , Infección por el Virus Zika/virología
6.
J Insect Sci ; 19(5)2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31606748

RESUMEN

Dengue, yellow fever, and Zika are viruses transmitted by yellow fever mosquito, Aedes aegypti [Linnaeus (Diptera: Culicidae)], to thousands of people each year. Mosquitoes transmit these viruses while consuming a blood meal that is required for oogenesis. Iron, an essential nutrient from the blood meal, is required for egg development. Mosquitoes receive a high iron load in the meal; although iron can be toxic, these animals have developed mechanisms for dealing with this load. Our previous research has shown iron from the blood meal is absorbed in the gut and transported by ferritin, the main iron transport and storage protein, to the ovaries. We now report the distribution of iron and ferritin in ovarian tissues before blood feeding and 24 and 72 h post-blood meal. Ovarian iron is observed in specific locations. Timing post-blood feeding influences the location and distribution of the ferritin heavy-chain homolog, light-chain homolog 1, and light-chain homolog 2 in ovaries. Understanding iron deposition in ovarian tissues is important to the potential use of interference in iron metabolism as a vector control strategy for reducing mosquito fecundity, decreasing mosquito populations, and thereby reducing transmission rates of vector-borne diseases.


Asunto(s)
Aedes/metabolismo , Ferritinas/metabolismo , Hierro/metabolismo , Ovario/metabolismo , Animales , Sangre/metabolismo , Femenino , Ferritinas/química , Porcinos
7.
Afr Health Sci ; 19(2): 2000-2007, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31656483

RESUMEN

Background: In the last five decades, dengue has emerged as one of the most important infectious diseases, following a 30-fold increase in global incidence throughout tropical and sub-tropical regions of the world. The actual numbers of dengue cases are under-reported and many cases are misclassified. Objectives: This article describes the epidemiology, pathophysiology, clinical features and management of dengue. It also explores the implications of infection with this flavivirus for Nigeria, and similar countries. Methods: The literature search for publications on dengue in West Africa was performed using PubMed, African Journals Online (AJOL), Google Scholar, Web of Science, databases and grey literature to identify all published papers regarding the topic. A snowballing strategy was adopted to identify additional publications. Results: Recent reports suggest that dengue is a growing public health problem in Nigeria, the magnitude of which needs to be more clearly defined. Nigeria, the most populous country in Africa has an abundance of the Aedes aegypti mosquito which is known to transmit dengue, Zika, as well as chikungunya (CHIKV) and West Nile viruses. Conclusion: This article provides practical suggestions for strengthening the dengue virus control programme in Nigeria. The Nigerian health system shares similarities with health systems in many other sub-Saharan countries. Therefore, the practical suggestions provided at the end of this review are likely to be applicable to many other African countries.


Asunto(s)
Aedes/virología , Virus del Dengue/aislamiento & purificación , Dengue/prevención & control , Control de Mosquitos , Mosquitos Vectores/virología , Animales , Dengue/diagnóstico , Humanos , Nigeria
8.
Rev Saude Publica ; 53: 84, 2019.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-31576944

RESUMEN

OBJECTIVE: To describe the infestation of the municipalities of São Paulo by the vectors Aedes aegypti and Aedes albopictus, characterize seasonality and analyze average temperatures and larval densities. METHODS: We used maps with information on the infestation of municipalities between 1986 and 2015. The analysis of larval density of the species by the Wilcoxon test used the Breteau index values for Ae. aegypti and Ae. albopictus obtained from the Superintendency for Endemic Diseases Control database. In the seasonal description, arithmetic means of each vector were calculated by month and year. Mean temperature analyses were presented on maps with color gradients. RESULTS: The state of São Paulo is currently almost totally infested, with co-occurrence of species in 93.64% of the municipalities. The seasonality analysis showed the first quarter as the most favorable period for larval abundance. The increase of mean temperatures in geographical areas coincided with the temporal trajectory of Ae. aegypti territorial expansion. The mean larval density found was higher for Ae. aegypti than for Ae. albopictus (p = 0.00). CONCLUSIONS: Initially, these Culicidae occupied distinct and opposing areas. Over time, however, co-occurrence showed how great their capacity for adaptation is, even in the face of different social and urban conjunctures. The increase of the mean temperature contributed to Ae. Aegypti 's geographic expansion, as well as to the clearly seasonal profile of both species. In general, larval infestation by Ae. aegypti prevailed, which evidenced its competitive superiority. These data provide a better understanding of the dynamics of arboviral transmission in the state of São Paulo and can be used in vector surveillance and control.


Asunto(s)
Aedes , Arbovirus , Mosquitos Vectores , Animales , Brasil/epidemiología , Ciudades/epidemiología , Densidad de Población , Estudios Retrospectivos , Estaciones del Año , Análisis Espacio-Temporal , Temperatura Ambiental , Factores de Tiempo
9.
BMC Infect Dis ; 19(1): 888, 2019 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-31651247

RESUMEN

BACKGROUND: Several Zika virus (ZIKV) outbreaks have occurred since October 2015. Because there is no effective treatment for ZIKV infection, developing an effective surveillance and warning system is currently a high priority to prevent ZIKV infection. Despite Aedes mosquitos having been known to spread ZIKV, the calculation approach is diverse, and only applied to local areas. This study used meteorological measurements to monitor ZIKV infection due to the high correlation between climate change and Aedes mosquitos and the convenience to obtain meteorological data from weather monitoring stations. METHODS: This study applied the Bayesian structured additive regression modeling approach to include spatial interactive terms with meteorological factors and a geospatial function in a zero-inflated Poisson model. The study area contained 32 administrative departments in Colombia from October 2015 to December 2017. Weekly ZIKV infection cases and daily meteorological measurements were collected. Mapping techniques were adopted to visualize spatial findings. A series of model selections determined the best combinations of meteorological factors in the same model. RESULTS: When multiple meteorological factors are considered in the same model, both total rainfall and average temperature can best assess the geographic disparities of ZIKV infection. Meanwhile, a 1-in. increase in rainfall is associated with an increase in the logarithm of relative risk (logRR) of ZIKV infection of at most 1.66 (95% credible interval [CI] = 1.09, 2.15) as well as a 1 °F increase in average temperature is significantly associated with at most 0.79 (95% CI = 0.12, 1.22) increase in the logRR of ZIKV. Moreover, after controlling rainfall and average temperature, an independent geospatial function in the model results in two departments with an excessive ZIKV risk which may be explained by unobserved factors other than total rainfall and average temperature. CONCLUSION: Our study found that meteorological factors are significantly associated with ZIKV infection across departments. The study determined both total rainfall and average temperature as the best meteorological factors to identify high risk departments of ZIKV infection. These findings can help governmental agencies monitor at risk areas according to meteorological measurements, and develop preventions in those at risk areas in priority.


Asunto(s)
Infección por el Virus Zika/epidemiología , Aedes/virología , Animales , Teorema de Bayes , Colombia/epidemiología , Brotes de Enfermedades , Humanos , Masculino , Conceptos Meteorológicos , Mosquitos Vectores/virología , Lluvia , Riesgo , Temperatura Ambiental
10.
Parasit Vectors ; 12(1): 474, 2019 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-31610804

RESUMEN

BACKGROUND: The global spread of mosquito-borne diseases (MBD) has presented increasing challenges to public health. The transmission of MBD is mainly attributable to the biting behaviors of female mosquitoes. However, the ecological pattern of hourly host-seeking behavior in Aedes albopictus and its association with climatic variables are still not well understood, especially for a precise requirement for establishing an effective risk prediction system of MBD transmission. METHODS: Mosquito samples and data on mosquito hourly density and site-specific climatic variables, including temperature, relative humidity, illuminance and wind speed, were collected simultaneously in urban outdoor environments in Guangzhou during 2016-2018. Kernel regression models were used to assess the temporal patterns of hourly host-seeking behavior in mosquito populations, and negative binomial regression models in the Bayesian framework were used to investigate the associations of host-seeking behavior with climatic variables. RESULTS: Aedes albopictus was abundant, constituting 82% (5569/6790) of the total collected mosquitoes. Host-seeking behavior in Ae. albopictus varied across time and was significantly influenced by climatic variables. The predicted hourly mosquito densities showed non-linear relationships with temperature and illuminance, whereas density increased with relative humidity but generally decreased with wind speed. The range of temperature estimates for female biting was 16.4-37.1 °C, peaking at 26.5 °C (95% credible interval: 25.3-28.1). During the favorable periods, biting behavior of female Ae. albopictus was estimated to occur frequently all day long, presenting a bimodal distribution with peaks within 2-3 h around both dawn and dusk (05:00-08:00 h and 16:00-19:00 h). Moreover, a short-term association in hourly density between the females and males was found. CONCLUSIONS: Our field-based modeling study reveals that hourly host-seeking behavior of Ae. albopictus exhibits a complex pattern, with hourly variation constrained significantly by climatic variables. These findings lay a foundation for improving MBD risk assessments as well as practical strategies for vector control. For instances of all-day-long frequent female biting during the favorable periods in Guangzhou, effective integrated mosquito control measures must be taken throughout the day and night.


Asunto(s)
Aedes/fisiología , Clima , Conducta de Búsqueda de Hospedador/fisiología , Mosquitos Vectores/fisiología , /prevención & control , Aedes/genética , Animales , Teorema de Bayes , Distribución Binomial , China/epidemiología , Complejo IV de Transporte de Electrones/genética , Femenino , Humanos , Humedad , Mordeduras y Picaduras de Insectos/epidemiología , Luz , Masculino , Mitocondrias/enzimología , Control de Mosquitos , Mosquitos Vectores/genética , Reacción en Cadena de la Polimerasa , Densidad de Población , Lluvia , Análisis de Regresión , Estaciones del Año , Temperatura Ambiental , Factores de Tiempo , Viento
11.
Parasit Vectors ; 12(1): 477, 2019 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-31610813

RESUMEN

BACKGROUND: The Asian tiger mosquito, Aedes (Stegomyia) albopictus (Skuse) is an important worldwide invasive species and can be a locally important vector of chikungunya, dengue and, potentially, Zika. This species is native to Southeast Asia where populations thrive in both temperate and tropical climates. A better understanding of the population structure of Ae. albopictus in Lao PDR is very important in order to support the implementation of strategies for diseases prevention and vector control. In the present study, we investigated the genetic variability of Ae. albopictus across a north-south transect in Lao PDR. METHODS: We used variability in a 1337-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), to assess the population structure of Ae. albopictus in Lao PDR. For context, we also examined variability at the same genetic locus in samples of Ae. albopictus from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA. RESULTS: We observed very high levels of genetic polymorphism with 46 novel haplotypes in Ae. albopictus from 9 localities in Lao PDR and Thailand populations. Significant differences were observed between the Luangnamtha population and other locations in Lao PDR. However, we found no evidence of isolation by distance. There was overall little genetic structure indicating ongoing and frequent gene flow among populations or a recent population expansion. Indeed, the neutrality test supported population expansion in Laotian Ae. albopictus and mismatch distribution analyses showed a lack of low frequency alleles, a pattern often seen in bottlenecked populations. When samples from Lao PDR were analyzed together with samples from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA, phylogenetic network and Bayesian cluster analysis showed that most populations from tropical/subtropical regions are more genetically related to each other, than populations from temperate regions. Similarly, most populations from temperate regions are more genetically related to each other, than those from tropical/subtropical regions. CONCLUSIONS: Aedes albopictus in Lao PDR are genetically related to populations from tropical/subtropical regions (i.e. Thailand, Singapore, and California and Texas in the USA). The extensive gene flow among locations in Lao PDR indicates that local control is undermined by repeated introductions from untreated sites.


Asunto(s)
Aedes/fisiología , Mosquitos Vectores/fisiología , Aedes/clasificación , Aedes/genética , Aedes/virología , Algoritmos , Animales , Asia Sudoriental , Teorema de Bayes , Análisis por Conglomerados , ADN/química , ADN/aislamiento & purificación , Complejo IV de Transporte de Electrones/genética , Lejano Oriente , Femenino , Variación Genética , Genética de Población , Haplotipos , Italia , Laos , Mitocondrias/enzimología , Control de Mosquitos , Mosquitos Vectores/clasificación , Mosquitos Vectores/genética , Mosquitos Vectores/virología , Filogenia , Análisis de Secuencia de ADN , Clima Tropical , Estados Unidos
12.
Rev. Pesqui. (Univ. Fed. Estado Rio J., Online) ; 11(5): 1333-1339, out.-dez. 2019. tab
Artículo en Inglés, Portugués | LILACS, BDENF - Enfermería | ID: biblio-1022140

RESUMEN

Objective: The study's purpose has been to identify the actions to fight the dengue fever vector, and also the way that patients bearing the symptoms have being handled. Methods: This research describes the semiological and pathophysiological aspects of dengue fever through the perception of health professionals, who assisted the patients bearing the symptoms of this disease. Furthermore, this study addresses the perception of endemic diseases combat agents and community health agents regarding the efficiency of vector control measures. Results: The health professionals are working according to the World Health Organization recommendations. The majority of the population contributes to the mosquito breeding sites elimination. The elevated number of closed properties and houses with difficult access has been the greatest obstacle to control the vector. Conclusion: These services need to be aware of the disease trends in order to quickly detect changes in its profile and guide control actions


Objetivo: Identificar as ações adotadas de combate ao vetor e as formas de manejo dos pacientes com sinais e sintomas de alarme para dengue grave. Métodos: Estudo que descreve, na percepção dos profissionais de saúde que atenderam pacientes com suspeita de dengue, os aspectos semiológicos e fisiopatológicos da doença. Apresenta a percepção dos Agentes de Combate a Endemias e Agentes Comunitários de Saúde sobre a eficiência das medidas de controle do vetor. Resultados: Os profissionais de saúde procedem o cuidado conforme orientações da Organização Mundial da Saúde. A maior parte da população contribui com a eliminação dos criadouros do mosquito. Imóveis fechados e o difícil acesso têm sido os principais desafios para o controle do vetor. Conclusão: Esses serviços precisam estar atentos às tendências dessa doença para rapidamente conseguir detectar mudanças em seu perfil e orientar ações de controle


Objetivo: Identificar la satisfacción de los pacientes seguidos en un ambulatorio de Educación para la Salud y evaluar el efecto de las variables antecedentes sobre el nivel de satisfacción de los pacientes. Método: Se trata de un estudio transversal realizado en un ambulatorio la Educación para la Salud. La muestra estuvo constituida por todos los pacientes cardíacos en el ambulatorio (17 pacientes). La satisfacción del paciente se evaluó a través del Instrumento de Satisfacción del Paciente (ISP). Resultados: Todos los pacientes informaron un alto nivel de satisfacción. Los dominios con los puntajes más altos y más bajos fueron el profesional y el educacional, respectivamente. No hubo correlación significativa entre los niveles de satisfacción con cualquiera de las variables antecedentes. Conclusión: Pacientes informaron un alto nivel de satisfacción y no hubo correlación significativa entre variables y los niveles de satisfacción


Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Satisfacción del Paciente , Agentes Comunitarios de Salud , Enfermedades Endémicas/prevención & control , Dengue/prevención & control , Aedes/patogenicidad , Monitoreo Epidemiológico
13.
BMC Med ; 17(1): 172, 2019 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-31495336

RESUMEN

BACKGROUND: Wolbachia-infected mosquitoes reduce dengue virus transmission, and city-wide releases in Yogyakarta city, Indonesia, are showing promising entomological results. Accurate estimates of the burden of dengue, its spatial distribution and the potential impact of Wolbachia are critical in guiding funder and government decisions on its future wider use. METHODS: Here, we combine multiple modelling methods for burden estimation to predict national case burden disaggregated by severity and map the distribution of burden across the country using three separate data sources. An ensemble of transmission models then predicts the estimated reduction in dengue transmission following a nationwide roll-out of wMel Wolbachia. RESULTS: We estimate that 7.8 million (95% uncertainty interval [UI] 1.8-17.7 million) symptomatic dengue cases occurred in Indonesia in 2015 and were associated with 332,865 (UI 94,175-754,203) lost disability-adjusted life years (DALYs). The majority of dengue's burden was due to non-severe cases that did not seek treatment or were challenging to diagnose in outpatient settings leading to substantial underreporting. Estimated burden was highly concentrated in a small number of large cities with 90% of dengue cases occurring in 15.3% of land area. Implementing a nationwide Wolbachia population replacement programme was estimated to avert 86.2% (UI 36.2-99.9%) of cases over a long-term average. CONCLUSIONS: These results suggest interventions targeted to the highest burden cities can have a disproportionate impact on dengue burden. Area-wide interventions, such as Wolbachia, that are deployed based on the area covered could protect people more efficiently than individual-based interventions, such as vaccines, in such dense environments.


Asunto(s)
Aedes/microbiología , Dengue/prevención & control , Modelos Teóricos , Control Biológico de Vectores/métodos , Wolbachia , Animales , Costo de Enfermedad , Dengue/epidemiología , Dengue/transmisión , Virus del Dengue , Humanos , Indonesia/epidemiología
14.
Parasit Vectors ; 12(1): 435, 2019 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-31500662

RESUMEN

BACKGROUND: The sterile insect technique (SIT) for use against mosquitoes consists of several steps including the production of the target species in large numbers, the separation of males and females, the sterilization of the males, and the packing, transport and release of the sterile males at the target site. The sterility of the males is the basis of the technique; for this, efficient and standardized irradiation methods are needed to ensure that the required level of sterility is reliably and reproducibly achieved. While several reports have found that certain biological factors, handling methods and varying irradiation procedures can alter the level of induced sterility in insects, few studies exist in which the methodologies are adequately described and discussed for the reproductive sterilization of mosquitoes. Numerous irradiation studies on mosquito pupae have resulted in varying levels of sterility. Therefore, we initiated a series of small-scale experiments to first investigate variable parameters that may influence dose-response in mosquito pupae, and secondly, identify those factors that potentially have a significantly large effect and need further attention. METHODS: In this study, we compiled the results of a series of experiments investigating variable parameters such as pupal age (Aedes aegypti), pupal size (Ae. aegypti), geographical origin of mosquito strains (Ae. aegypti and Ae. albopictus), exposure methods (in wet versus dry conditions, Ae. albopictus) and subsequently in low versus high oxygen environments [submerged in water (low O2 (< 5 %)] and in air [high O2 (~ 21 %)] on the radiosensitivity of male pupae (Ae. aegypti, Ae. albopictus and Anopheles arabiensis). RESULTS: Results indicate that radiosensitvity of Ae. aegypti decreases with increasing pupal age (99% induced sterility in youngest pupae, compared to 93% in oldest pupae), but does not change with differences in pupal size (P = 0.94). Differing geographical origin of the same mosquito species did not result in variations in radiosensitivity in Ae. aegypti pupae [Brazil, Indonesia, France (La Reunion), Thailand] or Ae. albopictus [Italy, France (La Reunion)]. Differences in induced sterility were seen following irradiation of pupae that were in wet versus dry conditions, which led to further tests showing significant radioprotective effects of oxygen depletion during irradiation procedures in three tested mosquito species, as seen in other insects. CONCLUSIONS: These findings infer the necessity to further evaluate significant factors and reassess dose-response for mosquitoes with controlled variables to be able to formulate protocols to achieve reliable and reproducible levels of sterility for application in the frame of the SIT.


Asunto(s)
Aedes/efectos de la radiación , Anopheles/efectos de la radiación , Mosquitos Vectores/efectos de la radiación , Pupa/efectos de la radiación , Tolerancia a Radiación , Irradiación Corporal Total/normas , Animales , Entomología/normas , Masculino
15.
Infect Dis Poverty ; 8(1): 71, 2019 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-31477185

RESUMEN

BACKGROUND: Dengue is a global disease, transmitted by the Aedes vectors. In 2018, there were 80 615 dengue cases with 147 deaths in Malaysia. Currently, the nationwide surveillance programs are dependent on Aedes larval surveys and notifications of lab-confirmed human infections. The existing, reactive programs appear to lack sensitivity and proactivity. More efficient dengue vector surveillance/control methods are needed. METHODS: A parallel, cluster, randomized controlled, interventional trial is being conducted for 18 months in Damansara Damai, Selangor, Malaysia, to determine the efficacy of using gravid oviposition sticky (GOS) trap and dengue non-structural 1 (NS1) antigen test for early surveillance of dengue among Aedes mosquitoes to reduce dengue outbreaks. Eight residential apartments were randomly assigned into intervention and control arms. GOS traps are set at the apartments to collect Aedes weekly, following which dengue NS1 antigen is detected in these mosquitoes. When a dengue-positive mosquito is detected, the community will be advised to execute vector search-and-destroy and protective measures. The primary outcome concerns the the percentage change in the (i) number of dengue cases and (ii) durations of dengue outbreaks. Whereas other outcome measures include the change in density threshold of Aedes and changes in dengue-related knowledge, attitude and practice among cluster inhabitants. DISCUSSION: This is a proactive and early dengue surveillance in the mosquito vector that does not rely on notification of dengue cases. Surveillance using the GOS traps should be able to efficiently provide sufficient coverage for multistorey dwellings where population per unit area is likely to be higher. Furthermore, trapping dengue-infected mosquitoes using the GOS trap, helps to halt the dengue transmission carried by the mosquito. It is envisaged that the results of this randomized controlled trial will provide a new proactive, cheap and targeted surveillance tool for the prevention and control of dengue outbreaks. TRIAL REGISTRATION: This is a parallel-cluster, randomized controlled, interventional trial, registered at ClinicalTrials.gov (ID: NCT03799237), on 8th January 2019 (retrospectively registered).


Asunto(s)
Aedes/fisiología , Aedes/virología , Antígenos Virales/análisis , Virus del Dengue/aislamiento & purificación , Oviposición , Proteínas no Estructurales Virales/análisis , Animales , Vigilancia de la Población , Ensayos Clínicos Controlados Aleatorios como Asunto
16.
Clinics (Sao Paulo) ; 74: e675, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31508718

RESUMEN

The present study aimed to review literature on studies of dengue cases conducted over 30 years in the state of Ceará.Between November 2015 and January 2016, articles published in Portuguese and English in 7 databases were searched using keywords and a Boolean operator. A total of 191 articles were identified in the databases; 133 were excluded according to the exclusion criteria, and 58 were included in the study.Of the 58 articles analyzed, 6 reported data from Brazil; including the Northeast region and the state of Ceará; 41 reported data for only the city of Fortaleza; 7 reported data for the state of Ceará; 4 reported data for cities in the interior of the state; and 3 included only children. The studies adopted different approaches and focused on different aspects of the disease. Study outcomes included the identification of serological, epidemiological, clinical, and laboratory characteristics; potential larvicides and biological predators of mosquitoes; potential antiviral agents; vector density characteristics; and educational dengue prevention and control strategies. Additionally, one vaccine trial was included.Although studies on dengue in the state of Ceará are scarce, they are encompassing, including several lines of research, and the number of studies and reports on dengue in the state of Ceará continues to increase.


Asunto(s)
Aedes/clasificación , Dengue/epidemiología , Enfermedades Endémicas/estadística & datos numéricos , Mosquitos Vectores/fisiología , Aedes/fisiología , Animales , Brasil/epidemiología , Dengue/prevención & control , Dengue/transmisión , Enfermedades Endémicas/prevención & control , Humanos , Conducta Predatoria , Proyectos de Investigación , Especificidad de la Especie
17.
PLoS Negl Trop Dis ; 13(9): e0007775, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31553724

RESUMEN

INTRODUCTION: The widespread emergence of resistance to insecticides used to control adult Aedes mosquitoes has made traditional control strategies inadequate for the reduction of various vector populations. Therefore, complementary vector control methods, such as the Sterile Insect Technique, are needed to enhance existing efforts. The technique relies on the rearing and release of large numbers of sterile males, and the development of efficient and standardized mass-rearing procedures and tools is essential for its application against medically important mosquitoes. METHODS: In the effort to reduce the cost of the rearing process, a prototype low-cost plexiglass mass-rearing cage has been developed and tested for egg production and egg hatch rate in comparison to the current Food and Agriculture Organization/International Atomic Energy Agency (FAO/IAEA) stainless-steel cage. Additionally, an adult-index was validated and used as a proxy to estimate the mosquito survival rates by counting the number of male and female mosquitoes that were resting within each of the 6 squares at a given point of time each day in the cage. RESULTS: The study has shown that the prototype mass-rearing cage is cheap and is as efficient as the FAO/IAEA stainless-steel cage in terms of egg production, with even better overall egg hatch rate. The mean numbers of eggs per cage, after seven cycles of blood feeding and egg collection, were 969,789 ± 138,101 and 779,970 ± 123,042, corresponding to 81 ± 11 and 65 ± 10 eggs per female over her lifespan, in the prototype and the stainless-steel-mass-rearing cages, respectively. The longevity of adult male and female mosquitoes was not affected by cage type and, the adult-index could be considered as an appropriate proxy for survival. Moreover, the mass-rearing cage prototype is easy to handle and transport and improves economic and logistic efficiency. CONCLUSION: The low-cost mass-rearing prototype cage can be recommended to produce Ae. aegypti in the context of rear and release techniques. The proposed adult-index can be used as a quick proxy of mosquito survival rates in mass-rearing settings.


Asunto(s)
Aedes/fisiología , Vivienda para Animales/economía , Aedes/crecimiento & desarrollo , Crianza de Animales Domésticos/instrumentación , Crianza de Animales Domésticos/métodos , Animales , Femenino , Vivienda para Animales/normas , Masculino , Mosquitos Vectores
18.
Rev Inst Med Trop Sao Paulo ; 61: e46, 2019 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-31531624

RESUMEN

The Asian tiger mosquito ( Aedes albopictus, Diptera: Culicidae) has spread rapidly in the last 30 years from its native region in Southeast Asia. In Argentina, studies on its potential distribution suggest that this species could be found in temperate zones of the province of Buenos Aires. However, since its initial detection in 1998 Ae. albopictus is bounded to the subtropical province of Misiones. To evaluate the presence and abundance of Ae. albopictus in the Northeast of Argentina, we preliminarily evaluated the presence of this vector by analyzing its presence in tires of 20 cities belonging to the province of Misiones and four cities in Northern Corrientes, and then performed an evaluation of the vector in the towns where the vector was detected. Aedes albopictus was present only in two cities of Misiones: Eldorado and Colonia Aurora. Aedes aegypti and Ae . albopictus accounted for 86% of the individuals collected in the domiciles of both towns. In Colonia Aurora both species were in similar abundances suggesting a co-dominance. The present study extends the austral distribution of Ae. albopictus in Argentina to the city of Colonia Aurora where the highest abundance recorded in Argentina was detected. Nevertheless, the reasons of its bounded distribution in the region are not known.


Asunto(s)
Aedes/clasificación , Mosquitos Vectores/clasificación , Animales , Argentina , Dengue/transmisión , Densidad de Población
19.
New Microbiol ; 42(4): 234-236, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31524944

RESUMEN

Human dirofilariosis is a zoonosis caused by different Dirofilaria species: D. repens, D. immitis, D. tenuis and D. ursi, thin nematodes belonging to the Onchocercidae family, whose larval stages are generally found in the natural (felines and canids) or accidental (human) definitive host. In Europe, human infection is rare, even in areas considered endemic such as Spain or Italy. In this paper we describe the case of an 82-year-old woman living in Modugno (Bari municipality), who came to our observation for a subcutaneous nodule on her right thigh that had appeared in the previous two weeks and gradually became necrotic. The woman lived in an apartment with a dog. An adult worm, white, thin, about 140 mm long, came out of the necrotic area spontaneously. After microscopic examination, the worm was identified as D. repens. In Apulia, a South-Italy region, human dirofilariosis is a rare disease and since 1885 only 11 cases have been reported. In recent years we have witnessed an increase in the number of diseases transmitted by vectors at all latitudes, and in our region an increase in the Aedes albopticus population has been reported, so it is reasonable to expect an increase in dirofilariosis cases in humans.


Asunto(s)
Dirofilaria repens , Dirofilariasis , Aedes/fisiología , Anciano de 80 o más Años , Animales , Dirofilariasis/diagnóstico , Dirofilariasis/parasitología , Femenino , Humanos , Italia , Mosquitos Vectores/parasitología , Mosquitos Vectores/fisiología
20.
PLoS Negl Trop Dis ; 13(9): e0007665, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31525199

RESUMEN

Dengue is one of the most serious mosquito-borne infectious diseases in the world. Aedes albopictus is the most invasive mosquito and one of the primary vectors of dengue. Vector control using insecticides is the only viable strategy to prevent dengue virus transmission. In Guangzhou, after the 2014 pandemic, massive insecticides have been implemented. Massive insecticide use may lead to the development of resistance, but few reports are available on the status of insecticide resistance in Guangzhou after 2014. In this study, Ae. albopictus were collected from four districts with varied dengue virus transmission intensity in Guangzhou from 2015 to 2017. Adult Ae. albopictus insecticide susceptibility to deltamethrin (0.03%), permethrin(0.25%), DDT(4%), malathion (0.8%) and bendiocarb (0.1%) was determined by the standard WHO tube test, and larval resistance bioassays were conducted using temephos, Bacillus thuringiensis israelensis (Bti), pyriproxyfen (PPF) and hexaflumuron. Mutations at the voltage-gated sodium channel (VGSC) gene and acetylcholinesterase (AChE) gene were analyzed. The effect of cytochrome P450s on the resistance of Ae. albopictus to deltamethrin was tested using the synergistic agent piperonyl butoxide (PBO). The results showed that Ae. albopictus populations have rapidly developed very high resistances to multiple commonly used insecticides at all study areas except malathion, Bti and hexaflumuron. We found 1534 codon mutations in the VGSC gene that were significantly correlated with the resistance to pyrethroids and DDT, and 11 synonymous mutations were also found in the gene. The resistance to deltamethrin can be significantly reduced by PBO but may generated cross-resistance to PPF. Fast emerging resistance in Ae. albopictus may affect mosquito management and threaten the prevention and control of dengue, similar to the resistance in Anopheles mosquitoes has prevented the elimination of malaria and call for timely and guided insecticide management.


Asunto(s)
Aedes/genética , Resistencia a los Insecticidas , Insecticidas , Animales , China , Dengue/prevención & control , Dengue/transmisión , Larva/efectos de los fármacos , Larva/genética , Control de Mosquitos , Mosquitos Vectores , Mutación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA