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1.
J UOEH ; 42(3): 231-236, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879187

RESUMO

To reach the target of ending the dengue epidemic by 2030, all effort shall be made to minimize the dengue transmission across the country through effective, efficient, low-cost and sustainable programs. In Indonesia, the evidence of community empowerment on dengue prevention is insufficient. The objective of this study is to explore the opinion of community and larva monitoring workers (Jumantik cadre) on dengue prevention. A structured free listing interview was conducted in April-May 2019 by targeting two groups: the community and larva workers in one village of Sleman, Yogyakarta. Door to door interviews were done until the quota and saturation were reached. Each group was asked four free listing questions. The analysis was performed in these stages: transcribing, coding, combining by the question, and calculating the salience score. The most salient score about vector control in the larva cadre was not hanging up dirty clothes; in the community it was cleaning the bathtub. Both groups cited themself as the salient motivator in joining the vector control. Protecting the environment and keeping healthy were the reasons for participating in the vector control. The larva cadre stated community refusal as the main challenge. The community cited the importance of larva cadre: to monitor the presence of larva. Community empowerment on dengue vector control has not been effortlessly executed at the bottom level.


Assuntos
Participação da Comunidade , Dengue/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Adulto , Dengue/epidemiologia , Feminino , Humanos , Indonésia/epidemiologia , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
PLoS Negl Trop Dis ; 14(9): e0008716, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32966283

RESUMO

The concurrent circulation of dengue and coronavirus disease 2019 (COVID-19) may produce many unfavourable outcomes-such as co-infections; delays in diagnosis, treatment, and mitigation measures; overwhelming of the healthcare system; underreporting of cases; deterioration in surveillance and control interventions; and exacerbation of social inequalities. Indeed, lockdown is greatly compromising the effectiveness of vector control, especially social mobilization campaigns and preventive insecticide spraying in private spaces (indoor and peridomestic spraying). Thus, failure to appropriately implement the full range of vector control interventions can lead to a reduction in their overall effectiveness and an increasing risk of vector-borne diseases circulating. Consequently, the health community and policy makers should develop proactive policies and allocate adequate resources to prevent and manage the resurgence of dengue and other vector-borne diseases in the new era of COVID-19.


Assuntos
Infecções por Coronavirus/epidemiologia , Dengue/epidemiologia , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Pneumonia Viral/epidemiologia , Prevenção Primária/métodos , Betacoronavirus , Assistência à Saúde , Humanos , Pandemias , Controle de Pragas/métodos , Saúde Pública , Tempo para o Tratamento
3.
Mem Inst Oswaldo Cruz ; 115: e200284, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785481

RESUMO

The coronavirus disease of 2019 (COVID-19) pandemic challenges public health systems around the world. Tropical countries will face complex epidemiological scenarios involving the simultaneous transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with viruses transmitted by Aedes aegypti. The occurrence of arboviral diseases with COVID-19 in the Latin America and the Caribbean (LAC) region presents challenges and opportunities for strengthening health services, surveillance and control programs. Financing of training, equipment and reconversion of hospital spaces will have a negative effect on already the limited resource directed to the health sector. The strengthening of the diagnostic infrastructure reappears as an opportunity for the national reference laboratories. Sharing of epidemiological information for the modeling of epidemiological scenarios allows collaboration between health, academic and scientific institutions. The fear of contagion by COVID-19 is constraining people with arboviral diseases to search for care which can lead to an increase in serious cases and could disrupt the operation of vector-control programs due to the reluctance of residents to open their doors to health personnel. Promoting intense community participation along with the incorporation of long lasting innovations in vector control offers new opportunities for control. The COVID-19 pandemic offers challenges and opportunities that must provoke positive behavioral changes and encourage more permanent self-care actions.


Assuntos
Aedes/microbiologia , Aedes/virologia , Infecções por Coronavirus , Coronavirus , Dengue/prevenção & controle , Pandemias , Pneumonia Viral , Febre Amarela/prevenção & controle , América , Animais , Betacoronavirus , Região do Caribe , Infecções por Coronavirus/epidemiologia , Humanos , Mosquitos Vetores , Pneumonia Viral/epidemiologia
4.
PLoS Negl Trop Dis ; 14(8): e0008428, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32853197

RESUMO

Vector-borne diseases are a major cause of morbidity and mortality worldwide. Aedes-borne diseases, in particular, including dengue, chikungunya, yellow fever, and Zika, are increasing at an alarming rate due to urbanisation, population movement, weak vector control programmes, and climate change. The World Health Organization calls for strengthening of vector control programmes in line with the Global Vector Control Response (GVCR) strategy, and many vector control programmes are transitioning to this new approach. The Singapore dengue control programme, situated within the country's larger vision of a clean, green, and sustainable environment for the health and well-being of its citizens, provides an excellent example of the GVCR approach in action. Since establishing vector control operations in the 1960s, the Singapore dengue control programme succeeded in reducing the dengue force of infection 10-fold by the 1990s and has maintained it at low levels ever since. Key to this success is consideration of dengue as an environmental disease, with a strong focus on source reduction and other environmental management methods as the dominant vector control strategy. The programme collaborates closely with other government ministries, as well as town councils, communities, the private sector, and academic and research institutions. Community engagement programmes encourage source reduction, and house-to-house inspections accompanied by a strong legislative framework with monetary penalties help to support compliance. Strong vector and epidemiological surveillance means that routine control activities can be heightened to specifically target dengue clusters. Despite its success, the programme continues to innovate to tackle challenges such as climate change, low herd immunity, and manpower constraints. Initiatives include development of novel vector controls such as Wolbachia-infected males and spatiotemporal models for dengue risk assessment. Lessons learnt from the Singapore programme can be applied to other settings, even those less well-resourced than Singapore, for more effective vector control.


Assuntos
Dengue/prevenção & controle , Controle de Mosquitos/métodos , Controle de Mosquitos/organização & administração , Aedes/virologia , Animais , Participação da Comunidade , Dengue/epidemiologia , Humanos , Mosquitos Vetores/virologia , Singapura/epidemiologia
5.
PLoS Pathog ; 16(8): e1008754, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776975

RESUMO

Arbovirus infection of Aedes aegypti salivary glands (SGs) determines transmission. However, there is a dearth of knowledge on SG immunity. Here, we characterized SG immune response to dengue, Zika and chikungunya viruses using high-throughput transcriptomics. We also describe a transcriptomic response associated to apoptosis, blood-feeding and lipid metabolism. The three viruses differentially regulate components of Toll, Immune deficiency (IMD) and c-Jun N- terminal Kinase (JNK) pathways. However, silencing of the Toll and IMD pathway components showed variable effects on SG infection by each virus. In contrast, regulation of the JNK pathway produced consistent responses in both SGs and midgut. Infection by the three viruses increased with depletion of the activator Kayak and decreased with depletion of the negative regulator Puckered. Virus-induced JNK pathway regulates the complement factor, Thioester containing protein-20 (TEP20), and the apoptosis activator, Dronc, in SGs. Individual and co-silencing of these genes demonstrate their antiviral effects and that both may function together. Co-silencing either TEP20 or Dronc with Puckered annihilates JNK pathway antiviral effect. Upon infection in SGs, TEP20 induces antimicrobial peptides (AMPs), while Dronc is required for apoptosis independently of TEP20. In conclusion, we revealed the broad antiviral function of JNK pathway in SGs and showed that it is mediated by a TEP20 complement and Dronc-induced apoptosis response. These results expand our understanding of the immune arsenal that blocks arbovirus transmission.


Assuntos
Aedes/imunologia , Apoptose , Febre de Chikungunya/imunologia , Proteínas do Sistema Complemento/imunologia , Dengue/imunologia , Sistema de Sinalização das MAP Quinases , Glândulas Salivares/imunologia , Infecção por Zika virus/imunologia , Aedes/virologia , Animais , Febre de Chikungunya/metabolismo , Febre de Chikungunya/prevenção & controle , Febre de Chikungunya/virologia , Vírus Chikungunya/imunologia , Proteínas do Sistema Complemento/metabolismo , Dengue/metabolismo , Dengue/prevenção & controle , Dengue/virologia , Vírus da Dengue/imunologia , Feminino , Interações Hospedeiro-Patógeno , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Insetos Vetores/imunologia , Insetos Vetores/virologia , Glândulas Salivares/virologia , Transcriptoma , Replicação Viral , Zika virus/imunologia , Infecção por Zika virus/metabolismo , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/virologia
6.
Washington; Organización Panamericana de la Salud; jul. 28, 2020.
Não convencional em Espanhol | LILACS | ID: biblio-1103086

RESUMO

En varios países y territorios del Caribe y América Central se inició la temporada de mayor circulación del dengue; la cual ocurre en un contexto de intensa transmisión de SARS-CoV-2 en las Américas. La Organización Panamericana de la Salud/Organización Mundial de la Salud (OPS/OMS) hace un llamado a los Estados Miembros para fortalecer las acciones de vigilancia, diagnóstico y tratamiento y a la vez realizar acciones para una eventual expansión de los servicios de atención primaria y especializada, principalmente en aquellos lugares donde se espera un incremento estacional del número de casos de dengue y otras arbovirosis, junto con el incremento de casos de COVID-19.


Assuntos
Humanos , Infecções por Arbovirus/prevenção & controle , Pneumonia Viral/epidemiologia , Atenção Primária à Saúde/organização & administração , Infecções por Coronavirus/epidemiologia , Dengue/prevenção & controle , Pandemias/prevenção & controle , Monitoramento Epidemiológico , Betacoronavirus , América/epidemiologia
8.
PLoS Negl Trop Dis ; 14(7): e0007278, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32614855

RESUMO

BACKGROUND: The frequency and magnitude of dengue epidemics has increased dramatically throughout the tropics in the past 40 years due to unplanned urbanization, globalization and lack of effective mosquito control. The commercial capital of Tanzania, Dar es Salaam, is now experiencing regular dengue outbreaks. Three dengue serotypes have been detected in Dar es Salaam (DNV 1, 2 and 3). Without adequate vector monitoring and control, further outbreaks will certainly occur. METHODS/FINDINGS: A case series study followed 97 individuals with confirmed dengue fever (NS1 and/or IgM on rapid diagnostic test and/or PCR positive) to their households in Kinondoni, Dar es Salaam during the 2014 outbreak from a random sample of 202 confirmed cases at Mwananyamala Hospital. Kinondoni wards of Manzese, Mwananyamala, Tandale and Mabibo had the highest number of confirmed cases: 18, 13, 13 and 9 respectively. Individuals were interviewed by questionnaire on dengue prevention practices and houses were inspected for mosquito breeding sites to validate a Habitat Suitability Score (HSS). This is a tool devised to predict the productivity of any potential breeding habitats (PBHs) before the rains begin. There were 12 /312 positive Aedes breeding habitats. Drums/barrels, flowerpots and tyres were the most common breeding habitats. The HSS correctly identified 9/12 of Aedes breeding habitats. Larviciding is already conducted in urban Tanzania for malaria control and the HSS may be a useful means to train individuals on productive Aedes aegypti breeding sites should this program be extended to include dengue control. The population remains poorly informed about dengue transmission and prevention: 22% of respondents said dengue is spread from one person to another and 60% first heard about dengue when already sick. Less than 20% of respondents used personal protection and >80% thought bednets protected against dengue. Mobile phones were owned by almost all individuals followed up and have the potential of being the prime medium for dissemination of information on dengue prevention.


Assuntos
Aedes , Dengue/prevenção & controle , Ecossistema , Conhecimentos, Atitudes e Prática em Saúde , Controle de Mosquitos , Adolescente , Adulto , Aedes/fisiologia , Idoso , Idoso de 80 Anos ou mais , Animais , Cruzamento , Dengue/epidemiologia , Dengue/imunologia , Características da Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tanzânia/epidemiologia , Adulto Jovem
9.
PLoS Pathog ; 16(7): e1008410, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32726353

RESUMO

The bacterial endosymbiont Wolbachia is a biocontrol tool that inhibits the ability of the Aedes aegypti mosquito to transmit positive-sense RNA viruses such as dengue and Zika. Growing evidence indicates that when Wolbachia strains wMel or wAlbB are introduced into local mosquito populations, human dengue incidence is reduced. Despite the success of this novel intervention, we still do not fully understand how Wolbachia protects mosquitoes from viral infection. Here, we demonstrate that the Wolbachia strain wPip does not inhibit virus infection in Ae. aegypti. We have leveraged this novel finding, and a panel of Ae. aegypti lines carrying virus-inhibitory (wMel and wAlbB) and non-inhibitory (wPip) strains in a common genetic background, to rigorously test a number of hypotheses about the mechanism of Wolbachia-mediated virus inhibition. We demonstrate that, contrary to previous suggestions, there is no association between a strain's ability to inhibit dengue infection in the mosquito and either its typical density in the midgut or salivary glands, or the degree to which it elevates innate immune response pathways in the mosquito. These findings, and the experimental platform provided by this panel of genetically comparable mosquito lines, clear the way for future investigations to define how Wolbachia prevents Ae. aegypti from transmitting viruses.


Assuntos
Aedes/microbiologia , Vírus da Dengue , Interações Microbianas/fisiologia , Mosquitos Vetores/microbiologia , Wolbachia , Animais , Dengue/prevenção & controle , Dengue/transmissão , Infecções por Bactérias Gram-Negativas , Controle Biológico de Vetores/métodos , Fenótipo
10.
PLoS Negl Trop Dis ; 14(6): e0008321, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32584822

RESUMO

Dengue fever (DF) is one of main public health problems along the China-Myanmar border, however, data about DF is still lacking in Kachin Special Region II (KSR2), Myanmar. To understand health beliefs in general, and knowledge and treatment-seeking and prevention behaviors related to DF among the neglected population, the study was carried out by using a combination of quantitative household questionnaire surveys (HHSs) and qualitative semi-structured in-depth interviews (SDIs). The HHS questionnaire was administered to a total of 258 household heads. The 215 (83.3%) HHS respondents believed in Christianity and Catholicism. However, the 141 (54.7%,) of the total respondents thought that people with evil practices might be punished by diseases. More respondents believed that too rainy weather and water were more related to disease in the internally displaced person (IDP) camp than the local community (P<0.01). Most of the HHS respondents had sound knowledge of dengue symptoms, causes, vectors, transmission and prevention. The 257 (99.6%) HHS respondents reported that their families went to the public health facilities first to seek treatment. The 210 (84.1%) respondents reported that they turned containers upside down within five days. The key informants (n = 18) identified that the appropriate knowledge and behaviors were attributable to formal school education and specific health education campaign during the outbreak response in 2017, and that Kachin people enjoy conversing with each other, neighbors talked about the dengue information they received. The study results indicated that Kachin people have a good knowledge and behaviors of dengue control. The actual situation of dengue is still not clear due to lacking data of laboratory test. In the context of resources shortage, more international assistance is still needed to promote local dengue control and prevention efforts.


Assuntos
Dengue/epidemiologia , Dengue/prevenção & controle , Transmissão de Doença Infecciosa/prevenção & controle , Grupos Étnicos , Conhecimentos, Atitudes e Prática em Saúde , Adolescente , Adulto , Idoso , Animais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mianmar/epidemiologia , Refugiados , Inquéritos e Questionários , Adulto Jovem
14.
Washington; Organización Panamericana de la Salud; mayo 27, 2020. 5 p.
Não convencional em Espanhol | LILACS | ID: biblio-1097252

RESUMO

El dengue y otras enfermedades transmitidas por el Aedes (como Chikungunya y Zika) afectan a 129 países con más de 4 mil millones de personas en riesgo de estas enfermedades en todo el mundo. El año 2019 fue testigo de un brote de dengue sin precedentes en muchos países de las Américas, con más de 3.1 millones de casos reportados, incluidos 28,176 casos graves y 1,535 muertes (1). Las epidemias de dengue tienden a tener patrones estacionales, y la transmisión suele alcanzar su punto máximo durante y después de las estaciones lluviosas...


Assuntos
Humanos , Pneumonia Viral , América/epidemiologia , Infecções por Coronavirus/prevenção & controle , Dengue/prevenção & controle , Dengue/epidemiologia , Pandemias/prevenção & controle , Betacoronavirus
15.
PLoS Negl Trop Dis ; 14(5): e0008273, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32392225

RESUMO

Increasing urbanization is having a profound effect on infectious disease risk, posing significant challenges for governments to allocate limited resources for their optimal control at a sub-city scale. With recent advances in data collection practices, empirical evidence about the efficacy of highly localized containment and intervention activities, which can lead to optimal deployment of resources, is possible. However, there are several challenges in analyzing data from such real-world observational settings. Using data on 3.9 million instances of seven dengue vector containment activities collected between 2012 and 2017, here we develop and assess two frameworks for understanding how the generation of new dengue cases changes in space and time with respect to application of different types of containment activities. Accounting for the non-random deployment of each containment activity in relation to dengue cases and other types of containment activities, as well as deployment of activities in different epidemiological contexts, results from both frameworks reinforce existing knowledge about the efficacy of containment activities aimed at the adult phase of the mosquito lifecycle. Results show a 10% (95% CI: 1-19%) and 20% reduction (95% CI: 4-34%) reduction in probability of a case occurring in 50 meters and 30 days of cases which had Indoor Residual Spraying (IRS) and fogging performed in the immediate vicinity, respectively, compared to cases of similar epidemiological context and which had no containment in their vicinity. Simultaneously, limitations due to the real-world nature of activity deployment are used to guide recommendations for future deployment of resources during outbreaks as well as data collection practices. Conclusions from this study will enable more robust and comprehensive analyses of localized containment activities in resource-scarce urban settings and lead to improved allocation of resources of government in an outbreak setting.


Assuntos
Dengue/epidemiologia , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Animais , Cidades/epidemiologia , Humanos , Incidência , Paquistão/epidemiologia , Análise Espaço-Temporal , População Urbana
16.
BMC Infect Dis ; 20(1): 347, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32414340

RESUMO

BACKGROUND: Dengue is endemic in over 100 countries and is an important public health problem worldwide. Dengue fever is not endemic in Taiwan; the importation of dengue viruses from neighboring countries via close commercial links and air travel is considered to be the cause of local outbreaks. Therefore, efforts toward disease control have focused on preventing the importation of dengue into Taiwan. In this study, we investigated the relationships between the numbers of imported and indigenous dengue cases to test the validity of this strategy. METHODS: Data on cases of dengue fever that occurred between 2013 and 2018 were obtained from the surveillance systems of the Taiwan Center for Disease Control and Kaohsiung City Health Department. Standard epidemiological data, including the monthly numbers of indigenous and imported cases of dengue, were calculated. Potential associations between the numbers of indigenous and imported cases were investigated using correlation analyses. RESULTS: We identified a possible relationship between the period of disease concealment and the number of imported dengue cases, which resulted in epidemics of indigenous dengue fever within local communities. Further analysis of confirmed cases during previous epidemics in Kaohsiung City found that the risk of indigenous dengue fever may be related to the likelihood that patients with imported dengue fever will stay within local communities. CONCLUSION: Given the correlations found between imported and indigenous cases of dengue fever, as well as the relationship between the disease concealment period and the risk of indigenous dengue fever, prevention of disease importation and efficient identification of dengue cases within high-risk communities remain the major priorities for disease control.


Assuntos
Dengue/epidemiologia , Surtos de Doenças/prevenção & controle , Viagem Aérea , Dengue/prevenção & controle , Feminino , Humanos , Masculino , Saúde Pública , Quarentena , Taiwan/epidemiologia
17.
PLoS Negl Trop Dis ; 14(4): e0008097, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32275653

RESUMO

Dengue is one of the most important vector-borne diseases, resulting in an estimated hundreds of millions of infections annually throughout the tropics. Control of dengue is heavily dependent upon control of its primary mosquito vector, Aedes aegypti. Innovative interventions that are effective at targeting the adult stage of the mosquito are needed to increase the options for effective control. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce the abundance of Ae. aegypti in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not been rigorously quantified. A parallel arm cluster-randomized controlled trial was conducted in Iquitos, Peru to quantify the impact of ITCs on DENV seroconversion as measured through plaque-reduction neutralization tests. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to seroconverting to DENV, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9-71.9), while those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2-51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Entomological indicators did not show statistically significant differences between ITC and non-ITC clusters. It's unclear how the lack of protective efficacy reported here is attributable to simple failure of the intervention to protect against Ae. aegypti bites, or the presence of a faulty intervention during much of the follow-up period. The higher risk of dengue seroconversion that was detected in the ITC clusters may have arisen due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITCs. Our study provides important lessons learned for conducting cluster randomized trials for vector control interventions against Aedes-transmitted virus infections.


Assuntos
Dengue/prevenção & controle , Dengue/transmissão , Transmissão de Doença Infecciosa/prevenção & controle , Mosquiteiros Tratados com Inseticida , Controle de Mosquitos/métodos , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Vírus da Dengue/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Peru , Soroconversão , Resultado do Tratamento , Adulto Jovem
18.
PLoS Comput Biol ; 16(4): e1007743, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32310958

RESUMO

Recent years have seen rising incidence of dengue and large outbreaks of Zika and chikungunya, which are all caused by viruses transmitted by Aedes aegypti mosquitoes. In most settings, the primary intervention against Aedes-transmitted viruses is vector control, such as indoor, ultra-low volume (ULV) spraying. Targeted indoor residual spraying (TIRS) has the potential to more effectively impact Aedes-borne diseases, but its implementation requires careful planning and evaluation. The optimal time to deploy these interventions and their relative epidemiological effects are, however, not well understood. We used an agent-based model of dengue virus transmission calibrated to data from Iquitos, Peru to assess the epidemiological effects of these interventions under differing strategies for deploying them. Specifically, we compared strategies where spray application was initiated when incidence rose above a threshold based on incidence in recent years to strategies where spraying occurred at the same time(s) each year. In the absence of spraying, the model predicted 361,000 infections [inter-quartile range (IQR): 347,000-383,000] in the period 2000-2010. The ULV strategy with the fewest median infections was spraying twice yearly, in March and October, which led to a median of 172,000 infections [IQR: 158,000-183,000], a 52% reduction from baseline. Compared to spraying once yearly in September, the best threshold-based strategy utilizing ULV had fewer median infections (254,000 vs. 261,000), but required more spraying (351 vs. 274 days). For TIRS, the best strategy was threshold-based, which led to the fewest infections of all strategies tested (9,900; [IQR: 8,720-11,400], a 94% reduction), and required fewer days spraying than the equivalent ULV strategy (280). Although spraying twice each year is likely to avert the most infections, our results indicate that a threshold-based strategy can become an alternative to better balance the translation of spraying effort into impact, particularly if used with a residual insecticide.


Assuntos
Biologia Computacional/métodos , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Aedes/fisiologia , Animais , Simulação por Computador , Dengue/epidemiologia , Dengue/transmissão , Surtos de Doenças , Humanos , Incidência , Inseticidas , Modelos Teóricos , Mosquitos Vetores , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/transmissão
19.
Am J Trop Med Hyg ; 103(1): 132-141, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32342848

RESUMO

Dengue disease and its causative agents, the dengue viruses (DENV-1-4), cause high morbidity in tropical and subtropical regions. We evaluated three dosing regimens of the investigational tetravalent AS03B-adjuvanted dengue-purified inactivated vaccine (DPIV+AS03B). In this phase 1/2, observer-blind, placebo-controlled study (NCT02421367), 140 healthy adults were randomized 1:1:2 to receive DPIV+AS03B according to the following regimens: 0-1 month (M), 0-1-6 M, or 0-3 M. Participants received DPIV+AS03B or placebo at M0, M1, M3, and M6 according to their dosing schedule. Primary objectives were 1) to evaluate the safety of DPIV+AS03B for 28 days (D) after each dose; 2) to demonstrate the added value of a booster dose (0-1-6 M versus 0-1 M) based on neutralizing antibody titers to each DENV type (DENV-1-4) at 28 D after the last dose; and, if this objective was met, 3) to demonstrate the benefit of a longer interval between the first and second doses (0-1 M versus 0-3 M). Adverse events (AEs) within 7 D after vaccination tended to be more frequent after DPIV+AS03B doses than placebo; the number of grade 3 AEs was low (≤ 4.5% after DPIV+AS03B; ≤ 2.9% after placebo), with no obvious differences across groups. Within 28 D following each dose, the frequency of unsolicited AEs after DPIV+AS03B appeared higher for three-dose (0-1-6 M) than two-dose (0-1 M and 0-3 M) regimens. No serious AEs were considered related to vaccination, and no potential immune-mediated diseases were reported during the study. All three schedules were well tolerated. Both primary immunogenicity objectives were demonstrated. The 0-3 M and 0-1-6 M regimens were more immunogenic than the 0-1 M regimen.


Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Vacinas contra Dengue/administração & dosagem , Vírus da Dengue/imunologia , Dengue/prevenção & controle , Vacinação/métodos , Adulto , Dengue/imunologia , Dengue/virologia , Vacinas contra Dengue/efeitos adversos , Vacinas contra Dengue/biossíntese , Feminino , Voluntários Saudáveis , Humanos , Imunogenicidade da Vacina , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Vacinas Atenuadas , Vacinas de Subunidades
20.
PLoS Negl Trop Dis ; 14(4): e0008204, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32243448

RESUMO

Wolbachia are being used to reduce dengue transmission by Aedes aegypti mosquitoes around the world. To date releases have mostly involved Wolbachia strains with limited fitness effects but strains with larger fitness costs could be used to suppress mosquito populations. However, such infections are expected to evolve towards decreased deleterious effects. Here we investigate potential evolutionary changes in the wMelPop infection transferred from Drosophila melanogaster to Aedes aegypti more than ten years (~120 generations) ago. We show that most deleterious effects of this infection have persisted despite strong selection to ameliorate them. The wMelPop-PGYP infection is difficult to maintain in laboratory colonies, likely due to the persistent deleterious effects coupled with occasional maternal transmission leakage. Furthermore, female mosquitoes can be scored incorrectly as infected due to transmission of Wolbachia through mating. Infection loss in colonies was not associated with evolutionary changes in the nuclear background. These findings suggest that Wolbachia transinfections with deleterious effects may have stable phenotypes which could ensure their long-term effectiveness if released in natural populations to reduce population size.


Assuntos
Aedes/microbiologia , Evolução Molecular , Mosquitos Vetores/microbiologia , Controle Biológico de Vetores/métodos , Wolbachia/fisiologia , Animais , Dengue/prevenção & controle , Drosophila melanogaster , Feminino , Interações entre Hospedeiro e Microrganismos , Modelos Lineares , Masculino , Controle de Mosquitos , Dinâmica Populacional , Wolbachia/patogenicidade
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