RESUMO
Yellow fever virus (YFV) causes a clinical syndrome of acute hemorrhagic hepatitis. YFV transmission involves non-human primates (NHP), mosquitoes and humans. By late 2016, Brazil experienced the largest YFV outbreak of the last 100 years, with 2050 human confirmed cases, with 681 cases ending in death and 764 confirmed epizootic cases in NHP. Among affected areas, Bahia state in Northeastern was the only region with no autochthonous human cases. By using next generation sequence approach, we investigated the molecular epidemiology of YFV in NHP in Bahia and discuss what factors might have prevented human cases. We investigated 47 YFV positive tissue samples from NHP cases to generate 8 novel YFV genomes. ML phylogenetic tree reconstructions and automated subtyping tools placed the newly generated genomes within the South American genotype I (SA I). Our analysis revealed that the YFV genomes from Bahia formed two distinct well-supported phylogenetic clusters that emerged most likely of an introduction from Minas Gerais and Espírito Santo states. Vegetation coverage analysis performed shows predominantly low to medium vegetation coverage in Bahia state. Together, our findings support the hypothesis of two independent YFV SA-I introductions. We also highlighted the effectiveness of the actions taken by epidemiological surveillance team of the state to prevented human cases.
Assuntos
Doenças dos Primatas/virologia , Febre Amarela/veterinária , Vírus da Febre Amarela/genética , Alouatta , Animais , Brasil/epidemiologia , Callithrix , Ecossistema , Genoma Viral , Humanos , Filogenia , Febre Amarela/epidemiologia , Febre Amarela/prevenção & controle , Febre Amarela/transmissão , Vírus da Febre Amarela/classificaçãoRESUMO
In Brazil, Dengue (DENV) and Zika (ZIKV) viruses are reported as being transmitted exclusively by Aedes aegypti in urban settings. This study established the vectors and viruses involved in an arbovirus outbreak that occurred in 2019 in a rural area of Espírito Santo state, Brazil. Mosquitoes collected were morphologically identified, sorted in samples, and submitted to molecular analysis for arboviruses detection. Phylogenetic reconstruction was performed for the viral sequence obtained. All 393 mosquitoes were identified as Aedes albopictus. DENV-1 genotype V was present in one sample and another sample was positive for ZIKV. The DENV-1 clustered with viruses that have circulated in previous years in large urban centers of different regions in Brazil. This is the first report of A. albopictus infected by DENV and ZIKV during an outbreak in a rural area in Brazil, indicating its involvement in arboviral transmission. The DENV-1 strain found in the A. albopictus was not new in Brazil, being involved previously in epidemics related to A. aegypti, suggesting the potential to A. albopictus in transmitting viruses already circulating in the Brazilian population. This finding also indicates the possibility of these viruses to disperse across urban and rural settings, imposing additional challenges for the control of the diseases.
Assuntos
Aedes/virologia , Vírus da Dengue/isolamento & purificação , Dengue/transmissão , Mosquitos Vetores/virologia , Infecção por Zika virus/transmissão , Zika virus/isolamento & purificação , Animais , Brasil , Surtos de Doenças , Humanos , FilogeniaRESUMO
The chikungunya East/Central/South/Africa virus lineage (CHIKV-ECSA) was first detected in Brazil in the municipality of Feira de Santana (FS) by mid 2014. Following that, a large number of CHIKV cases have been notified in FS, which is the second-most populous city in Bahia state, northeastern Brazil, and plays an important role on the spread to other Brazilian states due to climate conditions and the abundance of competent vectors. To better understand CHIKV dynamics in Bahia state, we generated 5 complete genome sequences from a local outbreak raised in Serraria Brasil, a neighbourhood in FS, by next-generation sequencing using Illumina approach. Phylogenetic reconstructions revealed that the new FS genomes belongs to the ECSA genotype and falls within a single strongly supported monophyletic clade that includes other older CHIKV sequences from the same location, suggesting the persistence of the virus during distinct epidemic seasons. We also performed minor variants analysis and found a small number of SNPs per sample (b_29L and e_45SR = 16 SNPs, c_29SR = 29 and d_45PL and f_45FL = 21 SNPs). Out of the 93 SNPs found, 71 are synonymous, 21 are non-synonymous and one generated a stop codon. Although those mutations are not related to the increase of virus replication and/or infectivity, some SNPs were found in non-structural proteins which may have an effect on viral evasion from the mammal immunological system. These findings reinforce the needing of further studies on those variants and of continued genomic surveillance strategies to track viral adaptations and to monitor CHIKV epidemics for improved public health control.
Assuntos
Febre de Chikungunya/epidemiologia , Vírus Chikungunya/genética , Vírus Chikungunya/fisiologia , Surtos de Doenças , Genótipo , Características de Residência/estatística & dados numéricos , Classe Social , Adulto , Brasil/epidemiologia , Vírus Chikungunya/classificação , Feminino , Humanos , Masculino , Filogenia , Adulto JovemRESUMO
The MinION sequencer was launched by the Oxford Nanopore Technologies start-up as a disruptive technology for genome sequencing based on single-molecule synthesis. Its characteristics as a portable device, low cost, and simple library preparation have made it a good candidate for field researchers. MinION has been used to sequence a number of microorganisms, such as bacteria, viruses, and fungi. Based on the experience that characterized the Ebola virus genetic diversity in Guinea during the 2014-2015 outbreak, the ZiBRA (Zika in Brazil Real-time Analysis) project aimed to sequence a large number of Zika virus genomes during a mobile laboratory trip in northeast Brazil to provide important epidemiological information about the spread of this disease in this country. In response to the positive and rapid results obtained by the ZiBRA project, the Brazilian Ministry of Health and many leading institutions, such as the Pan American Health Organization and WHO, have shown interest in expanding the strategy used in this project to other countries dealing with arbovirus infection. *This article is part of a curated collection.
Assuntos
Doenças Transmitidas por Vetores/virologia , Infecção por Zika virus/virologia , Zika virus/genética , Animais , Monitoramento Epidemiológico , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Zika virus/classificação , Zika virus/isolamento & purificaçãoRESUMO
The emergence of chikungunya virus (CHIKV) has raised serious concerns due to the virus' rapid dissemination into new geographic areas and the clinical features associated with infection. To better understand CHIKV dynamics in Rio de Janeiro, we generated 11 near-complete genomes by means of real-time portable nanopore sequencing of virus isolates obtained directly from clinical samples. To better understand CHIKV dynamics in Rio de Janeiro, we generated 11 near-complete genomes by means of real-time portable nanopore sequencing of virus isolates obtained directly from clinical samples. Our phylogenetic reconstructions indicated the circulation of the East-Central-South-African (ECSA) lineage in Rio de Janeiro. Time-measured phylogenetic analysis combined with CHIKV notified case numbers revealed the ECSA lineage was introduced in Rio de Janeiro around June 2015 (95% Bayesian credible interval: May to July 2015) indicating the virus was circulating unnoticed for 5 months before the first reports of CHIKV autochthonous transmissions in Rio de Janeiro, in November 2015. These findings reinforce that continued genomic surveillance strategies are needed to assist in the monitoring and understanding of arbovirus epidemics, which might help to attenuate public health impact of infectious diseases.
Assuntos
Febre de Chikungunya/genética , Vírus Chikungunya/genética , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Adulto , África/epidemiologia , Brasil/epidemiologia , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/transmissão , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Chikungunya is an emerging arbovirus that is characterized into four lineages. One of these, the Asian genotype, has spread rapidly in the Americas after its introduction in the Saint Martin island in October 2013. Unexpectedly, a new lineage, the East-Central-South African genotype, was introduced from Angola in the end of May 2014 in Feira de Santana (FSA), the second largest city in Bahia state, Brazil, where over 5,500 cases have now been reported. Number weekly cases of clinically confirmed CHIKV in FSA were analysed alongside with urban district of residence of CHIKV cases reported between June 2014 and October collected from the municipality's surveillance network. The number of cases per week from June 2014 until September 2015 reveals two distinct transmission waves. The first wave ignited in June and transmission ceased by December 2014. However, a second transmission wave started in January and peaked in May 2015, 8 months after the first wave peak, and this time in phase with Dengue virus and Zika virus transmission, which ceased when minimum temperature dropped to approximately 15°C. We find that shorter travelling times from the district where the outbreak first emerged to other urban districts of FSA were strongly associated with incidence in each district in 2014 (R(2)).