a blood meal-induced ixodes scapularis tick saliva serpin inhibits trypsin and thrombin, and interferes with platelet aggregation and blood clotting.ixodes scapularis is a medically important tick species that transmits causative agents of important human tick-borne diseases including borreliosis, anaplasmosis and babesiosis. an understanding of how this tick feeds is needed prior to the development of novel methods to protect the human population against tick-borne disease infections. this study characterizes a blood meal-induced i. scapularis (ixsc) tick saliva serine protease inhibitor (serpin (s)), in-house referred to as ixscs-1e1. the ...201424583183
powassan virus in mammals, alaska and new mexico, u.s.a., and russia, 2004-2007.powassan virus is endemic to the united states, canada, and the russian far east. we report serologic evidence of circulation of this virus in alaska, new mexico, and siberia. these data support further studies of viral ecology in rapidly changing arctic environments.024274336
powassan virus encephalitis, minnesota, usa. 023750562
deorphanization and target validation of cross-tick species conserved novel amblyomma americanum tick saliva protein.we previously identified a cross-tick species conserved tick feeding stimuli responsive amblyomma americanum (aam) av422 gene. this study demonstrates that aamav422 belongs to a novel group of arthropod proteins that is characterized by 14 cysteine amino acid residues: c(23)-x7/9-c(33)-x23/24-c(58)-x8-c(67)-x7-c(75)-x23-c(99)-x15-c(115)-x10-c(126)-x24/25/33-c(150)c(151)-x7-c(159)-x8-c(168)-x23/24-c(192)-x9/10-c(202) predicted to form seven disulfide bonds. we show that aamav422 protein is a ubiq ...201323428900
epidemiology of tick-borne encephalitis (tbe) in europe and its prevention by available vaccines.tick-borne encephalitis (tbe), which is caused by a flavivirus, is the most common tick-transmitted disease in central and eastern europe and russia. today, tbe is endemic in 27 european countries, and has become an international public health problem. the epidemiology of tbe is changing owing to various factors, such as improvements in diagnosis and case reporting, increased recreational activities in areas populated by ticks, and changes in climatic conditions affecting tick habitats. vaccinat ...201323377671
prevalence and genetic characterization of powassan virus strains infecting ixodes scapularis in connecticut.a total of 30 powassan virus (powv) isolates from ixodes scapularis collected from bridgeport and north branford, ct in 2008, 2010, 2011, and 2012 and one earlier isolate from ixodes cookei collected in old lyme, ct in 1978 were characterized by phylogenetic analysis of their envelope gene sequences. powassan virus sequences segregated into two major groups termed the deer tick virus (dtv) and powassan (pow) lineages. the lineage from i. cookei was pow. the remaining viruses from i. scapularis g ...201222890037
first dating of a recombination event in mammalian tick-borne flaviviruses.the mammalian tick-borne flavivirus group (mtbfg) contains viruses associated with important human and animal diseases such as encephalitis and hemorrhagic fever. in contrast to mosquito-borne flaviviruses where recombination events are frequent, the evolutionary dynamic within the mtbfg was believed to be essentially clonal. this assumption was challenged with the recent report of several homologous recombinations within the tick-borne encephalitis virus (tbev). we performed a thorough analysis ...201222384119
tick-borne encephalitis vaccines.tick-borne encephalitis (tbe) is a disease that is found from western europe across asia and into japan. in recent years the incidence rate has been increasing as has the endemic range of the virus. tick-borne encephalitis is caused by three genetically distinct sutypes of viruses within a single tbe virus (tbev) serocomplex. these three subtypes consist of far-eastern subtype tbev (tbev-fe), siberian subtype (tbev-sib) and european subtype (tbev-eu). each of these subtypes cause clinically dist ...023997980
powassan virus encephalitis in southeastern ontario. 06254625
a case of powassan virus encephalitis.a case of encephalitis due to powassan virus, probably transmitted through tick-bite, is reported in an 8-year-old boy. there was a 50-fold increase in neutralization titre against powassan virus, but the virus could not be isolated. other virological investigations were negative.the patient survived and early physiotherapy and speech re-education could be instituted. nine months after onset of illness the patient showed moderate sequelae, despite a very severe illness.04829843
tick-borne viruses: a review from the perspective of therapeutic approaches.several important human diseases worldwide are caused by tick-borne viruses. these diseases have become important public health concerns in recent years. the tick-borne viruses that cause diseases in humans mainly belong to 3 families: bunyaviridae, flaviviridae, and reoviridae. in this review, we focus on therapeutic approaches for several of the more important tick-borne viruses from these 3 families. these viruses are crimean-congo hemorrhagic fever virus (cchf) and the newly discovered tick- ...201424907187
flavivirus ns1: a multifaceted enigmatic viral protein.flaviviruses are emerging arthropod-borne viruses representing an immense global health problem. the prominent viruses of this group include dengue virus, yellow fever virus, japanese encephalitis virus, west nile virus tick borne encephalitis virus and zika virus. these are endemic in many parts of the world. they are responsible for the illness ranging from mild flu like symptoms to severe hemorrhagic, neurologic and cognitive manifestations leading to death. ns1 is a highly conserved non-stru ...201627473856
transmission bottlenecks and rnai collectively influence tick-borne flavivirus evolution.arthropod-borne rna viruses exist within hosts as heterogeneous populations of viral variants and, as a result, possess great genetic plasticity. understanding the micro-evolutionary forces shaping these viruses can provide insights into how they emerge, adapt, and persist in new and changing ecological niches. while considerable attention has been directed toward studying the population dynamics of mosquito-borne viruses, little is known about tick-borne virus populations. therefore, using a mo ...201628058113
lyme disease coinfections in the united states.lyme disease in north america is caused by infection with the spirochetal bacterium borrelia burgdorferi and transmitted by ixodes scapularis and ixodes pacificus ticks. these ticks also have the potential to transmit a rapidly expanding list of other pathogenic bacteria, viruses, and parasites, including anaplasma phagocytophilum, babesia microti, deer tick (powassan) virus, borrelia miyamotoi, and the ehrlichia muris-like organism. coinfections with b burgdorferi and these other agents are oft ...201526593260
management approaches for suspected and established lyme disease used at the lyme disease diagnostic center.2015 marks the 27th year that the lyme disease diagnostic center, located in new york state in the united states, has provided care for patients with suspected or established deer tick-transmitted infections. there are five deer tick-transmitted infectious in this geographic area of which lyme disease is the most common.for patients with erythema migrans, we do not obtain any laboratory testing. however, if the patient is febrile at the time of the visit or reports rigors and high-grade fevers, ...201626768265
west nile virus and other arboviral diseases--united states, 2012.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. however, several other arboviruses also cause sporadic cases and seasonal outbreaks of neuroinvasive disease (e.g., meningitis, encephalitis, and acute flaccid paralysis). in 2012, cdc received reports of 5,780 nationally notifiable arboviral disease cases (excludin ...201323803959
aedes aegypti d7 saliva protein inhibits dengue virus infection.aedes aegypti is the primary vector of several medically relevant arboviruses including dengue virus (denv) types 1-4. ae. aegypti transmits denv by inoculating virus-infected saliva into host skin during probing and feeding. ae. aegypti saliva contains over one hundred unique proteins and these proteins have diverse functions, including facilitating blood feeding. previously, we showed that ae. aegypti salivary gland extracts (sges) enhanced dissemination of denv to draining lymph nodes. in con ...201627632170
emerging causes of arbovirus encephalitis in north america: powassan, chikungunya, and zika viruses.arboviruses are arthropod-borne viruses transmitted by the bite of mosquitoes, ticks, or other arthropods. arboviruses are a common and an increasing cause of human illness in north america. powassan virus, chikungunya virus, and zika virus are arboviruses that have all recently emerged as increasing causes of neurologic illness. powassan virus almost exclusively causes encephalitis, but cases are rare, sporadic, and restricted to portions of north america and russia. chikungunya virus has sprea ...201728229397
emerging cases of powassan virus encephalitis in new england: clinical presentation, imaging, and review of the literature.powassan virus (powv) is a rarely diagnosed cause of encephalitis in the united states. in the northeast, it is transmitted by ixodes scapularis, the same vector that transmits lyme disease. the prevalence of powv among animal hosts and vectors has been increasing. we present 8 cases of powv encephalitis from massachusetts and new hampshire in 2013-2015.201626668338
transmission and evolution of tick-borne viruses.ticks transmit a diverse array of viruses such as tick-borne encephalitis virus, powassan virus, and crimean-congo hemorrhagic fever virus that are reemerging in many parts of the world. most tick-borne viruses (tbvs) are rna viruses that replicate using error-prone polymerases and produce genetically diverse viral populations that facilitate their rapid evolution and adaptation to novel environments. this article reviews the mechanisms of virus transmission by tick vectors, the molecular evolut ...201627569396
update and commentary on four emerging tick-borne infections: ehrlichia muris-like agent, borrelia miyamotoi, deer tick virus, heartland virus, and whether ticks play a role in transmission of bartonella henselae.emerging tick-borne infections continue to be observed in the united states and elsewhere. current information on the epidemiology, clinical and laboratory features, and treatment of infections due to ehrlichia muris-like agent, deer tick virus, borrelia miyamotoi sensu lato, and heartland virus was provided and critically reviewed. more research is needed to define the incidence and to understand the clinical and the laboratory features of these infections. there is also a growing need for the ...201525999230
detection of quang binh virus from mosquitoes in china.flaviviruses present a wide range of genetic diversity and exhibit diverse host relationships. mosquito-borne flaviviruses have recently been isolated and characterized worldwide. yunnan province of china is one of the richest areas of species diversity and is the center of multi-species evolution in mainland asia, which supports the circulation of numerous arthropod-borne viruses (arboviruses). in a screening program of arboviruses, mosquitoes were collected during the mosquito activity season ...201424342141
molecular detection of severe fever with thrombocytopenia syndrome and tick-borne encephalitis viruses in ixodid ticks collected from vegetation, republic of korea, 2014.ticks play an important role in transmission of arboviruses responsible for emerging infectious diseases, and have a significant impact on human, veterinary, and wildlife health. in the republic of korea (rok), little is known about information regarding the presence of tick-borne viruses and their vectors. a total of 21,158 ticks belonging to 3 genera and 6 species collected at 6 provinces and 4 metropolitan areas in the rok from march to october 2014 were assayed for selected tick-borne pathog ...201627211914
protective immunity spectrum induced by immunization with a vaccine from the tbev strain sofjin.tick-borne encephalitis (tbe) circulates widely in the territory of eurasia with up to 10,000 cases registered annually. the tbe virus (tbev) includes three main subtypes: european, siberian and far-eastern, and two new asiatic variants, phylogenetically distant from the others. the inactivated antigen of european or far-eastern strains is used in commercial tbe vaccines. a set of 14 tbev strains, isolated in 1937-2008, with different passage histories, representing all subtypes and variants, wa ...201627013433
modeling powassan virus infection in peromyscus leucopus, a natural host.the tick-borne flavivirus, powassan virus (powv) causes life-threatening encephalitis in humans in north america and europe. powv is transmitted by ixodid tick vectors that feed on small to medium-sized mammals, such as peromyscus leucopus mice, which may serve as either reservoir, bridge or amplification hosts. intraperitoneal and intracranial inoculation of 4-week old peromyscus leucopus mice with 103 pfu of powv did not result in overt clinical signs of disease. however, following intracrania ...201728141800
infection resistance and tolerance in peromyscus spp., natural reservoirs of microbes that are virulent for humans.the widely-distributed north american species peromyscus leucopus and p. maniculatus of cricetine rodents are, between them, important natural reservoirs for several zoonotic diseases of humans: lyme disease, human granulocytic anaplasmosis, babesiosis, erhlichiosis, hard tickborne relapsing fever, powassan virus encephalitis, hantavirus pulmonary syndrome, and plague. while these infections are frequently disabling and sometimes fatal for humans, the peromyscines display little pathology and ap ...201727381345
interaction of flaviviruses with reproduction inhibitors binding in β-og pocket: insights from molecular dynamics simulations.flaviviral diseases, including dengue fever, west nile fever, yellow fever, tick-borne encephalitis, omsk haemorrhagic fever, and powassan encephalitis, threaten human health all over the world. lack of effective antivirals targeting replication cycle of flaviviruses makes the search of such compounds a challenging task. recently we have identified a reproduction inhibitor effective against tick-borne encephalitis virus and powassan virus (powv) (acs med. chem. lett., 2013, 4, 869-874). to enabl ...201427485304
dating the origin of the genus flavivirus in the light of beringian biogeography.the genus flavivirus includes some of the most important human viral pathogens, and its members are found in all parts of the populated world. the temporal origin of diversification of the genus has long been debated due to the inherent problems with dating deep rna virus evolution. a generally accepted hypothesis suggests that flavivirus emerged within the last 10 000 years. however, it has been argued that the tick-borne powassan flavivirus was introduced into north america some time between t ...201424914065
[genetic characterisation of powassan virus (powv) isolated from haemophysalis longicornis ticks in primorye and two strains of tick-borne encephalitis virus (tbev) (flaviviridae, flavivirus): alma-arasan virus (aav) isolated from ixodes persulcatus ticks in kazakhstan and malyshevo virus isolated from aedes vexans nipponii mosquitoes in khabarovsk kray].the complete genomes of the three tick-borne flaviviruses (genus flavivirus, fam. bunyaviridae) were sequenced: povassan virus (powv, strain leiv-3070prm, isolated from haemophysalis logicornis in primorsky krai, russia in 1977), alma-arasan virus (aav, strain leiv-1380kaz, isolated from ixodes persulcatus ticks in kazakhstan in 1977) and malyshevo virus (isolated from a pool of aedes vexans nipponii mosquitoes, in the khabarovsk krai, russia in 1978). it is shown that aav and malyshevo virus ar ...201425895206
tick-borne diseases in minnesota: an update.tick-borne diseases endemic to minnesota include lyme disease, babesiosis, anaplasmosis/ehrlichiosis, powassan virus illness and rocky mountain spotted fever. physicians need to be aware of these diseases and be vigilant about testing for them when patients present with acute febrile illness or rash within one month of potential tick exposure. in addition, they need to educate patients about these diseases and encourage prevention measures, especially use of tick repellents. this article reviews ...201222953474
powassan virus infection presenting as acute disseminated encephalomyelitis in tennessee.powassan virus is a rarely diagnosed cause of encephalitis, and is associated with significant neurologic sequelae. although symptomatic infections with powassan virus occur primarily in adults, we report a case of confirmed powassan neuroinvasive disease in a child presenting to a tennessee hospital, with symptoms and imaging studies suggestive of acute disseminated encephalomyelitis.201120736878
leg weakness associated with powassan virus infection--ontario. 19892547526
[the significance of ixodes ticks in the southern far east in the circulation of powassan virus]. 20162552689
isolation of powassan virus from a spotted skunk in california. 19873029440
[electrophoretic characteristics of the virus-specific proteins of powassan virus]. 20162986362
powassan virus encephalitis resembling herpes simplex encephalitis.a boy from new york traveling in nova scotia had olfactory hallucinations and other signs of temporal lobe involvement, leading to a diagnosis of herpes simplex encephalitis. the patient was treated with vidarabine and made a complete recovery. however, hemagglutination inhibition, complement fixation, and neutralization tests identified powassan virus (pow) as the pathogen. shortly before his trip to nova scotia, the patient had traveled in an area where pow encephalitis had occurred in humans ...19836297420
light and electron microscope study of the neurotropism of powassan virus strain p-40.brains of adult white mice inoculated with the p-40 strain of powassan virus isolated in primorsky krai (u.s.s.r) from ticks were studied by light and electron microscopy. accumulations of virus particles were found in neurons and their dendrites and axons, in glial cells, and in intercellular spaces. in the nerve cells, most prevalent were changes of the type of chromatolysis and formation of small vacuoles, associated with the alteration of the endoplasmic reticulum induced by virus morphogene ...197935957
[neural pathway of powassan virus spread in the central nervous system of white mice].electron microscopic investigation of the brains and lumbar spinal cords of adult albino mice infected with powassan virus was carried out. virus particles were found within all parts of neurons (perikarya, dendrites, axon), as well as within synaptic apparatus and intercellular gaps of the central nervous tissue. the possibility of the virus spread both throughout the cytoplasm of nerve cells and their processes and the extracellular spaces of the brain was confirmed. localization of virions wi ...1978206238
powassan virus infection in the grey squirrel. 19714399143
california encephalitis and powassan virus activity in british columbia, 1969. 19705466318
the first isolations of powassan virus in new york state. 196514328910
powassan virus: field investigations in northern ontario, 1959 to 1961. 196220327133
powassan virus: investigations of possible natural cycles of infection. 201313774094
powassan virus: isolation of virus from a fatal case of encephalitis. 195913652010
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
powassan virus: an emerging arbovirus of public health concern in north america.powassan virus (powv, flaviviridae) is the only north american member of the tick-borne encephalitis serogroup of flaviviruses. it is transmitted to small- and medium-sized mammals by ixodes scapularis, ixodes cookei, and several other ixodes tick species. humans become infected with powv during spillover transmission from the natural transmission cycles. in humans, powv is the causative agent of a severe neuroinvasive illness with 50% of survivors displaying long-term neurological sequelae. pow ...201728498740
serologic evidence of powassan virus infection in patients with suspected lyme disease(1).powassan virus (powv) lineage ii is an emerging tickborne flavivirus with an unknown seroprevalence in humans. in a lyme disease-endemic area, we examined the seroreactivity to powv in 2 patient cohorts and described the clinical features of the powv-seroreactive patients. powv disease might be less neuroinvasive than previously thought.201728726610
west nile virus and other arboviral diseases - united states, 2013.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. however, several other arboviruses also cause sporadic cases and seasonal outbreaks of neuroinvasive disease (i.e., meningitis, encephalitis, and acute flaccid paralysis). this report summarizes surveillance data reported to cdc in 2013 for wnv and other nationally ...201424941331
west nile virus disease and other arboviral diseases - united states, 2011.arthropodborne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. symptomatic infections most often manifest as a systemic febrile illness and, less commonly, as neuroinvasive disease (e.g., meningitis, encephalitis, or acute flaccid paralysis). west nile virus (wnv) is the leading cause of domestically acquired arboviral disease in the united states. however, several other arboviruses also cause seasonal outbreaks and sporadic cases. in ...201222785342
detection of anaplasma phagocytophilum, babesia microti, borrelia burgdorferi, borrelia miyamotoi, and powassan virus in ticks by a multiplex real-time reverse transcription-pcr assay.ixodes scapularis ticks are implicated in transmission of anaplasma phagocytophilum, borrelia burgdorferi, borrelia miyamotoi, babesia microti, and powassan virus. we describe the establishment and implementation of the first multiplex real-time pcr assay with the capability to simultaneously detect and differentiate all five pathogens in a single reaction. the application of this assay for analysis of ticks at sites in new york and connecticut revealed a high prevalence of b. microti in ticks f ...201728435891
peromyscus leucopus mouse brain transcriptome response to powassan virus infection.powassan virus (powv) is a tick-borne flavivirus responsible for life-threatening encephalitis in north america and some regions of russia. the ticks that have been reported to transmit the virus belong to the ixodes species, and they feed on small-to-medium-sized mammals, such as peromyscus leucopus mice, skunks, and woodchucks. we previously developed a p. leucopus mouse model of powv infection, and the model is characterized by a lack of clinical signs of disease following intraperitoneal or ...201729147886
interferon signaling in peromyscus leucopus confers a potent and specific restriction to vector-borne flaviviruses.tick-borne flaviviruses (tbfvs), including powassan virus and tick-borne encephalitis virus cause encephalitis or hemorrhagic fevers in humans with case-fatality rates ranging from 1-30%. despite severe disease in humans, tbfv infection of natural rodent hosts has little noticeable effect. currently, the basis for resistance to disease is not known. we hypothesize that the coevolution of flaviviruses with their respective hosts has shaped the evolution of potent antiviral factors that suppress v ...201728650973
notes from the field: powassan virus disease in an infant - connecticut, 2016. 201728426641
powassan virus-a new reemerging tick-borne disease.powassan virus is a neurovirulent flavivirus consisting of two lineages causing meningoencephalitis. it is the only member of the tick-borne encephalitis serogroup which is present in mainland north america. with a total number of 27 cases from 1958 to 1998 and 98 cases from 1999 to 2016, reported cases have increased by 671% over the last 18 years. powassan infection is transmitted by different tick species in different geographical regions. ixodes scapularis is the primary vector that transmit ...201729312918
a roadmap for tick-borne flavivirus research in the "omics" era.tick-borne flaviviruses (tbfs) affect human health globally. human vaccines provide protection against some tbfs, and antivirals are available, yet tbf-specific control strategies are limited. advances in genomics offer hope to understand the viral complement transmitted by ticks, and to develop disruptive, data-driven technologies for virus detection, treatment, and control. the genome assemblies of ixodes scapularis, the north american tick vector of the tbf, powassan virus, and other tick vec ...201729312896
fatal deer tick virus infection in maine.deer tick virus (dtv), a genetic variant (lineage ii) of powassan virus, is a rare cause of encephalitis in north america. we report a fatal case of dtv encephalitis following a documented bite from an ixodes scapularis tick and the erythema migrans rash associated with lyme disease.201728903511
flavivirus infection of ixodes scapularis (black-legged tick) ex vivo organotypic cultures and applications for disease control.ixodes scapularis ticks transmit many infectious agents that cause disease, including tick-borne flaviviruses (tbfvs). tbfv infections cause thousands of human encephalitis cases worldwide annually. in the united states, human tbfv infections with powassan virus (powv) are increasing and have a fatality rate of 10 to 30%. additionally, langat virus (lgtv) is a tbfv of low neurovirulence and is used as a model tbfv. tbfv replication and dissemination within i. scapularis organs are poorly charact ...201728830948
development and validation of a serologic test panel for detection of powassan virus infection in u.s. patients residing in regions where lyme disease is endemic.powassan virus (powv) is an emerging tick-borne arbovirus presenting a public health threat in north america. powv lineage ii, also known as deer tick virus, is the strain of the virus most frequently found in ixodes scapularis ticks and is implicated in most cases of powv encephalitis in the united states. currently, no commercial tests are available to detect powv exposure in tick-borne disease (tbd) patients. we describe here the development and analytical validation of a serologic test panel ...201829359181
the blacklegged tick, ixodes scapularis: an increasing public health the united states, the blacklegged tick, ixodes scapularis, is a vector of seven human pathogens, including those causing lyme disease, anaplasmosis, babesiosis, borrelia miyamotoi disease, powassan virus disease, and ehrlichiosis associated with ehrlichia muris eauclarensis. in addition to an accelerated rate of discovery of i. scapularis-borne pathogens over the past two decades, the geographic range of the tick, and incidence and range of i. scapularis-borne disease cases, have increased. ...201829336985
data-driven predictions and novel hypotheses about zoonotic tick vectors from the genus ixodes.with the resurgence of tick-borne diseases such as lyme disease and the emergence of new tick-borne pathogens such as powassan virus, understanding what distinguishes vectors from non-vectors, and predicting undiscovered tick vectors is a crucial step towards mitigating disease risk in humans. we aimed to identify intrinsic traits that predict which ixodes tick species are confirmed or strongly suspected to be vectors of zoonotic pathogens.201829448923
pathogen transmission in relation to duration of attachment by ixodes scapularis ticks.the blacklegged tick, ixodes scapularis, is the primary vector to humans in the eastern united states of the deer tick virus lineage of powassan virus (powassan virus disease); the protozoan parasite babesia microti (babesiosis); and multiple bacterial disease agents including anaplasma phagocytophilum (anaplasmosis), borrelia burgdorferi and borrelia mayonii (lyme disease), borrelia miyamotoi (relapsing fever-like illness, named borrelia miyamotoi disease), and ehrlichia muris eauclairensis (a ...201829398603
zika virus-related neurotropic flaviviruses infect human placental explants and cause fetal demise in mice.although zika virus (zikv) infection in pregnant women can cause placental damage, intrauterine growth restriction, microcephaly, and fetal demise, these disease manifestations only became apparent in the context of a large epidemic in the americas. we hypothesized that zikv is not unique among arboviruses in its ability to cause congenital infection. to evaluate this, we tested the capacity of four emerging arboviruses [west nile virus (wnv), powassan virus (powv), chikungunya virus (chikv), an ...201829386359
fatal powassan encephalitis (deer tick virus, lineage ii) in a patient with fever and orchitis receiving rituximab.powassan virus is a rare but increasingly recognized cause of severe neurological disease.201829554185
a multiplex serologic platform for diagnosis of tick-borne diseases.tick-borne diseases are the most common vector-borne diseases in the united states, with serology being the primary method of diagnosis. we developed the first multiplex, array-based assay for serodiagnosis of tick-borne diseases called the tbd-serochip. the tbd-serochip was designed to discriminate antibody responses to 8 major tick-borne pathogens present in the united states, including anaplasma phagocytophilum, babesia microti, borrelia burgdorferi, borrelia miyamotoi, ehrlichia chaffeensis, ...201829453420
rapid detection of powassan virus in a patient with encephalitis by metagenomic sequencing.we describe a patient with severe and progressive encephalitis of unknown etiology. we performed rapid metagenomic sequencing from cerebrospinal fluid and identified powassan virus, an emerging tick-borne flavivirus that has been increasingly detected in the united states.201829020227
powassan virus postencephalitic parkinsonism. 201729431163
powassan virus and other arthropod-borne viruses in wildlife and ticks in ontario, canada.powassan virus (powv) is a tick-borne zoonosis maintained in natural enzootic cycles between ixodid ticks and wild mammals. reported human cases have increased in recent years; these infections can be fatal or lead to long-term neurologic sequelae. however, both the geographic distribution and the role of common, potential mammalian hosts in powv transmission are poorly understood, creating challenges to public health surveillance. we looked for evidence of powv infection among candidate wildlif ...201829869604
generation of a lineage ii powassan virus (deer tick virus) cdna clone: assessment of flaviviral genetic determinants of tick and mosquito vector competence.the flavivirus genus comprises a diverse group of viruses that utilize a wide range of vertebrate hosts and arthropod vectors. the genus includes viruses that are transmitted solely by mosquitoes or vertebrate hosts as well as viruses that alternate transmission between mosquitoes or ticks and vertebrates. nevertheless, the viral genetic determinants that dictate these unique flaviviral host and vector specificities have been poorly characterized. in this report, a cdna clone of a flavivirus tha ...201829782238
cross-neutralisation of viruses of the tick-borne encephalitis complex following tick-borne encephalitis vaccination and/or infection.the tick-borne encephalitis complex contains a number of flaviviruses that share close genetic homology, and are responsible for significant human morbidity and mortality with widespread geographical range. although many members of this complex have been recognised for decades, licenced human vaccines with broad availability are only available for tick-borne encephalitis virus. while tick-borne encephalitis virus vaccines have been demonstrated to induce significant protective immunity, as deter ...201729263866
west nile virus and other nationally notifiable arboviral diseases - united states, 2017.arthropodborne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes or ticks. west nile virus (wnv) is the leading cause of domestically acquired arboviral disease in the continental united states (1). other arboviruses, including jamestown canyon, la crosse, powassan, st. louis encephalitis, and eastern equine encephalitis viruses, cause sporadic cases of disease and occasional outbreaks. this report summarizes surveillance data reported to cdc from ...201830335737
zoonotic babesia: a scoping review of the global evidence.babesiosis is a parasitic vector-borne disease of increasing public health importance. since the first human case was reported in 1957, zoonotic species have been reported on nearly every continent. zoonotic babesia is vectored by ixodes ticks and is commonly transmitted in north america by ixodes scapularis, the tick species responsible for transmitting the pathogens that also cause lyme disease, powassan virus, and anaplasmosis in humans. predicted climate change is expected to impact the spre ...201931887120
powassan virus encephalitis, severe babesiosis and lyme carditis in a single patient.ixodes scapularis is responsible for transmission of borrelia burgdorferi, b. miyamotoi, babesia microti, anaplasma phagocytophilum and powassan virus to humans. we present a case of an 87-year-old man who presented with fever and altered mental status. initial workup revealed haemolytic anaemia, thrombocytopenia, mild hepatitis and acute kidney injury. patient tested positive for b. burgdorferi and babesia microti, and was started on doxycycline, atovaquone and azithromycin. he also underwent e ...201931712240
molecular survey of flaviviruses and orthobunyaviruses in amblyomma spp. ticks collected in minas gerais, brazil.due to anthropic environmental changes, vector-borne diseases are emerging worldwide. ticks are known vectors of several pathogens of concern among humans and animals. in recent decades, several examples of tick-borne emerging viral diseases have been reported (crimean congo hemorrhagic fever virus, powassan virus, encephalitis virus, heartland virus, severe fever with thrombocytopenia syndrome virus). unfortunately, few studies addressing the presence of viruses in wild ticks have been carried ...202031576974
possible prognostic value of serial brain mris in powassan virus encephalitis.powassan virus (powv) encephalitis is a rare tickborne illness. we describe the clinical course, laboratory findings, and imaging for a patient with powv in massachusetts, usa. clinical presentation and laboratory findings were nonspecific. improvement on brain magnetic resonance imaging after 2 weeks preceded clinical improvement by months, suggesting possible prognostic value.201931538917
an overview of powassan virus disease. 201931534605
ixodes scapularis salivary gland micrornas are differentially expressed during powassan virus transmission.successful tick feeding is facilitated by an assortment of pharmacologically-active factors in tick saliva that create an immunologically privileged micro-environment in the host's skin. through a process known as saliva-assisted transmission, bioactive tick salivary factors modulate the host environment, promoting transmission and establishment of a tick-borne pathogen. this phenomenon was previously demonstrated for powassan virus (powv), a north american tick-borne flavivirus that is the caus ...201931511580
polymicrobial nature of tick-borne diseases.tick-borne diseases have doubled in the last 12 years, and their geographic distribution has spread as well. the clinical spectrum of tick-borne diseases can range from asymptomatic to fatal infections, with a disproportionate incidence in children and the elderly. in the last few years, new agents have been discovered, and genetic changes have helped in the spread of pathogens and ticks. polymicrobial infections, mostly in ixodes scapularis, can complicate diagnostics and augment disease severi ...201931506314
n increased risk of tick-borne diseases with climate and environmental changes.climate warming and other environmental changes have contributed to the expansion of the range of several tick species into higher latitudes in north america. as temperatures increase in canada, the environment becomes more suitable for ticks and the season suitable for tick activity lengthens, so tick-borne diseases are likely to become more common in canada. in addition to lyme disease, four other tick-borne diseases (tbds) have started to emerge and are likely to increase: anaplasmosis; babes ...201931285697
prevalence and genetic characterization of deer tick virus (powassan virus, lineage ii) in ixodes scapularis ticks collected in maine.deer tick virus (dtv) is a genetic variant of powassan virus (powv) that circulates in north america in an enzootic cycle involving the blacklegged or "deer tick," ixodes scapularis, and small rodents such as the white-footed mouse. the number of reported human cases with neuroinvasive disease has increased substantially over the past few years, indicating that powv may be of increasing public health importance. to this end, we sought to estimate powv infection rates in questing i. scapularis co ...201931218999
polio-like manifestation of powassan virus infection with anterior horn cell involvement, canada.evidence of spinal cord involvement in powassan virus infection is largely limited to mouse models. we report a case of a polio-like illness caused by powassan virus infection in a 62-year-old man in canada. magnetic resonance imaging showed t2 hyperintensities in the anterior horns of the cervical spinal cord.201931158072
microbiome analysis of ixodes scapularis ticks from new york and connecticut.we employed high throughput sequencing to survey the microbiomes of ixodes scapularis collected in new york and connecticut. we examined 197 individual i. scapularis adults and pools from 132 adults and 197 nymphs. we detected borrelia burgdorferi sensu stricto in 56.3% of individual ticks, anaplasma phagocytophilum in 10.6%, borrelia miyamotoi in 5%, babesia microti in 7.6%, and powassan virus in 3.6%. we did not detect borrelia mayonii, ehrlichia muris eauclairensis, bartonella spp. or pathoge ...201931023629
tick-borne flavivirus reproduction inhibitors based on isoxazole core linked with adamantane.infections caused by flaviviruses pose a huge threat for public health all over the world. the search for therapeutically relevant compounds targeting tick-borne flaviviruses requires the exploration of novel chemotypes. in the present work a large series of novel polyfunctionalized isoxazole derivatives bearing substituents with various steric and electronic effects was obtained by our unique versatile synthetic procedure and their antiviral activity against tick-borne encephalitis, omsk hemorr ...201930947098
co-infections in persons with early lyme disease, new york, certain regions of new york state, usa, ixodes scapularis ticks can potentially transmit 4 pathogens in addition to borrelia burgdorferi: anaplasma phagocytophilum, babesia microti, borrelia miyamotoi, and the deer tick virus subtype of powassan virus. in a prospective study, we systematically evaluated 52 adult patients with erythema migrans, the most common clinical manifestation of b. burgdorferi infection (lyme disease), who had not received treatment for lyme disease. we used serologic t ...201930882316
seroprevalence of borrelia burgdorferi, b. miyamotoi, and powassan virus in residents bitten by ixodes ticks, maine, usa.we conducted a serosurvey of 230 persons in maine, usa, who had been bitten by ixodes scapularis or i. cookei ticks. we documented seropositivity for borrelia burgdorferi (13.9%) and b. miyamotoi (2.6%), as well as a single equivocal result (0.4%) for powassan encephalitis virus.201930882312
dissecting flavivirus biology in salivary gland cultures from fed and unfed ixodes scapularis (black-legged tick).the ixodes scapularis tick transmits a number of pathogens, including tick-borne flaviviruses (tbfvs). in the united states, confirmed human infections with the powassan virus (powv) tbfv have a fatality rate of ∼10% and are increasing in incidence. tick salivary glands (sgs) serve as an organ barrier to tbfv transmission, and little is known regarding the location of tbfv infection in sgs from fed ticks. previous studies showed i. scapularis vanin (vnn) involved with tbfv infection of i. scapul ...201930696737
an mrna vaccine protects mice against multiple tick-transmitted flavivirus infections.powassan virus (powv) is an emerging tick-transmitted flavivirus that circulates in north america and russia. up to 5% of deer ticks now test positive for powv in certain regions of the northern united states. although powv infections cause life-threatening encephalitis, there is no vaccine or countermeasure available for prevention or treatment. here, we developed a lipid nanoparticle (lnp)-encapsulated modified mrna vaccine encoding the powv prm and e genes and demonstrated its immunogenicity ...201830566864
tick-borne flaviviruses, with a focus on powassan virus.the tick-borne pathogen powassan virus is a rare cause of encephalitis in north america and the russian far east. the number of documented cases described since the discovery of powassan virus in 1958 may be <150, although detection of cases has increased over the past decade. in the united states, the incidence of powassan virus infections expanded from the estimated 1 case per year prior to 2005 to 10 cases per year during the subsequent decade. the increased detection rate may be associated w ...201930541872
the role of mammalian reservoir hosts in tick-borne flavivirus biology.small-to-medium sized mammals and large animals are lucrative sources of blood meals for ixodid ticks that transmit life-threatening tick-borne flaviviruses (tbfvs). tbfvs have been isolated from various organs obtained from wild-caught myodes and apodemus species in europe and asia. thus, these rodents are well-established reservoirs of tbfvs. wild-caught peromyscus species have demonstrated seropositivity against powassan virus, the only tbfv known to circulate in north america, suggesting tha ...201830234026
first confirmed case of powassan neuroinvasive disease in rhode island.the powassan virus is the arthropod-borne vector responsible for powassan neuroinvasive disease. the virus was first isolated in 1958 and has been responsible for approximately 100 cases of neuroinvasive disease. rates of infection have been on the rise over the past decade with numerous states reporting their first confirmed case; new jersey, new hampshire and connecticut all reported their first case within the last five years. we present here the first confirmed case of powassan neuroinvasive ...201829942757
tick-borne flaviviruses and the type i interferon response.flaviviruses are globally distributed pathogens causing millions of human infections every year. flaviviruses are arthropod-borne viruses and are mainly transmitted by either ticks or mosquitoes. mosquito-borne flaviviruses and their interactions with the innate immune response have been well-studied and reviewed extensively, thus this review will discuss tick-borne flaviviruses and their interactions with the host innate immune response.201829933625
powassan virus, a scoping review of the global evidence.powassan virus (powv), a flavivirus discovered in 1958, causes sporadic but severe cases of encephalitis in humans. since 2007, the number of human powassan cases diagnosed each year in the usa has steadily increased. this is in agreement with predictions that powassan cases may increase in north america as a result of increased exposure to infected ticks. however, the increase may also reflect improved diagnostics and reporting among other factors.201829911344
what's eating you? ixodes tick and related diseases, part 2: diagnosis and treatment of regional tick-borne diseases.the ixodes tick is an important arthropod vector in the transmission of human disease. although lyme disease is the most prevalent zoonosis transmitted by ixodes ticks, other less common diseases may be encountered, including human granulocytic anaplasmosis, babesiosis, powassan virus infection, tick-borne encephalitis, borrelia miyamotoi disease, and tick paralysis. in part 2 of this review, disease presentation, diagnosis, and treatment of these less commonly encountered tick-borne diseases ar ...201829763485
what's eating you? ixodes tick and related diseases, part 1: life cycle, local reactions, and lyme disease.the ixodes tick is an important arthropod vector in the transmission of human disease. this 3-part review highlights the biology of the ixodes tick and manifestations of related diseases. part 1 addresses the ixodes tick biology and life cycle; local reactions; and lyme disease, the most prevalent of associated diseases. part 2 will address human granulocytic anaplasmosis, babesiosis, powassan virus infection, borrelia miyamotoi disease, tick-borne encephalitis, and tick paralysis. part 3 will a ...201829718024
evidence of powassan/deer tick virus in adult black-legged ticks (ixodes scapularis) recovered from hunter-harvested white-tailed deer (odocoileus virginianus) in pennsylvania: a public health perspective.studies reporting tick infection rates for powassan virus (powv), an emerging zoonotic arthropod-borne pathogen responsible for powv disease in the commonwealth of pennsylvania, are limited. to determine the presence and ascertain a statewide prevalence of powv, ticks were collected from 9,912 hunter-harvested white-tailed deer (odocoileus virginianus) heads presented to six regional pennsylvania game commission chronic wasting disease sampling stations in early december of 2013, 2014 and 2015. ...201829707917
powassan virus - an emerging public health concern. 201829661817
powassan virus disease in the united states, 2006-2016.powassan virus (powv) is a tick-borne flavivirus that causes rare, but often severe, disease in humans. powv neuroinvasive disease was added to the u.s. nationally notifiable disease list in 2001 and nonneuroinvasive disease was added in 2004. the only previous review of the epidemiology of powv disease in the united states based on cases reported to the centers for disease control and prevention (cdc) covered the period from 1999 through 2005.201829652642
breast milk transmission of flaviviruses in the context of zika virus: a systematic review.since the zika virus epidemic in the americas began in 2015, zika virus transmission has occurred throughout the americas. however, limited information exists regarding possible risks of transmission of zika virus and other flaviviruses through breast feeding and human milk. we conducted a systematic review of the evidence regarding flaviviruses detection in and transmission through milk, specifically regarding zika virus, japanese encephalitis virus, tick-borne encephalitis virus, powassan viru ...201829882971
the liver x receptor agonist lxr 623 restricts flavivirus replication.the vector-borne flaviviruses (vbfvs) are well known for causing great misery and death in humans worldwide. the vbfvs include those transmitted by mosquitos, such as zika virus (zikv), dengue virus; and those transmitted by ticks including the tick-borne flavivirus serocomplex and powassan virus (powv). two of our recent reports showed that intracranial powv infection in the reservoir host, peromyscus leucopus, was restricted and caused no overt clinical disease. several modes of analyses sugge ...202134162308
powassan virus experimental infections in three wild mammal species.powassan virus (powv) is a tick-borne virus maintained in sylvatic cycles between mammalian wildlife hosts and ticks (primarily ixodes spp.). there are two currently recognized lineages, powv-lineage 1 (powv-l1) and deer tick virus (dtv; lineage 2), both of which can cause fatal neurologic disease in humans. increased numbers of human case reports in the northeastern and north central united states in recent years have fueled questions into powv epidemiology. we inoculated three candidate wildli ...202133534764
powassan virus: centers for disease control and prevention. 201931910483
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