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2.
Rev. argent. salud publica ; 39(9): 38-41, Julio 2019.
Artigo em Espanhol | LILACS, BINACIS, ARGMSAL | ID: biblio-1007593

RESUMO

: INTRODUCCIÓN: En Argentina desde 1998 ocurrieron brotes de dengue todos los años excepto 2001 y 2005 en diferentes áreas, en 15 jurisdicciones, con identificación de los 4 serotipos. El objetivo de este estudio fue identificar poblaciones con mayor riesgo de desarrollar formas graves de la enfermedad como insumo para la posible introducción de una estrategia de prevención. METODOS: Se realizó un estudio retrospectivo descriptivo de los casos de dengue confirmados autóctonos a partir de publicaciones oficiales, notificaciones al SNVS e información aportada por las áreas de epidemiología provinciales. Se elaboró una estratificación del riesgo de dengue grave por departamento para el período 1998-2018. RESULTADOS: Se elaboraron 5 criterios de estratificación de riesgo: registro de casos autóctonos en al menos 2 de los 5 cinco últimos años, registro de 2 o más serotipos causantes del 10% o más de los casos cada uno, incidencia acumulada mayor a 500 casos por 100 mil habitantes, incidencia acumulada mayor a 5 casos por mil menores de 15 años y registro de casos graves o fallecidos. Se obtuvieron 60 departamentos con 1 criterio, 19 con 2, 8 con 3, 4 con 4, 1 con 5 y 129 no cumplieron criterios. DISCUSION: Solo 13 departamentos sumaron 3 criterios o más, resultado del predominio de DENV-1, la baja incidencia en menores de 15 años y el bajo número de casos graves y fatales. La estratificación del riesgo poblacional con criterios de registro sistemático se orienta a obtener una herramienta de evaluación de los escenarios de dengue que puedan presentarse en el futuro.


Assuntos
Humanos , Dengue/epidemiologia , Sistema de Vigilância Sanitária , Argentina/epidemiologia , Epidemiologia Descritiva , Estudos Retrospectivos , Dengue/prevenção & controle
3.
Rev Soc Bras Med Trop ; 52: e20180341, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31271613

RESUMO

INTRODUCTION: Areas at risk of transmission of arboviruses have been monitored using ovitraps. This study aimed to evaluate the spatial distribution of Aedes aegypti in vulnerable areas for the transmission of arboviruses and assess the influence of climatic conditions on the infestation of these culicids. METHODS: Ovitraps were installed in Agrestina, Pernambuco, Northeastern Brazil. RESULTS: Overall, 44,936 eggs were collected, and the indexes of infestation varied. Relative humidity was significantly associated with the infestations. CONCLUSIONS: Using ovitraps, entomologic indexes and analysis of climatic factors might be good strategies for monitoring vulnerable areas for the transmission of arboviruses.


Assuntos
Arbovirus , Febre de Chikungunya/prevenção & controle , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Oviposição , Infecção por Zika virus/prevenção & controle , Aedes/fisiologia , Animais , Brasil , Febre de Chikungunya/transmissão , Dengue/transmissão , Humanos , Umidade , Mosquitos Vetores/fisiologia , Chuva , Características de Residência , Estações do Ano , Análise Espacial , Temperatura Ambiente , Infecção por Zika virus/transmissão
4.
BMC Public Health ; 19(1): 669, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146722

RESUMO

BACKGROUND: Thermal fogging of Insecticides is a vector control strategy used by the Medellin Secretary of Health to combat dengue. This method is employed during outbreaks to curb populations of potentially infectious adult mosquitoes and interrupt transmission cycles. While this strategy has been used in Medellin since 2007, in some years it has not reduced dengue cases as expected. Difficulties in the implementation of fumigation strategies, such as lack of opportunity for treatment and public perception may be factors that limit its utility. The objective of this study was to identify barriers that hinder the implementation of thermal fogging, as well as attitudes and beliefs that prevent its acceptance. METHODS: We used a cross-sectional observational study of mixed methods carried out in neighborhoods prioritized for fumigation treatment in Medellin, Colombia. First, we assessed the timeliness of treatment by determining the latency period between reported dengue cases and the implementation of fumigation in response to those cases. Next, we administered structured questionnaires to residents in the area of fumigation treatments (n = 4455 homes) to quantify acceptance and rejection, as well as factors associated with rejection. RESULTS: The median time between notification and treatment was 25 days (IQR 20.0-36.5). Fumigators were only able to treat 53.7% of total households scheduled for treatment; 9.6% rejected treatment, and treatment teams were unable to fumigate the remaining 36.7% of homes due to absent residents, no adults being present, and other reasons. The most frequent causes for rejection were residents being busy at the time of treatment (33.1%) and no interest in the treatment (24.5%). Other reasons for rejection include the perceptions that fumigation does not control pests other than mosquitoes (4.3%), that no mosquitoes were present in the home (3.3%), and that fumigation affects human health (3.1%). CONCLUSIONS: The high percentage of houses where it was not possible to perform fumigation limits control of the vector. Future strategies should consider more flexible treatment schedules and incorporate informational messages to educate residents about the safety and importance of treatment.


Assuntos
Dengue/prevenção & controle , Fumigação/estatística & dados numéricos , Inseticidas/administração & dosagem , Controle de Mosquitos/métodos , Adulto , Colômbia/epidemiologia , Estudos Transversais , Dengue/epidemiologia , Características da Família , Feminino , Fumigação/métodos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores , Características de Residência , Inquéritos e Questionários
5.
Environ Monit Assess ; 191(Suppl 2): 393, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31254076

RESUMO

India has the largest number of dengue cases in the world, contributing approximately 34% of the global burden. The framework for a geospatially enabled early warning and adaptive response system (EWARS) was first proposed in 2008. It was meant to be a decision support system for enhancing traditional surveillance methods for preventing mosquito-borne diseases in India by utilizing remote sensing data and fuzzy logic-based mathematical predictive modeling. This conceptual paper presents a significant evolution of EWARS such that it synthesizes inputs from not only traditional surveillance and reporting systems for dengue but also from the public via participatory disease surveillance. Two smartphone-based applications have been developed to support EWARS. The first-MOSapp-allows field health workers to upload surveillance data and collect key data on environmental parameters by both direct observation and via portable microclimate stations. The second-DISapp-collects relevant information directly from the community to support participatory disease surveillance. It also gives the user a real-time estimate of the risk of exposure to dengue in proximity to their home and has an educational component that provides information on relevant preventive measures. Both applications utilize a new mosquito abundance measure-the mosquito perception index (MPI)-as reported by the user. These data streams will feed into the EWARS model to generate dynamic risk maps that can guide resource optimization and strengthen disease surveillance, prevention, and response. It is anticipated that such an approach can assist in addressing gaps in the current system of dengue surveillance and control in India.


Assuntos
Aedes/fisiologia , Dengue/prevenção & controle , Aplicativos Móveis , Mosquitos Vetores/fisiologia , Animais , Dengue/epidemiologia , Dengue/transmissão , Monitoramento Epidemiológico , Humanos , Índia/epidemiologia , Modelos Teóricos , Medição de Risco
6.
Mem Inst Oswaldo Cruz ; 114: e180544, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31038548

RESUMO

BACKGROUND: Aedes aegypti populations in Brazil have been subjected to insecticide selection pressures with variable levels and sources since 1967. Therefore, the Brazilian Ministry of Health (MoH) coordinated the activities of an Ae. aegypti insecticide resistance monitoring network (MoReNAa) from 1999 to 2012. OBJECTIVES: The objective of this study was to consolidate all information available from between 1985 and 2017 regarding the resistance status and mechanisms of Brazilian Ae. aegypti populations against the main insecticide compounds used at the national level, including the larvicide temephos (an organophosphate) and the adulticide deltamethrin (a pyrethroid). METHODS: Data were gathered from two sources: a bibliographic review of studies published from 1985 to 2017, and unpublished data produced by our team within the MoReNAa between 1998 and 2012. A total of 146 municipalities were included, many of which were evaluated several times, totalling 457 evaluations for temephos and 274 for deltamethrin. Insecticide resistance data from the five Brazilian regions were examined separately using annual records of both the MoH supply of insecticides to each state and the dengue incidence in each evaluated municipality. FINDINGS: Ae. aegypti resistance to temephos and deltamethrin, the main larvicide and adulticide, respectively, employed against mosquitoes in Brazil for a long time, was found to be widespread in the country, although with some regional variations. Comparisons between metabolic and target-site resistance mechanisms showed that one or another of these was the main component of pesticide resistance in each studied population. MAIN CONCLUSIONS: (i) A robust dataset on the assessments of the insecticide resistance of Brazilian Ae. aegypti populations performed since 1985 was made available through our study. (ii) Our findings call into question the efficacy of chemical control as the sole methodology of vector control. (iii) It is necessary to ensure that sustainable insecticide resistance monitoring is maintained as a key component of integrated vector management. (iv) Consideration of additional parameters, beyond the supply of insecticides distributed by the MoH or the diverse local dynamics of dengue incidence, is necessary to find consistent correlations with heterogeneous vector resistance profiles.


Assuntos
Aedes/efeitos dos fármacos , Dengue/prevenção & controle , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Nitrilos/farmacologia , Piretrinas/farmacologia , Temefós/farmacologia , Animais , Bioensaio , Brasil/epidemiologia , Dengue/epidemiologia , Dengue/transmissão , Incidência , Inseticidas/administração & dosagem , Nitrilos/administração & dosagem , Piretrinas/administração & dosagem , Temefós/administração & dosagem
7.
ABCS health sci ; 44(1): 9-14, 02 maio 2019. tab
Artigo em Português | LILACS | ID: biblio-995003

RESUMO

INTRODUÇÃO: A dengue é uma arbovirose, transmitida para o homem através da picada do mosquito Aedes aegypti, e que acomete grande número de indivíduos no mundo. Nos últimos 50 anos, junto com o aumento da expansão geográfica, a incidência de dengue aumentou aproximadamente 30 vezes. Ao longo dos anos, diversas medidas de combate à dengue foram implementadas, a partir daí, no ano de 2004 foi possível evidenciar que houve redução de 290% nos casos de dengue em relação ao ano anterior. OBJETIVO: Descrever o conhecimento de escolares do Rio Grande do Sul sobre o tema dengue. MÉTODOS: Estudo com abordagem quantitativa do tipo descritiva realizado com jovens alunos da rede pública de educação da cidade de Tupãnciretã, por meio de um questionário estruturado. RESULTADOS: Evidenciou-se que a maioria dos alunos tinha conhecimento sobre como a dengue é transmitida, sendo que 35% acreditavam que a fêmea do mosquito transmite a doença e ainda, 58,8% afirmaram que conseguem reconhecer o mosquito. Uma parcela dos alunos acredita que o mosquito pica preferencialmente durante o dia, onde a principal forma de transmissão selecionada foi "O mosquito pica uma pessoa doente e transmite a doença à outra pessoa" e os principais sintomas assinalados foram febre, dor de cabeça e cansaço. CONCLUSÃO: O estudo demonstrou que boa parte dos jovens possuem conhecimentos sobre a dengue, entretanto, ainda há crianças e adolescentes que não conhecem o assunto, trazendo à tona a importância deste tema nas campanhas de saúde.


INTRODUCTION: Dengue is an arbovirus, transmitted to humans through the bite of the Aedes aegypti mosquito, and which affects a large number of individuals in the world. Over the past 50 years, along with increased geographic expansion, the incidence of dengue increased approximately 30-fold. Over the years, several measures to combat dengue have been implemented and due to this factor, in 2004, there was a 290% reduction in dengue cases in relation to the previous year. OBJECTIVE: To describe the knowledge of schoolchildren from Rio Grande do Sul on the subject of dengue. METHODS: A quantitative descriptive study carried out with young students of the public education system of the city of Tupãnciretã, through a structured questionnaire. RESULTS: It was evidenced that most of the students had knowledge about how dengue is transmitted, 35% believed that the mosquito female transmits the disease and 58.8% claim to be able to recognize the mosquito. A significant portion of the students believe that the mosquito bites preferentially during the day, where the main form of transmission selected was "The mosquito bites a sick person and transmits the disease to the other person" and the main symptoms were fever, headache and tiredness. CONCLUSION: The study showed that most of the young people have knowledge about dengue, however, there are still children and adolescents who do not know the subject, bringing to the fore the importance of this theme in health campaigns.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Adulto Jovem , Prevenção Primária , Epidemiologia , Conhecimento , Dengue , Dengue/prevenção & controle , Dengue/epidemiologia
8.
Value Health Reg Issues ; 18: 132-144, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31082793

RESUMO

OBJECTIVES: To review the literature on the cost-effectiveness of dengue vaccination in Southeast Asian countries and possibly to provide recommendations on promoting dengue vaccination in this region. METHODS: A systematic search was conducted to identify relevant articles in 3 major databases (ProQuest, American Society of Tropical Medicine and Hygiene, and PubMed). Complete economic evaluation studies, including willingness-to-pay (WTP) studies, that were conducted in any Southeast Asian country were included in this study. Systematic review, non-full-text, and non-English studies were specifically excluded. RESULTS: Nine selected studies highlighted the economic evaluation of dengue vaccination in Southeast Asian countries by considering many parameters (eg, vaccine cost, vaccine efficacy, cost-effectiveness threshold, economic assessment, public acceptance, and WTP). All studies confirmed that dengue vaccine can be used as a prevention strategy to reduce the incidence rate of dengue cases by providing a variance of high cost-effectiveness values. In addition, communities provided a good assessment, acceptance, and WTP value for the vaccine. CONCLUSIONS: The use of dengue vaccine could reduce the burden of disease and economic burden due to dengue infection in Southeast Asian countries. The efficacy of dengue vaccine was estimated to be 50-95% for those <9 years, 9 years, and >9 years. In particular, several studies reported that dengue vaccine could be categorized as a cost-effective intervention in Southeast Asian countries within certain conditions.


Assuntos
Vacinas contra Dengue/economia , Dengue/prevenção & controle , Ásia Sudeste , Análise Custo-Benefício , Dengue/economia , Dengue/epidemiologia , Humanos
9.
Appl Microbiol Biotechnol ; 103(12): 4977-4986, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31037380

RESUMO

Dengue virus (DENV) and Japanese encephalitis virus (JEV) are closely related mosquito-borne flaviviruses. Together, they caused most arthropod-borne diseases in the world. Previously, we had demonstrated that both live attenuated and inactivated JE vaccines elicited cross-protection against DENV infection, and a DNA vaccine candidate expressing JEV prM-E protein (named pCAG-JME) could provide effective protection against JEV infection in mice. In this study, we examined whether the same pCAG-JME could elicit cross-protection against DENV infection. Our results showed that pCAG-JME indeed induced cross-reactive antibodies and cross-protection against four different serotypes of DENV in mice. Interestingly, pCAG-JME-immunized mice also generated both Th1 and Th2 responses when stimulated by all four different serotypes of DENV antigens. Moreover, cross-primed CD8+ T cell response was also detected following the stimulation of DENV proteins using intracellular cytokine staining. In addition, sera from pCAG-JME-immunized mice significantly reduced the mortality caused by DENV2 infection in severe combination immunodeficiency mouse. These results suggest that both JE and DENV cross-reactive antibodies and cross-primed T cells might play important roles in the cross-protection. The findings of this study also indicate a possibility of developing novel multivalent genetically engineered vaccines against both JEV and DENV.


Assuntos
Antígenos Virais/imunologia , Proteção Cruzada , Vacinas contra Dengue/imunologia , Dengue/prevenção & controle , Vírus da Encefalite Japonesa (Espécie)/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/genética , Vacinas contra Dengue/genética , Vírus da Dengue/classificação , Vírus da Dengue/imunologia , Vírus da Encefalite Japonesa (Espécie)/genética , Feminino , Imunização , Imunização Passiva , Camundongos , Camundongos Endogâmicos BALB C , Sorogrupo , Imunodeficiência Combinada Severa , Células Th1/imunologia , Células Th2/imunologia , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Proteínas do Envelope Viral/genética
10.
Rev Saude Publica ; 53: 29, 2019 Apr 01.
Artigo em Inglês, Português | MEDLINE | ID: mdl-30942271

RESUMO

OBJECTIVE: To evaluate whether sites with large amount of potential breeding sites for immature forms of Aedes aegypti, called strategic points, influence in the active vector's dispersion into properties in their surroundings. METHODS: We selected four areas in the municipality of Campinas, three of them with strategic points classified as high, moderate, and low risk according to infestation and a control area, without strategic points. Between October 2015 and September 2016, we monthly installed oviposition traps and evaluated the infestation by Ae. aegypti in all properties of each selected area. To verify if there was vector dispersion from each strategic point, based on its location, we investigated the formation of clusters with excess of eggs or larvae or pupae containers, using the Gi spatial statistics. RESULTS: The amount of eggs collected in the ovitraps and the number of positive containers for Ae. aegypti did not show clusters of high values concerning its distance from the strategic point. Both presented random distribution not spatially associated with the positioning of strategic points in the area. CONCLUSIONS: Strategic points are not confirmed as responsible for the vector's dispersion for properties in their surroundings. We highlight the importance of reviewing the current strategy of the vector control program in Brazil, seeking a balance from the technical, operational, and economic point of view, without disregarding the role of strategic points as major producers of mosquitoes and their importance in the dissemination of arboviruses in periods of transmission.


Assuntos
Aedes/crescimento & desenvolvimento , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Mosquitos Vetores/crescimento & desenvolvimento , Oviposição/fisiologia , Pupa/crescimento & desenvolvimento , Aedes/virologia , Distribuição Animal/fisiologia , Animais , Brasil , Dengue/transmissão , Monitoramento Ambiental , Feminino , Controle de Mosquitos/estatística & dados numéricos , Mosquitos Vetores/virologia , Fatores de Risco , Análise Espacial , População Urbana
11.
PLoS Negl Trop Dis ; 13(4): e0007280, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31022175

RESUMO

Dengue is an important public health problem in the Philippines. We sought to describe the trends in dengue research in the country. We searched four databases and identified published studies on dengue research in the Philippines during the past 60 years. We reviewed 135 eligible studies, of which 33% were descriptive epidemiologic studies or case series, 16% were entomologic or vector control studies, 12% were studies on dengue virology and serologic response, 10% were socio-behavioral and economics studies, 8% were clinical trials, 7% were on burden of disease, 7% were investigations on markers of disease severity, 5% were on dengue diagnostics, and 2% were modeling studies. During the last decade, dengue research in the Philippines has increased and evolved from simple descriptive studies to those with more complex and diverse designs. We identified several key topics where more research would be useful.


Assuntos
Pesquisa Biomédica/tendências , Dengue/epidemiologia , Dengue/prevenção & controle , Aedes/crescimento & desenvolvimento , Animais , Dengue/diagnóstico , Dengue/virologia , Vírus da Dengue/imunologia , Vírus da Dengue/patogenicidade , Gerenciamento Clínico , Transmissão de Doença Infecciosa/prevenção & controle , Humanos , Controle de Mosquitos/métodos , Filipinas/epidemiologia
13.
Environ Sci Pollut Res Int ; 26(16): 16303-16315, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30977009

RESUMO

The effects of crude ethanol derived leaf extract Trichodesma indicum (Linn) (Ex-Ti) and their chief derivatives were accessed on the survival and development of the dengue mosquito Ae. aegypti also their non-toxic activity against mosquito predator. T. indicum is recognized to be the vital weed plant and a promising herb in the traditional ayurvedic medicine. In this study, the GC-MS chromatogram of Ex-Ti showed higher peak area percentage for cis-10-Heptadecenoic acid (21.83%) followed by cycloheptadecanone (14.32%). The Ex-Ti displayed predominant mortality in larvae with 96.45 and 93.31% at the prominent dosage (200 ppm) against III and IV instar. Correspondingly, sub-lethal dosage against the enzymatic profile of III and IV instar showed downregulation of α,ß-carboxylesterase and SOD protein profiles at the maximum concentration of 100 ppm. However, enzyme level of GST as well as CYP450 increased significantly dependent on sub-lethal concentration. Likewise, fecundity and hatchability of egg rate of dengue mosquito decreased to the sub-lethal concentration of Ex-Ti. Repellent assay illustrates that Ex-Ti concentration had greater protection time up to 210 min at 100 ppm. Also, activity of Ex-Ti on adult mosquito displayed 100% mortality at the maximum dosage of 600, 500 and 400 ppm within the period of 50, 60 and 70 min, respectively. Photomicrography screening showed that lethal dosage of Ex-Ti (100 ppm) produced severe morphological changes with dysregulation in their body parts as matched to the control. Effects of Ex-Ti on the Toxorhynchites splendens IV instar larvae showed less mortality (43.47%) even at the maximum dosage of 1500 ppm as matched to the chemical pesticide Temephos. Overall, the present research adds a toxicological valuation on the Ex-Ti and their active constituents as a larvicidal, repellent and adulticidal agents against the global burdening dengue mosquito.


Assuntos
Aedes/efeitos dos fármacos , Boraginaceae/química , Repelentes de Insetos/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Carboxilesterase , Culicidae/efeitos dos fármacos , Dengue/prevenção & controle , Feminino , Fertilidade/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Larva/efeitos dos fármacos , Praguicidas/farmacologia , Extratos Vegetais/análise , Folhas de Planta/química
14.
Math Biosci Eng ; 16(3): 1171-1189, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30947414

RESUMO

The dengue vaccine, CYD-TDV (Dengvaxia), has been licensed in 20 countries in Latin America and Southeast Asia beginning in 2015. In April 2018, the World Health Organization (WHO) advised that CYD-TDV should only be administered to individuals with a history of previous dengue virus infection. Using literature-based parameters, a mathematical model of dengue transmission and vaccination was developed to determine the optimal vaccination strategy while considering the effect of antibody-dependent enhancement (ADE). We computed the optimal vaccination rates under various vaccination costs and serological profiles. We observe that the optimal dengue vaccination rates for seropositive individuals are highest at the initial phase of a vaccination program, requiring intense effort at the early phase of an epidemic. The model shows that even in the presence of ADE, vaccination could reduce dengue incidence and provide population benefits. Specifically, optimal vaccination rates increase with a higher proportion of monotypic seropositive individuals, resulting in a higher impact of vaccination. Even in the presence of ADE and with limited vaccine efficacy, our work provides a population-level perspective on the potential merits of dengue vaccination.


Assuntos
Vacinas contra Dengue/uso terapêutico , Vírus da Dengue , Dengue/sangue , Dengue/prevenção & controle , Vacinação/métodos , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Calibragem , Dengue/epidemiologia , Humanos , Programas de Imunização/normas , Incidência , México/epidemiologia , Modelos Teóricos , Risco , Sorogrupo
15.
PLoS Comput Biol ; 15(3): e1006831, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30849074

RESUMO

Management of vector population is a commonly used method for mitigating transmission of mosquito-borne infections, but quantitative information on its practical public health impact is scarce. We study the effectiveness of Ultra-Low Volume (ULV) insecticide spraying in public spaces for preventing secondary dengue virus (DENV) cases in Porto Alegre, a non-endemic metropolitan area in Brazil. We developed a stochastic transmission model based on detailed entomological, epidemiological and population data, accounting for the geographical distribution of mosquitoes and humans in the study area and spatial transmission dynamics. The model was calibrated against the distribution of DENV cluster sizes previously estimated from the same geographical setting. We estimated a ULV-induced mortality of 40% for mosquitoes and found that the implemented control protocol avoided about 24% of symptomatic cases occurred in the area throughout the 2015-2016 epidemic season. Increasing the radius of treatment or the mortality of mosquitoes by treating gardens and/or indoor premises would greatly improve the result of control, but trade-offs with respect to increased efforts need to be carefully analyzed. We found a moderate effectiveness for ULV-spraying in public areas, mainly due to the limited ability of this strategy in effectively controlling the vector population. These results can be used to support the design of control strategies in low-incidence, non-endemic settings.


Assuntos
Dengue/prevenção & controle , Inseticidas , Controle de Mosquitos/métodos , Animais , Brasil/epidemiologia , Análise por Conglomerados , Dengue/epidemiologia , Dengue/transmissão , Humanos , Incidência , Mosquitos Vetores
16.
PLoS Comput Biol ; 15(3): e1006710, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30893294

RESUMO

Prophylactic vaccination is a powerful tool for reducing the burden of infectious diseases, due to a combination of direct protection of vaccinees and indirect protection of others via herd immunity. Computational models play an important role in devising strategies for vaccination by making projections of its impacts on public health. Such projections are subject to uncertainty about numerous factors, however. For example, many vaccine efficacy trials focus on measuring protection against disease rather than protection against infection, leaving the extent of breakthrough infections (i.e., disease ameliorated but infection unimpeded) among vaccinees unknown. Our goal in this study was to quantify the extent to which uncertainty about breakthrough infections results in uncertainty about vaccination impact, with a focus on vaccines for dengue. To realistically account for the many forms of heterogeneity in dengue virus (DENV) transmission, which could have implications for the dynamics of indirect protection, we used a stochastic, agent-based model for DENV transmission informed by more than a decade of empirical studies in the city of Iquitos, Peru. Following 20 years of routine vaccination of nine-year-old children at 80% coverage, projections of the proportion of disease episodes averted varied by a factor of 1.76 (95% CI: 1.54-2.06) across the range of uncertainty about breakthrough infections. This was equivalent to the range of vaccination impact projected across a range of uncertainty about vaccine efficacy of 0.268 (95% CI: 0.210-0.329). Until uncertainty about breakthrough infections can be addressed empirically, our results demonstrate the importance of accounting for it in models of vaccination impact.


Assuntos
Dengue/prevenção & controle , Dengue/transmissão , Análise de Sistemas , Incerteza , Vacinas Virais/administração & dosagem , Calibragem , Criança , Simulação por Computador , Humanos , Peru
17.
Artigo em Inglês | MEDLINE | ID: mdl-30841574

RESUMO

In this work, a two-strain dengue model with vertical transmission in the mosquito population is considered. Although vertical transmission is often ignored in models of dengue fever, we show that effective control of an outbreak of dengue can depend on whether or not the vertical transmission is a significant mode of disease transmission. We model the effect of a control strategy aimed at reducing human-mosquito transmissions in an optimal control framework. As the likelihood of vertical transmission increases, outbreaks become more difficult and expensive to control. However, even for low levels of vertical transmission, the additional, uncontrolled, transmission from infected mosquito to eggs may undercut the effectiveness of any control function. This is of particular importance in regions where existing control policies may be effective and the endemic strain does not exhibit vertical transmission. If a novel strain that does exhibit vertical transmission invades, then existing, formerly effective, control policies may no longer be sufficient. Therefore, public health officials should pay more attention to the role of vertical transmission for more effective interventions and policy.


Assuntos
Dengue/transmissão , Transmissão Vertical de Doença Infecciosa , Animais , Culicidae , Dengue/prevenção & controle , Vírus da Dengue , Surtos de Doenças/prevenção & controle , Humanos
18.
Cien Saude Colet ; 24(3): 1075-1082, 2019 Mar.
Artigo em Português | MEDLINE | ID: mdl-30892527

RESUMO

The scope of this study was to identify which categories of urban waste are associated with cases of dengue and to evaluate the impact of garbage collection on dengue infection in the City of Recife (Brazil). Data from categorized waste weighing and the confirmed cases of dengue in the city were used. The data were analyzed using Pearson's correlation coefficient for the 13 categories of urban garbage, followed by Multivariate Linear Regression, selecting the variables by the stepwise method. A negative correlation between dengue infections in seven categories was identified: household garbage (r = -0.835), differentiated residues (r = -0.835), special operations residues (r = -0.711), building rubble (r = -0.687), selective waste collection (r = -0.425) and tires (r = -0.423). The regression model was able to explain 75% of the variation, indicating that an increase of 1,000 tons in household garbage collection provides a decrease of 0.032 in cases of dengue, while the same increase in tire collection esults in a decrease of 0.465. The results show that garbage collection has a strong negative impact on dengue cases and can be adopted as a prevention strategy by municipal governments.


Assuntos
Dengue/epidemiologia , Resíduos de Alimentos , Eliminação de Resíduos/métodos , Brasil/epidemiologia , Cidades , Dengue/prevenção & controle , Características da Família , Feminino , Humanos , Modelos Lineares , Masculino , Análise Multivariada
19.
Artigo em Inglês | MEDLINE | ID: mdl-30897770

RESUMO

Effort to control dengue transmission requires community participation to ensure its sustainability. We carried out a knowledge attitude and practice (KAP) survey of dengue prevention to inform the design of a vector control intervention. A cross-sectional survey was conducted in June⁻August 2014 among 521 households in two villages of Yogyakarta, Indonesia. Demographic characteristics and KAP questions were asked using a self-managed questionnaire. Knowledge, attitudes and practice scores were summarized for the population according to sex, age, occupation and education. The average knowledge score was rather poor-3.7 out of 8-although both attitude and practice scores were good: 25.5 out of 32 and 9.2 out of 11 respectively. The best knowledge within the different groups were found among women, the age group 30⁻44 years, people with a university degree and government employees. Best practice scores were found among retired people and housewives. There were several significant gaps in knowledge with respect to basic dengue symptoms, preventive practices and biting and breeding habits of the Aedes mosquito. In contrast, people's practices were considered good, although many respondents failed to recognize outdoor containers as mosquito breeding sites. Accordingly, we developed a vector control card to support people's container cleaning practices. The card was assessed for eight consecutive weeks in 2015, with pre-post larvae positive houses and containers as primary outcome measures. The use of control cards reached a low engagement of the community. Despite ongoing campaigns aiming to engage the community in dengue prevention, knowledge levels were meagre and adherence to taught routines poor in many societal groups. To increase motivation levels, bottom-up strategies are needed to involve all community members in dengue control, not only those that already comply with best practices.


Assuntos
Participação da Comunidade/métodos , Dengue/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Controle de Mosquitos/métodos , Mosquitos Vetores/crescimento & desenvolvimento , Adolescente , Adulto , Fatores Etários , Animais , Estudos Transversais , Dengue/epidemiologia , Feminino , Humanos , Indonésia/epidemiologia , Masculino , Pessoa de Meia-Idade , Poder (Psicologia) , Fatores Sexuais , Fatores Socioeconômicos , Adulto Jovem
20.
Int J Med Sci ; 16(3): 355-365, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30911269

RESUMO

Dengue virus belongs to the Flaviviridae family which also includes viruses such as the Zika, West Nile and yellow fever virus. Dengue virus generally causes mild disease, however, more severe forms of the dengue virus infection, dengue haemorrhagic fever (DHF) and dengue haemorrhagic fever with shock syndrome (DSS) can also occur, resulting in multiple organ failure and even death, especially in children. The only dengue vaccine available in the market, CYD-TDV offers limited coverage for vaccinees from 9-45 years of age and is only recommended for individuals with prior dengue exposure. A number of mutations that were shown to attenuate virulence of dengue virus in vitro and/or in vivo have been identified in the literature. The mutations which fall within the conserved regions of all four dengue serotypes are discussed. This review hopes to provide information leading to the construction of a live attenuated dengue vaccine that is suitable for all ages, irrespective of the infecting dengue serotype and prior dengue exposure.


Assuntos
Vacinas contra Dengue/farmacologia , Vírus da Dengue/genética , Vírus da Dengue/patogenicidade , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Capsídeo/química , Ensaios Clínicos Fase III como Assunto , Dengue/prevenção & controle , Vacinas contra Dengue/imunologia , Genoma Viral , Humanos , Mutação , Vacinas Atenuadas/farmacologia , Vacinas Sintéticas/farmacologia , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Virulência , Fatores de Virulência/química , Fatores de Virulência/genética
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