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1.
Epidemiol Infect ; 149: e188, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34338179

RESUMO

In 2015-2016, simultaneous circulation of dengue, Zika and chikungunya in the municipality of Rio de Janeiro (Brazil) was reported. We conducted an ecological study to analyse the spatial distribution of dengue, Zika and chikungunya cases and to investigate socioeconomic factors associated with individual and combined disease incidence in 2015-2016. We then constructed thematic maps and analysed the bivariate global Moran indices. Classical and spatial models were used. A distinct spatial distribution pattern for dengue, Zika and chikungunya was identified in the municipality of Rio de Janeiro. The bivariate global Moran indices (P < 0.05) revealed negative spatial correlations between rates of dengue, Zika, chikungunya and combined arboviruses incidence and social development index and mean income. The regression models (P < 0.05) identified a negative relationship between mean income and each of these rates and between sewage and Zika incidence rates, as well as a positive relationship between urban areas and chikungunya incidence rates. In our study, spatial analysis techniques helped to identify high-risk and social determinants at the local level for the three arboviruses. Our findings may aid in backing effective interventions for the prevention and control of epidemics of these diseases.


Assuntos
Febre de Chikungunya/epidemiologia , Dengue/epidemiologia , Fatores Socioeconômicos , Infecção por Zika virus/epidemiologia , Aedes/virologia , Animais , Brasil/epidemiologia , Febre de Chikungunya/transmissão , Cidades , Estudos Transversais , Dengue/transmissão , Epidemias , Humanos , Incidência , Insetos Vetores/virologia , Modelos Estatísticos , Análise Espacial , Infecção por Zika virus/transmissão
2.
PLoS Negl Trop Dis ; 15(8): e0009603, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34370734

RESUMO

BACKGROUND: The COVID-19 pandemic has induced unprecedented reductions in human mobility and social contacts throughout the world. Because dengue virus (DENV) transmission is strongly driven by human mobility, behavioral changes associated with the pandemic have been hypothesized to impact dengue incidence. By discouraging human contact, COVID-19 control measures have also disrupted dengue vector control interventions, the most effective of which require entry into homes. We sought to investigate how and why dengue incidence could differ under a lockdown scenario with a proportion of the population sheltered at home. METHODOLOGY & PRINCIPAL FINDINGS: We used an agent-based model with a realistic treatment of human mobility and vector control. We found that a lockdown in which 70% of the population sheltered at home and which occurred in a season when a new serotype invaded could lead to a small average increase in cumulative DENV infections of up to 10%, depending on the time of year lockdown occurred. Lockdown had a more pronounced effect on the spatial distribution of DENV infections, with higher incidence under lockdown in regions with higher mosquito abundance. Transmission was also more focused in homes following lockdown. The proportion of people infected in their own home rose from 54% under normal conditions to 66% under lockdown, and the household secondary attack rate rose from 0.109 to 0.128, a 17% increase. When we considered that lockdown measures could disrupt regular, city-wide vector control campaigns, the increase in incidence was more pronounced than with lockdown alone, especially if lockdown occurred at the optimal time for vector control. CONCLUSIONS & SIGNIFICANCE: Our results indicate that an unintended outcome of lockdown measures may be to adversely alter the epidemiology of dengue. This observation has important implications for an improved understanding of dengue epidemiology and effective application of dengue vector control. When coordinating public health responses during a syndemic, it is important to monitor multiple infections and understand that an intervention against one disease may exacerbate another.


Assuntos
COVID-19/prevenção & controle , Dengue/epidemiologia , SARS-CoV-2 , Animais , Dengue/prevenção & controle , Dengue/transmissão , Humanos , Incidência , Controle de Mosquitos , Saúde Pública
4.
Emerg Med Clin North Am ; 39(3): 453-465, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34215396

RESUMO

The role of the emergency provider lies at the forefront of recognition and treatment of novel and re-emerging infectious diseases in children. Familiarity with disease presentations that might be considered rare, such as vaccine-preventable and non-endemic illnesses, is essential in identifying and controlling outbreaks. As we have seen thus far in the novel coronavirus pandemic, susceptibility, severity, transmission, and disease presentation can all have unique patterns in children. Emergency providers also have the potential to play a public health role by using lessons learned from the phenomena of vaccine hesitancy and refusal.


Assuntos
Doenças Transmissíveis Emergentes/epidemiologia , Pediatria , COVID-19/diagnóstico , COVID-19/terapia , COVID-19/transmissão , Varicela/diagnóstico , Varicela/terapia , Varicela/transmissão , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/terapia , Febre de Chikungunya/transmissão , Criança , Doenças Transmissíveis Emergentes/imunologia , Árvores de Decisões , Dengue/diagnóstico , Dengue/terapia , Dengue/transmissão , Medicina de Emergência , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/terapia , Doença pelo Vírus Ebola/transmissão , Humanos , Incidência , Malária/diagnóstico , Malária/terapia , Malária/transmissão , Sarampo/diagnóstico , Sarampo/terapia , Sarampo/transmissão , Papel do Médico , Saúde Pública , SARS-CoV-2 , Síndrome de Resposta Inflamatória Sistêmica , Doença Relacionada a Viagens , Vacinação , Recusa de Vacinação , Coqueluche/diagnóstico , Coqueluche/terapia , Coqueluche/transmissão , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/terapia , Infecção por Zika virus/transmissão
5.
N Engl J Med ; 384(23): 2177-2186, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-34107180

RESUMO

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


Assuntos
Aedes/microbiologia , Controle de Doenças Transmissíveis/métodos , Dengue/transmissão , Mosquitos Vetores , Wolbachia , Adolescente , Adulto , Aedes/virologia , Animais , Criança , Pré-Escolar , Dengue/diagnóstico , Dengue/epidemiologia , Dengue/prevenção & controle , Vírus da Dengue/isolamento & purificação , Feminino , Humanos , Incidência , Indonésia/epidemiologia , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologia , Adulto Jovem
6.
PLoS Negl Trop Dis ; 15(6): e0009420, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34111117

RESUMO

BACKGROUND: Dengue is one of the major public health problems in Sri Lanka. Its outbreak pattern depends on a multitude of drivers, including human mobility. Here we evaluate the impact of COVID-19 related mobility restriction (lockdown) on the risk of dengue in Sri Lanka. METHODOLOGY: Two-stage hierarchical models were fitted using an interrupted time-series design based on the notified dengue cases, January 2015 to July 2020. In the first stage model, the district level impact was estimated using quasi-Poisson regression models while accounting for temporal trends. Estimates were pooled at zonal and national levels in the second stage model using meta-analysis. The influence of the extended period of school closure on dengue in children in the western province was compared to adults. FINDINGS: Statistically significant and homogeneous reduction of dengue risk was observed at all levels during the lockdown. Overall an 88% reduction in risk (RR 0.12; 95% CI from 0.08 to 0.17) was observed at the national level. The highest impact was observed among children aged less than 19 years showing a 92% reduction (RR 0.8; 95% CI from 0.03 to 0.25). We observed higher impact in the dry zone having 91% reduction (RR 0.09; 95% CI from 0.05 to 0.15) compared to wet zone showing 83% reduction (RR 0.17; 95% CI from 0.09 to 0.30). There was no indication that the overall health-seeking behaviour for dengue had a substantial influence on these estimates. SIGNIFICANCE: This study offers a broad understanding of the change in risk of dengue during the COVID-19 pandemic and associated mobility restrictions in Sri Lanka. The analysis using the mobility restrictions as a natural experiment suggests mobility patterns to be a very important driver of dengue transmission.


Assuntos
COVID-19/prevenção & controle , Dengue/epidemiologia , Dengue/transmissão , Adulto , Criança , Clima , Controle de Doenças Transmissíveis , Humanos , Análise de Séries Temporais Interrompida , Distanciamento Físico , Instituições Acadêmicas/estatística & dados numéricos , Sri Lanka/epidemiologia
7.
PLoS Negl Trop Dis ; 15(5): e0009440, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34043621

RESUMO

BACKGROUND: Aedes mosquitoes are vectors for several major arboviruses of public health concern including dengue viruses. The relationships between Aedes infestation and disease transmission are complex wherein the epidemiological dynamics can be difficult to discern because of a lack of robust and sensitive indicators for predicting transmission risk. This study investigates the use of anti-Aedes saliva antibodies as a serological biomarker for Aedes mosquito bites to assess small scale variations in adult Aedes density and dengue virus (DENV) transmission risk in northeastern Thailand. Individual characteristics, behaviors/occupation and socio-demographics, climatic and epidemiological risk factors associated with human-mosquito exposure are also addressed. METHODS: The study was conducted within a randomized clustered control trial in Roi Et and Khon Kaen provinces over a consecutive 19 months period. Thirty-six (36) clusters were selected, each of ten houses. Serological and entomological surveys were conducted in all houses every four months and monthly in three sentinel households per cluster between September 2017 and April 2019 for blood spot collections and recording concurrent immature and adult Aedes indices. Additionally, the human exposure to Aedes mosquito bites (i.e., Mosquito Exposure Index or MEI) was estimated by ELISA measuring levels of human antibody response to the specific Nterm-34 kDa salivary antigen. The relationships between the MEI, vector infestation indices (adult and immature stages) and vector DENV infection were evaluated using a two-level (house and individual levels) mixed model analysis with one-month lag autoregressive correlation. RESULTS: There was a strong positive relationship between the MEI and adult Aedes (indoor and outdoor) density. Individuals from households with a medium mosquito density (mean difference: 0.091, p<0.001) and households with a high mosquito density (mean difference: 0.131, p<0.001) had higher MEI's compared to individuals from households without Aedes. On a similar trend, individuals from households with a low, medium or high indoor Aedes densities (mean difference: 0.021, p<0.007, 0.053, p<0.0001 and 0.037, p<0.0001 for low, medium and high levels of infestation, respectively) had higher MEI than individuals from houses without indoor Aedes. The MEI was driven by individual characteristics, such as gender, age and occupation/behaviors, and varied according to climatic, seasonal factors and vector control intervention (p<0.05). Nevertheless, the study did not demonstrate a clear correlation between MEI and the presence of DENV-infected Aedes. CONCLUSION: This study represents an important step toward the validation of the specific IgG response to the Aedes salivary peptide Nterm-34kDa as a proxy measure for Aedes infestation levels and human-mosquito exposure risk in a dengue endemic setting. The use of the IgG response to the Nterm-34 kDa peptide as a viable diagnostic tool for estimating dengue transmission requires further investigations and validation in other geographical and transmission settings.


Assuntos
Aedes/fisiologia , Aedes/virologia , Mordeduras e Picadas de Insetos/epidemiologia , Aedes/crescimento & desenvolvimento , Animais , Biomarcadores/sangue , Dengue/epidemiologia , Dengue/transmissão , Vírus da Dengue/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/análise , Mordeduras e Picadas de Insetos/imunologia , Masculino , Mosquitos Vetores/virologia , Saliva/imunologia , Tailândia/epidemiologia
9.
PLoS Negl Trop Dis ; 15(5): e0009397, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33951038

RESUMO

The world's most important mosquito vector of viruses, Aedes aegypti, is found around the world in tropical, subtropical and even some temperate locations. While climate change may limit populations of Ae. aegypti in some regions, increasing temperatures will likely expand its territory thus increasing risk of human exposure to arboviruses in places like Europe, Northern Australia and North America, among many others. Most studies of Ae. aegypti biology and virus transmission focus on locations with high endemicity or severe outbreaks of human amplified urban arboviruses, such as dengue, Zika, and chikungunya viruses, but rarely on areas at the margins of endemicity. The objective in this study is to explore previously published global patterns in the environmental suitability for Ae. aegypti and dengue virus to reveal deviations in the probability of the vector and human disease occurring. We developed a map showing one end of the gradient being higher suitability of Ae. aegypti with low suitability of dengue and the other end of the spectrum being equal and higher environmental suitability for both Ae. aegypti and dengue. The regions of the world with Ae. aegypti environmental suitability and no endemic dengue transmission exhibits a phenomenon we term 'aegyptism without arbovirus'. We then tested what environmental and socioeconomic variables influence this deviation map revealing a significant association with human population density, suggesting that locations with lower human population density were more likely to have a higher probability of aegyptism without arbovirus. Characterizing regions of the world with established populations of Ae. aegypti but little to no autochthonous transmission of human-amplified arboviruses is an important step in understanding and achieving aegyptism without arbovirus.


Assuntos
Aedes/fisiologia , Aedes/virologia , Dengue/epidemiologia , Animais , Clima , Dengue/transmissão , Vírus da Dengue , Ecossistema , Humanos , Mosquitos Vetores/fisiologia , Mosquitos Vetores/virologia , Densidade Demográfica , Fatores Socioeconômicos
10.
Nat Commun ; 12(1): 2619, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976183

RESUMO

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


Assuntos
Vírus da Dengue/imunologia , Dengue/epidemiologia , Suscetibilidade a Doenças/imunologia , Epidemias/estatística & dados numéricos , Infecção por Zika virus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Brasil/epidemiologia , Criança , Pré-Escolar , Dengue/imunologia , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Epidemias/prevenção & controle , Monitoramento Epidemiológico , Feminino , Genoma Viral/genética , Humanos , Imunidade Heteróloga , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Mosquitos Vetores/virologia , Filogeografia , Sorotipagem , Adulto Jovem , Zika virus/imunologia , Infecção por Zika virus/epidemiologia
11.
Sci Data ; 8(1): 134, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016998

RESUMO

Dengue virus (DENV) transmission occurs primarily in tropical and subtropical climates, but within the last decade it has extended to temperate regions. Santa Fe, a temperate province in Argentina, has experienced an increase in dengue cases and virus circulation since 2009, with the recent 2020 outbreak being the largest in the province to date. The aim of this work is to describe spatio-temporal fluctuations of dengue cases from 2009 to 2020 in Santa Fe Province. The data presented in this work provide a detailed description of DENV transmission for Santa Fe Province by department. These data are useful to assist in investigating drivers of dengue emergence in Santa Fe Province and for developing a better understanding of the drivers and the impacts of ongoing dengue emergence in temperate regions across the world. This work provides data useful for future studies including those investigating socio-ecological, climatic, and environmental factors associated with DENV transmission, as well as those investigating other variables related to the biology and the ecology of vector-borne diseases.


Assuntos
Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/transmissão , Dengue/epidemiologia , Dengue/transmissão , Surtos de Doenças , Aedes/virologia , Animais , Argentina/epidemiologia , Vírus da Dengue/isolamento & purificação , Humanos , Mosquitos Vetores/virologia
12.
J Virol ; 95(13): e0220320, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-33853965

RESUMO

Recent field trials have demonstrated that dengue incidence can be substantially reduced by introgressing strains of the endosymbiotic bacterium Wolbachia into Aedes aegypti mosquito populations. This strategy relies on Wolbachia reducing the susceptibility of Ae. aegypti to disseminated infection by positive-sense RNA viruses like dengue. However, RNA viruses are well known to adapt to antiviral pressures. Here, we review the viral infection stages where selection for Wolbachia-resistant virus variants could occur. We also consider the genetic constraints imposed on viruses that alternate between vertebrate and invertebrate hosts, and the likely selection pressures to which dengue virus might adapt in order to be effectively transmitted by Ae. aegypti that carry Wolbachia. While there are hurdles to dengue viruses developing resistance to Wolbachia, we suggest that long-term surveillance for resistant viruses should be an integral component of Wolbachia-introgression biocontrol programs.


Assuntos
Adaptação Fisiológica/fisiologia , Aedes/microbiologia , Vírus da Dengue/crescimento & desenvolvimento , Dengue/prevenção & controle , Wolbachia/metabolismo , Aedes/efeitos dos fármacos , Animais , Dengue/patologia , Dengue/transmissão , Drosophila/microbiologia , Evolução Molecular , Humanos , Resistência a Inseticidas/fisiologia , Mosquitos Vetores/microbiologia , Seleção Genética/genética
13.
PLoS Negl Trop Dis ; 15(4): e0009391, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33905415

RESUMO

BACKGROUND: Aedes albopictus is one of the most invasive species in the world as well as the important vector for mosquito-borne diseases such as dengue fever, chikungunya fever and zika virus disease. Chemical control of mosquitoes is an effective method to control mosquito-borne diseases, however, the wide and improper application of insecticides for vector control has led to serious resistance problems. At present, there have been many reports on the resistance to pyrethroid insecticides in vector mosquitoes including deltamethrin to Aedes albopictus. However, the fitness cost and vector competence of deltamethrin resistant Aedes albopictus remain unknown. To understand the impact of insecticide resistant mosquito is of great significance for the prevention and control mosquitoes and mosquito-borne diseases. METHODOLOGY/PRINCIPAL FINDINGS: A laboratory resistant strain (Lab-R) of Aedes albopictus was established by deltamethrin insecticide selecting from the laboratory susceptible strain (Lab-S). The life table between the two strains were comparatively analyzed. The average development time of Lab-R and Lab-S in larvae was 9.7 days and 8.2 days (P < 0.005), and in pupae was 2.0 days and 1.8 days respectively (P > 0.05), indicating that deltamethrin resistance prolongs the larval development time of resistant mosquitoes. The average survival time of resistant adults was significantly shorter than that of susceptible adults, while the body weight of resistant female adults was significantly higher than that of the susceptible females. We also compared the vector competence for dengue virus type-2 (DENV-2) between the two strains via RT-qPCR. Considering the results of infection rate (IR) and virus load, there was no difference between the two strains during the early period of infection (4, 7, 10 day post infection (dpi)). However, in the later period of infection (14 dpi), IR and virus load in heads, salivary glands and ovaries of the resistant mosquitoes were significantly lower than those of the susceptible strain (IR of heads, salivary glands and ovaries: P < 0.05; virus load in heads and salivary glands: P < 0.05; virus load in ovaries: P < 0.001). And then, fourteen days after the DENV-2-infectious blood meal, females of the susceptible and resistant strains were allow to bite 5-day-old suckling mice. Both stains of mosquito can transmit DENV-2 to mice, but the onset of viremia was later in the mice biting by resistant group as well as lower virus copies in serum and brains, suggesting that the horizontal transmission of the resistant strain is lower than the susceptible strain. Meanwhile, we also detected IR of egg pools of the two strains on 14 dpi and found that the resistant strain were less capable of vertical transmission than susceptible mosquitoes. In addition, the average survival time of the resistant females infected with DENV-2 was 16 days, which was the shortest among the four groups of female mosquitoes, suggesting that deltamethrin resistance would shorten the life span of female Aedes albopictus infected with DENV-2. CONCLUSIONS/SIGNIFICANCE: As Aedes albopictus developing high resistance to deltamethrin, the resistance prolonged the growth and development of larvae, shorten the life span of adults, as well as reduced the vector competence of resistant Aedes albopictus for DENV-2. It can be concluded that the resistance to deltamethrin in Aedes albopictus is a double-edged sword, which not only endow the mosquito survive under the pressure of insecticide, but also increase the fitness cost and decrease its vector competence. However, Aedes albopictus resistant to deltamethrin can still complete the external incubation period and transmit dengue virus, which remains a potential vector for dengue virus transmission and becomes a threat to public health. Therefore, we should pay high attention for the problem of insecticide resistance so that to better prevent and control mosquito-borne diseases.


Assuntos
Aedes/virologia , Vetores de Doenças , Resistência a Inseticidas , Mosquitos Vetores/virologia , Nitrilas/farmacologia , Piretrinas/farmacologia , Animais , Dengue/transmissão , Vírus da Dengue/efeitos dos fármacos , Feminino , Transmissão Vertical de Doenças Infecciosas , Controle de Insetos , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Glândulas Salivares/virologia
14.
PLoS Negl Trop Dis ; 15(4): e0009337, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33909610

RESUMO

BACKGROUND: As the three major arthropod-borne viruses, dengue virus (DENV), chikungunya virus (CHIKV), and zika virus (ZIKV) are posing a growing threat to global public health and socioeconomic development. Our study aimed to systematically review the global seroprevalences of these arboviruses from existing publications. METHODS: Articles published between Jan 01, 2000 and Dec 31, 2019 in the databases of Embase, Pubmed and Web of Science were searched and collected. Countries or areas with known local presence of Aedes vector mosquitoes were included. Random effects model was utilized to estimate the pooled seroprevalences and the proportion of inapparent infection. RESULTS: Out of 1375, a total of 133 articles involving 176,001 subjects were included for our analysis. The pooled seroprevalences of DENV, CHIKV and ZIKV were 38%, 25% and 18%, respectively; and their corresponding proportions of inapparent infections were 80%, 40% and 50%. The South-East Asia Region had the highest seroprevalences of DENV and CHIKV, while the Region of the Americas had the highest seroprevalence of ZIKV. The seroprevalences of DENV and CHIKV were similar when comparing developed and developing countries, urban and rural areas, or among different populations. In addition, we observed a decreased global seroprevalences in the new decade (2010-2019) comparing to the decade before (2000-2009) for CHIKV. For ZIKV, the positive rates tested with the nucleic acid detection method were lower than those tested with the antibody detection method. Lastly, numerous cases of dual seropositivity for CHIKV and DENV were reported. CONCLUSIONS: Our results revealed a varied prevalence of arbovirus infections in different geographical regions and countries, and the inapparent infection accounted an unneglected portion of infections that requires more attention. This study will shed lights on our understanding of the true burden of arbovirus infections and promote appropriate vaccination in the future.


Assuntos
Aedes/virologia , Febre de Chikungunya/epidemiologia , Dengue/epidemiologia , Infecção por Zika virus/epidemiologia , Animais , Febre de Chikungunya/transmissão , Febre de Chikungunya/virologia , Vírus Chikungunya/fisiologia , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/fisiologia , Saúde Global , Humanos , Mosquitos Vetores/virologia , Estudos Soroepidemiológicos , Zika virus/fisiologia , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
15.
Nat Commun ; 12(1): 2296, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863880

RESUMO

Brazil experienced a large dengue virus (DENV) epidemic in 2019, highlighting a continuous struggle with effective control and public health preparedness. Using Oxford Nanopore sequencing, we led field and classroom initiatives for the monitoring of DENV in Brazil, generating 227 novel genome sequences of DENV1-2 from 85 municipalities (2015-2019). This equated to an over 50% increase in the number of DENV genomes from Brazil available in public databases. Using both phylogenetic and epidemiological models we retrospectively reconstructed the recent transmission history of DENV1-2. Phylogenetic analysis revealed complex patterns of transmission, with both lineage co-circulation and replacement. We identified two lineages within the DENV2 BR-4 clade, for which we estimated the effective reproduction number and pattern of seasonality. Overall, the surveillance outputs and training initiative described here serve as a proof-of-concept for the utility of real-time portable sequencing for research and local capacity building in the genomic surveillance of emerging viruses.


Assuntos
Vírus da Dengue/genética , Dengue/epidemiologia , Epidemias/prevenção & controle , Monitoramento Epidemiológico , Brasil/epidemiologia , Dengue/prevenção & controle , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/isolamento & purificação , Estudos de Viabilidade , Variação Genética , Genoma Viral/genética , Humanos , Unidades Móveis de Saúde , Epidemiologia Molecular , Tipagem Molecular , Filogenia , Estudo de Prova de Conceito , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Sequenciamento Completo do Genoma
16.
Parasit Vectors ; 14(1): 162, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33736702

RESUMO

BACKGROUND: The larval bionomics of Aedes across the Jaffna peninsula in northern Sri Lanka was investigated to obtain information needed for developing more effective larval source reduction measures to control endemic arboviral diseases. METHODS: The habitats of preimaginal stages of Aedes mosquitoes were surveyed, and ovitrap collections were carried out in densely populated areas of the Jaffna peninsula. Aedes larval productivities were analysed against habitat characteristics, rainfall and dengue incidence. Adults emerging from collected larvae were tested for dengue virus (DENV). RESULTS: Only Aedes aegypti, Ae. albopictus and Ae. vittatus were identified in the field habitat collections and ovitraps. Aedes aegypti was the predominant species in both the field habitat and ovitrap collections, followed by Ae. albopictus and small numbers of Ae. vittatus. Tires and open drains were the preferred field habitats for Ae. aegypti, although larval productivity was higher in discarded plastic containers. The three Aedes species differed in field habitat preferences. Concomitant presence of the three Aedes species was observed in the field habitats and ovitraps. Larval productivities were inversely correlated with the salinity of the field habitat. Rainfall in the preceding month significantly correlated with larval productivity in the field habitats. DENV serotype 2 was detected in Ae. aegypti collected from ovitraps in the city of Jaffna. High Breteau, House and Container indices of 5.1, 5.1 and 7.9%, respectively, were observed in the field habitat surveys and ovitrap indices of up to 92% were found in Jaffna city. CONCLUSIONS: Aedes larval indices in populated areas of the peninsula showed a high potential for dengue epidemics. Unacceptable littering practices, failure to implement existing dengue control guidelines, vertical transmission of DENV in vector mosquitoes and preimaginal development in brackish water and open surface drains, as well as in domestic wells that provide potable water, are serious constraints to the current Aedes larval source reduction methods used to control dengue in the Jaffna peninsula. Similar shortcomings in arboviral disease control are likely present in other resource-constrained tropical coastal zones worldwide.


Assuntos
Aedes/fisiologia , Dengue/prevenção & controle , Dengue/transmissão , Ecologia/métodos , Larva/crescimento & desenvolvimento , Mosquitos Vetores/virologia , Animais , Dengue/epidemiologia , Ecossistema , Feminino , Salinidade , Sri Lanka/epidemiologia
17.
PLoS Negl Trop Dis ; 15(3): e0009257, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33740003

RESUMO

The management of mosquito-borne diseases is a challenge in southern coastal Ecuador, where dengue is hyper-endemic and co-circulates with other arboviral diseases. Prior work in the region has explored social-ecological factors, dengue case data, and entomological indices. In this study, we bring together entomological and epidemiological data to describe links between social-ecological factors associated with risk of dengue transmission at the household level in Machala, Ecuador. Households surveys were conducted from 2014-2017 to assess the presence of adult Aedes aegypti (collected via aspiration) and to enumerate housing conditions, demographics, and mosquito prevention behaviors. Household-level dengue infection status was determined by laboratory diagnostics in 2014-2015. Bivariate analyses and multivariate logistic regression models were used to identify social-ecological variables associated with household presence of female Ae. aegypti and household dengue infection status, respectively. Aedes aegypti presence was associated with interruptions in water service and weekly trash collection, and household air conditioning was protective against mosquito presence. Presence of female Ae. aegypti was not associated with household dengue infections. We identified shaded patios and head of household employment status as risk factors for household-level dengue infection, while window screening in good condition was identified as protective against dengue infection. These findings add to our understanding of the systems of mosquito-borne disease transmission in Machala, and in the larger region of southern Ecuador, aiding in the development of improved vector surveillance efforts, and targeted interventions.


Assuntos
Dengue/etiologia , Aedes , Animais , Dengue/epidemiologia , Dengue/transmissão , Ecologia , Equador/epidemiologia , Características da Família , Feminino , Humanos , Modelos Logísticos , Mosquitos Vetores , Fatores de Risco
19.
PLoS Negl Trop Dis ; 15(3): e0009122, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33684130

RESUMO

Dengue is an emerging vector-borne viral disease across the world. The primary dengue mosquito vectors breed in containers with sufficient water and nutrition. Outdoor containers can be detected from geotagged images using state-of-the-art deep learning methods. In this study, we utilize such container information from street view images in developing a risk mapping model and determine the added value of including container information in predicting dengue risk. We developed seasonal-spatial models in which the target variable dengue incidence was explained using weather and container variable predictors. Linear mixed models with fixed and random effects are employed in our models to account for different characteristics of containers and weather variables. Using data from three provinces of Thailand between 2015 and 2018, the models are developed at the sub-district level resolution to facilitate the development of effective targeted intervention strategies. The performance of the models is evaluated with two baseline models: a classic linear model and a linear mixed model without container information. The performance evaluated with the correlation coefficients, R-squared, and AIC shows the proposed model with the container information outperforms both baseline models in all three provinces. Through sensitivity analysis, we investigate the containers that have a high impact on dengue risk. Our findings indicate that outdoor containers identified from street view images can be a useful data source in building effective dengue risk models and that the resulting models have potential in helping to target container elimination interventions.


Assuntos
Aedes/crescimento & desenvolvimento , Dengue/epidemiologia , Dengue/transmissão , Controle de Mosquitos/métodos , Mosquitos Vetores/crescimento & desenvolvimento , Aedes/virologia , Animais , Cruzamento , Geografia , Humanos , Internet , Modelos Teóricos , Mosquitos Vetores/virologia , Análise Espacial , Tailândia/epidemiologia , Tempo (Meteorologia)
20.
PLoS Negl Trop Dis ; 15(3): e0009182, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33735293

RESUMO

Climate change and variability influence temperature and rainfall, which impact vector abundance and the dynamics of vector-borne disease transmission. Climate change is projected to increase the frequency and intensity of extreme climate events. Mosquito-borne diseases, such as dengue fever, are primarily transmitted by Aedes aegypti mosquitoes. Freshwater availability and temperature affect dengue vector populations via a variety of biological processes and thus influence the ability of mosquitoes to effectively transmit disease. However, the effect of droughts, floods, heat waves, and cold waves is not well understood. Using vector, climate, and dengue disease data collected between 2013 and 2019 in Kenya, this retrospective cohort study aims to elucidate the impact of extreme rainfall and temperature on mosquito abundance and the risk of arboviral infections. To define extreme periods of rainfall and land surface temperature (LST), we calculated monthly anomalies as deviations from long-term means (1983-2019 for rainfall, 2000-2019 for LST) across four study locations in Kenya. We classified extreme climate events as the upper and lower 10% of these calculated LST or rainfall deviations. Monthly Ae. aegypti abundance was recorded in Kenya using four trapping methods. Blood samples were also collected from children with febrile illness presenting to four field sites and tested for dengue virus using an IgG enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). We found that mosquito eggs and adults were significantly more abundant one month following an abnormally wet month. The relationship between mosquito abundance and dengue risk follows a non-linear association. Our findings suggest that early warnings and targeted interventions during periods of abnormal rainfall and temperature, especially flooding, can potentially contribute to reductions in risk of viral transmission.


Assuntos
Aedes/crescimento & desenvolvimento , Clima , Dengue/epidemiologia , Dengue/transmissão , Adolescente , Animais , Criança , Pré-Escolar , Vírus da Dengue/isolamento & purificação , Humanos , Lactente , Quênia , Mosquitos Vetores/crescimento & desenvolvimento , Chuva , Estudos Retrospectivos , Temperatura
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