Signs and symptoms
... Most people infected with the West Nile virus have no signs or symptoms. About 20 percent of people develop a mild infection called West Nile fever. Common signs and symptoms of West Nile fever includ...

Causes
... The main route of West Nile infection is through the bite of an infected mosquito. Here''s how the transmission cycle works: When a mosquito bites a bird infected with the West Nile virus, the virus e...

Risk factors
... Anyone bitten by an infected mosquito is at risk of acquiring the virus. Your risk of contracting West Nile virus depends on these factors: Time of year. The risk of West Nile virus follows a seasonal...

When to seek medical advice
... See your doctor as soon as possible after you experience signs and symptoms that might suggest West Nile infection — especially if you''re pregnant or breast-feeding. Although most people infect...

Screening and diagnosis
... Your doctor can confirm the presence of West Nile virus in your body by drawing a sample of your blood to be analyzed in the laboratory. If you have West Nile virus, an analysis of your blood sample m...