What does the west nile virus actually do to your body?

Variable: Usually, no symptoms at all. In some, causes a flu-like syndrome for a few days. In rare patients, especially immunologically suppressed folks, can create a life-threatening meningo-encephalitis, and even rarer a polio-myelitis resulting in motor nerve cell damage in the spinal cord. Have seen all of these variations, but mostly, the mosquito bite causes only local itching.