Diagnosis of West Nile virus (WNV) infection in a person is usually made through review of the person's symptoms and exposure. It is confirmed by testing the person's blood and/or cerebrospinal fluid.
WNV testing is used to determine whether someone is currently or has recently been infected with WNV. It is also used to screen units of blood for WNV, screen living donors of tissue and organs, and to track the spread of WNV through a community and across the country. Testing includes: