Tick-Borne Flaviviruses, with a Focus on Powassan Virus

  title={Tick-Borne Flaviviruses, with a Focus on Powassan Virus},
  author={G{\'a}bor Kemenesi and Kriszti{\'a}n B{\'a}nyai},
  journal={Clinical Microbiology Reviews},
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. SUMMARY 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… 
Powassan Virus Encephalitis Following Brief Attachment of Connecticut Deer Ticks.
The first clinical and epidemiologic evidence that POWV/DTV can be rapidly transmitted to a human host, that is, within hours of tick attachment, which is distinctive when compared to other deer tick-transmitted infections such as Lyme disease is provided.
Population genomics of louping ill virus provide new insights into the evolution of tick-borne flaviviruses
The sequencing of 22 LIV isolates, which have been sampled from several host species across the past century, provided a more reliable LIV phylogeny, improving knowledge of the evolution of tick-borne flaviviruses.
The continued threat of emerging flaviviruses
The basic biology of these viruses, their life cycles, the diseases they cause and available therapeutic options are reviewed, and the global distribution of flaviviruses is discussed, with a focus on lesser-known species that have the potential to emerge more broadly in human populations.
Molecular survey of flaviviruses and orthobunyaviruses in Amblyomma spp. ticks collected in Minas Gerais, Brazil.
Molecular detection in wild ticks collected in the state of Minas Gerais, Brazil detected activity of Orthobunyavirus in 8 Amblyomma tick specimens, the first report of this virus among ticks in South America.
Powassan virus: What is the risk to the blood supply?
While no intervention is likely indicated, one probable case of transfusion‐transmitted POWV in the context of an increase in the incidence of POWV and other tick‐borne infections, merits vigilance.
The Ecology of New Constituents of the Tick Virome and Their Relevance to Public Health
Comparative phylogenetic analyses of tick viruses from these different countries reveals distinct geographical clustering of the new tick viruses, and indicates that the global tick virome is dominated by RNA viruses.
Flavivirus Persistence in Wildlife Populations
Findings are presented that aid in understanding how vector-borne flavivirus persistence is established in wildlife and underscore the viral–host relationships in wildlife animals and could be used to elucidate the underlying mechanisms responsible for the establishment of viral persistence in these animals.


Powassan Virus: An Emerging Arbovirus of Public Health Concern in North America
This review provides an overview of Powassan virus, including the epidemiology, transmission, clinical disease, and diagnosis of POWV infection, and recent research developments and future priorities with regard to the disease are emphasized.
Molecular epidemiology of Powassan virus in North America
It is confirmed that POW and DTV sequences are relatively stable over time, which suggests strong evolutionary constraint, and support field observations that suggest that tick-borne flavivirus populations are extremely stable in enzootic foci.
Increased recognition of Powassan encephalitis in the United States, 1999-2005.
Although POWV disease is probably under-recognized, and it causes significant morbidity, and thus is an additional tick-borne emerging infectious disease entity, the basis of prevention is personal protection from ticks and reduced exposure to peridomestic wild mammals.
Stable prevalence of Powassan virus in Ixodes scapularis in a northern Wisconsin focus.
Findings suggest stable transmission of POWV in this focus over ten years and highlight the potential for this agent to emerge as a public health concern.
Outbreak of Powassan encephalitis--Maine and Vermont, 1999-2001.
  • Medicine
    MMWR. Morbidity and mortality weekly report
  • 2001
The findings underscore the need for personal protective measures to prevent tick bites and continued encephalitis surveillance and the risk for human exposure to POW virus.
[Role of Powassan virus in the etiological structure of tick-borne encephalitis in the Primorsky Kray].
Composite studies conducted annually in the Primorsky kray showed the tick-borne encephalitis virus to play the main etiological role in the group of encephalites with the spring-summer incidence and antibody to ticks, Powassan virus and both viruses simultaneously was found in patients with progredient forms of ticks and in subjects with the history of tick attachment.
Update on Powassan virus: emergence of a North American tick-borne flavivirus.
  • G. Ebel
  • Biology
    Annual review of entomology
  • 2010
This review highlights recent research into POW, focusing on virus genetics and ecology and human disease, and establishes a genetically diverse group of virus genotypes that are maintained in distinct enzootic transmission cycles.
Tick-borne flaviviruses.
Immune Cell Targets of Infection at the Tick-Skin Interface during Powassan Virus Transmission
This is the first report demonstrating that macrophages and fibroblasts contain POWV antigens, which suggests that they are early cellular targets of infection at the tick feeding site, and provides key insights towards defining the complex interactions between the host immune response and early tick-mediated immunomodulation.
Genomic sequencing of deer tick virus and phylogeny of powassan-related viruses of North America.
The lineage of DT virus is classified as a distinct genotype of POW virus, one of which had the prototype POW virus and the other DT virus, both of which can cause central nervous system infection in humans.