What type of virus is Powassan?
What type of virus is Powassan?
Powassan virus is a tickborne flavivirus that is related to some mosquitoborne viruses such as West Nile virus. The virus is named after Powassan, Ontario where it was first discovered in 1958. Two types of Powassan virus have been found in North America and include lineage 1 and lineage 2 Powassan viruses.
Is Powassan an arbovirus?
Powassan encephalitis, caused by the Powassan virus (POWV), a flavivirus also known as the deer tick virus, is a form of arbovirus infection that results from tick bites. It can occur as a co-infection with Lyme disease since both are transmitted to humans by the same species of tick.
What is the difference between alphavirus and Flavivirus?
Flavivirus virions are spherical, ca. 50 nm in diameter, and consist of a nucleoprotein capsid enclosed in a lipid envelope. The RNA is a single 40S (ca. 10.9 kilobases) positive-sense strand and is capped at the 5′ end, but, unlike alphaviruses, has no poly A segment at the 3′ end.
What type of viruses are flaviviruses characterized as?
The Flaviviridae are a family of positive, single-stranded, enveloped RNA viruses. They are found in arthropods, (primarily ticks and mosquitoes), and can occasionally infect humans. Members of this family belong to a single genus, Flavivirus, and cause widespread morbidity and mortality throughout the world.
Where is the Powassan virus located?
In the United States, cases of Powassan virus disease (Powassan) have been reported primarily from northeastern states and the Great Lakes region. These cases occur primarily in the late spring, early summer, and mid-fall when ticks are most active.
How is Powassan virus diagnosed?
Laboratory diagnosis is generally accomplished by testing of serum or cerebrospinal fluid (CSF) to detect Powassan virus-specific IgM and neutralizing antibodies. Immunoassays for Powassan virus IgM antibodies are available commercially and through state public health laboratories and CDC.
What is vector of Powassan encephalitis?
Powassan encephalitis, first isolated in 1958, typifies a New World TBEV with a confined regional distribution in the New England states and Eastern Canada, several ixodid tick vectors, primarily Ixodes spp., an extensive wild animal reservoir in rodents and medium-sized mammals, especially woodchucks and skunks, and a …
Is Powassan virus a flavivirus?
Powassan virus is a tickborne flavivirus that is related to some mosquitoborne viruses such as West Nile virus.
What is the shape of Rhabdovirus?
The family Rhabdoviridae consists of more than 100 single-stranded, negative-sense, nonsegmented viruses that infect a wide variety of hosts, including vertebrates, invertebrates, and plants. Common to all members of the family is a distinctive rod- or bullet-shaped morphology.
What causes alphavirus?
Terrestrial alphavirus infections are spread by insect vectors such as mosquitoes. Once a human is bitten by the infected mosquito, the virus can gain entry into the bloodstream, causing viremia. The alphavirus can also get into the CNS where it is able to grow and multiply within the neurones.
What is the shape of Flavivirus?
The capsid of viruses in this family are icosahedral shaped and around the viral capsid a spherical shaped envelope is present. The capsids are approximately 40-50 nanometers in diameter and are composed of a single type of capsid protein. Unlike cellular mRNA, the genome of Flavivirus lacks a poly-A tail.
Why is Flavivirus significant?
Background. Flaviviruses are enveloped single-stranded RNA viruses and major human pathogens. They are responsible for causing outbreaks and therefore they represent a serious health issue worldwide (1).
What is the evolutionary rate of Powassan virus?
According to the last data, evolutionary rate of Powassan virus is 3.3 × 10 −5 nucleotide substitution per site per year (95% HPD, 2.0 × 10 −5 –4.7 × 10 −5 ), which is significantly lower than values reported in the previous studies.
What are the symptoms of the Powassan virus?
People affected by Powassan virus generally first show symptoms 1 to 3 weeks after infection. The initial symptoms include fever, headache, nausea, occasional confusion, and weakness. With severe Powassan illnesses the victims should be hospitalized, because the symptoms do worsen.
What are the characteristics of flaviviruses?
They are about 40–60 nm in diameter. Members of the family Flaviviridae have monopartite, linear, single-stranded RNA genomes of positive polarity, and 9.6 to 12.3 kilobase in total length. The 5′-termini of flaviviruses carry a methylated nucleotide cap, while other members of this family are uncapped and encode an internal ribosome entry site.
What diseases are transmitted by flaviviruses?
Flaviviridae. Other Flaviviruses are transmitted by ticks and are responsible of encephalitis and hemorrhagic diseases: Tick-borne Encephalitis (TBE), Kyasanur Forest Disease (KFD) and Alkhurma disease, and Omsk hemorrhagic fever.