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West Nile Virus Infection

Medically reviewed by Last updated on May 1, 2023.

West Nile virus (WNV) is carried by mosquitoes. The virus spreads to humans when they are bitten by infected mosquitoes. The virus can be passed from one person to another through blood transfusions or organ transplants. An infected mother who is pregnant or breastfeeding may pass the virus to her child.


Informed consent

is a legal document that explains the tests, treatments, or procedures that you may need. Informed consent means you understand what will be done and can make decisions about what you want. You give your permission when you sign the consent form. You can have someone sign this form for you if you are not able to sign it. You have the right to understand your medical care in words you know. Before you sign the consent form, understand the risks and benefits of what will be done. Make sure all your questions are answered.

A neurologic exam

can show healthcare providers how well your brain works after an injury or illness. A provider will check how your pupils react to light. The provider may check your memory and how easily you wake up. Your hand grasp and balance may also be tested.


  • Antipyretics help lower a fever.
  • Pain medicine may be given. Do not wait until the pain is severe before you ask for more medicine.
  • Anticonvulsants prevent, decrease, or stop seizures.
  • Antibiotics may be given if you have a bacterial infection in addition to your WNV infection.
  • Antiviral medicine treats an infection caused by a virus.


  • Blood samples may be tested for WNV infection.
  • CT scan or MRI pictures may show inflammation in your brain. You may be given contrast liquid to help your brain show up better in the pictures. Tell the healthcare provider if you have ever had an allergic reaction to contrast liquid. Do not enter the MRI room with anything metal. Metal can cause serious injury. Tell healthcare providers if you have any metal in or on your body.
  • A lumbar puncture, or spinal tap, may be used to A needle is inserted into your spinal canal through your back. Healthcare providers will collect a sample of spinal fluid and send it to a lab for test for signs of infection.
  • An EEG prints a paper tracing of brain wave activity from different parts of your brain. Healthcare providers look at the tracing to see how your brain is working.

Respiratory support:

  • Oxygen may be needed if your blood oxygen level is lower than it should be. You may get oxygen through a mask placed over your nose and mouth or through small tubes placed in your nostrils.
  • A ventilator is a machine that gives you oxygen and breathes for you when you cannot breathe well on your own. An endotracheal (ET) tube is put into your mouth or nose and attached to the ventilator. You may need a trach if an ET tube cannot be placed. A trach is a tube put through an incision and into your windpipe.


If WNV spreads to your brain (viral encephalitis), it may damage your brain and spinal cord. You may have problems with hearing, seeing, talking, or learning. It may cause seizures or paralysis, and can become life-threatening.


You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment.

© Copyright Merative 2023 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.