The first human case of West Nile virus in Nevada this year was reported in Lyon County earlier this month. The man is less than 50 years old and he was hospitalized with a milder form of the virus. In 2007, at least 12 cases of West Nile were reported in Nevada.

The virus has three effects on humans and they are all different. The first one is an asymptomatic infection; the second is a mild febrile syndrome and the third is a neuroinvasive disease, also called West Nile meningitis or encephalitis. West Nile virus is transmitted through mosquito vectors, which bite and infect birds. These birds are only hosts of the virus.

Still, the mammals bitten by the infected mosquitoes don’t get sick so easily because they don’t ingest enough viruses to get infected.
 
Humans are mainly infected with the virus through the bite of an infected mosquito. The genetic material of the West Nile Virus is a single strand of RNA which has between 11,000 and 12,000 nucleotides long.

The disease killed two people in Orange County by now. A 64-year-old man from Garden Grove and a 72-year-old woman from Buena Park were infected with the virus and died shortly after.

Most people who get infected with this type of virus have no symptoms, but about 20% of the sick ones experience fever, body aches, headache, nausea or vomiting. The people over 50 years old are advised by the CDC to be very careful, as the disease affects them more than the youth.