RESUMO
Rocio virus (ROCV) is a highly neuropathogenic mosquito-transmitted flavivirus responsible for an unprecedented outbreak of human encephalitis during 1975-1976 in Sao Paulo State, Brazil. Previous studies have shown an increased number of inflammatory macrophages in the central nervous system (CNS) of ROCV-infected mice, implying a role for macrophages in the pathogenesis of ROCV. Here, we show that ROCV infection results in increased expression of CCL2 in the blood and in infiltration of macrophages into the brain. Moreover, we show, using CCR2 knockout mice, that CCR2 expression is essential for macrophage infiltration in the brain during ROCV infection and that the lack of CCR2 results in increased disease severity and mortality. Thus, our findings show the protective role of CCR2-mediated infiltration of macrophages in the brain during ROCV infection.
Assuntos
Encefalite/metabolismo , Infecções por Flavivirus/metabolismo , Flavivirus/patogenicidade , Macrófagos/metabolismo , Receptores CCR2/metabolismo , Animais , Encéfalo , Brasil , Encefalite/virologia , Feminino , Infecções por Flavivirus/virologia , Macrófagos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Abstract INTRODUCTION: Cacipacore virus (CPCV), a possible bird-associated flavivirus, has yet to be detected in mosquitoes. Our purpose is examining CPCV in mosquitoes from the Amazon region of Brazil. METHODS: Approximately 3,253 Culicidae (grouped into 264 pools) were collected from the Amazon region during 2002-2006 and analyzed using a Flavivirus genus-specific reverse transcription- polymerase chain reaction followed by nested polymerase chain reaction assay and by nucleotide sequencing of amplicons. RESULTS: Nucleotide sequences from five mosquito samples showed high similarity to the those of CPCV originally isolated in the Amazon region. CONCLUSIONS: This is the first report of CPCV-infected mosquitoes which has implications on the arbovirus maintenance in nature and transmission to man.
Assuntos
Animais , Flavivirus/genética , Culicidae/virologia , Filogenia , Brasil , Sequência de Bases , Reação em Cadeia da Polimerase , Flavivirus/classificação , Culicidae/classificaçãoRESUMO
Cacipacoré virus (CPCV) is a potential emerging virus classified in the genus Flavivirus, family Flaviviridae. In the present study, we present the genetic characterization of a CPCV isolated from ticks (Amblyomma cajennense) collected from a sick capybara (Hydrochoerus hydrochaeris) in São Paulo State, Brazil. The CPCV isolate shares the typical genomic organization of flaviviruses with 10,857 nucleotides in length and a single open reading frame of 10,284 nucleotides encoding a polyprotein of 3,427 amino acids. Phylogenetic analysis revealed that CPCV is unique, as a potentially tick-borne virus, in the Japanese encephalitis virus serogroup.
Assuntos
Vetores Aracnídeos/virologia , Infecções por Flavivirus/veterinária , Flavivirus/genética , Flavivirus/isolamento & purificação , Doenças dos Roedores/virologia , Carrapatos/virologia , Animais , Brasil , Flavivirus/classificação , Infecções por Flavivirus/transmissão , Infecções por Flavivirus/virologia , Genoma Viral , Filogenia , Doenças dos Roedores/transmissão , Roedores , Proteínas Virais/genéticaRESUMO
The Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), located in Manaus, the capital of the State of Amazonas (Western Brazilian Amazon), is a pioneering institution in this region regarding the syndromic surveillance of acute febrile illness, including arboviral infections. Based on the data from patients at the FMT-HVD, we have detected recurrent outbreaks in Manaus by the four dengue serotypes in the past 15 years, with increasing severity of the disease. This endemicity has culminated in the simultaneous circulation of all four serotypes in 2011, the first time this has been reported in Brazil. Between 1996 and 2009, 42 cases of yellow fever (YF) were registered in the State of Amazonas, and 71.4% (30/42) were fatal. Since 2010, no cases have been reported. Because the introduction of the yellow fever virus into a large city such as Manaus, which is widely infested by Aedes mosquitoes, may pose a real risk of a yellow fever outbreak, efforts to maintain an appropriate immunization policy for the populace are critical. Manaus has also suffered silent outbreaks of Mayaro and Oropouche fevers lately, most of which were misdiagnosed as dengue fever. The tropical conditions of the State of Amazonas favor the existence of other arboviruses capable of producing human disease. Under this real threat, represented by at least 4 arboviruses producing human infections in Manaus and in other neighboring countries, it is important to develop an efficient public health surveillance strategy, including laboratories that are able to make proper diagnoses of arboviruses.
Assuntos
Animais , Melanose/genética , Pigmentação/genética , Receptor Tipo 1 de Melanocortina/genética , Sciuridae/genética , Sequência de Aminoácidos , Evolução Molecular , Estudos de Associação Genética , Variação Genética , Dados de Sequência Molecular , Linhagem , Sciuridae/classificação , Deleção de Sequência/genéticaRESUMO
Chikungunya virus (CHIKV) and Mayaro virus (MAYV) are emergent arthropod-borne viruses that produce outbreaks of acute febrile illness with arthropathy. Despite their different continental origins, CHIKV and MAYV are closely related and are components of the Semliki Forest Complex of the Alphavirus (Togaviridae). MAYV and, more recently, CHIKV, which are both transmitted by Aedes mosquitoes, have resulted in severe public health problems in the Americas, including Brazil. In this review, we present aspects of the pathogenesis, clinical presentation and treatment of febrile illnesses produced by CHIKV and MAYV. We also discuss the epidemiological aspects and effects related to the prophylaxis of infections by both viruses.