West Nile virus is a mosquito-borne disease that is transmitted to humans and animals through the bite of infected mosquitoes. The virus first emerged in Africa in 1937 and has since spread to many countries around the world. There are several synonyms for West Nile virus, including West Nile fever, West Nile encephalitis, and West Nile neuroinvasive disease. These terms are all used to describe different aspects of the disease, such as the fever and flu-like symptoms that are common in mild cases, as well as the more severe neurological complications that can occur in some people. Despite being a relatively new disease, West Nile virus has become a significant public health concern in many parts of the world, and efforts are underway to develop effective vaccines and treatments for it.