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pathogenesis and shedding of usutu virus in juvenile chickens.usutu virus (usuv; family: flaviviridae, genus: flavivirus), is an emerging zoonotic arbovirus that causes severe neuroinvasive disease in humans and has been implicated in the loss of breeding bird populations in europe. usuv is maintained in an enzootic cycle between ornithophilic mosquitos and wild birds. as a member of the japanese encephalitis serocomplex, usuv is closely related to west nile virus (wnv) and st. louis encephalitis virus (slev), both neuroinvasive arboviruses endemic in wild ...202133769213
serological evidence of west nile virus infection in white-tailed deer in central texas.white-tailed deer (wtd) are abundant mammals widely distributed across the united states. as a result, wtd are considered to be excellent sentinels for detecting arboviral activity in certain geographic areas. evidence of west nile virus (wnv) antibody in wtd has been reported previously in several states. however, wnv infection in wtd has not been reported from texas, where the incidence of human west nile (wn) cases is among the highest in the united states. therefore, the aim of this study wa ...202032746746
movement of st. louis encephalitis virus in the western united states, 2014- 2018.st. louis encephalitis virus (slev) is a flavivirus that circulates in an enzootic cycle between birds and mosquitoes and can also infect humans to cause febrile disease and sometimes encephalitis. although slev is endemic to the united states, no activity was detected in california during the years 2004 through 2014, despite continuous surveillance in mosquitoes and sentinel chickens. in 2015, slev-positive mosquito pools were detected in maricopa county, arizona, concurrent with an outbreak of ...202032520944
mosquito iridescent virus: new records from nature and infections using strelkovimermis spiculatus (mermithidae) as a vector under laboratory conditions.iridoviridae is a dna virus family that affects both vertebrates and invertebrates. immature aquatic stages of many dipteran species infected with iridovirus have been found in different places worldwide. the most represented genera of the culicidae family are aedes and psorophora. to date, sixteen species of aedes naturally infected with iridoviruses have been reported. moreover, there are four records for the genus psorophora, one for culiseta, and two for culex. in this paper, we report two n ...202031903519
specific diagnostic method for st. louis encephalitis virus using a non-structural protein as the antigen.st. louis encephalitis virus (slev) is a mosquito-borne re-emerging flavivirus in argentina. it is currently necessary to develop specific serological tests that can efficiently discriminate the flaviviruses that circulate in our country. the immunoassays to diagnose slev lack specificity because they are based on the detection of structural viral proteins and the human immunoglobulins produced during infection against these proteins cross-react with other flaviviruses. here, we describe an enzy ...201931846411
serological evidence of arboviruses and coccidia infecting horses in the amazonian region of brazil.arboviruses and protozoans can cause neurologic disorders in horses. in brazilian amazon, several horses presenting signs compatible with disorders caused by these infectious agents have been observed.201931830142
ecological aspects of potential arbovirus vectors (diptera: culicidae) in an urban landscape of southern amazon, brazil.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 presen ...201931751525
silent circulation of the saint louis encephalitis virus among humans and equids, southeast brazil.saint louis encephalitis virus (slev) is a mosquito-borne flavivirus that occurs throughout the americas, and is considered a public health threat. in brazil, slev has been detected from human cases associated with dengue-like disease, but no neurological symptoms were reported. furthermore, the epidemiology of slev in human populations is still poorly explored in the country. we reported serological and molecular detection of slev in a healthy population of equids and humans from rural areas in ...201931694207
flaviviruses as agents of childhood central nervous system infections in brazil.flaviviruses are agents of a major emerging human public health issue and members of this genus have been associated with central nervous system (cns) infections. in brazil, a country endemic for some arboviruses, the most clinically relevant neurotropic flaviviruses include dengue virus and zika virus. flaviviruses cause diseases ranging from mild or sub-clinical infections to severe cases as cns infections. there is a lack of data about the incidence of flaviviruses in the cns of children in b ...201931312458
vector competence for west nile virus and st. louis encephalitis virus (flavivirus) of three tick species of the genus amblyomma (acari: ixodidae).many species of amblyomma ticks are commonly found infesting wild birds in south america, where birds are important hosts for several arboviruses, such as west nile virus (wnv) and st. louis encephalitis virus (slev). in this study, wnv and slev transmission experiments were performed to evaluate the vector competence of three south american tick species: amblyomma ovale, amblyomma tigrinum, and amblyomma tonelliae. larval and nymphal ticks of each species were allowed to feed on chicks needle i ...201930887949
bloodmeal host selection of culex quinquefasciatus (diptera: culicidae) in las vegas, nevada, united states.st. louis encephalitis virus (slev) and west nile virus (wnv) have recently emerged in the southwestern united states. surveillance for arboviruses in las vegas, nv, detected a surge of slev activity in the southern house mosquito (culex quinquefasciatus say) during 2016. to identify candidate avian amplifiers, we assessed the identification, viral infection, and immune status of vertebrate hosts for 195 blood-engorged cx. quinquefasciatus mosquitoes collected in august and september 2016. blood ...201930668743
molecular characterization of viruses associated with encephalitis in são paulo, brazil.the objective of this study was to characterize the prevalence of viral encephalitis due to arbovirus infection of the togaviridae and flaviviridae families in são paulo, brazil. a total of 500 cerebrospinal fluid (csf) samples collected between august 2012 and january 2013, from patients with symptoms of acute encephalitis were analyzed. findings suggestive of viral encephalitis-elevations in cell concentration, glucose and total protein-were observed in 234 (46.8%) samples, designated as group ...201930640927
reemergence of st. louis encephalitis virus in the americas.we summarize and analyze historical and current data regarding the reemergence of st. louis encephalitis virus (slev; genus flavivirus) in the americas. historically, slev caused encephalitis outbreaks in the united states; however, it was not considered a public health concern in the rest of the americas. after the introduction of west nile virus in 1999, activity of slev decreased considerably in the united states. during 2014-2015, slev caused a human outbreak in arizona and caused isolated h ...201830457961
first detection of mansonia titillans (diptera: culicidae) infected with st. louis encephalitis virus (flaviviridae: flavivirus) and bunyamwera serogroup (peribunyaviridae: orthobunyavirus) in argentina. 201830408293
st. louis encephalitis virus disease in the united states, 2003-2017.st. louis encephalitis virus (slev), an arthropod-borne flavivirus, can cause disease presentations ranging from mild febrile illness through severe encephalitis. we reviewed u.s. national slev surveillance data for 2003 through 2017, including human disease cases and nonhuman infections. over the 15-year period, 198 counties from 33 states and the district of columbia reported slev activity; 94 (47%) of those counties reported slev activity only in nonhuman species. a total of 193 human cases o ...201830182919
production of recombinant ns1 protein and its possible use in encephalitic flavivirus differential diagnosis.saint louis encephalitis virus (slev) and west nile virus (wnv) are two of the major causes of arboviral encephalitis in the americas. the co-circulation of related flaviviruses in the americas and prior vaccination against flaviviruses pose problems to the diagnostic specificity of serological assays due to the development of cross-reactive antibodies. an accurate diagnosis method capable of differentiating these related viruses is needed. ns1 is a glycosylated, nonstructural protein, of about ...201930125621
north american culex pipiens and culex quinquefasciatus are competent vectors for usutu virus.usutu virus (usuv) is a member of the japanese encephalitis virus (jev) serocomplex in the flaviviridae family. emergence of usuv in europe has led to disease burdens in birds and created increasing concern for the potential zoonotic transmission to humans. whilst usuv has not been detected in the new world, the identification of competent vector species in north america is critical in the assessment of the likelihood of its dispersal and establishment of enzootic transmission cycles. the object ...201830118480
neuronal degeneration in mice induced by an epidemic strain of saint louis encephalitis virus isolated in argentina.saint louis encephalitis virus (slev) is a neglected flavivirus that causes severe neurological disorders. the epidemic strain of slev, cbaar-4005, isolated during an outbreak in córdoba city (argentina), causes meningitis and encephalitis associated with neurological symptoms in a murine experimental model. here, we identified the affected brain areas and the damage triggered by this neurotropic arbovirus. we performed a detailed analysis of brain neurodegeneration associated with cbaar-4005 sl ...201829930541
ilheus and saint louis encephalitis viruses elicit cross-protection against a lethal rocio virus challenge in mice.rocio virus (rocv) was the causative agent of an unprecedented outbreak of encephalitis during the 1970s in the vale do ribeira, sao paulo state, in the southeast region of brazil. surprisingly, no further cases of rocv infection were identified after this outbreak; however, serological surveys have suggested the circulation of rocv among humans and animals in different regions of brazil. cross-protective immunity among flaviviruses is well documented; consequently, immunity induced by infection ...201829897990
comparative studies of stenogamous behaviour in the mosquito culex pipiens complex.understanding the processes of reproductive behaviour in mosquitoes is crucial for improving mating competitiveness and mating specificity for sterile insect release programmes. the culex pipiens (linneaus) (diptera: culicidae) forms pipiens and molestus (forskål), two biotypes of the cx. pipiens complex, are vectors for west nile virus, st louis encephalitis virus and lymphatic filariases. hybridization of these biotypes is known to occur in nature, although form pipiens mates above ground in l ...201829856079
evaluation of argentinean bird species as amplifying hosts for st. louis encephalitis virus (flavivirus, flaviviridae).st.louis encephalitis virus (slev) is an emerging human pathogen flavivirus in argentina. recently, it has reemerged in the united states. we evaluated the role as amplifying host of six resident bird species and analyzed their capacity as host during the 2005 encephalitis outbreak of slev in córdoba. eared dove, picui ground dove, and house sparrow were the three species with highest host competence index. at a city level, eared dove and picui ground dove were the most important amplifying host ...201829761767
human and equine infection with alphaviruses and flaviviruses in panamá during 2010: a cross-sectional study of household contacts during an encephalitis outbreak.members of the genera alphavirus (family togaviridae) and flavivirus (family flaviridae) are important zoonotic human and equine etiologic agents of neurologic diseases in the new world. in 2010, an outbreak of madariaga virus (madv; formerly eastern equine encephalitis virus) and venezuelan equine encephalitis virus (veev) infections was reported in eastern panamá. we further characterized the epidemiology of the outbreak by studying household contacts of confirmed human cases and of equine cas ...201829737271
scented sugar baits enhance detection of st. louis encephalitis and west nile viruses in mosquitoes in suburban california.scented sugar baits deployed in california deserts detected early west nile virus (wnv) transmission by mosquitoes, representing a potential improvement to conventional arbovirus surveillance that relies heavily on infection rates in mosquito pools. in this study, we expanded deployment of scented sugar baits into suburban sacramento and yolo (2015, 2016) and riverside counties (2016), california. the goal of the study was to determine whether scented sugar baits detect wnv and st. louis encepha ...201829718284
serological evidence of widespread exposure of grenada fruit bats to chikungunya virus.antibody detection against selected potentially zoonotic vector-borne alphaviruses and flaviviruses was conducted on sera from bats from all six parishes in grenada, west indies. sera were tested for (i) antibodies to flaviviruses west nile virus, st. louis encephalitis virus, ilhéus virus, bussuquara virus (bsqv), rio bravo virus and all four serotypes of dengue virus (denv) by plaque reduction neutralization test (prnt); (ii) antibodies to alphaviruses western equine encephalitis virus, venezu ...201829575672
environmental stochasticity and intraspecific competition influence the population dynamics of culex quinquefasciatus (diptera: culicidae).members of the culex pipiens complex (cx. pipiens quinquefasciatus in southern usa) play a critical role in the spillover of urban arboviruses such as west nile virus or st. louis encephalitis virus. field studies have shown strong correlation between the periodicity of rainfall events and larval proliferation. however, mechanistic determinants driving this relationship are poorly understood. we hypothesize that rainfall events decrease strain from intraspecific competition through the associate ...201829482608
seroprevalence of selected flaviviruses in free-living and captive capuchin monkeys in the state of pernambuco, brazil.mosquito-borne diseases such as dengue, yellow fever and, more recently, chikungunya virus (chikv) and zika virus (zikv) have a great impact in the public health. in addition, the presence of such viruses might have an impact on wild animal conservation as well as their possible role as animal reservoir. here, we performed a serological survey searching for antibodies against a panel of flaviviruses [zikv, dengue virus (denv), yellow fever virus (yfv), west nile virus (wnv), saint louis encephal ...201829424106
host-feeding patterns of culex stigmatosoma (diptera: culicidae) in southern california.knowledge of the blood-feeding patterns exhibited by arthropod vectors is essential for understanding the complex dynamics of vector-borne disease transmission. some species of mosquitoes belonging to the genus culex have been implicated as having major roles in the transmission of arboviruses such as west nile virus, saint louis encephalitis virus, and western equine encephalitis virus. although the host-feeding patterns for many of these culex species are well studied, the host-feeding pattern ...201728968822
diagnosis of fatal human case of st. louis encephalitis virus infection by metagenomic sequencing, california, 2016.we used unbiased metagenomic next-generation sequencing to diagnose a fatal case of meningoencephalitis caused by st. louis encephalitis virus in a patient from california in september 2016. this case is associated with the recent 2015-2016 reemergence of this virus in the southwestern united states.201728930022
wing variation in culex nigripalpus (diptera: culicidae) in urban parks.culex nigripalpus has a wide geographical distribution and is found in north and south america. females are considered primary vectors for several arboviruses, including saint louis encephalitis virus, venezuelan equine encephalitis virus and eastern equine encephalitis virus, as well as a potential vector of west nile virus. in view of the epidemiological importance of this mosquito and its high abundance, this study sought to investigate wing variation in cx. nigripalpus populations from urban ...201728923116
st. louis encephalitis virus possibly transmitted through blood transfusion-arizona, 2015.st. louis encephalitis virus is a mosquito-borne flavivirus that infrequently causes epidemic central nervous system infections. in the united states, blood donors are not screened for st. louis encephalitis virus infection, and transmission through blood transfusion has not been reported. during september 2015, st. louis encephalitis virus infection was confirmed in an arizona kidney transplant recipient. an investigation was initiated to determine the infection source.201728905395
neuroinvasive st. louis encephalitis virus infection in solid organ transplant recipients.in summer 2015, three unrelated solid organ transplant recipients in phoenix, arizona, had meningoencephalitis suggestive of west nile virus (wnv) infection. testing was inconclusive but was later confirmed as st. louis encephalitis (sle). we retrospectively reviewed clinical manifestations, treatment, and outcomes of these transplant recipients. common symptoms were fever, rigors, diarrhea, headache, and confusion. one patient died 3 days after hospitalization. therapy for the other two patient ...201728452107
saint louis encephalitis virus, another re-emerging arbovirus: a literature review of worldwide research.not available.201728353461
development of a model of saint louis encephalitis infection and disease in mice.flaviviruses are a genre of closely related viral pathogens which emerged in the last decades in brazil and in the world. saint (st.) louis encephalitis virus (slev) is a neglected flavivirus that can cause a severe neurological disease that may lead to death or sequelae. st. louis encephalitis pathogenesis is poorly understood, which hinders the development of specific treatment or vaccine.201728330482
mutagen resistance and mutation restriction of st. louis encephalitis virus.the error rate of the rna-dependent rna polymerase (rdrp) of rna viruses is important in maintaining genetic diversity for viral adaptation and fitness. numerous studies have shown that mutagen-resistant rna virus variants display amino acid mutations in the rdrp and other replicase subunits, which in turn exhibit an altered fidelity phenotype affecting viral fitness, adaptability and pathogenicity. st. louis encephalitis virus (slev), like its close relative west nile virus, is a mosquito-borne ...201728284278
tissue tropism of saint louis encephalitis virus: histopathology triggered by epidemic and non-epidemic strains isolated in argentina.saint louis encephalitis virus (slev) reemerged in south america, and caused encephalitis outbreaks at the beginning of the 21st century. to enhance our knowledge about slev virulence, we performed comparative pathogenesis studies in swiss albino mice inoculated with two different variants, the epidemic strain cbaar-4005 and the non-epidemic strain coran-9275. only the infection of mice with slev strain cbaar-4005 resulted in high viremia, invasion of peripheral tissues including the lungs, kidn ...201728279829
thiosemicarbazones and phthalyl-thiazoles compounds exert antiviral activity against yellow fever virus and saint louis encephalitis virus.arboviruses, arthropod-borneviruses, are frequency associated to human outbreak and represent a serious health problem. the genus flavivirus, such as yellow fever virus (yfv) and saint louis encephalitis virus (slev), are important pathogens with high morbidity and mortality worldwide. in brazil, yfv is maintained in sylvatic cycle, but many cases are notified annually, despite the efficiency of vaccine. slev causes an acute encephalitis and is widely distributed in the americas. there is no spe ...201728068627
mutagen resistance and mutation restriction of st. louis encephalitis virus.the error rate of the rna-dependent rna polymerase (rdrp) of rna viruses is important in maintaining genetic diversity for viral adaptation and fitness. numerous studies have shown that mutagen-resistant rna virus variants display amino acid mutations in the rdrp and other replicase subunits, which in turn exhibit an altered fidelity phenotype affecting viral fitness, adaptability, and pathogenicity. st. louis encephalitis virus (slev), like its close relative west nile virus (wnv), is a mosquit ...201627959789
reemergence of st. louis encephalitis virus, california, 2015.st. louis encephalitis virus infection was detected in summer 2015 in southern california after an 11-year absence, concomitant with an arizona outbreak. sequence comparisons showed close identity of california and arizona isolates with 2005 argentine isolates, suggesting introduction from south america and underscoring the value of continued arbovirus surveillance.027869600
searching for putative avian malaria vectors in a seasonally dry tropical forest in brazil.haemosporidian parasites of the genera plasmodium and haemoproteus can have detrimental effects on individual birds and populations. despite recent investigations into the distribution and richness of these parasites and their vertebrate hosts, little is known about their dipteran vectors. the neotropics has the highest diversity of mosquitoes in the world, but few studies have tried to identify vectors in this area, hampering the understanding of the ecology of avian malaria in the highly diver ...201627852326
identification of a new broadly cross-reactive epitope within domain iii of the duck tembusu virus e protein.in 2010, a pathogenic flavivirus termed duck tembusu virus (dtmuv) caused widespread outbreak of egg-drop syndrome in domesticated ducks in china. although the glycoprotein e of dtmuv is an important structural component of the virus, the b-cell epitopes of this protein remains uncharacterized. using phage display and mutagenesis, we identified a minimal b-cell epitope, (374)exe/dppfg(380), that mediates binding to a nonneutralizing monoclonal antibody. dtmuv-positive duck serum reacted with the ...201627824100
low sensitivity of the tourniquet test for differential diagnosis of dengue: an analysis of 28,000 trials in patients.the aim of this study was to evaluate the utility of the tourniquet test (tt) for dengue diagnosing. to our knowledge, no previous study with such a large sample, of this duration, with as many laboratory methods referenced, or relating the results of the tt to the 2009 who classification of severity has been conducted thus far.201627809813
waiting in the wings: the potential of mosquito transmitted flaviviruses to emerge.the sudden dramatic emergence of the mosquito transmitted flavivirus zika virus has bought to the world's attention a relatively obscure virus that was previously only known to specialist researchers. the genus flavivirus of the family flaviviridae contains a number of well-known mosquito transmitted human pathogenic viruses including the dengue, yellow fever, japanese encephalitis and west nile viruses. however, the genus also contains a number of lesser known human pathogenic viruses transmitt ...201627800692
molecular detection of flaviviruses and alphaviruses in mosquitoes (diptera: culicidae) from coastal ecosystems in the colombian caribbean.arboviruses belonging to the genera flavivirus and alphavirus were detected in mosquitoes in a rural area of san bernardo del viento (córdoba, colombia). a total of 22,180 mosquitoes were collected, sorted into 2,102 pools, and tested by generic/nested reverse transcription-polymerase chain reaction. venezuelan equine encephalitis virus, dengue virus, west nile virus, st. louis encephalitis virus, yellow fever virus, and culex flavivirus were detected and identified by sequencing. the detection ...201627706377
differential infectivities among different japanese encephalitis virus genotypes in culex quinquefasciatus mosquitoes.during the last 20 years, the epidemiology of japanese encephalitis virus (jev) has changed significantly in its endemic regions due to the gradual displacement of the previously dominant genotype iii (giii) with clade b of gi (gi-b). whilst there is only limited genetic difference distinguishing the two gi clades (gi-a and gi-b), gi-b has shown a significantly wider and more rapid dispersal pattern in several regions in asia than the gi-a clade, which remains restricted in its geographic distri ...201627706157
climate change influences on the global potential distribution of the mosquito culex quinquefasciatus, vector of west nile virus and lymphatic filariasis.rapid emergence of most vector-borne diseases (vbds) may be associated with range expansion of vector populations. culex quinquefasciatus say 1823 is a potential vector of west nile virus, saint louis encephalitis virus, and lymphatic filariasis. we estimated the potential distribution of cx. quinquefasciatus under both current and future climate conditions. the present potential distribution of cx. quinquefasciatus showed high suitability across low-latitude parts of the world, reflecting the c ...201627695107
a serological protein microarray for detection of multiple cross-reactive flavivirus infections in horses for veterinary and public health surveillance.the genus flavivirus in the family flaviviridae includes some of the most important examples of emerging zoonotic arboviruses that are rapidly spreading across the globe. japanese encephalitis virus (jev), west nile virus (wnv), st. louis encephalitis virus (slev) and usutu virus (usuv) are mosquito-borne members of the jev serological group. although most infections in humans are asymptomatic or present with mild flu-like symptoms, clinical manifestations of jev, wnv, slev, usuv and tick-borne ...201627633257
detection of chikungunya virus circulation using sugar-baited traps during a major outbreak in french guiana. 201627606960
activity patterns of st. louis encephalitis and west nile viruses in free ranging birds during a human encephalitis outbreak in argentina.st. louis encephalitis virus (slev) (flavivirus) is a reemerging arbovirus in the southern cone of south america. in 2005, an outbreak of slev in central argentina resulted in 47 human cases with 9 deaths. in argentina, the ecology of slev is poorly understood. because certain birds are the primary amplifiers in north america, we hypothesized that birds amplify slev in argentina as well. we compared avian slev seroprevalence in a variety of ecosystems in and around córdoba city from 2004 (before ...201627564679
evaluation of realstar reverse transcription-polymerase chain reaction kits for filovirus detection in the laboratory and field.diagnosis of ebola virus (ebov) disease (evd) requires laboratory testing.201627549586
background review for diagnostic test development for zika virus infection.to review the state of knowledge about diagnostic testing for zika virus infection and identify areas of research needed to address the current gaps in knowledge.027516635
zika virus: indian perspectives.the emergence of zika virus (ziv), a mosquito borne flavivirus like dengue (den) and chikungunya (chik), in brazil in 2014 and its spread to various countries have led to a global health emergency. aedes aegypti is the major vector for ziv. fast dissemination of this virus in different geographical areas posses a major threat especially to regions where the population lacks herd immunity against the ziv and there is abundance of aedes mosquitoes. in this review, we focus on current global scenar ...027487998
serosurvey of selected arboviral pathogens in free-ranging, two-toed sloths (choloepus hoffmanni) and three-toed sloths (bradypus variegatus) in costa rica, 2005-07.we screened for antibodies to 16 arboviruses in four populations of free-ranging sloths in costa rica. blood samples were taken from 16 hoffman's two-toed sloths (htss; choloepus hoffmanni ) and 26 brown-throated sloths (btss; bradypus variegatus ) over a 3-yr period. we used serologic assays to detect antibodies against 10 arboviruses previously described in sloths (st. louis encephalitis [slev], changuinola, venezuelan equine encephalitis, ilheus [ilhv], oropouche, mayaro, utinga, murutucu, pu ...201627479900
west nile virus in europe and safety of blood transfusion.west nile virus (wnv) has become an increasing issue in the transfusion setting since 2002, when it was firstly shown in the usa that it can be transmitted through blood transfusion. since then, several precautionary measures have been introduced in europe in order to reduce the possible risk of transmission via transfusion/solid organ transplantation. in addition, the epidemiological surveillance has been tightened and the network for communication of human wnv cases strengthened. this review w ...201627403087
[saint louis encephalitis: case report].saint louis encephalitis is transmitted by culex mosquitoes. in argentina sporadic cases are registered. symptomatic illness is unusual in children. we present a case of meningoencephalitis caused by an uncommon viral infection. the clinical signs and symptoms are unusual for pediatric patients and the bilateral thalamic compromise showed on magnetic resonance has not been described previously. an 8-year-old girl consulted due to fever, behavior disorders and ataxia. clonus and neck stiffness we ...201627399031
dengue virus genome uncoating requires ubiquitination.the process of genome release or uncoating after viral entry is one of the least-studied steps in the flavivirus life cycle. flaviviruses are mainly arthropod-borne viruses, including emerging and reemerging pathogens such as dengue, zika, and west nile viruses. currently, dengue virus is one of the most significant human viral pathogens transmitted by mosquitoes and is responsible for about 390 million infections every year around the world. here, we examined for the first time molecular aspect ...201627353759
evaluation of the honey-card technique for detection of transmission of arboviruses in florida and comparison with sentinel chicken seroconversion.zoonotic mosquito-borne viruses, such as the west nile virus (wnv) and eastern equine encephalitis virus (eeev), are major public health threats in the united states. early detection of virus transmission and targeted vector management are critical to protect humans against these pathogens. sentinel chickens and pool screening of mosquitoes, the most widely used methods of arbovirus early detection, have technical time-lags that compromise their early-detection value. the exploitation of sugar-f ...201627330092
combining reverse-transcription multiplex pcr and microfluidic electrophoresis to simultaneously detect seven mosquito-transmitted zoonotic encephalomyelitis viruses.several mosquito-transmitted viruses are causative agents for zoonotic encephalomyelitis. rapid identification of these viruses in mosquito populations is an effective method for surveying these diseases. to detect multiple mosquito-transmitted viral agents, including west nile virus, saint louis encephalitis virus, venezuelan equine encephalomyelitis virus, western equine encephalomyelitis virus, eastern equine encephalomyelitis virus, highlands j virus and japanese encephalitis virus, an assay ...201627256022
liposomal systems as nanocarriers for the antiviral agent ivermectin.rna virus infections can lead to the onset of severe diseases such as fever with haemorrhage, multiorgan failure, and mortality. the emergence and reemergence of rna viruses continue to pose a significant public health threat worldwide with particular attention to the increasing incidence of flaviviruses, among others dengue, west nile virus, and yellow fever viruses. development of new and potent antivirals is thus urgently needed. ivermectin, an already known antihelminthic drug, has shown pot ...201627242902
a glance at subgenomic flavivirus rnas and micrornas in flavivirus infections.the family flaviviridae comprises a wide variety of viruses that are distributed worldwide, some of which are associated with high rates of morbidity and mortality. there are neither vaccines nor antivirals for most flavivirus infections, reinforcing the importance of research on different aspects of the viral life cycle. during infection, cytoplasmic accumulation of rna fragments mainly originating from the 3' utrs, which have been designated subgenomic flavivirus rnas (sfrnas), has been detect ...201627233361
a proline-rich n-terminal region of the dengue virus ns3 is crucial for infectious particle production.dengue virus is currently the most important insect-borne viral human pathogen. viral nonstructural protein 3 (ns3) is a key component of the viral replication machinery that performs multiple functions during viral replication and participates in antiviral evasion. using dengue virus infectious clones and reporter systems to dissect each step of the viral life cycle, we examined the requirements of different domains of ns3 on viral particle assembly. a thorough site-directed mutagenesis study b ...201627009958
astrocyte response to st. louis encephalitis virus.st. louis encephalitis virus (slev), a flavivirus transmitted to humans by culex mosquitoes, causes clinical symptoms ranging from acute febrile disorder to encephalitis. to reach the central nervous system (cns) from circulating blood, the pathogen must cross the blood-brain barrier formed by endothelial cells and astrocytes. because astrocytes play an essential role in cns homeostasis, in this study these cells were infected with slev and investigated for astrogliosis, major histocompatibility ...201626975980
surveys for antibodies against mosquitoborne encephalitis viruses in california birds, 1996-2013.from 1996 through 2013, 54,546 individual birds comprising 152 species and 7 orders were banded, bled, and released at four study areas within california, from which 28,388 additional serum samples were collected at one or more recapture encounters. of these, 142, 99, and 1929 birds from 41 species were positive for neutralizing antibodies against western equine encephalomyelitis virus (weev), st. louis encephalitis virus (slev), or west nile virus (wnv) at initial capture or recapture, respecti ...201626974395
duck tembusu virus exhibits pathogenicity to kunming mice by intracerebral inoculation.in this study, kunming mice were used as the animal models to study the pathogenicity of tmuv. three groups of 3-week-old female kunming mice (n = 15 mice per group) were infected with the sdsg strain of tmuv in 50 μl allantoic fluid (10(4.8) eld50/0.2 ml) respectively by the intracerebral (i.c.), subcutaneous (s.c.) and intranasal (i.n.) routes. the control group (n = 15 mice) was inoculated with 50 μl sterile phosphate-buffered saline. clinical signs, gross, and microscopic lesions, viral load ...201626925054
recovery of west nile virus envelope protein domain iii chimeras with altered antigenicity and mouse virulence.flaviviruses are positive-sense, single-stranded rna viruses responsible for millions of human infections annually. the envelope (e) protein of flaviviruses comprises three structural domains, of which domain iii (eiii) represents a discrete subunit. the eiii gene sequence typically encodes epitopes recognized by virus-specific, potently neutralizing antibodies, and eiii is believed to play a major role in receptor binding. in order to assess potential interactions between eiii and the remainder ...201626912625
gene regulatory network inference of immunoresponsive gene 1 (irg1) identifies interferon regulatory factor 1 (irf1) as its transcriptional regulator in mammalian macrophages.immunoresponsive gene 1 (irg1) is one of the highest induced genes in macrophages under pro-inflammatory conditions. its function has been recently described: it codes for immune-responsive gene 1 protein/cis-aconitic acid decarboxylase (irg1/cad), an enzyme catalysing the production of itaconic acid from cis-aconitic acid, a tricarboxylic acid (tca) cycle intermediate. itaconic acid possesses specific antimicrobial properties inhibiting isocitrate lyase, the first enzyme of the glyoxylate shunt ...201626872335
reconstruction of the evolutionary history and dispersal of usutu virus, a neglected emerging arbovirus in europe and africa.usutu virus (usuv), one of the most neglected old world encephalitic flaviviruses, causes epizootics among wild and captive birds and sporadic infection in humans. the dynamics of usuv spread and evolution in its natural hosts are unknown. here, we present the phylogeny and evolutionary history of all available usuv strains, including 77 newly sequenced complete genomes from a variety of host species at a temporal and spatial scaled resolution. the results showed that usuv can be classified into ...201626838717
highly conserved regions in ebola virus rna dependent rna polymerase may be act as a universal novel peptide vaccine target: a computational approach.ebola virus (ebov) is such kind of virus which is responsible for 23,825 cases and 9675 deaths worldwide only in 2014 and with an average diseases fatality rate between 25 % and 90 %. although, medical technology has tried to handle the problems, there is no food and drug administration (fda)-approved therapeutics or vaccines available for the prevention, post exposure, or treatment of ebola virus disease (evd).201526820892
surveillance for western equine encephalitis, st. louis encephalitis, and west nile viruses using reverse transcription loop-mediated isothermal amplification.collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. vector control districts in california routinely monitor for three human pathogenic viruses including west nile virus (wnv), western equine encephalitis virus (weev), and st. louis encephalitis virus (slev). reverse transcription quantitative polymerase chain reaction ...201626807734
mayaro virus and dengue virus 1 and 4 natural infection in culicids from cuiabá, state of mato grosso, brazil.this study aimed to verify the diversity of culicidae species and their frequency of infection with flaviviruses and alphaviruses in cuiabá, state of mato grosso, brazil. mosquitoes were captured with nasci aspirators and hand net in 200 census tracts, identified alive at species level and pooled in one-20 (11,090 mosquitoes, 14 species). female pools (n = 610) were subjected to multiplex seminested-reverse transcription-polymerase chain reaction (rt-pcr) for 11 flavivirus and five alphavirus. p ...026784852
the interferon-stimulated gene ifi27l2a restricts west nile virus infection and pathogenesis in a cell-type- and region-specific manner.the mammalian host responds to viral infections by inducing expression of hundreds of interferon-stimulated genes (isgs). while the functional significance of many isgs has yet to be determined, their cell type and temporal nature of expression suggest unique activities against specific pathogens. using a combination of ectopic expression and gene silencing approaches in cell culture, we previously identified ifi27l2a as a candidate antiviral isg within neuronal subsets of the central nervous sy ...201526699642
concurrent outbreaks of st. louis encephalitis virus and west nile virus disease - arizona, 2015.st. louis encephalitis virus (slev) and west nile virus (wnv) are closely related mosquito-borne flaviviruses that can cause outbreaks of acute febrile illness and neurologic disease. both viruses are endemic throughout much of the united states and have the same culex species mosquito vectors and avian hosts (1); however, since wnv was first identified in the united states in 1999, slev disease incidence has been substantially lower than wnv disease incidence, and no outbreaks involving the two ...201526656306
the yin and yang of antiviral innate immunity in central nervous system.the innate immune system provides protection against invading neurotropic viruses. it acts as the first line of defense against invading viruses and plays an elementary role in their pathogenesis. the list of viruses capable of infecting human central nervous system (cns) is quite long, most important of them are japanese encephalitis virus (jev), rabies virus, west nile virus (wnv), herpes simplex virus (hsv), st. louis encephalitis virus (slev), la crosse virus, tick borne encephalitis virus ( ...201626635264
[serological evidence of st. louis encephalitis virus circulation in birds from buenos aires city, argentina].our goal was to determine the presence of neutralizing antibodies against st. louis encephalitis virus (slev) and west nile virus (wnv) in sera of wild and domestic birds from buenos aires city, argentina. from october 2012 to april 2013, 180 samples were collected and processed by the microneutralization technique. a 7.2% of the sampled birds were seropositive for slev, while no seropositive birds for wnv were detected.201626627114
the molecular epidemiology and evolution of murray valley encephalitis virus: recent emergence of distinct sub-lineages of the dominant genotype 1.recent increased activity of the mosquito-borne murray valley encephalitis virus (mvev) in australia has renewed concerns regarding its potential to spread and cause disease.201526600318
viral interference and persistence in mosquito-borne flaviviruses.mosquito-borne flaviviruses are important pathogens for humans, and the detection of two or more flaviviruses cocirculating in the same geographic area has often been reported. however, the epidemiological impact remains to be determined. mosquito-borne flaviviruses are primarily transmitted through aedes and culex mosquitoes; these viruses establish a life-long or persistent infection without apparent pathological effects. this establishment requires a balance between virus replication and the ...201526583158
serologic evidence of flavivirus infections in peridomestic rodents in merida, mexico.we conducted surveillance for flavivirus infection in peridomestic rodents in merida, mexico in 2011-12. we captured 161 rodents inside private residences, using sherman traps, including 86 house mice (mus musculus) and 75 black rats (rattus rattus). serum from each animal was assayed by plaque reduction neutralization test (prnt) using two vertebrate-specific flaviviruses (apoi and modoc viruses) and five mosquito-borne flaviviruses (dengue 2, dengue 4, st. louis encephalitis virus, west nile, ...201626540177
mitochondrial genomes and comparative analyses of culex camposi, culex coronator, culex usquatus and culex usquatissimus (diptera:culicidae), members of the coronator group.the coronator group currently encompasses six morphologically similar species (culex camposi dyar, culex coronator dyar and knab, culex covagarciai forattini, culex usquatus dyar, culex usquatissimus dyar, and culex ousqua dyar). culex coronator has been incriminated as a potential vector of west nile virus (wnv), saint louis encephalitis virus (slev), and venezuelan equine encephalitis virus (veev). the complete mitochondrial genome of cx. coronator, cx. usquatus, cx.usquatissimus, and cx. camp ...201526489754
fighting arbovirus transmission: natural and engineered control of vector competence in aedes mosquitoes.control of aedine mosquito vectors, either by mosquito population reduction or replacement with refractory mosquitoes, may play an essential role in the fight against arboviral diseases. in this review, we will focus on the development and application of biological approaches, both natural or engineered, to limit mosquito vector competence for arboviruses. the study of mosquito antiviral immunity has led to the identification of a number of host response mechanisms and proteins that are required ...201526463078
differential replicative ability of clinical dengue virus isolates in an immunocompetent c57bl/6 mouse model.several experimental animal models have been used to study the pathogenesis of dengue disease; however, most of the studies used laboratory-adapted viruses, which lack the virulence of viruses circulating in humans. the aim of this study was to analyze the ability of clinical dengue virus (denv) isolates (d2/br/rp/rmb/09 and d3/br/sl3/02) to infect immunocompetent c57bl/6 mice.201526415508
factors that influence the transmission of west nile virus in florida.west nile virus (wnv) was first detected in north america in new york city during the late summer of 1999 and was first detected in florida in 2001. although wnv has been responsible for widespread and extensive epidemics in human populations and epizootics in domestic animals and wildlife throughout north america, comparable epidemics have never materialized in florida. here, we review some of the reasons why wnv has yet to cause an extensive outbreak in florida. the primary vector of mosquito- ...201526336216
multiplex qrt-pcr for the detection of western equine encephalomyelitis, st. louis encephalitis, and west nile viral rna in mosquito pools (diptera: culicidae).following the introduction of west nile virus into california during the summer of 2003, public health and vector control programs expanded surveillance efforts and were in need of diagnostics capable of rapid, sensitive, and specific detection of arbovirus infections of mosquitoes to inform decision support for intervention. development of a multiplex taqman or real-time semiquantitative reverse transcription polymerase chain reaction (rt-pcr) assay in which three virus specific primer-probe se ...201526334826
west nile virus and other nationally notifiable arboviral diseases - united states, 2014.arthropod-borne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. west nile virus (wnv) is the leading cause of domestically acquired arboviral disease in the united states (1). however, several other arboviruses also cause sporadic cases and seasonal outbreaks. this report summarizes surveillance data reported to cdc in 2014 for wnv and other nationally notifiable arboviruses, excluding dengue. forty-two states and the district of colu ...201526334477
molecular identification of saint louis encephalitis virus genotype iv in colombia.saint louis encephalitis virus (slev) is a member of the japanese-encephalitis virus serocomplex of the genus flavivirus. slev is broadly distributed in the americas and the caribbean islands, where it is usually transmitted by mosquitoes of the genus culex and primarily to birds and mammalian-hosts. humans are occasionally infected by the virus and are dead-end hosts. slev causes encephalitis in temperate regions, while in tropical regions of the americas, several human cases and a wide biologi ...201526313538
exploring genomic, geographic and virulence interactions among epidemic and non-epidemic st. louis encephalitis virus (flavivirus) strains.st. louis encephalitis virus (slev) is a re-emerging arbovirus in south america. in 2005, an encephalitis outbreak caused by slev was reported in argentina. the reason for the outbreak remains unknown, but may have been related to virological factors, changes in vectors populations, avian amplifying hosts, and/or environmental conditions. the main goal of this study was to characterize the complete genome of epidemic and non-epidemic slev strains from argentina. seventeen amino acid changes were ...201526312485
flavivirus rna synthesis in vitro.establishment of in vitro systems to study mechanisms of rna synthesis for positive strand rna viruses have been very useful in the past and have shed light on the composition of protein and rna components, optimum conditions, the nature of the products formed, cis-acting rna elements and trans-acting protein factors required for efficient synthesis. in this review, we summarize our current understanding regarding the requirements for flavivirus rna synthesis in vitro. we describe details of rea ...201526272247
saint louis encephalitis virus in mato grosso, central-western brazil.the dengue virus (denv), which is frequently involved in large epidemics, and the yellow fever virus (yfv), which is responsible for sporadic sylvatic outbreaks, are considered the most important flaviviruses circulating in brazil. because of that, laboratorial diagnosis of acute undifferentiated febrile illness during epidemic periods is frequently directed towards these viruses, which may eventually hinder the detection of other circulating flaviviruses, including the saint louis encephalitis ...026200961
a crispr-based screen identifies genes essential for west-nile-virus-induced cell death.west nile virus (wnv) causes an acute neurological infection attended by massive neuronal cell death. however, the mechanism(s) behind the virus-induced cell death is poorly understood. using a library containing 77,406 sgrnas targeting 20,121 genes, we performed a genome-wide screen followed by a second screen with a sub-library. among the genes identified, seven genes, emc2, emc3, sel1l, derl2, ube2g2, ube2j1, and hrd1, stood out as having the strongest phenotype, whose knockout conferred stro ...201526190106
west nile virus encephalitis: the first human case recorded in brazil.a brazilian ranch worker with encephalitis and flaccid paralysis was evaluated in the regional acute encephalitis syndromic surveillance program. this was the first brazilian patient who met the centers for disease control and prevention (cdc) confirmation criteria for west nile virus disease. owing to the overlapping of neurological manifestations attributable to several viral infections of the central nervous system, this report exemplifies the importance of human acute encephalitis surveillan ...201526055749
is transfusion-transmitted dengue fever a potential public health threat?dengue is an arboviruses due to single-stranded enveloped ribonucleic acid viruses, named dengue viruses (denv), that include four serotypes and are mainly transmitted via the bite of mosquitoes of the genus aedes (a. aegypti and a. albopictus). the distribution of the disease was historically limited to intertropical areas; however, during the last thirty years, the perimeter of the disease extended considerably and temperate areas are now at risk of outbreaks. the present global burden of deng ...025964876
natural transovarial transmission of dengue virus 4 in aedes aegypti from cuiabá, state of mato grosso, brazil.dengue is the most prevalent arboviral disease in tropical areas. in mato grosso, outbreaks are reported every year, but studies on dengue in this state are scarce.201525860459
st. louis encephalitis virus mosquito vectors dynamics in three different environments in relation to remotely sensed environmental conditions.in argentina the st. louis encephalitis virus (slev) is an endemic and widely distributed pathogen transmitted by the cosmopolitan mosquito culex quinquefasciatus. during two outbreaks in córdoba city, in 2005 and 2010, culex interfor was also found infected, but its role as vector of slev is poorly known. this mosquito species is distributed from central argentina to southern brazil. the primary aim of this study was to analyze the population dynamic of cx. interfor and cx. quinquefasciatus in ...201525792419
monoclonal antibody against saint louis encephalitis prm viral protein.saint louis encephalitis virus belongs to flavivirus genus; flaviviridae family jointly with other medically important flaviviruses including dengue virus and west nile virus. the biological properties and functions of prm flavivirus protein are under investigation due to its importance in the generation of infectious virion and host interactions. monoclonal antibodies have become powerful tools in this approach. also the use of monoclonal antibodies has been successfully applied for antigenic a ...201525744380
first genome sequence of st. louis encephalitis virus (slev) isolated from a human in brazil.st. louis encephalitis virus (slev), a member of the family flaviviridae, genus flavivirus, is a causative agent of encephalitis in the americas. in brazil, sporadic cases of slev infection have been reported since 1953, but the first outbreak of slev in brazil was identified only in 2007, concomitant with an outbreak of dengue virus (denv) serotype 3. this finding, along with other reports, indicates that slev circulation in brazil is largely unknown, and there may be epidemiological implicatio ...201525740285
overlapping local and long-range rna-rna interactions modulate dengue virus genome cyclization and replication.the dengue virus genome is a dynamic molecule that adopts different conformations in the infected cell. here, using rna folding predictions, chemical probing analysis, rna binding assays, and functional studies, we identified new cis-acting elements present in the capsid coding sequence that facilitate cyclization of the viral rna by hybridization with a sequence involved in a local dumbbell structure at the viral 3' untranslated region (utr). the identified interaction differentially enhances v ...201525589642
[molecular detection of saint louis encephalitis virus in mosquitoes in buenos aires].during march 2013 a population of eared doves (zenaida auriculata) was established in the center of city of buenos aires. considering the role of these birds as host competent for saint louis encephalitis virus (slev), a cdc light trap was put in place to perform entomologic surveillance. during this month 5 pools of mosquitoes (n = 48) were collected and taxonomically determined. three of them were classified as culex pipiens (n = 10) and the other two were culex spp. (n = 38). in this case, th ...201425555001
commentary. 201425540529
the roles of mosquito and bird communities on the prevalence of west nile virus in urban wetland and residential habitats.this study investigated the impacts of urban wetlands and their adjacent residential environments on the transmission dynamics of west nile virus (wnv) within the state of new jersey (usa). a working hypothesis was that urban wetlands decrease the local prevalence of wnv through the dilution effect from increased bird diversity, and through relative reductions in the numbers of competent avian host and mosquito species commonly associated with wnv. surveys of mosquito and bird communities were u ...025484570
saint louis encephalitis virus and other arboviruses in the differential diagnosis for dengue. 201425467251
development, characterization and application of monoclonal antibodies against brazilian dengue virus isolates.dengue is the most prevalent human arboviral disease. the morbidity related to dengue infection supports the need for an early, quick and effective diagnostic test. brazil is a hotspot for dengue, but no serological diagnostic test has been produced using brazilian dengue virus isolates. this study aims to improve the development of immunodiagnostic methods for dengue virus (denv) detection through the production and characterization of 22 monoclonal antibodies (mabs) against brazilian isolates ...201425412181
two distinct sets of ns2a molecules are responsible for dengue virus rna synthesis and virion assembly.flavivirus nonstructural protein 2a (ns2a) plays important roles in both viral rna synthesis and virion assembly. the molecular details of how the ns2a protein modulates the two distinct events have not been defined. to address this question, we have performed a systematic mutagenesis of ns2a using dengue virus (denv) serotype 2 (denv-2) as a model. we identified two sets of ns2a mutations with distinct defects during a viral infection cycle. one set of ns2a mutations (d125a and g200a) selective ...201425392211
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