Experimental encephalitis in monkeys caused by the Powassan virus

1985 ◽  
Vol 15 (1) ◽  
pp. 62-69 ◽  
Author(s):  
M. P. Frolova ◽  
L. M. Isachkova ◽  
N. M. Shestopalova ◽  
V. V. Pogodina
Keyword(s):  
Powassan Virus ◽  
Experimental Encephalitis

A Fatal Case of Powassan Virus Encephalitis

2020 ◽  
Vol 79 (11) ◽  
pp. 1239-1243
Author(s):  
Qiqi Yu ◽  
Eduard Matkovic ◽  
Sarah Reagan-Steiner ◽  
Amy M Denison ◽  
Rebecca Osborn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Neuronal Degeneration ◽  
Fatal Case ◽  
Central Nervous System Involvement ◽  
Immunohistochemical Analysis ◽  
The United States ◽  
Nodule Formation ◽  
Powassan Virus ◽  
Life Threatening ◽  
Autopsy Tissues

Abstract Powassan virus (POWV) is a flavivirus of the tick-borne encephalitis serogroup that causes a rare and potentially life-threatening neuroinvasive disease. Viral transmission occurs during zoonotic spillover from mammals by the bite of an infected tick in endemic regions of North America. The number of reported POWV cases has recently increased in the United States. We report a fatal case of POWV meningoencephalomyelitis in Northern Wisconsin following a documented tick bite. Histologic examination of the brain demonstrated widespread intraparenchymal and perivascular lymphohistocytic infiltration, microglial nodule formation, and marked neuronal degeneration, most severely involving the substantia nigra, anterior horn of spinal cord and cerebellum. Although no viral inclusions were seen in routine light microscopy, electron microscopy identified multiple neurons containing cytoplasmic clusters of virus particles ∼50 nm in diameter. POWV infection was confirmed using immunohistochemical analysis and reverse transcription-polymerase chain reaction. This report demonstrates in detail regional central nervous system involvement and ultrastructural characteristics of Powassan viral particles by transmission electron microscopy, while highlighting the utility of evaluating fixed autopsy tissues in cases of unexplained meningoencephalomyelitis.

scholarly journals Genetic Analysis of Powassan virus Genotypes Circulating in North America [University of Findlay]

2019 ◽  
Author(s):  
Kristen Huseman ◽  
Abby L Levitt
Keyword(s):  
North America ◽  
Host Species ◽  
Evolutionary Dynamics ◽  
Genetic Recombination ◽  
Ixodes Scapularis ◽  
Geographic Location ◽  
Recombination Analysis ◽  
Phenotypic Characters ◽  
Geographical Regions ◽  
Powassan Virus

Powassan virus (POWV), a tick-borne flavivirus, is the only member of the tick-borne encephalitis serogroup found in North America. Two distinct lineages, prototype lineage (POWV, lineage I) and deer tick virus (DVT, lineage II) are maintained in enzootic transmission cycles by different tick species based on different geographical regions. In North America, Ixodes scapularis acts as the primary vector throughout the Northeast, and Ixodes cookei throughout the Midwest and much of Canada. Importantly, the incidence of human disease due to POWV has increased by 671% over the last 18 years; with DVT perhapes being the most worrisome genotype due to the wide spread range and prevalence of the vector species. The aim of this study is to assess the evolutionary dynamics of the POWV/DTV complex using the most current full-genome, envelope, and 3’UTR sequences available. Bayesian phylogenetic inferences support the two distinct, monophyletic lineages corresponding to POWV and DTV. Additional analysis were performed in order to quantify the degree to which viral phenotypic characters (such as geographic location, and host species utilization) are correlated with shared ancestry within the two different genotypes. The results of this phylogeny-trait correlation analysis suggest significant clustering of viral sequence by sample location. Such in situ evolution is compatible with the relatively limited distances traveled by most ticks and their prefered host species. Lastly, genetic recombination analysis shows no evidence of between genotype recombination, however further analysis needs to be conducted using within genotype recombination analysis as recombination events may be restricted to only closely genetically related viruses.

scholarly journals Nanoscale Structure Determination of Murray Valley Encephalitis and Powassan Virus Non-coding RNAs

2020 ◽  
Author(s):  
Tyler Mrozowich ◽  
Amy Henrickson ◽  
Borries Demeler ◽  
Trushar R Patel
Keyword(s):  
Computational Modeling ◽  
Small Angle ◽  
Genetic Material ◽  
Size Exclusion ◽  
Low Resolution ◽  
Modeling Tools ◽  
X Ray ◽  
X Ray Scattering ◽  
Powassan Virus ◽  
Ray Scattering

AbstractViral infections are responsible for numerous deaths worldwide. Flaviviruses, which contain RNA as their genetic material, are one of the most pathogenic families of viruses. There is an increasing amount of evidence suggesting that their 5’ and 3’ non-coding terminal regions are critical for their survival. In this study, the 5’ and 3’ terminal regions of Murray Valley Encephalitis and Powassan virus were examined using biophysical and computational modeling methods. First, the purity of in-vitro transcribed RNAs were investigated using size exclusion chromatography and analytical ultracentrifuge methods. Next, we employed small-angle X-ray scattering techniques to study solution conformation and low-resolution structures of these RNAs, which suggested that the 3’ terminal regions are highly extended, compared to the 5’ terminal regions for both viruses. Using computational modeling tools, we reconstructed 3-dimensional structures of each RNA fragment and compared them with derived small-angle X-ray scattering low-resolution structures. This approach allowed us to further reinforce that the 5’ terminal regions adopt more dynamic structures compared to the mainly double-stranded structures of the 3’ terminal regions.

Powassan virus (POWV) Infection in Animals and Humans: A Review

2014 ◽  
Vol 9 (3) ◽  
pp. 177-189 ◽  
Author(s):  
K. Dhama ◽  
R.V.S. Pawaiya ◽  
S. Chakrabort ◽  
R. Tiwari ◽  
A.K. Verma
Keyword(s):  
Powassan Virus
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