Treatment & Prevention


There is no specific treatment for West Nile virus (WNV) disease; clinical management is supportive. Patients with severe meningeal symptoms often require pain control for headaches and antiemetic therapy and rehydration for associated nausea and vomiting.

Patients with encephalitis require close monitoring for the development of elevated intracranial pressure and seizures. Patients with encephalitis or poliomyelitis should be monitored for inability to protect their airway. Acute neuromuscular respiratory failure may develop rapidly, and prolonged ventilatory support may be required.

Various drugs have been evaluated or empirically used for WNV disease, as described in a review of the literature for health care providers [PDF – 10 pages]. However, none have shown specific benefit to date. The National Institutes of Health maintains a registry of federally and privately supported clinical trials conducted in the United States and around the world.


No WNV vaccines are licensed for use in humans. In the absence of a vaccine, prevention of WNV disease depends on community-level mosquito control programs to reduce vector densities, personal protective measures to decrease exposure to infected mosquitoes, and screening of blood and organ donors. Personal protective measures include use of mosquito repellents, wearing long-sleeved shirts and long pants, and limiting outdoor exposure from dusk to dawn. Using air conditioning, installing window and door screens, and reducing mosquito breeding sites around the home, can further decrease the risk for WNV exposure. More information on personal protective measures can be found here.

Blood and some organ donations in the United States are screened for WNV infection; healthcare professionals should remain vigilant for the possible transmission of WNV through blood transfusion or organ transplantation. Any suspected WNV infections temporally associated with blood transfusion or organ transplantation should be reported promptly to the appropriate state or local health department. People with confirmed WNV infections should not donate blood for 4 months after their illness.