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2.
An Acad Bras Cienc ; 91(3): e20180860, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31553367

RESUMO

The first cases of Zika virus infection in Colombia were reported and confirmed in October 2015. The objective of the study was estimate the seroprevalence of ZIKV infection during the pre-epidemic phase in Barranquilla, Colombia, and demonstrate the presence of virus before the Colombian Ministry of Health confirmed the first case. We conducted a descriptive study of the seroprevalence of Zika virus in 390 samples obtained from a blood bank located in Barranquilla, Colombia - a city endemic for dengue, and with a recent history of a Chikungunya disease epidemic. The serum pools were tested using Euroimmun ZIKV ELISA kit. Seroprevalence of Zika virus IgG were: May 2015: 0%, June and July 2015: 2.62% (95% CI = 0.28-12.13) and August 2015: 5.35% (95% CI = 1.74-16.74). This brings to our attention the need for extending the surveillance period of this virus in order to adequately assess its teratogenic effects.


Assuntos
Anticorpos Antivirais/sangue , Doadores de Sangue/estatística & dados numéricos , Imunoglobulina G/sangue , Infecção por Zika virus/sangue , Zika virus/imunologia , Colômbia/epidemiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Estudos Soroepidemiológicos
3.
Rev Panam Salud Publica ; 43, September 2019
Artigo em Português | PAHO-IRIS | ID: phr-51551

RESUMO

[RESUMO]. Em 2015, o Brasil enfrentou uma epidemia de infecção pelo vírus Zika que se propagou por países do mundo. Posteriormente, recomendações acerca dos critérios de notificação de casos de síndrome congênita do Zika (SCZ) foram divulgadas através de protocolos. As mudanças frequentes nessas recomendações podem ter afetado o gerenciamento clínico e o acesso a suporte pós-diagnóstico por crianças afetadas mas não identificadas. No presente estudo, 39 casos de SCZ notificados no estado do Espírito Santo no período de 2015 a 2016 foram reclassificados quanto ao seu diagnóstico de acordo com o protocolo atualmente vigente, diferente daquele que vigorava em 2015. Pela reclassificação, apenas oito dos 36 casos seriam confirmados, respeitando o critério de dois ou mais sinais ou sintomas da SCZ com ou sem microcefalia e confirmação sorológica. Ainda, pela diminuição no perímetro cefálico que define microcefalia, 17 casos passaram a não se enquadrar nessa condição. Apesar de o protocolo vigente não utilizar somente o perímetro cefálico como critério para notificação e confirmação da SCZ, cabe ressaltar que este achado ainda é o maior sinalizador para as equipes de saúde, indicando um risco da não detecção precoce da SCZ. Seria prudente uma revisão dos casos “descartados” no momento de transição entre protocolos, a fim de avaliar se foram corretamente classificados.


[ABSTRACT]. In 2015, Brazil faced a Zika virus epidemic that spread to other countries in the world. As a result, recommendations regarding reporting criteria for congenital Zika syndrome (CZS) were issued in the form of protocols. The frequent changes in these recommendations may have affected clinical management and the access to post-diagnostic support by children who were affected by CZS, but who ended up not being identified. In the present study, 39 cases of CZS reported in the state of Espírito Santo, Brazil, from 2015 to 2016 were re-classified in terms of diagnosis using the current protocol, which is different from the protocol used in 2015. According to this re-classification, only eight out of 36 cases would be confirmed, based on the criterion of two or more signs or symptoms of CZS with or without microcephaly plus positive serologic results. Also, considering the decrease in the head circumference cut-off point defining microcephaly, 17 cases would no longer meet the definition for this condition. Even though the current protocol does not rely on head circumference alone for CZS reporting and confirmation, it should be noted that this is still the main sign considered by health care teams, and therefore the decrease in the cut-off point might have compromised early CZS detection. A review of “ruled out” cases would be advisable in moments of protocol transition to determine whether these cases have been correctly classified.


[RESUMEN]. En el 2015, Brasil enfrentó una epidemia de infección por el virus del Zika que se propagó por varios países del mundo. Posteriormente, se divulgaron recomendaciones acerca de los criterios de notificación de casos del síndrome congénito por el virus del Zika (SCZ) por medio de protocolos. Los cambios frecuentes de esas recomendaciones podrían haber afectado el manejo clínico y el acceso al apoyo posterior al diagnóstico de los niños afectados, pero no identificados. En el presente estudio, se reclasificó el diagnóstico de 39 casos del SCZ notificados en el estado de Espírito Santo en el período 2015-2016, de acuerdo con el protocolo vigente en la actualidad, que es distinto del que regía en el 2015. Por causa de la reclasificación, se confirmaron únicamente ocho de los 36 casos, con observancia del criterio de dos o más signos o síntomas del SCZ acompañados o no de microcefalia y con confirmación serológica. Además, por la disminución del perímetro cefálico que define la microcefalia, 17 casos no correspondieron a esa afección. A pesar de que en el protocolo vigente no se utiliza solamente el perímetro cefálico como criterio para la notificación y confirmación del SCZ, cabe resaltar que este hallazgo es, con todo, la mayor señal para los equipos de salud, puesto que indica un riesgo de falta de detección temprana del SCZ. Convendría examinar los casos “descartados” en el momento de la transición entre protocolos, con el fin de determinar si se clasificaron correctamente.


Assuntos
Zika virus , Microcefalia , Doenças Transmissíveis , Saúde Pública , Brasil , Zika virus , Microcefalia , Doenças Transmissíveis , Saúde Pública , Brasil , Zika virus , Doenças Transmissíveis , Saúde Pública
4.
Acta Virol ; 63(3): 316-321, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507198

RESUMO

The recent Zika virus (ZIKV) outbreaks and rapid spread in tropical Latin America since introduction to Brazil in 2014, and now appearing cases in the USA, are alarming. World Health Organization (WHO) has considered transmission of ZIKV, a serious public health problem because of the increasing number of outbreaks. There are currently no drugs approved for the treatment of ZIKV infection. Discovery of safe and effective drugs are hampered by the risk in treating pregnant woman and toxicity to the fetus. Sweet basil, known as Ocimum basilicum in the scientific community, is a very well-known medicinal herb. Numerous studies have documented its beneficial activity against a great variety of human pathogens ranging from bacteria and virus to fungus and protozoans. Although, basil extracts and oils have been tested successfully against other viruses, its application to tackle ZIKV infection has not been exploited at all. In this study, we report for the first time that highly diluted ethanol extracts prepared from basil leaves can effectively inhibit ZIKV replication in Vero E6 cells with a half maximal inhibitory concentration (IC50) value of 1:134. The diluted extract as well as the amount of ethanol that goes into its preparation have been found to be completely non-toxic to the above mentioned cell line. The extract seems to inhibit the virus at the step of attachment and entry into the host cell. The specific inhibition of ZIKV observed using the basil leaf extract suggests a new alternative mode of treatment against flavivirus. Keywords: Zika virus; basil extract; antiviral.


Assuntos
Ocimum basilicum , Extratos Vegetais , Internalização do Vírus , Infecção por Zika virus , Animais , Sobrevivência Celular/efeitos dos fármacos , Cercopithecus aethiops , Etanol/química , Ocimum basilicum/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Plantas Medicinais/química , Células Vero , Internalização do Vírus/efeitos dos fármacos , Zika virus/efeitos dos fármacos , Zika virus/fisiologia
5.
Stud Health Technol Inform ; 264: 1874-1875, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438386

RESUMO

Understanding public risk perceptions, and how these affect behavior, is critical to public health's ability to leverage technology for risk communications. However, little is known about Zika virus risk perceptions. We addressed this gap by analyzing nationally representative (U.S.) survey data. Our results suggest that a minority of U.S. adults perceive Zika to be a major threat (13%), and only about 15% have taken protective actions. Our findings have implications for improving technology-supported risk communication.


Assuntos
Tecnologia da Informação , Infecção por Zika virus , Zika virus , Adulto , Comunicação , Humanos , Saúde Pública , Fatores de Risco
6.
Rev Inst Med Trop Sao Paulo ; 61: e40, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31432989

RESUMO

Several arboviruses have emerged and/or re-emerged in North, Central and South-American countries. Viruses from some regions of Africa and Asia, such as the Zika and Chikungunya virus have been introduced in new continents causing major public health problems. The aim of this study was to investigate the presence of RNA from Zika, Dengue and Chikungunya viruses in symptomatic patients from Rondonia, where the epidemiological profile is still little known, by one-step real-time RT-PCR. The main clinical signs and symtoms were fever (51.2%), headache (78%), chills (6.1%), pruritus (12.2%), exanthema (20.1%), arthralgia (35.3%), myalgia (26.8%) and retro-orbital pain (19.5%). Serum from 164 symptomatic patients were collected and tested for RNA of Zika, Dengue types 1 to 4 and Chikungunya viruses, in addition to antibodies against Dengue NS1 antigen. Direct microscopy for Malaria was also performed. Only ZIKV RNA was detected in 4.3% of the patients, and in the remaining 95.7% of the patients RNA for Zika, Dengue and Chikungunya viruses were not detected. This finding is intriguing as the region has been endemic for Dengue for a long time and more recently for Chikungunya virus as well. The results indicated that medical and molecular parameters obtained were suitable to describe the first report of symptomatic Zika infections in this region. Furthermore, the low rate of detection, compared to clinical signs and symptoms as the solely diagnosis criteria, suggests that molecular assays for detection of viruses or other pathogens that cause similar symptoms should be used and the corresponding diseases could be included in the compulsory notification list.


Assuntos
Febre de Chikungunya/epidemiologia , Vírus Chikungunya/genética , Vírus da Dengue/genética , Dengue/epidemiologia , Infecção por Zika virus/epidemiologia , Zika virus/genética , Brasil/epidemiologia , Febre de Chikungunya/diagnóstico , Dengue/diagnóstico , Humanos , Vírus de RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Infecção por Zika virus/diagnóstico
7.
Mem Inst Oswaldo Cruz ; 114: e190098, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31411310

RESUMO

BACKGROUND: Dengue virus (DENV) has circulated in Brazil for over 30 years. During this time, one serotype has cyclically replaced the other, until recently, when all four distinct serotypes began to circulate together. Persistent circulation of DENV for long time periods makes sequential infections throughout a person's life possible. After primary DENV infection, life-long immunity is developed for the infecting serotype. Since DENV and Zika virus (ZIKV) are antigenically similar, the possibility of cross-reactions has attracted attention and has been demonstrated in vitro. OBJECTIVE: The aim of this study was to investigate whether immune-sera from DENV and ZIKV infected patients would cross-react in vitro with other Flaviviridae family members. METHODS: Cross-reaction of the studied samples with yellow fever virus (YFV), West Nile virus (WNV), Rocio virus (ROCV), Saint Louis virus (SLEV) and Ilheus virus (ILHV) has been investigated by plaque reduction neutralisation test (PRNT) and the antibody-dependent enhancement (ADE) by flow-cytometry. FINDINGS: Antibodies against ZIKV and DENV virus cross-reacted with other flaviviruses either neutralising or enhancing the infection. Thus, viral entrance into FcRFcɣRII-expressing cells were influenced by the cross-reactive antibodies. ZIKV or DENV immune sera enhanced cellular infection by WNV, ILHV, ROCV and SLEV. Finally, DENV immune sera presented higher neutralising activity for YFV and SLEV. While ZIKV immune sera neutralised WNV, ILHV and ROCV with high frequencies of positivity. MAIN CONCLUSIONS: The co-circulation of those viruses in the same area represents a risk for the development of severe infections if they spread throughout the country. Successive flavivirus infections may have an impact on disease pathogenesis, as well as on the development of safe vaccine strategies.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vírus da Dengue/imunologia , Zika virus/imunologia , Reações Cruzadas/imunologia , Flavivirus/classificação , Flavivirus/imunologia , Citometria de Fluxo , Humanos , Testes de Neutralização
8.
Mem Inst Oswaldo Cruz ; 114: e190150, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31432892

RESUMO

BACKGROUND: Zika virus (ZIKV) infections reported in recent epidemics have been linked to clinical complications that had never been associated with ZIKV before. Adaptive mutations could have contributed to the successful emergence of ZIKV as a global health threat to a nonimmune population. However, the causal relationships between the ZIKV genetic determinants, the pathogenesis and the rapid spread in Latin America and in the Caribbean remain widely unknown. OBJECTIVES: The aim of this study was to characterise three ZIKV isolates obtained from patient samples during the 2015/2016 Brazilian epidemics. METHODS: The ZIKV genomes of these strains were completely sequenced and in vitro infection kinetics experiments were carried out in cell lines and human primary cells. FINDINGS: Eight nonsynonymous substitutions throughout the viral genome of the three Brazilian isolates were identified. Infection kinetics experiments were carried out with mammalian cell lines A549, Huh7.5, Vero E6 and human monocyte-derived dendritic cells (mdDCs) and insect cells (Aag2, C6/36 and AP61) and suggest that some of these mutations might be associated with distinct viral fitness. The clinical isolates also presented differences in their infectivity rates when compared to the well-established ZIKV strains (MR766 and PE243), especially in their abilities to infect mammalian cells. MAIN CONCLUSIONS: Genomic analysis of three recent ZIKV isolates revealed some nonsynonymous substitutions, which could have an impact on the viral fitness in mammalian and insect cells.


Assuntos
Aedes/virologia , Replicação Viral , Infecção por Zika virus/virologia , Zika virus/genética , Animais , Brasil , Cercopithecus aethiops , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , Células Vero , Carga Viral , Cultura de Vírus
9.
An Acad Bras Cienc ; 91(suppl 3): e20190407, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31460596

RESUMO

We review the potential of Amazon forest as a source for circulation and maintenance of native arboviruses as well its capacity to host exotic arboviruses introduced in Brazil during their process of adapting to the Amazon environment. After a brief introduction about arboviruses isolated in Amazon region and description of the main arboviruses pathogenic to humans, we highlight the history of the last two exotic viruses introduced in Brazil - Chikungunya virus (CHIKV) and Zika virus (ZIKV) - and their consequences to the public health. Finally, we discuss and hypothesize what will happen with them after the outbreak. We look to the past to predict the future.


Assuntos
Arbovirus/classificação , Doenças Transmissíveis Emergentes/virologia , Animais , Brasil , Vírus Chikungunya , Vírus da Dengue , Humanos , Orthobunyavirus , Vírus da Febre Amarela , Zika virus
10.
Rev Panam Salud Publica ; 43, August 2019
Artigo em Inglês | PAHO-IRIS | ID: phr-51511

RESUMO

To the editor: Dengue, zika, and chikungunya outbreaks in Central and South America countries have presented significant challenges related to their prevention and control. From the virologic point of view, the possibility has been raised that the co-circulation of the three viruses could generate cross-protection between the three alphaviruses. In order to discuss this hypothesis it must be taken into account that Zika, dengue (DENV) and chikungunya viruses are closely related flaviviruses, with identical urban transmission and some immune interactions (1). Also, it is known that secondary DENV infections may be more severe than primary infections due to the antibody-dependent immune response (i.e., heterotypic sub-neutralizing antibodies that increase virus entry into poorly susceptible cells) (2,3). In addition, the recent introduction of Zika and chikungunya viruses in the Americas and the large-scale exposure of a uniformly unexposed population could affect subsequent transmission of dengue virus. This hypothesis has not been tested, largely because insufficient epidemiological data are available for the affected sites. However, in Salvador, Brazil, after the zika outbreak there was a significant decrease in the frequency of dengue cases (4). A similar situation was observed in Colombia, where the decrease in dengue cases following the zika and chikungunya outbreaks went from 334.1 cases per 100 000 people in 2015 to 90.7 cases per 100 000 in 2017 and 173,1 cases per 100 000 in 2018 (5). Although temporary associations do not prove causation, the strength and consistency of the observations suggest that infections with Zika virus and chikungunya virus could induce cross-protective immunity against dengue. Prospective studies are needed to fully assess the risk of dengue infection after exposure to Zika and chikungunya viruses and to determine whether the supposed cross-protection is long-lasting. Although observations support this hypothesis, the potential direct implications of this hypothesis for epidemiological surveillance, immunological research on pathogenesis and vaccine development require additional studies.


Assuntos
Zika virus , Dengue , Vírus Chikungunya , Américas , Vírus , Colômbia
11.
Rev Panam Salud Publica ; 43, August 2019
Artigo em Inglês | PAHO-IRIS | ID: phr-51510

RESUMO

To the Editor: We read the publication on “Co-circulation of dengue, chikungunya, and Zika viruses in Colombia from 2008 to 2018” with a great interest (1). Rico-Mendoza et al. concluded that “The decrease in the number of dengue cases after co-circulation of the three viruses could indicate possible cross-protection” (1). We would like to share ideas on this report. An interesting question is whether there is a cross-protection or not. Based on our setting in Indochina, a similar co-circulation of the three viruses presently exists but there has never been any decrease in number of dengue. In addition, there is no clear report showing that there is a cross-protection due to the three virus co-circulation. Priyamvada et al. mentioned that there might be a common host immune response among viruses due to viral structural similarity, but it is still no data regarding the immunoprotection (2). Based on a recent publication by Wen et al., it is observed that there might be a cross protection via CD8+ but Wen et al. mentioned that “passive transfer studies suggest that DENV-immune serum does not protect against ZIKV infection” (3). Based on the data by Rico-Mendoza et al., there is also a fluctuation of the number of the cases (such as between 2016 and 2018) (1). The fluctuation, increased and decreased rate, might be due to several factors including to the environmental factors that might stimulate or suppress the epidemic of the vector borne disease. Due to the worldwide concern on Zika virus, there might be some intensified prevention program against mosquito borne disease.


Assuntos
Zika virus , Dengue , Colômbia , Vírus Chikungunya
12.
Recurso na Internet em Português | LIS - Localizador de Informação em Saúde | ID: lis-LISBR1.1-46660

RESUMO

Microcefalia é uma malformação congênita em que o cérebro não se desenvolve de maneira adequada. Essa malformação pode ser efeito de uma série de fatores de diferentes origens, como substâncias químicas e infecciosas, além de bactérias, vírus e radiação. Em relação ao aleitamento materno, como não há evidência científica que demonstre a transmissão do vírus Zika pelo leite, o Ministério da Saúde recomenda que seja mantida a amamentação contínua até os dois anos ou mais, sendo ele exclusivo até os seis primeiros meses de vida da criança.


Assuntos
Zika virus , Leite Humano , Infecção por Zika virus , Microcefalia , Recém-Nascido , Gestantes , Sistema Único de Saúde , Saúde da Criança
13.
Rev Soc Bras Med Trop ; 52: e20190105, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31340371

RESUMO

INTRODUCTION: Clinical and epidemiological data on suspected congenital Zika syndrome (CZS) cases from southern Mato Grosso (MT) in Brazil during the Zika virus (ZIKV) outbreak in 2015-2016 were evaluated. METHODS: This is a descriptive case series study of newborns whose mothers were suspected cases of ZIKV infections during their pregnancies. The medical records of all the suspected CZS cases (mothers and newborns) treated by the specialized ambulatory service from June 2015 to August 2016 were analyzed. RESULTS: Twenty suspected CZS cases were included in these analyses. They were categorized into four groups based on the clinical and laboratory findings: confirmed cases (n=1), highly probable cases (n=13), moderately probable cases (n=5), and somewhat probable cases (n=1). The mothers tested negative for STORCH (syphilis, toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex) and other important congenital infections; however, specific ZIKV tests were not performed during the study period. Microcephaly was observed in the majority of these newborns, and all the patients showed altered cranial computed tomography image findings. Extracranial abnormalities such as arthrogryposis, and otological and ophthalmological manifestations were also observed. CONCLUSIONS: Although ZIKV was not confirmed to cause the congenital malformations, this study demonstrated that the clinical and epidemiological findings associated with a STORCH exclusion strengthened the CZS diagnosis. The suspected cases in MT occurred simultaneously with the first CZS cases reported in Brazil, suggesting ZIKV circulation in the study region during the same period.


Assuntos
Microcefalia/virologia , Complicações Infecciosas na Gravidez/virologia , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/epidemiologia , Zika virus/isolamento & purificação , Adolescente , Adulto , Brasil/epidemiologia , Surtos de Doenças , Feminino , Humanos , Recém-Nascido , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Fatores Socioeconômicos , Adulto Jovem , Infecção por Zika virus/complicações , Infecção por Zika virus/congênito
14.
BMC Infect Dis ; 19(1): 590, 2019 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-31277583

RESUMO

BACKGROUND: Transfusion-Transmitted Zika virus (TT-ZIKV) has become an emerging threat to world blood banks due to the fast spread of ZIKV epidemics and high rate of asymptomatic infections. For the risk assessment of ZIKV infection in blood products, relevant studies in blood donations or blood donors tested for ZIKV were collected and analyzed systematically. The overall prevalence of ZIKV infection were estimated through meta-analysis and potential risk factors were detected. The results will provide important clues for the protocol design of blood screening tests. METHODS: Relevant articles about the rate of ZIKV detected in blood samples were identified from PubMed, Scopus and Web Of Science using key terms search strategy until October 7, 2017. Eligible articles were screened following inclusion and exclusion criteria. Meta-analysis and subgroup analyses were performed by software R3.4.1. Overall postdonation and posttransfusion follow-ups were analyzed. RESULTS: Ten literatures (528,947 blood samples) were included for meta-analysis. The overall pooled prevalence of ZIKV (RNA and antibody) in blood donations was 1.02% (95%CI 0.36-1.99). The pooled prevalence of ZIKV RNA in blood donations was 0.85% (95%CI 0.21-1.88) less than the pooled prevalence of anti-ZIKV antibodies 1.61% (95%CI 0.03-5.21), however the difference was not statistically significant (p = 0.52). The prevalence varied significantly in different geographical regions (p < 0.001). Blood donations were more than two times likely to be infected by ZIKV in Zika epidemic period (1.37, 95%CI 0.91-1.91) than in non-epidemic period (0.61, 95%CI 0-2.55). The prevalence of anti-ZIKV antibodies (1.61, 95%CI 0.03-5.21) was almost twice as much as ZIKV nucleic acid detected in blood donations (0.85, 95%CI 0.21-1.88). However, statistically significant differences were not observed. A total of 122 ZIKV positive blood donors were followed, of which 48 (39%) reported symptoms postdonation, but none of the 13 followed recipients reported any clinical symptoms related to Zika infection posttransfusion. CONCLUSION: The pooled prevalence of Zika infection in blood donations was 1.02%. The prevalence varied greatly and reached to high-risk level in most of the situations. The results suggest that nucleic acid tests (NAT) for blood screening and pathogen reduction/inactivation technology (PRT) should be implemented in Zika-endemic areas and appropriate strategies should be designed according to different conditions. More studies are needed in the future to provide more evidence.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Infecção por Zika virus , Zika virus , Anticorpos Antivirais/sangue , Humanos , Prevalência , RNA Viral/sangue , Zika virus/genética , Zika virus/imunologia , Infecção por Zika virus/sangue , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/epidemiologia
15.
Ecol Lett ; 22(10): 1690-1708, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31286630

RESUMO

Mosquito-borne diseases cause a major burden of disease worldwide. The vital rates of these ectothermic vectors and parasites respond strongly and nonlinearly to temperature and therefore to climate change. Here, we review how trait-based approaches can synthesise and mechanistically predict the temperature dependence of transmission across vectors, pathogens, and environments. We present 11 pathogens transmitted by 15 different mosquito species - including globally important diseases like malaria, dengue, and Zika - synthesised from previously published studies. Transmission varied strongly and unimodally with temperature, peaking at 23-29ºC and declining to zero below 9-23ºC and above 32-38ºC. Different traits restricted transmission at low versus high temperatures, and temperature effects on transmission varied by both mosquito and parasite species. Temperate pathogens exhibit broader thermal ranges and cooler thermal minima and optima than tropical pathogens. Among tropical pathogens, malaria and Ross River virus had lower thermal optima (25-26ºC) while dengue and Zika viruses had the highest (29ºC) thermal optima. We expect warming to increase transmission below thermal optima but decrease transmission above optima. Key directions for future work include linking mechanistic models to field transmission, combining temperature effects with control measures, incorporating trait variation and temperature variation, and investigating climate adaptation and migration.


Assuntos
Aedes/parasitologia , Aedes/virologia , Temperatura Ambiente , Animais , Mudança Climática , Vírus da Dengue , Malária/transmissão , Mosquitos Vetores/parasitologia , Mosquitos Vetores/virologia , Plasmodium , Vírus do Rio Ross , Viroses/transmissão , Zika virus
16.
Parasit Vectors ; 12(1): 344, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300061

RESUMO

BACKGROUND: In 2015-2016, Zika virus (ZIKV) caused serious epidemics in Brazil. The key epidemiological parameters and spatial heterogeneity of ZIKV epidemics in different states in Brazil remain unclear. Early prediction of the final epidemic (or outbreak) size for ZIKV outbreaks is crucial for public health decision-making and mitigation planning. We investigated the spatial heterogeneity in the epidemiological features of ZIKV across eight different Brazilian states by using simple non-linear growth models. RESULTS: We fitted three different models to the weekly reported ZIKV cases in eight different states and obtained an R2 larger than 0.995. The estimated average values of basic reproduction numbers from different states varied from 2.07 to 3.41, with a mean of 2.77. The estimated turning points of the epidemics also varied across different states. The estimation of turning points nevertheless is stable and real-time. The forecast of the final epidemic size (attack rate) is reasonably accurate, shortly after the turning point. The knowledge of the epidemic turning point is crucial for accurate real-time projection of the outbreak. CONCLUSIONS: Our simple models fitted the epidemic reasonably well and thus revealed the spatial heterogeneity in the epidemiological features across Brazilian states. The knowledge of the epidemic turning point is crucial for real-time projection of the outbreak size. Our real-time estimation framework is able to yield a reliable prediction of the final epidemic size.


Assuntos
Sistemas de Computação , Surtos de Doenças/estatística & dados numéricos , Modelos Teóricos , Infecção por Zika virus/epidemiologia , Número Básico de Reprodução , Brasil/epidemiologia , Epidemias/prevenção & controle , Epidemias/estatística & dados numéricos , Humanos , Incidência , Saúde Pública , Zika virus , Infecção por Zika virus/transmissão
17.
Nan Fang Yi Ke Da Xue Xue Bao ; 39(6): 699-704, 2019 Jun 30.
Artigo em Chinês | MEDLINE | ID: mdl-31270049

RESUMO

OBJECTIVE: To establish a non-coated enzyme-linked immunosorbent assay (ELISA) based on zika virus envelope (E) protein for detecting the expression of E protein in infected cells. METHODS: Adherent Vero-143 cells infected with zika virus in a 96-well plate were fixed, and the antibodies against zika virus E protein were added at an optimized concentration to establish the non-coated ELISA method for E protein. The antiviral activities of lignans compound C1 was evaluated using this method. The accuracy of this non-coated ELISA was verified by RT-PCR, and the cross reaction with dengue virus was assessed. RESULTS: After optimization, the background absorbance at 450 nm of uninfected cells was reduced to about 0.20. The antiviral activities of lignans compound C1 detected by this method were basically consistent with the results of RT-PCR. No cross reaction with dengue virus was found in this assay. CONCLUSIONS: A non- coated ELISA method based on zika virus E protein was established, which can be used for screening antiviral agents against zika virus.


Assuntos
Infecção por Zika virus , Zika virus , Anticorpos Antivirais , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G , Imunoglobulina M , Proteínas do Envelope Viral
18.
BMC Public Health ; 19(1): 987, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337359

RESUMO

BACKGROUND: The Gulf Coast of the United States is home to mosquito vectors that may spread disease causing pathogens, and environmental conditions that are ideal for the sustained transmission of mosquito-borne pathogens. Understanding public perceptions of mosquito-borne diseases and mosquito prevention strategies is critical for the development of effective vector control strategies and public health interventions. Here, we present a survey conducted in Mobile, Alabama along the Gulf Coast to better understand public perceptions of mosquito-borne diseases, mosquito control activities, and potential risk factors. METHODS: Using Knowledge, Attitude, and Practice (KAPs) assessments, we surveyed populations living in 12 zip codes in Mobile, Alabama using a 7-point Likert scale and frequency assessments. Survey participants were asked about vector control efforts, knowledge of mosquito-borne diseases, and understanding of mosquito ecology and breeding habitats. RESULTS: One hundred twenty-six surveys were completed in Mobile, Alabama, revealing that 73% of participants reported being bitten by a mosquito in the last 30 days and mosquitoes were frequently seen in their homes. Ninety-four percent of respondents had heard of Zika Virus at the time of the survey, and respondents reported being least familiar with dengue virus and chikungunya virus. CONCLUSIONS: Chikungunya virus, dengue virus, malaria, West Nile virus, and Zika virus have been documented in the Gulf Coast of the United States. The mosquitoes which vector all of these diseases are presently in the Gulf Coast meaning all five diseases pose a potential risk to human health. The results of this survey emphasize knowledge gaps that public health officials can address to empower the population to reduce their risk of these mosquito-borne diseases. Each species of mosquito has specific preferences for breeding and feeding and there is no one size fits all prevention approach, educating people on the need for a variety of approaches in order to address all species will further empower them to control mosquitoes where they live and further reduce their risk of disease.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Controle de Mosquitos/métodos , Mosquitos Vetores , Alabama , Vírus Chikungunya , Vírus da Dengue , Humanos , Malária/prevenção & controle , Saúde Pública , Fatores de Risco , Inquéritos e Questionários , Vírus do Nilo Ocidental , Zika virus
19.
Washington, D. C.; OPAS; 2019-07-21.
em Português | PAHO-IRIS | ID: phr-51374

RESUMO

[Introdução]. A história do controle das doenças transmitidas por vetores nas Américas é muito extensa, e as evidências mostram que, no passado, vários programas foram exitosos. O controle da febre amarela e do paludismo em Cuba e no Panamá, sob a direção de William Gorgas (1901-1910); a eliminação de Anopheles gambiae no Brasil (1940); a eliminação de Aedes aegypti entre 1950 e 1960, promovida pela OPAS e dirigida por Fred Soper; a eliminação da transmissão da doença de Chagas por Triatoma infestans no Brasil e no Uruguai; e a recente erradicação da oncocercose de 11 dos 13 focos endêmicos na Colômbia, no Equador, no México e na Guatemala (2013-2016) são exemplos recentes de intervenções que combinaram o uso de inseticidas, da engenharia sanitária e a disponibilidade de vacinas ou medicamentos efetivos, apoiados pela participação comunitária e outros métodos de controle... Hoje em dia, estima-se que cerca de metade da população mundial viva em áreas em risco de dengue. Além disso, mais de 100 países apresentam transmissão e são produzidas entre 300 e 500 milhões de infecções anuais, das quais 96 milhões apresentam manifestações clínicas e 500.000 são casos severos, com aproximadamente 25.000 mortes. A infecção é endêmica nas regiões das Américas, Ásia Sul-Oriental, Pacífico Ocidental, África e Mediterrâneo Oriental, e nos últimos 50 anos a incidência cresceu 30 vezes, sem que haja sinais de reversão dessa tendência. O cenário epidemiológico mostra que o número de casos vem aumentando, que os surtos apresentam maior duração e magnitude e que as áreas afetadas e as populações expostas se encontram em constante expansão. A meta da OMS, para o 2020, de reduzir a mortalidade em 50% e a morbidade em 25% é considerada um desafio diante da carência de bons sistemas de vigilância que quantifiquem corretamente a carga de doença e as deficiências dos programas de controle de vetores nos países endêmicos...


Assuntos
Aedes , Mosquitos Vetores , Controle de Mosquitos , Dengue , Wolbachia , Zika virus , Vírus Chikungunya , Febre Amarela
20.
Oecologia ; 191(1): 1-10, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31227906

RESUMO

Food quality and quantity serve as the basis for cycling of key chemical elements in trophic interactions; yet the role of nutrient stoichiometry in shaping host-pathogen interactions is under appreciated. Most of the emergent mosquito-borne viruses affecting human health are transmitted by mosquitoes that inhabit container systems during their immature stages, where allochthonous input of detritus serves as the basal nutrients. Quantity and type of detritus (animal and plant) were manipulated in microcosms containing newly hatched Aedes aegypti mosquito larvae. Adult mosquitoes derived from these microcosms were allowed to ingest Zika virus-infected blood and then tested for disseminated infection, transmission, and total nutrients (percent carbon, percent nitrogen, ratio of carbon to nitrogen). Treatments lacking high-quality animal (insect) detritus significantly delayed development. Survivorship to adulthood was closely associated with the amount of insect detritus present. Insect detritus was positively correlated with percent nitrogen, which affected Zika virus infection. Disseminated infection and transmission decreased with increasing insect detritus and percent nitrogen. We provide the first definitive evidence linking nutrient stoichiometry to arbovirus infection and transmission in a mosquito using a model system of invasive Ae. aegypti and emergent Zika virus.


Assuntos
Aedes , Infecção por Zika virus , Zika virus , Animais , Interações Hospedeiro-Patógeno , Humanos , Nutrientes
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