Which virus causes tick-borne encephalitis?
Tick-borne encephalitis, or TBE, is a human viral infectious disease involving the central nervous system. TBE is caused by the tick-borne encephalitis virus (TBEV), a member of the family Flaviviridae, and was initially isolated in 1937.
Are encephalitis viruses enveloped?
Capsid binds to viral RNA and forms a nucleocapsid that is enveloped by an endoplasmic reticulum-derived membrane containing E and prM. E proteins are responsible for cellular attachment and possess a hydrophobic loop that mediates fusion of viral and host membranes (3, 8, 11, 21, 32, 42).
How common is TBE?
TBE is a rare disease, but it is much more common in the Sörmland, Uppsala and Stockholm regions than in the rest of the country, despite increasing rates of vaccination. In 2018, at least 40 cases of TBE were reported in Sörmland, although none of these affected children of preschool age.
Is Japanese encephalitis virus enveloped?
Japanese encephalitis virus The enveloped virus is closely related to the West Nile virus and the St. Louis encephalitis virus. The positive sense single-stranded RNA genome is packaged in the capsid which is formed by the capsid protein. The outer envelope is formed by envelope protein and is the protective antigen.
Why is it called Japanese encephalitis?
Japanese encephalitis virus JEV is the most important cause of viral encephalitis in Asia. It is a mosquito-borne flavivirus, and belongs to the same genus as dengue, yellow fever and West Nile viruses. The first case of Japanese encephalitis viral disease (JE) was documented in 1871 in Japan.
Can you recover from tbe?
Most patients with TBE encephalitis will recover but up to one third will suffer long-term complications of the disease. There is no specific treatment for TBE once you are infected but there is an effective vaccine that prevents infection.
Does Lyme disease show up on brain MRI?
Lyme disease symptoms may also have a relapsing-remitting course. In addition, Lyme disease occasionally produces other abnormalities that are similar to those seen in MS, including positive findings on magnetic resonance imaging (MRI) scans of the brain and analysis of cerebrospinal fluid (CSF).
Is TBE contagious?
The TBE virus is not directly transmitted from human to human, apart from the possibility of vertical transmission from an infected mother to the foetus.
Is TBE treatable?
There is no specific drug therapy for TBE. Meningitis, encephalitis, or meningoencephalitis requires hospitalization and supportive care based on syndrome severity. Anti-inflammatory drugs, such as corticosteroids, may be considered under specific circumstances for symptomatic relief.
How are RNA viruses synthesized?
During replication of RNA viruses, there are at least three types of RNA that must be synthesized: the genome, a copy of the genome (copy genome), and mRNAs. Some RNA viruses also synthesize copies of subgenomic mRNAs. RdRp is the key player for all of these processes. RdRps of all RNA viruses probably arose from a common ancestor.
What are the RdRPs of RNA viruses?
The RdRps of RNA viruses control RNA synthesis error rates. Molecular/biochemical studies have revealed that RdRp mutations can have a measurable impact on fidelity and this in turn measurably impacts virus fitness. A well-studied example is polio virus (PV) a picornavirus.
How do RNA viruses regulate genome and transcripts?
Mechanisms to Regulate Synthesis of Genomes and Transcripts Even with fairly simple genomes, RNA viruses must, and do, regulate the amounts of genome, copy genome, and mRNAs that are synthesized during an infection. It would be “wasteful” if a positive-strand RNA virus had to make a new copy genome for synthesis of every genome.
Which negative-strand RNA viruses produce mRNAs sequentially?
A large group of unsegmented negative-strand RNA viruses (Order Mononegavirales) synthesize mRNAs sequentially, from the 3′ end to the 5′ end of the infecting genome (Chapters 19–22Chapter 19Chapter 20Chapter 21Chapter 22: Family Rhabdoviridae, Families Paramyxoviridaeand Pneumoviridae, Family Filoviridae, and Family Bornaviridae) (Fig. 10.5).