West nile virus natural history

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Possible Complications

Complications from mild West Nile virus infection are very rare.

Complications from severe West Nile virus infection include:

• Brain damage
• Permanent muscle weakness (sometimes similar to polio)
• Death

Prognosis

In general, the outcome of a mild West Nile virus infection is excellent.

For patients with severe cases of West Nile virus infection, the outlook is more uncertain. West Nile encephalitis or meningitis may lead to brain damage and death. Approximately 10% of patients with brain inflammation do not survive.