The West Nile Virus (WNV) is an arbovirus, short for arthropod-borne virus, is transmitted by the bite of mosquitoes of the Culex species. These mosquitoes thrive in hot weather and are less noticeable than typical floodwater mosquitoes. Since transmission is dependent on mosquitoes, WNV is typically acquired during warmer months until first freeze of the fall. Most persons bitten by an infected mosquito will experience no symptoms of the disease or will have very mild symptoms including fever and headache. Persons older than 50 years of age are most susceptible to developing serious illness. Approximately 1 to 2 percent of all cases will develop recognizable symptoms. Symptoms of a severe WNV infection may produce a rapid onset of severe headache, high fever, muscle aches, difficulty with muscle coordination, and disorientation. Most patients recover fully, although severe infection may, infrequently, result in neurologic damage or death.