West Nile virus (WNV) is an infectious disease that first appeared in the United States in 1999. Infected mosquitoes spread the virus that causes it. People who get WNV usually have no mild symptoms or symptoms. Symptoms include fever, headache, body aches, rashes, and swollen lymph nodes. West Nile virus was the first isolated from a febrile adult woman in the West Nile district. The virus responsible for the disease belongs to the family Flaviviridae. It is a single-stranded RNA virus.
The seroprevalence reported is higher in migratory birds than in migratory birds. Hundreds of wild and domestic avian species, including passerines, mainly the corvid family, gulls, flamingos, pelicans, hawks and owls, and companion birds have decent WNV infection. The virus is kept in the wild through a bird-mosquito-bird transmission cycle. Other less common means include disease transmission, including blood transfusion, transplacental transmission, organ transplantation, breastfeeding, and laboratory transmission. However, Mosquitoes (mainly Culex species) can transmit the virus from natural hosts to humans and other mammals, usually horses..
The West Nile virus virion is an RNA genome with an icosahedral particle associated with a nucleocapsid, which is surrounded by a lipid bilayer. A high proportion of capsid proteins localize in the nucleus, while the viral assembly takes place in the cytoplasm, with budding in the endoplasmic reticulum (ER). Although the capsid of the nuclear functions are not fully understood, recent evidence suggests that the role of histone proteins in regulating genes is involved. During the assembly of the virus, the envelope protein integrates into the lipid bilayer of the virus and is exposed to the surface of the virion. The envelope protein is responsible for binding the receptor to the cell surface for viral entry. The prM protein is also known to integrate into the lipid bilayer and is known to protect the E surface of the virus from exocytosis during premature fusion. During infection, the viral population contains a variable number of immature prM protein molecules containing both mature and immature viral particles