| a new tick-borne encephalitis-like virus infecting new england deer ticks, ixodes dammini. | to determine if eastern north american ixodes dammini, like related ticks in eurasia, maintain tick-borne encephalitis group viruses, we analyzed ticks collected from sites where the agent of lyme disease is zoonotic. two viral isolates were obtained by inoculating mice with homogenates from tick salivary glands. the virus, which was described by reverse transcriptase polymerase chain reaction and direct sequencing of the amplification products, was similar to, but distinct from, powassan virus ... | 1997 | 9204297 |
| a focus of deer tick virus transmission in the northcentral united states. | we screened salivary glands from adult deer ticks collected near spooner and hayward, wisconsin, to determine whether deer tick virus, a recently described flavivirus, occurs with other tickborne agents in the upper midwest. intraacinar inclusions suggestive of replicating virus were detected in 4 (4.6%) of 87 ticks. the virus was isolated by suckling-mouse inoculation. | 1999 | 10460180 |
| enzootic transmission of deer tick virus in new england and wisconsin sites. | to determine whether rodents that are intensely exposed to the deer tick-transmitted agents of lyme disease, human granulocytic ehrlichiosis, and human babesiosis are also exposed to deer tick virus (dtv), we assayed serum samples from white-footed mice (peromyscus leucopus) and meadow voles (microtus pennsylvanicus) in sites densely infested by deer ticks. to conduct serosurveys, we developed an enzyme-linked immunosorbent assay (elisa) and western blot assay by cloning, expressing, and purifyi ... | 2000 | 11357992 |
| phylogeny of north american powassan virus. | to determine whether powassan virus (pow) and deer tick virus (dtv) constitute distinct flaviviral populations transmitted by ixodid ticks in north america, we analysed diverse nucleotide sequences from 16 strains of these viruses. two distinct genetic lineages are evident, which may be defined by geographical and host associations. the nucleotide and amino acid sequences of lineage one (comprising new york and canadian pow isolates) are highly conserved across time and space, but those of linea ... | 2001 | 11413377 |
| nucleotide sequencing and serological evidence that the recently recognized deer tick virus is a genotype of powassan virus. | deer tick virus (dtv) is a recently recognized north american virus isolated from ixodes dammini ticks. nucleotide sequencing of fragments of structural and non-structural protein genes suggested that this virus was most closely related to the tick-borne flavivirus powassan (pow), which causes potentially fatal encephalitis in humans. to determine whether dtv represents a new and distinct member of the flavivirus genus of the family flaviviridae, we sequenced the structural protein genes and 5' ... | 2001 | 11551648 |
| genomic sequencing of deer tick virus and phylogeny of powassan-related viruses of north america. | powassan (pow) virus is responsible for central nervous system infection in humans in north america and the eastern parts of russia. recently, a new flavivirus, deer tick (dt) virus, related to pow virus was isolated in the united states, but neither its pathogenic potential in human nor the taxonomic relationship with pow virus has been elucidated. in this study, we obtained the near-full-length genomic sequence of the dt virus and complete sequences of 3 genomic regions of 15 strains of pow-re ... | 2001 | 11716135 |
| the modeled structure of the rna dependent rna polymerase of gbv-c virus suggests a role for motif e in flaviviridae rna polymerases. | the flaviviridae virus family includes major human and animal pathogens. the rna dependent rna polymerase (rdrp) plays a central role in the replication process, and thus is a validated target for antiviral drugs. despite the increasing structural and enzymatic characterization of viral rdrps, detailed molecular replication mechanisms remain unclear. the hepatitis c virus (hcv) is a major human pathogen difficult to study in cultured cells. the bovine viral diarrhea virus (bvdv) is often used as ... | 2005 | 16225688 |
| cleavage targets and the d-arginine-based inhibitors of the west nile virus ns3 processing proteinase. | mosquito-borne wnv (west nile virus) is an emerging global threat. the ns3 proteinase, which is essential for the proteolytic processing of the viral polyprotein precursor, is a promising drug target. we have isolated and biochemically characterized the recombinant, highly active ns3 proteinase. we have determined that the ns3 proteinase functions in a manner that is distantly similar to furin in cleaving the peptide and protein substrates. we determined that aprotinin and d-arginine-based 9-12- ... | 2006 | 16229682 |
| stable prevalence of powassan virus in ixodes scapularis in a northern wisconsin focus. | deer tick virus (dtv), a variant of powassan virus (powv), appears to be maintained in nature in an enzootic cycle between ixodes scapularis ticks and small mammals. although powv infection of human beings is rare, a recent report suggests increasing incidence and the possibility that powv may be an emerging tick-borne zoonosis. therefore, we assessed the long-term stability of the powv transmission cycle in northwestern wisconsin. adult i. scapularis and dermacentor variabilis were collected fr ... | 2008 | 19052313 |
| fatal case of deer tick virus encephalitis. | deer tick virus is related to powassan virus, a tickborne encephalitis virus. a 62-year-old man presented with a meningoencephalitis syndrome and eventually died. analyses of tissue samples obtained during surgery and at autopsy revealed a widespread necrotizing meningoencephalitis. nucleic acid was extracted from formalin-fixed tissue, and the presence of deer tick virus was verified on a flavivirus-specific polymerase-chain-reaction (pcr) assay, followed by sequence confirmation. immunohistoch ... | 2009 | 19439744 |
| update on powassan virus: emergence of a north american tick-borne flavivirus. | powassan virus (pow) (flaviviridae: flavivirus) is the cause of rare but severe neuroinvasive disease in north america and russia. the virus is transmitted among small- and medium-sized mammals by ixodid ticks. human infections occur via spillover from the main transmission cycle(s). since the late 1990s, the incidence of human disease seems to be increasing. in addition, pow constitutes a genetically diverse group of virus genotypes, including deer tick virus, that are maintained in distinct en ... | 2010 | 19961325 |
| rapid identification of vector-borne flaviviruses by mass spectrometry. | flaviviruses are a highly diverse group of rna viruses classified within the genus flavivirus, family flaviviridae. most flaviviruses are arthropod-borne, requiring a mosquito or tick vector. several flaviviruses are highly pathogenic to humans; however, their high genetic diversity and immunological relatedness makes them extremely challenging to diagnose. in this study, we developed and evaluated a broad-range flavivirus assay designed to detect both tick- and mosquito-borne flaviviruses by us ... | 2010 | 20412852 |
| homogeneity of powassan virus populations in naturally infected ixodes scapularis. | powassan virus (powv, flaviviridae: flavivirus) is the sole north american member of the tick-borne encephalitis complex and consists of two distinct lineages that are maintained in ecologically discrete enzootic transmission cycles. the underlying genetic mechanisms that lead to niche partitioning in arboviruses are poorly understood. therefore, intra- and interhost genetic diversity was analyzed to determine if powv exists as a quasispecies in nature and quantify selective pressures within and ... | 2010 | 20434750 |
| molecular epidemiology of powassan virus in north america. | powassan virus (pow) is a tick-borne flavivirus distributed in canada, the northern usa and the primorsky region of russia. pow is the only tick-borne flavivirus endemic to the western hemisphere, where it is transmitted mainly between ixodes cookei and groundhogs (marmota monax). deer tick virus (dtv), a genotype of pow that has been frequently isolated from deer ticks (ixodes scapularis), appears to be maintained in an enzootic cycle between these ticks and white-footed mice (peromyscus leucop ... | 2010 | 20631087 |
| persistence of pathogens with short infectious periods in seasonal tick populations: the relative importance of three transmission routes. | the flaviviruses causing tick-borne encephalitis (tbe) persist at low but consistent levels in tick populations, despite short infectious periods in their mammalian hosts and transmission periods constrained by distinctly seasonal tick life cycles. in addition to systemic and vertical transmission, cofeeding transmission has been proposed as an important route for the persistence of tbe-causing viruses. because cofeeding transmission requires ticks to feed simultaneously, the timing of tick acti ... | 2010 | 20668521 |
| tick cell lines for study of crimean-congo hemorrhagic fever virus and other arboviruses. | abstract continuous cell lines derived from many of the vectors of tick-borne arboviruses of medical and veterinary importance are now available. their role as tools in arbovirus research to date is reviewed and their potential application in studies of tick cell responses to virus infection is explored, by comparison with recent progress in understanding mosquito immunity to arbovirus infection. a preliminary study of propagation of the human pathogen crimean-congo hemorrhagic fever virus (cc ... | 2011 | 21955214 |
| potential role of deer tick virus in powassan encephalitis cases in lyme disease-endemic areas of new york, u.s.a. | powassan virus, a member of the tick-borne encephalitis group of flaviviruses, encompasses 2 lineages with separate enzootic cycles. the prototype lineage of powassan virus (powv) is principally maintained between ixodes cookei ticks and the groundhog (marmota momax) or striped skunk (mephitis mephitis), whereas the deer tick virus (dtv) lineage is believed to be maintained between ixodes scapularis ticks and the white-footed mouse (peromyscus leucopus). we report 14 cases of powassan encephalit ... | 2013 | 24274334 |
| isolation of deer tick virus (powassan virus, lineage ii) from ixodes scapularis and detection of antibody in vertebrate hosts sampled in the hudson valley, new york state. | deer tick virus, dtv, is a genetically and ecologically distinct lineage of powassan virus (powv) also known as lineage ii powv. human incidence of pow encephalitis has increased in the last 15 years potentially due to the emergence of dtv, particularly in the hudson valley of new york state. we initiated an extensive sampling campaign to determine whether powv was extant throughout the hudson valley in tick vectors and/or vertebrate hosts. | 2013 | 24016533 |
| lyme disease. | | 2014 | 25119621 |
| clinical practice. lyme disease. | | 2014 | 24785207 |
| the prevalence of zoonotic tick-borne pathogens in ixodes scapularis collected in the hudson valley, new york state. | ixodes scapularis, the blacklegged tick, is capable of transmitting the pathogens that cause lyme disease (borrelia burgdorferi), babesiosis (babesia microti), anaplasmosis (anaplasma phagocytophilum), and to a lesser extent powassan encephalitis (deer tick virus [dtv]). these pathogens represent significant public health problems, but little is known about the occurrence and co-infection prevalence of these pathogens in i. scapularis. here, we used standard pcr and pathogen-specific primers to ... | 2014 | 24689680 |
| human pathogens associated with the blacklegged tick ixodes scapularis: a systematic review. | the blacklegged tick ixodes scapularis transmits borrelia burgdorferi (sensu stricto) in eastern north america; however, the agent of lyme disease is not the sole pathogen harbored by the blacklegged tick. the blacklegged tick is expanding its range into areas of southern canada such as ontario, an area where exposure to blacklegged tick bites and tick-borne pathogens is increasing. we performed a systematic review to evaluate the public health risks posed by expanding blacklegged tick populatio ... | 2016 | 27151067 |
| an easy operating pathogen microarray (eopm) platform for rapid screening of vertebrate pathogens. | infectious diseases emerge frequently in china, partly because of its large and highly mobile population. therefore, a rapid and cost-effective pathogen screening method with broad coverage is required for prevention and control of infectious diseases. the availability of a large number of microbial genome sequences generated by conventional sanger sequencing and next generation sequencing has enabled the development of a high-throughput high-density microarray platform for rapid large-scale scr ... | 2013 | 24053492 |
| identification of a flavivirus sequence in a marine arthropod. | phylogenetic analysis has yet to uncover the early origins of flaviviruses. in this study, i mined a database of expressed sequence tags in order to discover novel flavivirus sequences. flavivirus sequences were identified in a pool of mrna extracted from the sea spider endeis spinosa (pycnogonida, pantopoda). reconstruction of the translated sequences and blast analysis matched the sequence to the flavivirus ns5 gene. additional sequences corresponding to envelope and the ns5 mtase domain were ... | 2015 | 26717191 |
| characterization of a novel insect-specific flavivirus from brazil: potential for inhibition of infection of arthropod cells with medically important flaviviruses. | in the past decade, there has been an upsurge in the number of newly described insect-specific flaviviruses isolated pan-globally. we recently described the isolation of a novel flavivirus (tentatively designated 'nhumirim virus'; nhuv) that represents an example of a unique subset of apparently insect-specific viruses that phylogenetically affiliate with dual-host mosquito-borne flaviviruses despite appearing to be limited to replication in mosquito cells. we characterized the in vitro growth p ... | 2014 | 25146007 |
| molecular archaeology of flaviviridae untranslated regions: duplicated rna structures in the replication enhancer of flaviviruses and pestiviruses emerged via convergent evolution. | rna secondary structures in the 3'untranslated regions (3'utr) of the viruses of the family flaviviridae, previously identified as essential (promoters) or beneficial (enhancers) for replication, have been analysed. duplicated enhancer elements are revealed as a global feature in the evolution of the 3'utr of distantly related viruses within the genera flavivirus and pestivirus. for the flaviviruses, duplicated structures occur in the 3'utr of all four distantly related ecological virus subgroup ... | 2014 | 24647143 |
| seroprevalence of powassan virus in new england deer, 1979-2010. | powassan virus and its subtype, deer tick virus, are closely related tick-borne flaviviruses that circulate in north america. the incidence of human infection by these agents appears to have increased in recent years. to define exposure patterns among white-tailed deer, potentially useful sentinels that are frequently parasitized by ticks, we screened serum samples collected during 1979-2010 in connecticut, maine, and vermont for neutralizing antibody by using a novel recombinant deer tick virus ... | 2013 | 23568288 |
| immune cell targets of infection at the tick-skin interface during powassan virus transmission. | powassan virus (powv) is a tick-borne flavivirus that can result in a severe neuroinvasive disease with 50% of survivors displaying long-term neurological sequelae. human powv cases have been documented in canada, the united states, and russia. although the number of reported powv human cases has increased in the past fifteen years, powv remains one of the less studied human pathogenic flaviviruses. ixodes ticks are the vectors for powv, and the virus is transmitted to a host's skin very early d ... | 2016 | 27203436 |
| 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. | 0 | 24274336 |
| 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 ... | 2012 | 22890037 |
| 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 ... | 2015 | 26593260 |
| 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 ... | 2015 | 25999230 |
| 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, ... | 2016 | 26768265 |
| 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. | 2016 | 26668338 |
| changing epidemiology of powassan encephalitis in north america suggests the emergence of the deer tick virus subtype. | | 2013 | 24124795 |
| diagnosis of acute deer tick virus encephalitis. | deer tick virus (dtv) is a tick-borne flavivirus that has only recently been appreciated as a cause of viral encephalitis. we describe the clinical presentation of a patient who had dtv encephalitis diagnosed before death and survived for 8 months despite severe neurologic dysfunction. | 2013 | 23166187 |
| powassan/deer tick virus and borrelia burgdorferi infection in wisconsin tick populations. | powassan/deer tick virus (powv/dtv) is an emerging cause of arboviral neuroinvasive disease in the upper midwest. these studies describe the prevalence and geographic distribution of wisconsin ticks carrying powv/dtv as well as the high frequency of ixodes scapularis ticks coinfected with both powv/dtv and borrelia burgdorferi, the causative agent of lyme disease. these findings suggest that concurrent transmission of powv/dtv and b. burgdorferi from coinfected ticks is likely to occur in humans ... | 2017 | 28488932 |
| 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 ... | 2017 | 28498740 |
| 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. | 2017 | 28726610 |
| 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 ... | 2019 | 31218999 |
| 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. ... | 2018 | 29707917 |
| 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 ... | 2021 | 33534764 |