how do you know if you have west nile?

Answer 1

Most people who are infected with WNV will never know it because they'll never get sick and never have symptoms. Many who do have WNV find out about it when they try to donate blood. Blood supplies are screened for WNV. If your donation comes up positive, the blood bank will let you know.

Of course, if you are in the lucky minority (about 20% of infected) of folks who do get West Nile Fever, you can expect fevers, headaches, fatigue, swollen lymph nodes, rash and stiffness in the neck. The stiffness in the neck indicates encephalitis. So if that's a symptom you have, go to a hospital ASAP.

People with weak immune systems are at highest risk of severe West Nile Fever.