West Nile virus (WNV) is a mosquito-borne disease that can cause encephalitis or brain infection. It is historically found in portions of Africa, the Middle East, and Central Europe. In 1999, WNV invaded New York City and has since spread to all but four states in the continental United States. Nationwide last year 4,161 people became ill and 284 people died from WNV infection. However, less than 1 percent of the people infected with WNV become seriously ill. About one-third of the people infected develop flu-like symptoms and the majority of people never get sick. Two non-fatal human cases were reported in Wyoming last year but the number of human infections will likely increase as the virus continues to expand throughout the state, said Terry Creekmore, the West Nile virus surveillance coordinator for the Wyoming Department
of Health.

Mosquitoes spread this virus after they feed on infected birds and then bite people, other birds and animals. WNV is not spread by person-to-person contact and there is no evidence that people can get the virus by handling infected animals.

Surveillance for West Nile virus was initiated in Wyoming in 2001 and currently involves the reporting and testing of dead birds, and the testing of sick horses. Suspected human cases are also tested in the Wyoming Department of Health`s public health lab. People with mild infections may experience fever, headache, body aches, skin rash and swollen lymph glands. This is called West Nile fever. People with more severe infections may experience high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, and paralysis. This is called West Nile encephalitis. If you have any of these symptoms, contact your health care provider. Please see your primary care physician for more details.