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1.
Pestic Biochem Physiol ; 176: 104882, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34119224

RESUMEN

In order to increase the virulence of two commonly used entomopathogens namely Beauveria bassiana and Metarhizium anisopliae for effective mosquito control programs, we developed new combined formulation by the use of immunosuppressive concentration of imidacloprid. Exposure of sublethal concentration (LC10 1.34 ppb) of imidacloprid to second instar larvae for 92 h that differently modulated the larval biochemical markers by decreasing the total protein (20.65% reduction), acetylcholinesterase (35.74% reduction) and increases the ß-carboxylesterase (26.59% increase) and acid phosphatase (30.69% increase) levels while no significant difference was noticed in alkaline phosphatase of C. quinquefasciatus. Further we demonstrated that the imidacloprid exposure brings about reduction in phenoloxidase level (39.48% decrease) and nitric oxide production (37.64% decrease) in larval homogenate over control. The reduction in viability of hemocytes (15.37% decrease) and phagocytic activity of hemocytes (32.18% decrease) was noticed in imidacloprid treatment. Moreover in laboratory condition, exposure of 1 × 107 spores/ml of B. bassiana (984) and M. anisopliae (6060) alone for 92 h cumulative toxicity assay exhibited larval mortality of 36.47% and 47.64% respectively against C. quinquefasciatus. However in the synergistic experimental studies with LC10 of imidacloprid and 1 × 107 spores/ml of B. bassiana or M. anisopliae to the larvae for 92 h cumulative assay brought 60% and 50.59% more insecticidal activity than the respective entomopathogens alone. The substantial increase of larvicidal activity noticed in the synergistic test conditions against larvae of C. quinquefasciatus revealed that the inclusion of sublethal concentration was proved to be useful for effective larval control.


Asunto(s)
Beauveria , Culex , Metarhizium , Animales , Larva , Mosquitos Vectores , Neonicotinoides , Nitrocompuestos , Control Biológico de Vectores , Virulencia
2.
N Engl J Med ; 384(23): 2177-2186, 2021 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-34107180

RESUMEN

BACKGROUND: Aedes aegypti mosquitoes infected with the wMel strain of Wolbachia pipientis are less susceptible than wild-type A. aegypti to dengue virus infection. METHODS: We conducted a cluster-randomized trial involving releases of wMel-infected A. aegypti mosquitoes for the control of dengue in Yogyakarta, Indonesia. We randomly assigned 12 geographic clusters to receive deployments of wMel-infected A. aegypti (intervention clusters) and 12 clusters to receive no deployments (control clusters). All clusters practiced local mosquito-control measures as usual. A test-negative design was used to assess the efficacy of the intervention. Patients with acute undifferentiated fever who presented to local primary care clinics and were 3 to 45 years of age were recruited. Laboratory testing was used to identify participants who had virologically confirmed dengue (VCD) and those who were test-negative controls. The primary end point was symptomatic VCD of any severity caused by any dengue virus serotype. RESULTS: After successful introgression of wMel into the intervention clusters, 8144 participants were enrolled; 3721 lived in intervention clusters, and 4423 lived in control clusters. In the intention-to-treat analysis, VCD occurred in 67 of 2905 participants (2.3%) in the intervention clusters and in 318 of 3401 (9.4%) in the control clusters (aggregate odds ratio for VCD, 0.23; 95% confidence interval [CI], 0.15 to 0.35; P = 0.004). The protective efficacy of the intervention was 77.1% (95% CI, 65.3 to 84.9) and was similar against the four dengue virus serotypes. The incidence of hospitalization for VCD was lower among participants who lived in intervention clusters (13 of 2905 participants [0.4%]) than among those who lived in control clusters (102 of 3401 [3.0%]) (protective efficacy, 86.2%; 95% CI, 66.2 to 94.3). CONCLUSIONS: Introgression of wMel into A. aegypti populations was effective in reducing the incidence of symptomatic dengue and resulted in fewer hospitalizations for dengue among the participants. (Funded by the Tahija Foundation and others; AWED ClinicalTrials.gov number, NCT03055585; Indonesia Registry number, INA-A7OB6TW.).


Asunto(s)
Aedes/microbiología , Control de Enfermedades Transmisibles/métodos , Dengue/transmisión , Mosquitos Vectores , Wolbachia , Adolescente , Adulto , Aedes/virología , Animales , Niño , Preescolar , Dengue/diagnóstico , Dengue/epidemiología , Dengue/prevención & control , Virus del Dengue/aislamiento & purificación , Femenino , Humanos , Incidencia , Indonesia/epidemiología , Masculino , Persona de Mediana Edad , Mosquitos Vectores/microbiología , Mosquitos Vectores/virología , Adulto Joven
3.
Mem Inst Oswaldo Cruz ; 116: e200547, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34076041

RESUMEN

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.


Asunto(s)
Aedes , Virus del Dengue , Dengue , Aedes/genética , Animales , Colombia , Virus del Dengue/genética , Mosquitos Vectores/genética , ARN , Transcriptoma/genética
4.
Sensors (Basel) ; 21(10)2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-34064829

RESUMEN

Insects constitute a very important part of the global ecosystem and include pollinators, disease vectors, and agricultural pests, all with pivotal influence on society. Monitoring and control of such insects has high priority, and automatic systems are highly desirable. While capture and analysis by biologists constitute the gold standard in insect identification, optical and laser techniques have the potential for high-speed detection and automatic identification based on shape, spectroscopic properties such as reflectance and fluorescence, as well as wing-beat frequency analysis. The present paper discusses these approaches, and in particular presents a novel method for automatic identification of mosquitos based on image analysis, as the insects enter a trap based on a combination of chemical and suction attraction. Details of the analysis procedure are presented, and selectivity is discussed. An accuracy of 93% is achieved by our proposed method from a data set containing 122 insect images (mosquitoes and bees). As a powerful and cost-effective method, we finally propose the combination of imaging and wing-beat frequency analysis in an integrated instrument.


Asunto(s)
Culicidae , Animales , Abejas , Ecosistema , Insectos , Mosquitos Vectores , Alas de Animales
5.
BMC Genomics ; 22(1): 422, 2021 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-34103015

RESUMEN

BACKGROUND: Whole genome re-sequencing provides powerful data for population genomic studies, allowing robust inferences of population structure, gene flow and evolutionary history. For the major malaria vector in Africa, Anopheles gambiae, other genetic aspects such as selection and adaptation are also important. In the present study, we explore population genetic variation from genome-wide sequencing of 765 An. gambiae and An. coluzzii specimens collected from across Africa. We used t-SNE, a recently popularized dimensionality reduction method, to create a 2D-map of An. gambiae and An. coluzzii genes that reflect their population structure similarities. RESULTS: The map allows intuitive navigation among genes distributed throughout the so-called "mainland" and numerous surrounding "island-like" gene clusters. These gene clusters of various sizes correspond predominantly to low recombination genomic regions such as inversions and centromeres, and also to recent selective sweeps. Because this mosquito species complex has been studied extensively, we were able to support our interpretations with previously published findings. Several novel observations and hypotheses are also made, including selective sweeps and a multi-locus selection event in Guinea-Bissau, a known intense hybridization zone between An. gambiae and An. coluzzii. CONCLUSIONS: Our results present a rich dataset that could be utilized in functional investigations aiming to shed light onto An. gambiae s.l genome evolution and eventual speciation. In addition, the methodology presented here can be used to further characterize other species not so well studied as An. gambiae, shortening the time required to progress from field sampling to the identification of genes and genomic regions under unique evolutionary processes.


Asunto(s)
Anopheles , Malaria , África , Animales , Anopheles/genética , Guinea Bissau , Islas , Malaria/genética , Mosquitos Vectores/genética
6.
An Acad Bras Cienc ; 93(2): e20200058, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34105613

RESUMEN

Aedes aegypti is the main vector of the four arboviruses in America which have the greatest impact on human health. The introduction of Aedes albopictus in South America and Argentina acquires importance given the possibility that this species may be a new vector of arboviruses in this region. For this reason, the studies of the biology of their parasites, such as Ascogregarina spp., should be important for the knowledge of the invasive behavior of these vectors. We reported the finding of Ascogregarina culicis in Aedes aegypti and Ascogregarina sp. in Ae. albopictus populations in subtropical Argentina. The prevalence of parasitism by A. culicis in Ae. aegypti and Ascogregrarina sp. in Ae. albopictus was 34.81% (n = 464) and 37.23% (n = 70), respectively, differing between the seasons and habitats. The infection intensity caused by A. culicis and Ascogregarina sp. varied between 1 to 250 and 1 to 327 trophozoites respectively. Ascogregarina culicis was found throughout the all sampling period of Ae. aegypti (June 2016-April 2018). However the presence of Ascogregarina sp. in the midgut of Ae. albopictus was not recorded throughout the whole sampling period despite the presence of the host.


Asunto(s)
Aedes , Apicomplexa , Animales , Argentina , Humanos , Mosquitos Vectores , América del Sur
7.
Braz J Biol ; 83: e240118, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34133488

RESUMEN

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.


Asunto(s)
Insecticidas , Infección por el Virus Zika , Virus Zika , Animales , Aberraciones Cromosómicas , Daño del ADN , Humanos , Insecticidas/toxicidad , Malatión/toxicidad , Índice Mitótico , Mosquitos Vectores , Cebollas , Raíces de Plantas
8.
Pan Afr Med J ; 38: 248, 2021.
Artículo en Francés | MEDLINE | ID: mdl-34104296

RESUMEN

Yellow fever (YF) is a viral haemorrhagic fever caused by yellow fever virus transmitted by Aedes mosquitoes. Since 2013, in Chad, four cases of yellow fever have been detected and confirmed as part of the national fever surveillance program. We here report the last clinical case confirmed in the health district of Lai. The patient was a 57-year-old man with no significant medical and surgical history and unknown immunisation status. He consulted on April 21st, 2020 for fever, moderate to low abundance jaundice and epistaxis (nosebleed) and painful hepatomegaly. Paraclinical examinations, such as RT-PCR, objectified yellow fever virus in post-mortem tissue sample. Thus, confirmed yellow fever cases in this district, the low level of vaccination coverage, the circulation of the virus and the presence of vector in the country should warn of a real threat of reemergence of yellow fever in Chad.


Asunto(s)
Fiebre Amarilla/diagnóstico , Virus de la Fiebre Amarilla/aislamiento & purificación , Aedes/virología , Animales , Chad , Humanos , Masculino , Persona de Mediana Edad , Mosquitos Vectores/virología , Recurrencia , Fiebre Amarilla/transmisión , Fiebre Amarilla/virología , Vacuna contra la Fiebre Amarilla/administración & dosificación
9.
An Acad Bras Cienc ; 93(3): e20201012, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34076184

RESUMEN

Aedes aegypti is currently the mosquito with major impact on public health in Brazil and a proven vector of several emerging arboviruses. By consequence, its name is frequently being spoken by lay people of the media and general public, as well as by researchers in this country both in general media and academic events. However, the generic name Aedes, contrary to its etymological origin and worldwide correct pronunciation ("A-e-des"), has been frequently mispronounced as "Edes" on many occasions by media spokespersons and by researchers and lay people in Brazil. However, based on historical and linguistic evidence, it is confirmed here that the correct historical pronunciation (A-e-des) must be maintained and observed in Brazil as it is enunciated all over the World.


Asunto(s)
Aedes , Arbovirus , Animales , Brasil , Humanos , Mosquitos Vectores
10.
Front Public Health ; 9: 611152, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34046385

RESUMEN

The extreme north of Chile presents a subtropical climate permissive of the establishment of potential disease vectors. Anopheles (Ano.) pseudopunctipennis is distributed from the south of the United States to the north of Argentina and Chile, and is one of the main vectors of malaria in Latin America. Malaria was eradicated from Chile in 1945. Nevertheless, the vector persists in river ravines of the Arica and Tarapacá regions. The principal effect of climate change in the north of Chile is temperature increase. Precipitation prediction is not accurate for this region because records were erratic during the last century. The objective of this study was to estimate the current and the projected distribution pattern of this species in Chile, given the potential impact due to climate change. We compiled distributional data for An. (Ano.) pseudopunctipennis and constructed species distribution models to predict the spatial distribution of this species using the MaxEnt algorithm with current and RCP 4.5 and 8.5 scenarios, using environmental and topographic layers. Our models estimated that the current expected range of An. (Ano.) pseudopunctipennis extends continuously from Arica to the north of Antofagasta region. Furthermore, the RCP 4.5 and 8.5 projected scenarios suggested that the range of distribution of An. (Ano.) pseudopunctipennis may increase in longitude, latitude, and altitude limits, enhancing the local extension area by 38 and 101%, respectively, and local presence probability (>0.7), from the northern limit in Arica y Parinacota region (18°S) to the northern Antofagasta region (23°S). This study contributes to geographic and ecologic knowledge about this species in Chile, as it represents the first local study of An. (Ano.) pseudopunctipennis. The information generated in this study can be used to inform decision making regarding vector control and surveillance programs of Latin America. These kinds of studies are very relevant to generate human, animal, and environmental health knowledge contributing to the "One Health" concept.


Asunto(s)
Anopheles , Malaria , Animales , Argentina , Chile , Vectores de Enfermedades , Humanos , Mosquitos Vectores
11.
Nat Commun ; 12(1): 2635, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33976132

RESUMEN

The scale-up of malaria control efforts has led to marked reductions in malaria burden over the past twenty years, but progress has slowed. Implementation of indoor residual spraying (IRS) of insecticide, a proven vector control intervention, has been limited and difficult to sustain partly because questions remain on its added impact over widely accepted interventions such as bed nets. Using data from 14 enhanced surveillance health facilities in Uganda, a country with high bed net coverage yet high malaria burden, we estimate the impact of starting and stopping IRS on changes in malaria incidence. We show that stopping IRS was associated with a 5-fold increase in malaria incidence within 10 months, but reinstating IRS was associated with an over 5-fold decrease within 8 months. In areas where IRS was initiated and sustained, malaria incidence dropped by 85% after year 4. IRS could play a critical role in achieving global malaria targets, particularly in areas where progress has stalled.


Asunto(s)
Anopheles/parasitología , Insecticidas , Malaria/epidemiología , Control de Mosquitos/métodos , Mosquitos Vectores/parasitología , Animales , Monitoreo Epidemiológico , Geografía , Humanos , Incidencia , Malaria/parasitología , Malaria/prevención & control , Malaria/transmisión , Uganda/epidemiología
12.
Nat Commun ; 12(1): 2619, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33976183

RESUMEN

After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017-2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases. In this study we use epidemiological, climatological and genomic data to investigate dengue dynamics in recent years in Brazil. First, we estimate dengue virus force of infection (FOI) and model mosquito-borne transmission suitability since the early 2000s. Our estimates reveal that DENV transmission was low in 2017-2018, despite conditions being suitable for viral spread. Our study also shows a marked decline in dengue susceptibility between 2002 and 2019, which could explain the synchronous decline of dengue in the country, partially as a result of protective immunity from prior ZIKV and/or DENV infections. Furthermore, we performed phylogeographic analyses using 69 newly sequenced genomes of dengue virus serotype 1 and 2 from Brazil, and found that the outbreaks in 2018-2019 were caused by local DENV lineages that persisted for 5-10 years, circulating cryptically before and after the Zika epidemic. We hypothesize that DENV lineages may circulate at low transmission levels for many years, until local conditions are suitable for higher transmission, when they cause major outbreaks.


Asunto(s)
Virus del Dengue/inmunología , Dengue/epidemiología , Susceptibilidad a Enfermedades/inmunología , Epidemias/estadística & datos numéricos , Infección por el Virus Zika/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/inmunología , Brasil/epidemiología , Niño , Preescolar , Dengue/inmunología , Dengue/transmisión , Dengue/virología , Virus del Dengue/genética , Virus del Dengue/aislamiento & purificación , Epidemias/prevención & control , Monitoreo Epidemiológico , Femenino , Genoma Viral/genética , Humanos , Inmunidad Heteróloga , Incidencia , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Tipificación Molecular , Mosquitos Vectores/virología , Filogeografía , Serotipificación , Adulto Joven , Virus Zika/inmunología , Infección por el Virus Zika/epidemiología
13.
BMC Res Notes ; 14(1): 200, 2021 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-34022919

RESUMEN

OBJECTIVE: In the framework of EVALMOUS study aiming to assess the use and effectiveness of mosquito nets by pregnant women and other members of their household in a lagoon area in southern Benin, the behaviour of pregnant women relative to the time they go to bed using the net were recorded. Malaria vectors biting rhythm, Plasmodium falciparum infection and insecticide resistance genes in malaria vectors were also determined. RESULTS: Overall, 3848 females of Anopheles gambiae s. l were collected and 280 pregnant women responded to the survey. Almost all Anopheles gambiae s. l. tested were Anopheles coluzzi Coetzee and Wilkerson 2013 (Diptera: Culicidae). The CSP index in malaria vector was 1.85% and the allelic frequency of kdr gene was 74.4%. Around 90% of bites and Plasmodium falciparum Welch, 1897 (Haemosporida: Plasmodiidae) transmission occurred between 10 p.m. and 6 a.m., which coincides with the period when more than 80% of pregnant women were under bednet. Despite a slight early evening and early morning biting activity of malaria vectors in the study area, the good use of nets might remain a useful protection tool against mosquito biting and malaria transmission.


Asunto(s)
Anopheles , Insecticidas , Malaria , Animales , Anopheles/genética , Benin , Conducta Alimentaria , Femenino , Humanos , Malaria/prevención & control , Mosquitos Vectores , Embarazo , Mujeres Embarazadas
14.
Rev Soc Bras Med Trop ; 54(suppl 1): e2020609, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34008724

RESUMEN

This article addresses the vector, sexual and vertical transmissions of the Zika virus, a topic covered in the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections, published by the Brazilian Ministry of Health in 2020. Although in Brazil Zika virus is transmitted more predominantly by Aedes aegypti, the vertical and sexual transmission routes are of significant importance for reproductive health. Sexual transmission demands specific prophylactic interventions, including the use of male or female condoms, especially among couples in a risk situation and planning pregnancy. Vertical transmission is linked to severe structural abnormalities of the central nervous system, and there is still no vaccine or known pharmacological resources that can prevent it. As the disease is predominantly asymptomatic, failure to comply with the basic principles of care and guidelines associated with the spread of the infection transcends the severity of the disease's symptoms. Although in Brazil Zika virus is predominantly transmitted by the Aedes aegypti mosquito, vertical and sexual transmission routes are important for reproductive health. Vertical transmission causes severe central nervous system structural abnormalities.


Asunto(s)
Aedes , Enfermedades de Transmisión Sexual , Infección por el Virus Zika , Virus Zika , Animales , Brasil , Femenino , Humanos , Masculino , Mosquitos Vectores , Embarazo , Infección por el Virus Zika/prevención & control
15.
Nat Commun ; 12(1): 2553, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33953207

RESUMEN

Pyrethrum extracts from flower heads of Chrysanthemum spp. have been used worldwide in insecticides and repellents. While the molecular mechanisms of its insecticidal action are known, the molecular basis of pyrethrum repellency remains a mystery. In this study, we find that the principal components of pyrethrum, pyrethrins, and a minor component, (E)-ß-farnesene (EBF), each activate a specific type of olfactory receptor neurons in Aedes aegypti mosquitoes. We identify Ae. aegypti odorant receptor 31 (AaOr31) as a cognate Or for EBF and find that Or31-mediated repellency is significantly synergized by pyrethrin-induced activation of voltage-gated sodium channels. Thus, pyrethrum exerts spatial repellency through a novel, dual-target mechanism. Elucidation of this two-target mechanism may have potential implications in the design and development of a new generation of synthetic repellents against major mosquito vectors of infectious diseases.


Asunto(s)
Chrysanthemum cinerariifolium/metabolismo , Culicidae/efectos de los fármacos , Repelentes de Insectos/farmacología , Insecticidas/farmacología , Piretrinas/farmacología , Aedes/efectos de los fármacos , Animales , Chrysanthemum cinerariifolium/genética , Técnicas de Inactivación de Genes , Control de Mosquitos , Mosquitos Vectores , Neuronas , Receptores Odorantes/genética , Canales de Sodio Activados por Voltaje
16.
BMJ Open ; 11(3): e046664, 2021 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-34006037

RESUMEN

INTRODUCTION: The massive scale-up of long-lasting insecticidal nets (LLINs) has led to major reductions in malaria burden in many sub-Saharan African countries. This progress is threatened by widespread insecticide resistance among malaria vectors. This cluster-randomised controlled trial (c-RCT) compares three of the most promising dual active ingredients LLINs (dual-AI LLINs), which incorporate mixtures of insecticides or insecticide synergists to standard LLINs in an area of pyrethroid insecticide resistance. METHODS: A four-arm, single-blinded, c-RCT will evaluate the effectiveness of three types of dual-AI LLINs (1) Royal Guard, combining two insecticides, pyriproxyfen and the pyrethroid alpha-cypermethrin; (2) Interceptor G2, combining chlorfenapyr and alpha-cypermethrin; (3) Olyset Plus, an LLIN combining a synergist, piperonyl butoxide and the pyrethroid permethrin, compared with; (4) Interceptor LN, a standard LLIN containing the pyrethroid alpha-cypermethrin as the sole AI. The primary outcomes are malaria infection prevalence in children aged 6 months-14 years and entomological inoculation rate (EIR), as a standard measure of malaria transmission at 24 months postintervention and cost-effectiveness. ETHICS AND DISSEMINATION: Ethical approval was received from the institutional review boards of the Tanzanian National Institute for Medical Research, Kilimanjaro Christian Medical University College, London School of Hygiene and Tropical Medicine, and University of Ottawa. Study findings will be actively disseminated via reports and presentations to stakeholders, local community leaders, and relevant national and international policy makers as well as through conferences, and peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT03554616.


Asunto(s)
Culicidae , Mosquiteros Tratados con Insecticida , Malaria , Piretrinas , Animales , Niño , Humanos , Resistencia a los Insecticidas , Londres , Malaria/prevención & control , Mosquitos Vectores , Ensayos Clínicos Controlados Aleatorios como Asunto , Método Simple Ciego , Tanzanía
17.
Nat Commun ; 12(1): 2960, 2021 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-34017003

RESUMEN

Culex mosquitoes are a global vector for multiple human and animal diseases, including West Nile virus, lymphatic filariasis, and avian malaria, posing a constant threat to public health, livestock, companion animals, and endangered birds. While rising insecticide resistance has threatened the control of Culex mosquitoes, advances in CRISPR genome-editing tools have fostered the development of alternative genetic strategies such as gene drive systems to fight disease vectors. However, though gene-drive technology has quickly progressed in other mosquitoes, advances have been lacking in Culex. Here, we develop a Culex-specific Cas9/gRNA expression toolkit and use site-directed homology-based transgenesis to generate and validate a Culex quinquefasciatus Cas9-expressing line. We show that gRNA scaffold variants improve transgenesis efficiency in both Culex quinquefasciatus and Drosophila melanogaster and boost gene-drive performance in the fruit fly. These findings support future technology development to control Culex mosquitoes and provide valuable insight for improving these tools in other species.


Asunto(s)
Sistemas CRISPR-Cas/genética , Culex/genética , Tecnología de Genética Dirigida/métodos , Control de Mosquitos/métodos , Mosquitos Vectores/genética , Animales , Animales Modificados Genéticamente , Drosophila melanogaster/genética , Femenino , Resistencia a los Insecticidas , Masculino , Mutagénesis Sitio-Dirigida/métodos , ARN Guia/genética
18.
BMC Genomics ; 22(1): 337, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33971808

RESUMEN

BACKGROUND: Malaria control is heavily reliant on the use of insecticides that target and kill the adult female Anopheline vector. The intensive use of insecticides of the pyrethroid class has led to widespread resistance in mosquito populations. The intensity of pyrethroid resistance in some settings in Africa means mosquitoes can contact bednets treated with this insecticide class multiple times with minimal mortality effects. Furthermore, both ageing and diel cycle have been shown to have large impacts on the resistance phenotype. Together, these traits may affect other aspects of vector biology controlling the vectorial capacity or fitness of the mosquito. RESULTS: Here we show that sublethal exposure of a highly resistant Anopheles coluzzii population originally from Burkina Faso to the pyrethroid deltamethrin results in large and sustained changes to transcript expression. We identify five clear patterns in the data showing changes to transcripts relating to: DNA repair, respiration, translation, behaviour and oxioreductase processes. Further, we highlight differential regulation of transcripts from detoxification families previously linked with insecticide resistance, in addition to clear down-regulation of the oxidative phosphorylation pathway both indicative of changes in metabolism post-exposure. Finally, we show that both ageing and diel cycle have major effects on known insecticide resistance related transcripts. CONCLUSION: Sub-lethal pyrethroid exposure, ageing and the diel cycle results in large-scale changes in the transcriptome of the major malaria vector Anopheles coluzzii. Our data strongly supports further phenotypic studies on how transcriptional changes such as reduced expression of the oxidative phosphorylation pathway or pyrethroid induced changes to redox state might impact key mosquito traits, such as vectorial capacity and life history traits.


Asunto(s)
Anopheles , Insecticidas , Malaria , Piretrinas , Envejecimiento/genética , Animales , Anopheles/genética , Burkina Faso , Femenino , Resistencia a los Insecticidas/genética , Insecticidas/toxicidad , Control de Mosquitos , Mosquitos Vectores/genética , Piretrinas/toxicidad , Transcriptoma
19.
Ann Parasitol ; 67(1): 1-10, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33980006

RESUMEN

Over the past years, the nematode species from the Onchocercidae family, Setaria tundra, has expanded its range by thousands of kilometres from subpolar to subtropical climate zone. Its presence has been confirmed in seven new countries. The appearance of this parasite in many other European countries, especially central and southern ones, is highly probable. In recent years, its mass appearance has led to the numerous fall of reindeer in Fennoscandia, thus causing significant economic damage. There is also a growing risk of its gradation in Central Europe, which threatens overpopulated wild deer species and possibly farm animals, however there is no information if other than mosquitoes blood-sucking arthropods act as its vector. This paper covers the range of occurrence of S. tundra in Europe, all of the reported intermediate and definitive hosts, phylogeny, biology, morphology, health effects, and treatment methods.


Asunto(s)
Ciervos , Setaria (Nematodo) , Animales , Europa (Continente) , Mosquitos Vectores , Tundra
20.
Rev Esp Salud Publica ; 952021 May 10.
Artículo en Español | MEDLINE | ID: mdl-33967267

RESUMEN

OBJECTIVE: Environmental management of imported arboviruses such as dengue (DENV), Zika (ZIKV) or Chikungunya (CHIKV) is a task of great significance for Public Health since the arrival and establishment of the competent vector Aedes albopictus (Asian tiger mosquito) in numerous cities of our country. There are recent examples of autochthonous transmission of some of these arboviruses in Spain probably linked to undetected and / or unmanaged imported cases. METHODS: Vector management interventions were carried out in the city of Valencia (Spain) by the Health Service of the Valencia City Council between 2016 and 2018. These actions took place within the framework of a coordination protocol established with the Health authorities of the Valencia regional government. RESULTS: A total of 21 arbovirus cases were reported and led to entomological surveillance and vector control interventions in the city of Valencia: 8 DENV, 7 CHIKV and 6 ZIKV. In 8 of these 21 cases (38%) the presence of Ae. Albopictus was detected within the risk zones established for each case. CONCLUSIONS: Vector surveillance and control strategies associated with imported cases of arboviruses, provide accurate information on the environmental risks of amplification of these viruses and also allow reducing these risks through population control of vectors. Due to the short duration of the viremic phases, these interventions should be carried out as quickly as possible in order to reduce the hypothetical contact between the infected person and vector as much as possible.


Asunto(s)
Aedes/virología , Fiebre Chikungunya/prevención & control , Dengue/prevención & control , Control de Mosquitos , Mosquitos Vectores/virología , Infección por el Virus Zika/prevención & control , Animales , Fiebre Chikungunya/epidemiología , Ciudades/epidemiología , Dengue/epidemiología , Humanos , España/epidemiología , Infección por el Virus Zika/epidemiología
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