How virulent is West Nile virus?
West Nile virus can cause a fatal neurological disease in humans. However, approximately 80% of people who are infected will not show any symptoms. West Nile virus is mainly transmitted to people through the bites of infected mosquitoes. The virus can cause severe disease and death in horses.
Which factor is associated with the West Nile virus?
Infection with WNV is dependent on many factors including climate, mosquito habitats and immunologically naïve bird populations. In addition, variations within individuals contribute to the risk of severe disease, in particular, advanced age, hypertension, immunosuppression and critical elements of the immune response.
What virulence factors do viruses have?
Virus virulence factors allow it to replicate, modify host defenses, and spread within the host, and they are toxic to the host. They determine whether infection occurs and how severe the resulting viral disease symptoms are. Viruses often require receptor proteins on host cells to which they specifically bind.
How does the immune system fight West Nile virus?
West Nile infection triggers production of interferon, a group of proteins that are crucial in immune defense. Interferon, which binds to IFNAR, subsequently signals the JAK-STAT molecular pathway, a series of biochemical reactions essential for turning on immune-defense genes, allowing the body to clear out the virus.
What is the meaning of virulence factor?
Virulence is described as an ability of an organism to infect the host and cause a disease. Virulence factors are the molecules that assist the bacterium colonize the host at the cellular level. These factors are either secretory, membrane associated or cytosolic in nature.
Can you get West Nile virus twice?
Can a human get West Nile virus twice? Medical professionals don’t believe so. Like many other viruses, medical tests indicate that once a person has been infected with West Nile, he/she develops a natural immunity to future infection by the virus for life.
Can you get West Nile twice?
What are virulent viruses?
A virus that lyses its host immediately upon infection and often cause disease. Supplement. Viruses may be virulent or temperate. Virulent viruses tend to kill their host upon entry through cell lysis whereas temperate viruses ‘restrain’ by not immediately causing cell lysis but replicating while in latent state.
Does having West Nile virus give you immunity?
Like many other viruses, medical tests indicate that once a person has been infected with West Nile, he/she develops a natural immunity to future infection by the virus for life. However, this immunity may decrease over time or with further health conditions that compromise the immune system.
How does West Nile virus avoid host defense?
WNV has successfully evolved countermeasures to overcome host innate immunity and productively infect host cells by using a combination of two strategies: (1) passive evasion of the interaction with cellular PRRs and/or (2) active inhibition of different steps of the intracellular pathways that lead to type I IFN …