Lab Tests for West Nile Virus

West Nile Virus, first identified in the U.S. in 1999, is a disease spread by mosquitoes. Most people who get WNV have no symptoms or only mild symptoms, but a small percentage of people will have severe symptoms. This usually happens in people over 50, young children, or immune compromised individuals. When someone is sick from WNV they may not know they have the disease. If you have concerns about WNV see your doctor right away. Your doctor will take a health history then order tests. First, your doctor may order blood tests or test your cerebrospinal fluid to screen for West Nile Virus. These blood tests screen for the flavivirus (the virus that causes WNV disease) and include: • ELISA (Enzyme-Linked Immunosorbent Assay) • HI assay • IFA (indirect immunofluorescent antibody) Your doctor will ask a series of questions including: your travel history, when you began having symptoms, unusual health conditions, and state and county of residence. S/he will make a diagnosis and submit this information with the lab test. Next, your doctor will ask for a confirmatory test to rule out similar diseases such as Eastern Equine Encephalitis (EEE), Saint Louis Encephalitis (SLE), and Japanese Encephalitis (JE).