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1.
Parasit Vectors ; 13(1): 353, 2020 Jul 17.
Article in English | MEDLINE | ID: mdl-32680549

ABSTRACT

BACKGROUND: The wide distribution of Aedes aegypti, the main vector of dengue and yellow fever viruses, currently puts three billion people in the world at risk of infection with these viruses. Continuous transmission of these and other viruses despite aggressive efforts to prevent this emphasizes the need to develop new control strategies. Proposals to control disease transmission based on vector engineering, including both population suppression and population replacement, rely on the development of transgenes under the control of regulatory elements able to drive molecules in a specific tissue, time and strength. METHODS: Here we report the characterization of a promoter active in both the female germline and early zygote, derived from the transcription factor bZip1 in the mosquito Ae. aegypti, using transposon-based methods and RT-qPCR. RESULTS: We generated seven transgenic lines carrying AabZip1-reporter constructs and observed expression in both the ovary and early embryo. RT-qPCR analysis was performed to evaluate transcript expression patterns for each line, confirming that transgenic expression from the AabZip1 promoter largely recapitulated the endogenous expression pattern, albeit the strength of maternal expression appeared to be strongly influenced by chromosomal position. CONCLUSIONS: This study provides a new regulatory sequence that can be useful for generating transgenic lines that can become a tool in vector control strategies.

2.
J Proteomics ; : 103918, 2020 Jul 23.
Article in English | MEDLINE | ID: mdl-32712372

ABSTRACT

Bacterial insecticidal proteins, such as the Bin toxin from Lysinibacillus sphaericus, could be used more extensively to control insecticide resistant mosquitoes. This study was aimed at identification of mosquito cell proteins binding Bin toxin. Results showed that purified toxin was toxic to Anopheles gambiae larvae and Ag55 cultured cells. Clathrin heavy chain (an endocytosis protein) and glycolytic enzymes such as pyruvate kinase, enolase and dihydrolipoamide dehydrogenase were identified as binders of Bin toxin. The viability of Ag55 cells in the presence of endocytosis inhibitor, pitstop2, was significantly decreased upon Bin treatment, while the inhibitor chlorpromazine did not affect Bin toxicity. Bin toxin treatment decreased ATP production and mitochondrial respiration in Ag55 cells, whereas non-mitochondrial oxygen consumption significantly increased after Bin toxin treatment. These findings are steps towards understanding how Bin toxin kills mosquitoes. SIGNIFICANCE: Mosquitoes are vectors of pathogens causing human diseases such as dengue fever, yellow fever, zika virus and malaria. An insecticidal toxin from Lysinibacillus sphaericus called Binary, or Bin, toxin could be used more extensively to control insecticide resistant mosquitoes. Bin toxin enter cells in susceptible mosquitoes and induces apoptosis or autophagy. In the current research, we used the malaria mosquito Anopheles gambiae Ag55 cell line as a model. A proteomic-based approach identified proteins that interact with Bin toxin. Interacting proteins include clathrin heavy chain (endocytosis protein) and glycolysis enzymes such as pyruvate kinase, enolase and dihydrolipoamide dehydrogenase. In Ag55 cell toxicity assays, an endocytosis inhibitor, pitstop2, increased Bin toxicity. Real time assays with a Seahorse™ flux analyzer showed that Bin significantly effects mitochondrial respiration, a result consistent with cell death via apoptosis or autophagy. These research findings add insights into how an unusual binary protein exploits cellular machinery to kill mosquitoes.

3.
J Travel Med ; 2020 Jul 30.
Article in English | MEDLINE | ID: mdl-32729905

ABSTRACT

BACKGROUND: More people on immunosuppression live in or wish to travel to yellow fever virus (YFV)-endemic areas. Data on the safety and immunogenicity of yellow fever vaccination (YFVV) during immunosuppression are scarce. The aim of this study was to compare the safety and immunogenicity of a primary YFVV between travellers on methotrexate and controls. METHODS: We conducted a prospective multi-centre controlled observational study from 2015-2017 in six Swiss travel clinics. 15 adults (nine with rheumatic diseases, five with dermatologic conditions and one with a gastroenterological disease) on low-dose methotrexate (≤20 mg/week) requiring a primary YFVV and 15 age and sex-matched controls received a YFVV. Solicited/unsolicited adverse reactions were recorded, YFV-RNA was measured in serum samples on days 3, 7, 10, 14, 28 and neutralising antibodies on days 0, 7, 10, 14, 28. RESULTS: Patients´ and controls' median ages were 53 and 52 years; nine patients and ten controls were female. 43% of patients and 33% of controls showed local side effects (p = 0.71); 86% of patients and 66% of controls reported systemic reactions (p = 0.39). YFV-RNA was detected in patients and controls on day 3-10 post-vaccination and was never of clinical significance. Slightly more patients developed YFV-RNAaemia (day 3: n = 5 vs. n = 2, day 7: n = 9 vs. n = 7, day 10: n = 3 vs. n = 2, all p > 0.39). No serious reactions occurred. On day ten, a minority of vaccinees was seroprotected (patients: n = 2, controls: n = 6). On day 28, all vaccinees were seroprotected. CONCLUSIONS: First-time yellow fever vaccination was safe and immunogenic in travellers on low-dose methotrexate. Larger studies are needed to confirm these promising results.

4.
Enferm. actual Costa Rica (Online) ; (38): 61-74, Jan.-Jun. 2020.
Article in Portuguese | LILACS, BDENF - Nursing | ID: biblio-1090087

ABSTRACT

Resumo Este estudo teve como objetivo discutir as percepções dos Agentes Comunitários de Saúde e Agentes de Combate a Endemias sobre o processo de orientação da população quanto à prevenção e controle do Aedes Aegypti. Tratase de estudo descritivo-exploratório de natureza qualitativa, realizado com 07 Agentes de Combate a Endemias e 12 Agentes Comunitários de Saúde em uma cidade no interior da Bahia, cujos dados foram coletados por meio de entrevista semiestruturada, gravada com auxílio de gravador e analisado através da técnica do discurso do sujeito coletivo, que permitiu a construção de discursos coletivos. Os resultados mostram que na percepção de tais profissionais, a população não contribui para a prevenção e controle do Aedes Aegypti de modo eficaz, deixando apenas que os profissionais em questão atuem de forma ativa, sendo que este trabalho deve ser em conjunto com a população e os Agentes. Concluímos que com base nos resultados obtidos a população é orientada quanto aos cuidados para a prevenção do AA, no entanto, grande parte das pessoas não colocam em prática o que é pasado para eles, sendo assim, existe a necessidade de implementação de atividades para sensibilização deles.


Abstract This study aimed to discuss the perceptions of Community Health Agents and Endemic Control Agents on the process of guiding the population regarding the prevention and control of Aedes Aegypti. This is a descriptive and exploratory study of qualitative nature, conducted with 07 Endemic Disease Agents and 12 Community Health Agents in a city in the interior of Bahia, whose data were collected through semi-structured interviews, recorded with the aid of tape recorder and analyzed through the technique of collective subject discourse, which allowed the construction of collective discourses. The results show that in the perception of such professionals, the population does not contribute to the prevention and control of Aedes Aegypti effectively, leaving only the professionals in question to act actively, and this work should be together with the population and the agents. We conclude that based on the results obtained the population is oriented towards care for the prevention of AA, however, most people do not put into practice what is passed on to them, so there is a need to implement activities to raise awareness of them.


Resumen Este estudio tuvo como objetivo discutir las percepciones de los Agentes de Salud Comunitaria y los Agentes de Control Endémico sobre el proceso de orientación de la población con respecto a la prevención y el control del Aedes Aegypti. Este es un estudio descriptivo y exploratorio de naturaleza cualitativa, realizado con 07 Agentes de Enfermedades Endémicas y 12 Agentes de Salud Comunitaria en una ciudad del interior de Bahía, cuyos datos fueron recolectados a través de entrevistas semiestructuradas, registradas con la ayuda de una grabadora y analizados a través de la técnica del discurso del sujeto colectivo, que permitió la construcción de discursos colectivos. Los resultados muestran que, en la percepción de tales profesionales, la población no contribuye a la prevención y al control del Aedes Aegypti de manera efectiva, dejando solamente a los profesionales en cuestión para que actúen activamente, y este trabajo debe ser realizado juntamente con la población y con los agentes. Concluimos que, en base a los resultados obtenidos, la población está orientada hacia la atención para la prevención de AA, sin embargo, la mayoría de las personas no ponen en práctica lo que se les transmite, por lo que es necesario implementar actividades para crear conciencia sobre ellos.


Subject(s)
Humans , Primary Prevention/education , Brazil , Public Health , Community Health Workers , Community Health Services , Endemic Diseases , Aedes , Public Health Surveillance
6.
J Med Entomol ; 2020 Jun 02.
Article in English | MEDLINE | ID: mdl-32484559

ABSTRACT

Aedes aegypti (L.) is the primary vector of Zika, dengue, yellow fever, and chikungunya viruses. Insecticides used in mosquito control can help prevent the spread of vector-borne diseases. However, it is essential to determine insecticide resistance (IR) status before control measures are undertaken. Only the most effective insecticides should be used to avoid ineffective control and/or promotion of IR. Pyrethroids and organophosphates are the most commonly used insecticides for mosquito control. Here, the efficacy of two active ingredients (AIs; permethrin [pyrethroid], chlorpyrifos [organophosphate]), two formulated products (FPs; Biomist [AI: permethrin]) and (Mosquitomist [AI: chlorpyrifos]), and three synergists (piperonyl butoxide, diethyl maleate, S-S-S-tributyl phosphorotrithioate) was evaluated in two Ae. aegypti colonies (pyrethroid resistant and susceptible). Mosquitomist was most effective against the pyrethroid-resistant colony (100% mortality at diagnostic time). Pre-exposure to synergists did not increase the efficacy of AIs against the pyrethroid-resistant colony. Further research is needed to discover how synergists may affect the efficacy of insecticides when used on pyrethroid-resistant mosquitoes.

7.
Transplant Proc ; 52(5): 1291-1293, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32505502

ABSTRACT

Yellow fever (YF) is a vaccine-preventable disease, but live attenuated YF vaccine (YFV) is contraindicated in immunosuppressed patients due to the risk of life-threatening YFV-associated side effects. This study aimed to evaluate 1. the knowledge of renal transplant recipients (RTRs) about the contraindication and risks of YFV; 2. the prevalence of inadvertent vaccination of RTRs against YF; and 3. the outcome of these patients. A cross-sectional telephone contact study was conducted with 200 RTRs selected from the outpatient clinic of our transplantation unit. There were 116 successful telephone contacts (58%). A total of 11 vaccinated patients were identified: 5 received YFV in the pretransplant period and 6 in the post-transplant period. All patients received the full dose of the vaccine. Among those vaccinated after transplant, only 1 reported a mild adverse event (nausea) after receiving the vaccine. All vaccinated patients who were post-transplant did not know about vaccine contraindications as a result of their clinical condition. Among the unvaccinated patients, this rate was 12.4%. YFV is the main tool for disease prevention and control as there is no specific antiviral treatment for YF. Our results confirm the evidence that transplant recipients tolerate YFV well. However, data are not strong enough to recommend this vaccine in transplant recipients. Counseling RTRs on the contraindications of YFV is important to prevent inadvertent use of this vaccine in this population.

8.
J Virol ; 2020 Jun 17.
Article in English | MEDLINE | ID: mdl-32554698

ABSTRACT

The nonstructural protein 1 (NS1) of several flaviviruses, including West Nile, dengue, and yellow fever viruses, is capable of inducing variable degrees of protection against flavivirus infection in animal models. However, the immunogenicity of NS1 protein of Zika virus (ZIKV) is less understood. Here, we determined the efficacy of ZIKV NS1-based vaccine candidates using two delivery platforms, methyltransferase-defective recombinant vesicular stomatitis virus (mtdVSV) and a DNA vaccine. We first show that expression of ZIKV NS1 could be significantly enhanced by optimizing the signal peptide. A single dose of mtdVSV-NS1-based vaccine or two doses of DNA vaccine induced high levels of NS1-specfic antibody and T cell immune responses but provided only partial protection against ZIKV viremia in BALB/c mice. In Ifnar1-/- mice, neither NS1-based vaccine provided protection against a lethal high dose (105 PFU) ZIKV challenge, but mtdVSV-NS1-based vaccine prevented deaths from a low dose (103 PFU) challenge, though they experienced viremia and body weight loss. We conclude that ZIKV NS1 alone conferred substantial, but not complete, protection against ZIKV infection. Nevertheless, these results highlight the value of ZIKV NS1 for vaccine development.Importance Most Zika virus (ZIKV) vaccine research has focused on the E or prM-E proteins and the induction of high levels of neutralizing antibodies. However, these ZIKV neutralizing antibodies cross react with other flaviviruses, which may aggravate the disease via an Antibody Dependent Enhancement (ADE) mechanism. ZIKV NS1 protein may be an alternative antigen for vaccine development, as antibodies to NS1 do not bind to the virion, thereby eliminating the risk of ADE. Here we show that recombinant VSV and DNA vaccines expressing NS1, alone, confer partial protection against ZIKV infection in both immunocompetent and immunodeficient mice, highlighting the value of NS1 as a potential vaccine candidate.

9.
Article in English | MEDLINE | ID: mdl-32491144

ABSTRACT

Eleven lactating women were inadvertently vaccinated with 17DD yellow fever vaccine in a small city of Sao Paulo State, Brazil. Their infants were being exclusively breast-fed and the breastfeeding was interrupted for 10 days. Serum and breastmilk were collected from the vaccinated mothers and tested for the presence of genomic RNA of the vaccine strain 8, 10 and 15 days after vaccination. Viral RNA was not detected in any of the serum and human milk samples tested and the infants remained asymptomatic. Our result strengthens the effectineness of stopping breastfeeding for 10 days after the inadvertent yellow fever vaccination of lactating women.


Subject(s)
Breast Feeding/adverse effects , Milk, Human/virology , Yellow Fever Vaccine/adverse effects , Yellow Fever/prevention & control , Yellow fever virus/immunology , Antibodies, Viral/blood , Antigens, Viral/blood , Brazil , Female , Humans , Infant, Newborn , RNA, Viral/blood , Yellow Fever/transmission , Yellow Fever Vaccine/administration & dosage
11.
Pest Manag Sci ; 2020 Jun 27.
Article in English | MEDLINE | ID: mdl-32592440

ABSTRACT

BACKGROUND: Understanding pest incursion pathways is critical for preventing new invasions and for stopping the transfer of alleles that reduce the efficacy of local control methods. The mosquitoes Aedes albopictus (Skuse) and Ae. aegypti (Linnaeus) are both highly invasive disease vectors, and through a series of ongoing international incursions are continuing to colonize new regions and spread insecticide resistance alleles among established populations. This study uses high-resolution molecular markers and a set of 241 reference genotypes to trace incursion pathways of Ae. albopictus into mainland Australia, where no successful invasions have yet been observed. We contrast these results with incursion pathways of Ae. aegypti, investigated previously. RESULTS: Assignments successfully identified China, Japan, Singapore and Taiwan as source locations. Incursion pathways of Ae. albopictus were entirely different to those of Ae. aegypti, despite broad sympatry of these species throughout the Indo-Pacific region. Incursions of Ae. albopictus appeared to have come predominantly along marine routes from key trading locations, while Ae. aegypti was mostly linked to aerial routes from tourism hotspots. CONCLUSION: These results demonstrate how genomics can help decipher otherwise cryptic incursion pathways. The inclusion of reference genotypes from the Americas may help resolve some unsuccessful assignments. While many congeneric taxa will share common incursion pathways, this study highlights that this is not always the case, and incursion pathways of important taxa should be specifically investigated. Species differences in aerial and marine incursion rates may reflect the efficacy of ongoing control programmes such as aircraft disinsection.

12.
Hum Vaccin Immunother ; : 1-8, 2020 Jun 23.
Article in English | MEDLINE | ID: mdl-32574095

ABSTRACT

Plasmid-launched live-attenuated vaccines (PLLAV), also called infectious DNA (iDNA) vaccines, combine the assets of genetic immunization with the potency of replication-competent live viral vaccines. However, due to their origin as bacterial plasmid DNA, efficient delivery of PLLAV may be hampered by innate signaling pathways such as the cGAS-STING-mediated sensing of cytosolic DNA, resulting in an unfavorable proinflammatory and antiviral response locally at the site of immunization. Employing several complementary cell-based systems and using the yellow fever vaccine (YF17D) and the respective PLLAV-YF17D, we screened a panel of small molecules known to interfere with antiviral signaling for their proviral activity and identified two potent inhibitors of the TANK-binding kinase 1 (TBK1), BX795 and CYT387, to enhance YF17D replication and hence efficacy of PLLAV-YF17D transfection. In tissue culture, BX795 could fully revert the block that plasmid transfection poses on YF17D infection in a type I interferon dependent manner, as confirmed by (i) a marked change in gene expression signatures, (ii) a rescue of full YF17D replication, and (iii) a massively increased virus yield. Inhibitors of TBK1 may hence be considered an adjuvant to potentiate novel PLLAV vaccines, which might boost PLLAV delivery toward their use in vivo.

13.
Microbes Infect ; 2020 Apr 27.
Article in English | MEDLINE | ID: mdl-32353601

ABSTRACT

Zika Virus (ZIKV), an arbovirus that belongs to the Flaviviridae family, has become a global concern since its outbreak in the Americas in 2015. With symptoms similar to other Flavivirus as Dengue and Yellow Fever viruses, infections by ZIKV have also been related to several neurological complications such as microcephaly in newborns and Guillain-Barre syndrome. Considering the high prevalence of ZIKV infection in certain areas, the risks that the virus poses to fetal brain development, and the fact that there is no vaccine or specific prophylaxis available, an effective treatment capable of preventing the infection is of potential interest. Therefore, in the present investigation, the antiviral activity on ZIKV of a group of xanthenodiones and intermediate ketones involved in their synthesis was evaluated for the first time. It was found that the compound 2-(2,6-dichlorobenzylidene)cyclohexane-1,3-dione 27 was able to completely inhibit the viral infection of Vero cells as well as to significantly reduce viral load in the brains of newborn Swiss mice. These effects are related to a direct interaction of the compound with the viral particle, blocking the viral adsorption.

14.
Lancet Infect Dis ; 20(6): e129-e137, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32386609

ABSTRACT

For centuries, yellow fever virus infection generated substantial fear among explorers, tourist travellers, workers, military personnel, and others entering areas of transmission. Currently, there is transmission only in some areas of tropical South America and sub-Saharan Africa. When symptomatic, yellow fever infection causes severe liver dysfunction and coagulopathy with elevated mortality rates. Since there is no effective treatment, vaccination against yellow fever, available since 1937, represents an important preventive intervention in endemic areas. Every year, an increasing number of individuals are travelling to yellow fever endemic areas, many of whom have complex medical conditions. Travel health practitioners should do individualised assessments of the risks and benefits of yellow fever vaccination to identify potential contraindications. The most relevant contraindications include a history of thymoma or thymus dysfunction, AIDS, and individuals receiving immunosuppressive drugs including biological therapies or chemotherapy. We briefly review strategies to prevent yellow fever infection in travellers with the use of yellow fever vaccination and the use of personal protection measures to avoid mosquito bites.

15.
Article in English | MEDLINE | ID: mdl-32358223

ABSTRACT

OBJECTIVE: To determine whether live-attenuated yellow fever vaccine (YFV) was associated with MS relapse, we evaluated the clinical courses of 23 patients in the year before and the year after immunization at the university hospital of Geneva, Switzerland. METHODS: This self-controlled retrospective cohort included adult patients with MS receiving YFV between 2014 and 2018 and defined the year before vaccination, the 3 months thereafter, and the 9 months following as the pre-exposure (PEP), exposure-risk (ERP), and postrisk (PRP) periods, respectively. The primary outcome was the relative incidence of relapse in the ERP vs the PEP. Secondary end points included the presence of new T2-weighted (T2) or T1-weighted gadolinium-positive (T1Gd+) MRI lesions. RESULTS: Of 23 patients with MS receiving YFV (20 relapsing MS and 3 primary progressive MS), 17 (74%) were women; mean age was 34 years (SD ±10); and 10 of 23 (40%) were treated with disease-modifying therapies (DMTs). Although 9 patients experienced 12 relapses in the PEP, only one experienced a relapse in the ERP; 3 other patients experienced one relapse each in the PRP. None of the 8 patients receiving natalizumab at the time of vaccination experienced relapse thereafter. In the PEP, ERP, and PRP, 18, 2, and 9 patients had new brain and/or spinal cord lesions on T2 or T1Gd + MRI, respectively. CONCLUSIONS: In this cohort, YF vaccination was associated with neither an increase in MS relapse nor emergence of brain and/or spinal lesions. Further studies are warranted to confirm these findings. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for persons with MS, YFV may not increase relapse risk.

16.
Environ Sci Pollut Res Int ; 27(22): 27870-27884, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32405938

ABSTRACT

Aedes aegypti is the main mosquito vector of dengue, zika, chikungunya, and yellow fever diseases. The low effectiveness of vector control options is mainly related to the increased insect's resistance and to the toxicity of products used for non-target organisms. The development of new environmentally friendly and safer products is imperative. Technical cashew nut shell liquid (tCNSL), mostly composed by cardanol (C), is an abundant by-product of the cashew (Anacardium occidentale L.) production chain, available at low cost, and with proven larvicidal activity. However, chemical modifications in both tCNSL and cardanol were required to increase their water solubilities. Our objectives were to synthesise and characterise sustainable, low-cost and easy-to-use multiple function products based on tCNSL, cardanol, and the sulphonates obtained from both; and to evaluate all these products efficacy as surfactants, larvicidal, and antimicrobial agents. None of the sulphonates presented antimicrobial and larvicidal activities. tCNSL and cardanol were successfully emulsified with sodium technical cashew nut shell liquid sulphonate (NatCNSLS, complex mixture of surfactants). The emulsions obtained presented larvicidal activity due to the presence of tCNSL and cardanol in their composition. Our results showed that the tCNSL+NatCNSLS mixture emulsion was an effective larvicide and surfactant multiple function product, with high availability and easy-to-use, which can facilitate its large-scale use in different environments. Graphical abstract.


Subject(s)
Aedes , Anacardium , Insecticides , Zika Virus Infection , Zika Virus , Animals , Emulsions , Larva , Nuts , Phenols
17.
Parasit Vectors ; 13(1): 257, 2020 May 15.
Article in English | MEDLINE | ID: mdl-32414396

ABSTRACT

BACKGROUND: Aedes aegypti (L.) is the main vector of dengue, yellow fever, Zika and chikungunya viruses. A new method for controlling this mosquito has been developed based on the possibility that wild adult mosquitoes exposed to artificial resting sites contaminated with a larvicide, can disseminate it to larval breeding sites, is named "auto-dissemination". The present study was undertaken to evaluate if a chitin synthesis inhibitor like lufenuron can be disseminated to larval breeding sites and prevent adult emergence and also if forced contact of Ae. aegypti females with treated surfaces can affect its fertility, fecundity, and blood intake capacity. METHODS: Larval susceptibility to lufenuron was measured through EI50 and EI90. On the other hand, gravid females were exposed by tarsal contact to lufenuron-treated papers, we used the WHO susceptibility test kit tube to line the papers, and 1, 3 or 5 females for the transference. We also evaluated if the exposure of female mosquitoes to lufenuron-treated papers (0.4 and 1 mg a.i./cm2) has an effect on their fertility, fecundity or in the ability to feed on blood. In each assay 12-15 female mosquitoes were exposed to lufenuron for 1 h, 24 h before blood meal (BBM) or 24 h after a blood meal (ABM). RESULTS: Lufenuron proved to be very active against Ae. aegypti larvae with an EI50 of 0.164 ppb and EI90 of 0.81 ppb. We also found that lufenuron can be transferred by females from treated surfaces to clean containers causing the inhibition of emergence of the larvae (between 30 and 50%). This effect was dependent on the concentration applied on the paper and the number of females added to each cage. CONCLUSIONS: This study introduces an innovation by first exploring the possibility that an insect growth regulator (IGR) belonging to the group of benzoylphenyl ureas, such as lufenuron, can be transferred by gravid females to breeding sites and that at the same time can have an effect on fertility, fecundity and blood intake capacity of adult mosquitoes.

18.
Environ Sci Pollut Res Int ; 27(23): 28737-28748, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32458306

ABSTRACT

Aedes (Stegomyia) aegypti is a cosmopolitan species that transmits arbovirus of medical importance as dengue, Zika, and chikungunya. The main strategy employed for the control of this mosquito is the use of larvicidal agents. However, the overuse of synthetic chemical larvicides has led to an increase in resistant insects, making management difficult. Therefore, the use of botanical insecticide-based nanosystems as an alternative to the use of synthetic agents for the control of Ae. aegypti has gained more considerable attention in the last years, mainly due to the advantages of nanostructured delivery systems, such as (a) controlled release; (b) greater surface area; (c) improvement of biological activity; (d) protection of natural bioactive agents from the environment and thus achieving stability; and (e) lipophilic drugs are easier dispersed even in aqueous vehicles. This review summarizes the current knowledge about botanical insecticide-based nanosystems as larvicidal against Ae. aegypti larvae. The majority of papers used metallic nanoparticles (NPs) as larvicidal agents, mainly silver nanoparticles (AgNPs), showing potential for their use as an alternative, followed by nanoemulsions containing vegetable oils, most essential oils, nanosystems that allow the dispersion of this high hydrophobic product in water, the environment of larval development. The final section describes scientific findings about the mode of action of these NPs, showing the gap about this subject in literature.


Subject(s)
Aedes , Insecticides , Metal Nanoparticles , Zika Virus Infection , Zika Virus , Animals , Larva , Mosquito Control , Silver
19.
Hum Vaccin Immunother ; : 1-5, 2020 May 15.
Article in English | MEDLINE | ID: mdl-32412830

ABSTRACT

Introduction: International tourism has grown tremendously in the past 2-3 decades in India resulting in exposure of travelers to varied spectrum of diseases prevalent in different parts of the world. Immunization plays a prominent role in protection of the exposed individuals. The objective of the present study was to assess the awareness and knowledge regarding yellow fever and other travel vaccinations amongst travelers of eastern India.Materials and methods: In the present cross-sectional study, participants attending Yellow Fever Vaccination Clinic at All India Institute of Medical Sciences, Bhubaneswar, during August-September 2018 were approached. Newly registered participants aged 15 y and above were interviewed consecutively till the required sample size of 300 was fulfilled. Awareness and knowledge regarding travel vaccinations and their adverse effects were assessed with pretested structured interview schedule. Bivariate and multivariate logistic regressions were done to assess the association of various factors with awareness of travel vaccinations.Results: Among the participants, most of them were males (90.7%), belonged to the age group of 15-45 y (87.3%), married (64.3%), graduates (19%), and were working (78.3%). Most of the participants were traveling to South Africa (85.4%). Only 57.3% participants were aware of any travel vaccinations. Only 37.5% participants knew that yellow fever vaccine confers lifelong immunity. On multivariate logistic regression higher education, working occupation and history of previous vaccination were significantly associated with awareness of travel vaccinations.Conclusion: Awareness regarding travel vaccinations is important to prevent fatal diseases like yellow fever. Vital information pertaining to diseases in different locations and availability of vaccines for prevention needs to be disseminated to the travelers to prevent occurrence of travel bound diseases.

20.
PLoS Negl Trop Dis ; 14(5): e0008304, 2020 05.
Article in English | MEDLINE | ID: mdl-32379756

ABSTRACT

BACKGROUND: To counter the increasing global risk of Yellow fever (YF), the World Health Organisation initiated the Eliminate Yellow fever Epidemics (EYE) strategy. Estimating YF burden, as well as vaccine impact, while accounting for the features of urban YF transmission such as indirect benefits of vaccination, is key to informing this strategy. METHODS AND FINDINGS: We developed two model variants to estimate YF burden in sub-Saharan Africa, assuming all infections stem from either the sylvatic or the urban cycle of the disease. Both relied on an ecological niche model fitted to the local presence of any YF reported event in 34 African countries. We calibrated under-reporting using independent estimates of transmission intensity provided by 12 serological surveys performed in 11 countries. We calculated local numbers of YF infections, deaths and disability-adjusted life years (DALYs) lost based on estimated transmission intensity while accounting for time-varying vaccination coverage. We estimated vaccine demand and impact of future preventive mass vaccination campaigns (PMVCs) according to various vaccination scenarios. Vaccination activities conducted in Africa between 2005 and 2017 were estimated to prevent from 3.3 (95% CI 1.2-7.7) to 6.1 (95% CI 2.4-13.2) millions of deaths over the lifetime of vaccinees, representing extreme scenarios of none or maximal herd effects, respectively. By prioritizing provinces based on the risk of urban YF transmission in future PMVCs, an average of 37.7 million annual doses for PMVCs over eight years would avert an estimated 9,900,000 (95% CI 7,000,000-13,400,000) infections and 480,000 (180,000-1,140,000) deaths over the lifetime of vaccinees, corresponding to 1.7 (0.7-4.1) deaths averted per 1,000 vaccine doses. CONCLUSIONS: By estimating YF burden and vaccine impact over a range of spatial and temporal scales, while accounting for the specificity of urban transmission, our model can be used to inform the current EYE strategy.


Subject(s)
Cost of Illness , Disease Transmission, Infectious/prevention & control , Epidemics/prevention & control , Yellow Fever Vaccine/administration & dosage , Yellow Fever/epidemiology , Yellow Fever/prevention & control , Adolescent , Adult , Africa/epidemiology , Aged , Aged, 80 and over , Child , Child, Preschool , Epidemiologic Methods , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Models, Statistical , Yellow Fever Vaccine/immunology , Young Adult
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