Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.025
Filtrar
1.
Glob Health Action ; 16(1): 2166650, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36700745

RESUMO

BACKGROUND: Releases of Wolbachia (wMel)-infected Aedes aegypti mosquitoes significantly reduced the incidence of virologically confirmed dengue in a previous cluster randomised trial in Yogyakarta City, Indonesia. Following the trial, wMel releases were extended to the untreated control areas, to achieve city-wide coverage of Wolbachia. OBJECTIVE: In this predefined analysis, we evaluated the impact of the wMel deployments in Yogyakarta on dengue hemorrhagic fever (DHF) case notifications and on the frequency of perifocal insecticide spraying by public health teams. METHODS: Monthly counts of DHF cases notified to the Yogyakarta District Health Office between January 2006 and May 2022 were modelled as a function of time-varying local wMel treatment status (fully- and partially-treated vs untreated, and by quintile of wMel prevalence). The frequency of insecticide fogging in wMel-treated and untreated areas was analysed using negative binomial regression. RESULTS: Notified DHF incidence was 83% lower in fully treated vs untreated periods (IRR 0.17 [95% CI 0.14, 0.20]), and 78% lower in areas with 80-100% wMel prevalence compared to areas with 0-20% wMel (IRR 0.23 [0.17, 0.30]). A similar intervention effect was observed at 60-80% wMel prevalence as at 80-100% prevalence (76% vs 78% efficacy, respectively). Pre-intervention, insecticide fogging occurred at similar frequencies in areas later randomised to wMel-treated and untreated arms of the trial. After wMel deployment, fogging occurred significantly less frequently in treated areas (IRR 0.17 [0.10, 0.30]). CONCLUSIONS: Deployments of wMel-infected Aedes aegypti mosquitoes resulted in an 83% reduction in the application of perifocal insecticide spraying, consistent with lower dengue case notifications in wMel-treated areas. These results show that the Wolbachia intervention effect demonstrated previously in a cluster randomised trial was also measurable from routine surveillance data.


Assuntos
Aedes , Vírus da Dengue , Dengue , Inseticidas , Wolbachia , Animais , Humanos , Dengue/epidemiologia , Dengue/prevenção & controle
2.
PLoS One ; 18(1): e0279970, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36608030

RESUMO

Rio de Janeiro is a dengue-endemic city that experienced Zika and chikungunya epidemics between 2015 and 2019. Differential diagnosis is crucial for indicating adequate treatment and assessing prognosis and risk of death. This study aims to derive and validate a clinical rule for diagnosing chikungunya based on 3,214 suspected cases consecutively treated at primary and secondary health units of the sentinel surveillance system (up to 7 days from onset of symptoms) in Rio de Janeiro, Brazil. Of the total sample, 624 were chikungunya, 88 Zika, 51 dengue, and 2,451 were negative for all these arboviruses according to real-time polymerase chain reaction (RT-qPCR). The derived rule included fever (1 point), exanthema (1 point), myalgia (2 points), arthralgia or arthritis (2 points), and joint edema (2 points), providing an AUC (area under the receiver operator curve) = 0.695 (95% CI: 0.662-0.725). Scores of 4 points or more (validation sample) showed 74.3% sensitivity (69.0% - 79.2%) and 51.5% specificity (48.8% - 54.3%). Adding more symptoms improved the specificity at the expense of a lower sensitivity compared to definitions proposed by government agencies based on fever alone (European Center for Disease Control) or in combination with arthralgia (World Health Organization) or arthritis (Pan American Health Organization, Brazilian Ministry of Health). The proposed clinical rule offers a rapid, low-cost, easy-to-apply strategy to differentiate chikungunya fever from other arbovirus infections during epidemics.


Assuntos
Artrite , Febre de Chikungunya , Dengue , Infecção por Zika virus , Zika virus , Humanos , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Dengue/diagnóstico , Dengue/epidemiologia , Brasil/epidemiologia , Infecção por Zika virus/epidemiologia , Artralgia/diagnóstico , Febre
3.
Euro Surveill ; 28(2)2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36695478

RESUMO

BackgroundSuriname, a country endemic for dengue virus (DENV), is a popular destination for Dutch travellers visiting friends and relatives and tourist travellers. Chikungunya and Zika virus (CHIKV, ZIKV) were introduced in 2014 and 2015, respectively. Data on infection risks among travellers are limited.AimWe aimed to prospectively study incidence rate (IR) and determinants for DENV, ZIKV and CHIKV infection in adult travellers to Suriname from 2014 through 2017.MethodsParticipants kept a travel diary and were tested for anti-DENV, anti-ZIKV and anti-CHIKV IgG antibodies (Euroimmun). Selected samples were subjected to an in-house DENV and ZIKV PRNT50. The IR (infections/1,000 person-months of travel) and IR ratio and determinants for infection were calculated.ResultsTravel-acquired infections were found in 21 of 481 participants: 18 DENV, four ZIKV and two CHIKV, yielding an IRDENV of 47.0 (95% CI: 29.6-74.6), IRZIKV of 11.6 (95% CI: 4.4-31.0) and IRCHIKV of 5.6 (95% CI: 1.4-22.2)/1,000 person-months. In nine DENV and three ZIKV infected participants, infections were PRNT50-confirmed, yielding a lower IRDENV of 23.3 (95% CI: 12.1-44.8) and an IRZIKV of 8.4 (95% CI: 2.7-26.1) per 1,000 person-months. Tourist travel was associated with DENV infection. ZIKV and CHIKV infections occurred soon after their reported introductions.ConclusionsDespite an overestimation of serologically confirmed infections, Dutch travellers to Suriname, especially tourists, are at substantial risk of DENV infection. As expected, the risk of contracting ZIKV and CHIKV was highest during outbreaks. Cross-reaction and potential cross-protection of anti-DENV and -ZIKV antibodies should be further explored.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Adulto , Humanos , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/epidemiologia , Estudos Prospectivos , Suriname/epidemiologia , Dengue/epidemiologia
4.
Trials ; 24(1): 9, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36600308

RESUMO

BACKGROUND: Spatial repellents (SRs) have been widely used for prevention of mosquito bites, but their efficacy in reducing Aedes-borne viruses (ABV) has not been tested rigorously at large scale in Asia. To address this knowledge gap, a trial to evaluate the efficacy of Mosquito Shield™, a transfluthrin SR, was developed in Gampaha District of Sri Lanka across three Medical Officer of Health areas; i.e., Negombo, Wattala, and Kelaniya. METHODS: This trial is a cluster-randomized, placebo-controlled, double-blinded clinical trial. A total of ~14,430 subjects aged ≥ 6 months in 30 clusters (15 intervention, 15 placebo) from ~3900 households (HH) will be randomly selected for enrolment into a "febrile surveillance cohort." A subset of the surveillance cohort, ~3570 subjects aged ≥4-16 years that test seronegative (naïve) or are serologically positive for a previous single dengue virus (DENV) infection (monotypic) at baseline sampling, will be enrolled into a "longitudinal cohort" for measuring DENV infection based on laboratory-confirmed seroconversion during the trial. Persons identified positive for antibodies against multiple DENV serotypes (multitypic) at baseline will be monitored for secondary analyses. Active ABV disease will be assessed using an enhanced passive surveillance system with case ascertainment performed in designated healthcare facilities. Serum samples will be taken from longitudinal cohort subjects within 1-2 weeks of when intervention is first deployed (T0) with additional samples taken ~12 (T1) and ~24 months (T2) from baseline sampling. DENV seroconversion and ABV active disease rates from baseline (pre-intervention) and follow-up (post-intervention) samples will be compared between intervention and placebo clusters. Participating houses will be monitored entomologically (indoor adult Aedes aegypti population densities and adult female blood fed status) within 3 months before intervention deployment and monthly during the intervention phase. Entomological surveys will monitor indoor adult Ae. aegypti population densities and blood fed status. Dengue incidence in each cohort will be estimated and compared to determine the public health benefit of using an SR. Entomological parameters will be measured to determine if there are entomological correlates of SR efficacy that may be useful for the evaluation of new SR products. DISCUSSION: The trial will serve as an efficacy assessment of SR products in South Asia. Results will be submitted to the World Health Organization Vector Control Advisory Group for assessment of public health value towards an endorsement to recommend inclusion of SRs in ABV control programs. TRIAL REGISTRATION: Sri Lanka Clinical Trial Registry SLCTR /2022/018. Registered on July 1, 2022. CLINICALTRIALS: gov NCT05452447 . Registered on July 11, 2022. The Universal Trial Number is U1111-1275-3055.


Assuntos
Aedes , Dengue , Viroses , Adulto , Animais , Criança , Humanos , Feminino , Pré-Escolar , Adolescente , Dengue/diagnóstico , Dengue/epidemiologia , Dengue/prevenção & controle , Sri Lanka/epidemiologia , Mosquitos Vetores , Controle de Mosquitos/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
Viruses ; 15(1)2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36680274

RESUMO

Dengue and obesity are currently highly prevalent conditions worldwide and the association between these two conditions may result in greater risk for DENV infection and disease severity. In this study the association between obesity and recent, inapparent dengue was investigated. Serum DENV IgM and NS1 were evaluated in 49 adult volunteers (15 lean and 34 individuals with obesity, according to body mass index), between September 2017 and June 2018. Adiposity, endocrine, metabolic, and immune data of the participants were also obtained. None of the study participants tested positive for the DENV NS1 antigen. DENV IgM was detected in 33.3% of the lean individuals, and in 44.1% of those with obesity; the presence of DENV IgM was not associated with body mass index (OR = 1.32, 95% CI = 0.59-2.98, p = 0.48). However, body fat index was higher in obese individuals who had recent inapparent dengue (14.7 ± 3.1 versus 12.7 ± 2.1 kg/m2, p = 0.04), as was the expression of CD11b by classical (CD14++CD16-) monocytes (1103.0 ± 311.3 versus 720.3 ± 281.1 mean fluoresce intensity). Our findings suggest an association between adiposity and recent inapparent dengue and the involvement of classical monocytes in this association.


Assuntos
Vírus da Dengue , Dengue , Adulto , Humanos , Dengue/epidemiologia , Monócitos , Prevalência , Anticorpos Antivirais , Imunoglobulina M , Obesidade/epidemiologia , Proteínas não Estruturais Virais , Ensaio de Imunoadsorção Enzimática
6.
Viruses ; 15(1)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36680294

RESUMO

Vector control methods are considered effective in averting dengue transmission. However, several factors may modify their impact. Of these controls, chemical methods, in the long run, may increase mosquitoes' resistance to chemicides, thereby decreasing control efficacy. The biological methods, which may be self-sustaining and very effective, could be hampered by seasonality or heatwaves (resulting in, e.g., loss of Wolbachia infection). The environmental methods that could be more effective than the chemical methods are under-investigated. In this study, a systematic review is conducted to explore the present understanding of the effectiveness of vector control approaches via dengue transmission models.


Assuntos
Aedes , Dengue , Wolbachia , Animais , Humanos , Dengue/epidemiologia , Dengue/prevenção & controle , Mosquitos Vetores , Modelos Teóricos
7.
PLoS Negl Trop Dis ; 17(1): e0011047, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36638136

RESUMO

Dengue fever is a vector-borne disease affecting millions yearly, mostly in tropical and subtropical countries. Driven mainly by social and environmental factors, dengue incidence and geographical expansion have increased in recent decades. Therefore, understanding how climate variables drive dengue outbreaks is challenging and a problem of interest for decision-makers that could aid in improving surveillance and resource allocation. Here, we explore the effect of climate variables on relative dengue risk in 32 cantons of interest for public health authorities in Costa Rica. Relative dengue risk is forecast using a Generalized Additive Model for location, scale, and shape and a Random Forest approach. Models use a training period from 2000 to 2020 and predicted climatic variables obtained with a vector auto-regressive model. Results show reliable projections, and climate variables predictions allow for a prospective instead of a retrospective study.


Assuntos
Dengue , Animais , Humanos , Dengue/epidemiologia , Costa Rica/epidemiologia , Estudos Prospectivos , Estudos Retrospectivos , Mosquitos Vetores , Surtos de Doenças , Aprendizado de Máquina , Incidência
8.
Sci Rep ; 13(1): 1525, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707624

RESUMO

A dramatic increase in the number of outbreaks of dengue has recently been reported, and climate change is likely to extend the geographical spread of the disease. In this context, this paper shows how a neural network approach can incorporate dengue and COVID-19 data as well as external factors (such as social behaviour or climate variables), to develop predictive models that could improve our knowledge and provide useful tools for health policy makers. Through the use of neural networks with different social and natural parameters, in this paper we define a Correlation Model through which we show that the number of cases of COVID-19 and dengue have very similar trends. We then illustrate the relevance of our model by extending it to a Long short-term memory model (LSTM) that incorporates both diseases, and using this to estimate dengue infections via COVID-19 data in countries that lack sufficient dengue data.


Assuntos
COVID-19 , Dengue , Humanos , Dengue/epidemiologia , COVID-19/epidemiologia , Ásia Sudeste , América do Sul/epidemiologia , Surtos de Doenças
9.
PeerJ ; 11: e14504, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36643644

RESUMO

Dengue fever is an endemic disease in India, transmitted by an infected mosquito bite. In India, the number of concurrent infections and the circulation of multiple dengue virus (DENV) serotypes has increased in recent decades. Molecular surveillance among the DENV serotype is important to keep track of the circulating serotypes, evolutionary changes, and key mutations that can alter the diagnostics. The current study included patients admitted for dengue in the Eastern Uttar Pradesh (E-UP) region during 2018-2019. The genetic characterization of the circulating DENV was accomplished through partial CprM (511 bp) gene amplification via reverse transcriptase polymerase chain reaction and sequencing. Phylogenetic analysis revealed the circulation of all four DENV1-4 serotypes. DENV-2 was the most abundant serotype (44%, 27/61), followed by DENV-3 (32%, 20/61). DENV-1 had a 16% (10/61) predominance, while DENV-4 (6%, 4/61) was found to be the least abundant serotype. DENV-2 genotypes were distributed among lineages I (7.4%), II (85%) and III (7.4%) of genotype IV, DENV-3 to lineage III of genotype III, DENV-1 to genotype III; DENV-2 to lineage B (75%) and C (25%) of genotype I. This primary report on the co-circulation of DENV1-4 serotypes from the E-UP region highlights the requirement of continuous molecular surveillance for monitoring circulating DENV serotypes.


Assuntos
Vírus da Dengue , Dengue , Humanos , Vírus da Dengue/genética , Dengue/epidemiologia , Sorogrupo , Filogenia , Índia/epidemiologia
10.
Math Biosci Eng ; 20(1): 955-974, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36650797

RESUMO

Age as a risk factor is common in vector-borne infectious diseases. This is partly because children depend on adults to take preventative measures, and adults are less susceptible to mosquito bites because they generally spend less time outdoors than children. We propose a dengue disease model that considers the human population as divided into two subpopulations: children and adults. This is in order to take into consideration that children are more likely than adults to be bitten by mosquitoes. We calculated the basic reproductive number of dengue, using the next-generation operator method. We determined the local and global stability of the disease-free equilibrium. We obtained sufficient conditions for the global asymptotic stability of the endemic equilibrium using the Lyapunov functional method. When the infected periods in children and adults are the same, we that the endemic equilibrium is globally asymptotically stable in the interior of the feasible region when the threshold quantity $ R_0 > 1 $. Additionally, we performed a numerical simulation using parameter values obtained from the literature. Finally, a local sensitivity analysis was performed to identify the parameters that have the greatest influence on changes in $ (R_0) $, and thereby obtain a better biological interpretation of the results.


Assuntos
Dengue , Animais , Criança , Humanos , Dengue/epidemiologia , Mosquitos Vetores , Modelos Biológicos , Número Básico de Reprodução , Simulação por Computador
11.
JAMA Netw Open ; 6(1): e2249440, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36598784

RESUMO

Importance: Dengue fever is a climate-sensitive infectious disease. However, its association with local hydrological conditions and the role of city development remain unclear. Objective: To quantify the association between hydrological conditions and dengue fever incidence in China and to explore the modification role of city development in this association. Design, Setting, and Participants: This cross-sectional study collected data between January 1, 2013, and December 31, 2019, from 54 cities in 4 coastal provinces in southeast China. The Standardized Precipitation Evapotranspiration Index (SPEI) was calculated from ambient temperature and precipitation, with SPEI thresholds of 2 for extreme wet conditions and -2 for extreme dry conditions. The SPEI-dengue fever incidence association was examined over a 6-month lag, and the modification roles of 5 city development dimensions were assessed. Data were analyzed in May 2022. Exposures: City-level monthly temperature, precipitation, SPEI, and annual city development indicators from 2013 to 2019. Main Outcomes and Measures: The primary outcome was city-level monthly dengue fever incidence. Spatiotemporal bayesian hierarchal models were used to examine the SPEI-dengue fever incidence association over a 6-month lag period. An interaction term between SPEI and each city development indicator was added into the model to assess the modification role of city development. Results: Included in the analysis were 70 006 dengue fever cases reported in 54 cities in 4 provinces in China from 2013 to 2019. Overall, a U-shaped cumulative curve was observed, with wet and dry conditions both associated with increased dengue fever risk. The relative risk [RR] peaked at a 1-month lag for extreme wet conditions (1.27; 95% credible interval [CrI], 1.05-1.53) and at a 6-month lag for extreme dry conditions (1.63; 95% CrI, 1.29-2.05). The RRs of extreme wet and dry conditions were greater in areas with limited economic development, health care resources, and income per capita. Extreme dry conditions were higher and prolonged in areas with more green space per capita (RR, 1.84; 95% CrI, 1.37-2.46). Highly urbanized areas had a higher risk of dengue fever after extreme wet conditions (RR, 1.80; 95% CrI, 1.26-2.56), while less urbanized areas had the highest risk of dengue fever in extreme dry conditions (RR, 1.70; 95% CrI, 1.11-2.60). Conclusions and Relevance: Results of this study showed that extreme hydrological conditions were associated with increased dengue fever incidence within a 6-month lag period, with different dimensions of city development playing various modification roles in this association. These findings may help in developing climate change adaptation strategies and public health interventions against dengue fever.


Assuntos
Dengue , Humanos , Incidência , Dengue/epidemiologia , Teorema de Bayes , Estudos Transversais , China/epidemiologia
12.
Emerg Infect Dis ; 29(1): 160-163, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36573590

RESUMO

We assessed predominantly pediatric patients in Vietnam with dengue and other febrile illness 3 months after acute illness. Among dengue patients, 47% reported >1 postacute symptom. Most resolved by 3 months, but alopecia and vision problems often persisted. Our findings provide additional evidence on postacute dengue burden and confirm children are affected.


Assuntos
Dengue , Humanos , Criança , Dengue/complicações , Dengue/diagnóstico , Dengue/epidemiologia , Vietnã/epidemiologia
13.
15.
J Med Virol ; 94(1): 366-371, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34546584

RESUMO

Co-epidemics happening simultaneously can generate a burden on healthcare systems. The co-occurrence of SARS-CoV-2 with vector-borne diseases (VBD), such as malaria and dengue in resource-limited settings represents an additional challenge to the healthcare systems. Herein, we assessed the coinfection rate between SARS-CoV-2 and VBD to highlight the need to carry out an accurate diagnosis and promote timely measures for these infections in Luanda, the capital city of Angola. This was a cross-sectional study conducted with 105 subjects tested for the SARS-CoV-2 and VBD with a rapid detection test in April 2021. The participants tested positive for SARS-CoV-2 (3.80%), malaria (13.3%), and dengue (27.6%). Low odds related to testing positivity to SARS-CoV-2 or VBD were observed in participants above or equal to 40 years (odds ratio [OR]: 0.60, p = 0.536), while higher odds were observed in male (OR: 1.44, p = 0.392) and urbanized areas (OR: 3.78, p = 0.223). The overall co-infection rate between SARS-CoV-2 and VBD was 11.4%. Our findings showed a coinfection between SARS-CoV-2 with malaria and dengue, which could indicate the need to integrate the screening for VBD in the SARS-CoV-2 testing algorithm and the adjustment of treatment protocols. Further studies are warranted to better elucidate the relationship between COVID-19 and VBD in Angola.


Assuntos
COVID-19/epidemiologia , Coinfecção/epidemiologia , Dengue/epidemiologia , Malária/epidemiologia , Doenças Transmitidas por Vetores/epidemiologia , Adolescente , Adulto , Fatores Etários , Angola/epidemiologia , Anticorpos Antiprotozoários/sangue , Anticorpos Antivirais/sangue , Teste para COVID-19 , Febre de Chikungunya/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , RNA Viral/sangue , SARS-CoV-2/isolamento & purificação , Fatores Sexuais , Adulto Jovem , Infecção por Zika virus/epidemiologia
17.
Goiânia; SES-GO; dez. 2022. 1-13 p. ilus, quad, mapas.(Boletim Epidemiológico: monitoramento dos casos de arboviroses em Goiás, 4, 4).
Monografia em Português | LILACS, Coleciona SUS, CONASS, SES-GO | ID: biblio-1401535

RESUMO

As arboviroses transmitidas pelo mosquito Aedes aegypti são um dos principais problemas de saúde pública no Estado de Goiás. O boletim epidemiológico das arboviroses é uma produção mensal, objetivando apresentar a situação epidemiológica dos casos no estado, utilizando como fonte de dados os registros de casos suspeitos e confirmados ocorridos nos últimos anos, disponíveis no Sinan Online e Sinan Net


Arboviruses transmitted by the Aedes aegypti mosquito are one of the main public health problems in the State of Goiás. The epidemiological bulletin of arboviruses is a monthly production, aiming to present the epidemiological situation of cases in the state, using as a data source the records of suspected and confirmed cases that occurred in recent years, available on Sinan Online and Sinan Net


Assuntos
Humanos , Masculino , Feminino , Gravidez , Recém-Nascido , Dengue/epidemiologia , Febre de Chikungunya/epidemiologia , Infecção por Zika virus/epidemiologia , Infecções por Arbovirus/epidemiologia , Dengue/mortalidade , Febre de Chikungunya/mortalidade , Infecção por Zika virus/mortalidade , Microcefalia/epidemiologia
18.
Sci Adv ; 8(51): eabq7345, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36542722

RESUMO

Aedes aegypti (Linnaeus, 1762) is the main mosquito vector for dengue and other arboviral infectious diseases. Control of this important vector highly relies on the use of insecticides, especially pyrethroids. The high frequency (>78%) of the L982W substitution was detected at the target site of the pyrethroid insecticide, the voltage-gated sodium channel (Vgsc) of A. aegypti collected from Vietnam and Cambodia. Alleles having concomitant mutations L982W + F1534C and V1016G + F1534C were also confirmed in both countries, and their frequency was high (>90%) in Phnom Penh, Cambodia. Strains having these alleles exhibited substantially higher levels of pyrethroid resistance than any other field population ever reported. The L982W substitution has never been detected in any country of the Indochina Peninsula except Vietnam and Cambodia, but it may be spreading to other areas of Asia, which can cause an unprecedentedly serious threat to the control of dengue fever as well as other Aedes-borne infectious diseases.


Assuntos
Aedes , Doenças Transmissíveis , Dengue , Inseticidas , Piretrinas , Animais , Inseticidas/farmacologia , Resistência a Inseticidas/genética , Mutação , Aedes/genética , Ásia , Dengue/epidemiologia , Dengue/genética
19.
J Vector Borne Dis ; 59(3): 198-205, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36511035

RESUMO

BACKGROUND & OBJECTIVES: Recently, the incidences of chikungunya, dengue and Zika infections have increased due to globalization and urbanization. It is vital that reliable detection tools become available to assess the viral prevalence within mosquito populations. METHODS: Based on the previous publications on clinical diagnosis in human infections, for the first time, we described a customized triplex RT-qPCR protocol for simultaneous detection of chikungunya virus (CHIKV), dengue virus serotypes 1-4 (DENV1-4) and Zika virus (ZIKV) in mosquitoes. RESULTS: In preliminary assessment to determine the specificity and sensitivity of primers and probes, all six targets were detected individually with the following thresholds as indicated by calculated pfu equivalents: 3.96x100 for CHIKV, 3.80x101 for DENV1, 3.20x101 for DENV2, 8.00x104 for DENV3, 1.58x100 for DENV4, and 6.20x100 for ZIKV When tested in a full combination of six targets (CDZ mix), CHIKV, DENV1-4 mix or ZIKV were all detected with the thresholds of 1.32x100 for CHIKV, 3.79x100 for DENV1-4 and 2.06x100 for ZIKV All targets, individually or in full combination were detected in the mixtures of Aedes aegypti (L.) homogenate and viral lysates. A robust evaluation with three replicates in each of three plates for CHIKV, DENV1-4 and ZIKV individually or in full combination was conducted. In individual assays, CHIKV was detected to 3.96x10-1, DENV1-4 to 1.14x100 and ZIKV to 3.20x100. In full combination assays, CHIKV was detected to 1.32x104, DENV1-4 to 3.79x101 and ZIKV to 1.07x100. INTERPRETATION & CONCLUSION: This triplex RT-qPCR assay appears to consistently detect all six targets and does not cross react with Ae. aegypti homogenate, making it a feasible, practical, and immediately adoptable protocol for use among vector control and other entities, particularly in the endemic areas of CHIKV, DENVs and ZIKV.


Assuntos
Aedes , Febre de Chikungunya , Vírus Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Animais , Humanos , Zika virus/genética , Infecção por Zika virus/epidemiologia , Vírus da Dengue/genética , Mosquitos Vetores , Febre de Chikungunya/epidemiologia , Vírus Chikungunya/genética , Dengue/epidemiologia
20.
Trials ; 23(1): 1023, 2022 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-36528590

RESUMO

BACKGROUND: Dengue is a severe environmental public health challenge in tropical and subtropical regions. In Singapore, decreasing seroprevalence and herd immunity due to successful vector control has paradoxically led to increased transmission potential of the dengue virus. We have previously demonstrated that incompatible insect technique coupled with sterile insect technique (IIT-SIT), which involves the release of X-ray-irradiated male Wolbachia-infected mosquitoes, reduced the Aedes aegypti population by 98% and dengue incidence by 88%. This novel vector control tool is expected to be able to complement current vector control to mitigate the increasing threat of dengue on a larger scale. We propose a multi-site protocol to study the efficacy of IIT-SIT at reducing dengue incidence. METHODS/DESIGN: The study is designed as a parallel, two-arm, non-blinded cluster-randomized (CR) controlled trial to be conducted in high-rise public housing estates in Singapore, an equatorial city-state. The aim is to determine whether large-scale deployment of male Wolbachia-infected Ae. aegypti mosquitoes can significantly reduce dengue incidence in intervention clusters. We will use the CR design, with the study area comprising 15 clusters with a total area of 10.9 km2, covering approximately 722,204 residents in 1713 apartment blocks. Eight clusters will be randomly selected to receive the intervention, while the other seven will serve as non-intervention clusters. Intervention efficacy will be estimated through two primary endpoints: (1) odds ratio of Wolbachia exposure distribution (i.e., probability of living in an intervention cluster) among laboratory-confirmed reported dengue cases compared to test-negative controls and (2) laboratory-confirmed reported dengue counts normalized by population size in intervention versus non-intervention clusters. DISCUSSION: This study will provide evidence from a multi-site, randomized controlled trial for the efficacy of IIT-SIT in reducing dengue incidence. The trial will provide valuable information to estimate intervention efficacy for this novel vector control approach and guide plans for integration into national vector control programs in dengue-endemic settings. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT05505682 . Registered on 16 August 2022. Retrospectively registered.


Assuntos
Aedes , Dengue , Wolbachia , Animais , Masculino , Humanos , Controle de Mosquitos/métodos , Dengue/epidemiologia , Dengue/prevenção & controle , Mosquitos Vetores , Incidência , Estudos Soroepidemiológicos , Singapura/epidemiologia , Ensaios Clínicos Controlados Aleatórios como Assunto
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...