RESUMO
We describe the circulation of Saint Louis encephalitis virus (SLEV) in two Brazilian States during outbreaks of Dengue and Zika viruses. We detected the virus in a patient from Araraquara, State of São Paulo, and in patients and in a mosquito pool of Culex quinquefasciatus from Sinop, State of Mato Grosso. Phylogenetic analysis grouped samples from this study within genotype V, which are closely related to other strains that previously circulated in other parts of the country. Genotype V seems to have established circulation in Brazil.
Assuntos
Culicidae/virologia , Vírus da Encefalite de St. Louis/genética , Encefalite de St. Louis/virologia , Genótipo , Adolescente , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Dengue/epidemiologia , Surtos de Doenças , Vírus da Encefalite de St. Louis/isolamento & purificação , Feminino , Humanos , Lactente , Masculino , Filogenia , Infecção por Zika virus/epidemiologiaRESUMO
The use of serological tests is valuable to diagnose Zika virus (ZIKV) infection and carry out epidemiological surveillance. However, ZIKV serological tests may result in false positives due to cross-reactivity between antibodies against other Flavivirus, especially dengue virus that worldwide disseminated. We used three online tools to predict amino acid sequences of B-cell epitopes. We selected and synthetized two epitopes that showed appropriate features in the molecular dynamic simulation and demonstrated to be suitable for serological assays.
Assuntos
Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Anticorpos Antivirais , Reações Cruzadas , Epitopos de Linfócito B , Humanos , Testes SorológicosRESUMO
INTRODUCTION: DENV-2 is the cause of most dengue epidemics worldwide and is associated with severe cases. METHODS: We investigated arboviruses in 164 serum samples collected from patients presenting with clinical symptoms of dengue fever and 152 mosquito pools. RESULTS: We detected the Asian II genotype of DENV-2 in humans and mosquitoes. Our results confirmed the circulation of the Asian II genotype in Brazil, in addition to the prevalent Asian/American genotype. CONCLUSIONS: The detection of Asian II genotype of DENV-2 in mosquito pools collected in a forest park may be related to a spillback event of human dengue virus.
Assuntos
Culicidae/virologia , Vírus da Dengue/genética , Dengue/virologia , Animais , Brasil , Culicidae/classificação , Genótipo , Humanos , Filogenia , Reação em Cadeia da Polimerase , RNA Viral/genética , Estações do AnoRESUMO
Amazon has been under intense human pressure, especially in the so-called "Arc of Deforestation" in the Eastern and Southern regions. Changes in biodiversity due to landscape disturbance in municipalities at the Arc of Deforestation are likely to impact mosquito species leading to the potential for emergence of arboviruses. Our aim was to describe the composition and structure of culicids in Sinop, a municipality located in the Southern Amazon at the State of Mato Grosso, as well as their presence in urban habitats, analyzing climate variables and potential risk of arbovirus transmission. Mosquitoes were collected in four habitats located in urban environments for 12 months. We recovered 5,210 adult mosquitoes from mosquito traps. Among the 33 species identified, 19 are associated with arbovirus transmission. Higher abundance, richness, diversity, and equitability of mosquito species were observed in urban forest parks and in new neighborhoods located in the outskirts of the city, nearby forest fragments and agricultural areas. As the environment consolidates as urban, both abundance and richness decrease. Highly urbanized neighborhoods had higher dominance of Culex quinquefasciatus, a mosquito associated with different arboviruses, including West Nile and Saint Louis encephalitis virus. The medically important species Cx. declarator, Cx. (Melanoconion) ssp., Aedeomyia squamipennis and Aedes scapularis were found in the four habitats. It is possible that these mosquitoes are adapting to different habitats and as a consequence, they are reaching urbanized areas. Mosquito abundance was higher in the days of high temperature and low precipitation in urban forest parks and in highly urbanized neighborhoods. These results suggest that Sinop region is a key area for surveillance of arbovirus vectors.
Assuntos
Arbovírus/fisiologia , Culicidae/virologia , Mosquitos Vetores/virologia , Animais , Biodiversidade , Brasil , Cidades , Clima , Culicidae/fisiologia , Ecossistema , Florestas , Humanos , Parques Recreativos , UrbanizaçãoRESUMO
BACKGROUND: Arbovirus surveillance in field-collected mosquitoes is essential in monitoring virus activity to avoid emergence and outbreaks of arboviruses. METHODS: We used reverse transcription polymerase chain reaction methods to search for arbovirus in mosquitoes collected in Brazil's southeast Amazon forest remnants during 2015-2016. RESULTS: We detected Iheus virus (ILHV) RNA in Culex declarator, Culex (Melanoconion) and Ochlerotatus serratus mosquitoes. CONCLUSIONS: These results indicate ILHV circulation in the studied area, highlighting its potential emergence in human population. More studies are necessary to confirm the roles of these three species in ILHV maintenance.
Assuntos
Arbovírus/isolamento & purificação , Culicidae/virologia , Animais , Brasil , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Abstract INTRODUCTION: DENV-2 is the cause of most dengue epidemics worldwide and is associated with severe cases. METHODS: We investigated arboviruses in 164 serum samples collected from patients presenting with clinical symptoms of dengue fever and 152 mosquito pools. RESULTS: We detected the Asian II genotype of DENV-2 in humans and mosquitoes. Our results confirmed the circulation of the Asian II genotype in Brazil, in addition to the prevalent Asian/American genotype. CONCLUSIONS: The detection of Asian II genotype of DENV-2 in mosquito pools collected in a forest park may be related to a spillback event of human dengue virus.